Appendix B. Compatibility 

Determinations 

 

 

COMPATIBILITY DETERMINATION 

(June 2008) 

Use: Bicycling 

Refuge Name: Sacramento and Colusa National Wildlife Refuges, located in Glenn and 

Colusa Counties, California. 

Establishing and Acquisition Authority(ies): 

Sacramento National Wildlife Refuge (Refuge) was established in 1937. Legal authorities 

include: Executive Order 7562, February 27, 1937, Migratory Bird Conservation Act of 

1929 (16 U.S.C. 715d), Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as 

amended, the Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 

Statute 884), and the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Colusa Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884), and 

the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Refuge Purpose(s): 

Sacramento Refuge purposes include: 

“... as a refuge and breeding ground for migratory birds and other wildlife...” 

Executive Order 7562, February 27, 1937. 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, 

(2) the protection of natural resources, (3) the conservation of endangered species 

or threatened species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use 

... real ... property. Such acceptance may be accomplished under the terms and 

conditions of restrictive covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge 

Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection 

of fish and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the 

United States Fish and Wildlife Service, in performing its activities and services. 

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Such acceptance may be subject to the terms of any restrictive or affirmative 

covenant, or condition of servitude ...” 16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 

1956) 

Colusa Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

National Wildlife Refuge System Mission: “To administer a national network of lands 

and waters for the conservation, management, and where appropriate, restoration of the 

fish, wildlife, and plant resources and their habitats within the United States for the 

benefit of present and future generations of Americans.” (National Wildlife Refuge 

System Administration Act of 1966, as amended [16 U.S.C. 668dd-ee]). 

Description of Use: 

Bicycles may be used on Sacramento and Colusa Refuges on designated public roadways, 

including the entrance roads and auto tour routes from May through August from one 

hour before sunrise to one hour after sunset. Bicycles are currently allowed only on 

Sacramento Refuge (1994 Bicycling Compatibility Determination). This use is identified 

and discussed in detail in the Draft Comprehensive Conservation Plan (CCP) and 

Environmental Assessment (USFWS 2008) which are incorporated by reference. 

Bicycling facilitates priority public uses, including wildlife observation, photography, 

environmental education, and interpretation, and involves observing the natural 

landscape, animals, and plant communities from a bicycle. On the auto tour routes, riders 

may stop at designated park and stretch areas only. 

The use mainly occurs in groups, with an average group size of 2-4 riders. Groups of 10 or 

more riders will contact the Refuges for a special use permit prior to using the Refuges. 

This will help protect the Refuges’ resources and ensure that larger groups do not conflict 

with concurrent public uses. 

Bicycle travel on the Refuges will be conducted in accordance with the stipulations 

necessary to ensure compatibility. Travel will be limited to designated roads (i.e. off-road 

cycling is prohibited). 

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Availability of Resources: The following funding/annual costs (based on FY 2007 costs) 

would be required to administer and manage plant gathering activities as described 

above: 

Annual Costs 

Administration, monitoring. And 

law enforcement 

$1,000 

TOTAL $1,000 

Refuge operational funds are currently available through the Service budget process to 

administer this program. 

Anticipated Impacts of Use: 

Soil Impacts: Bicycle wheels can cause physical impacts on soil surfaces. Cessford (1995) 

notes the shearing action of wheels creates damage to trails, which increases when trail 

conditions are wet or when traveling up a steep slope. It is anticipated that bicycle use of 

designated routes will cause minor to no soil erosion and compaction. Routes designated 

for this use have very little elevation change, with no steep grades. The designated routes 

are existing paved or gravel roads that have been previously altered by vehicles and 

equipment; therefore, soils are generally compacted and less susceptible to physical 

impact and mechanical erosion. Based on the conditions of designated routes and current 

levels of use, this activity will have very minor impacts to soils. 

Plant Impacts: Bicycle use will occur on designated roads that have little to no vegetation, 

since they are graveled or paved. Off-road cycling is not permitted. Therefore, it is 

anticipated that bicycles will have very minor impacts on plant communities. 

Wildlife Impacts: Human uses can result in habitat modification and can create 

disturbances to wildlife. Disturbances vary with the wildlife species involved and the type, 

level, frequency, duration, and the time of year such activities occur. Whittaker and 

Knight (1998) note that wildlife response can include attraction, habituation, and 

avoidance. Human induced avoidance by wildlife can prevent animals from using 

otherwise suitable habitat. Knight and Cole (1991) describe behavioral changes as a result 

of disturbance from recreational use. Effects range from short-term shifts in habitat use, 

to complete abandonment of disturbed areas in favor of undisturbed sites. Disturbance 

can have negative effects such as increasing the energy demands on wildlife. Flight in 

response to other disturbance can lower songbird nesting productivity, cause disease, and 

in extreme cases (predation) can result in death. Knight and Cole (1991) suggest that 

recreational activities occurring simultaneously may have a combined negative impact on 

wildlife. Hammitt and Cole (1998) conclude that the frequent presence of humans in 

wildland areas can dramatically change the normal behavior of wildlife, mostly as a result 

of unintentional harassment. 

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Seasonal sensitivities are also important in wildlife responses to human disturbance. For 

example, when an animal species is already stressed, human disturbance can compound 

the effect on that individual. Examples of these disturbances include: regularly flushing 

birds during nesting, exposing juvenile animals to greater predation levels, or causing 

mammals to flee during winter months. These disturbances can cause large amounts of 

stored fat reserves to be consumed. Hammitt and Cole (1998) note that females (such as 

deer) with young are more likely to flee from a disturbance than those without young. 

This indicates increased sensitivity to human disturbance during the breeding season. 

Anticipated impacts of bicycle use on wildlife include temporal disturbances to species 

using habitat directly adjacent to the designated routes. Although there is some 

temporary disturbance to wildlife due to human activities, the disturbance is generally 

localized and will not adversely impact overall populations. During the proposed time 

frame of May through August, both visitor use and wildlife disturbance along designated 

routes would be at its lowest. Bicyclists are required to stay on their bicycle unless in the 

designated park and stretch areas. 

Bicycling is not permitted year-round on the Refuges. During the winter months, 

hundreds of thousands of waterfowl are present in the wetlands adjacent to the auto tour 

routes. The Service requires visitors to stay in their vehicles on the auto tour route 

because of the disturbance to wildlife, except in designated park and stretch areas. 

Bicycling, other than during the designated timeframe, would cause immense wildlife 

disturbance and would be incompatible with the purposes for which the Refuges were 

established. It would also cause a user conflict, as visitors are required to stay inside their 

vehicles on the auto tour routes. 

Education: Education helps make visitors aware that their actions can have negative 

impacts on birds, and will increase the likelihood that visitors will abide by restrictions on 

their actions. For example, Klein (1993) demonstrated that visitors who had spoken with 

refuge staff or volunteers were less likely to disturb birds. Increased surveillance and 

imposed fines may also help reduce visitor caused disturbance (Knight and Gutzwiller 

1995). Monitoring is recommended to adjust management techniques over time, 

particularly because it is often difficult to generalize about the impacts of specific types of 

recreation in different environments. Local and site -specific knowledge is necessary to 

determine effects on birds, and to develop effective management strategies (Hockin et al. 

1992; Klein et al. 1995; Hill et al. 1997). 

Disturbance of wildlife is the primary concern regarding this use. Disturbance to wildlife, 

such as the flushing or interruption of feeding, resting, or nesting birds, is inherent to this 

activity. 

Bicycling on designated roads is not anticipated to have significant short-term or longterm impacts. The anticipated use is viewed as an effective and justifiable method of 

travel that allows the public to discover, experience, and enjoy priority public uses on the 

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 X 

Refuges. Continued monitoring of the effects of bicycling and associated human activities 

is necessary to better understand the impacts of the use on the Refuges’ habitats, plant 

and wildlife communities, and visitors. Monitoring will identify any actions needed to 

respond to new information (adaptive management) and correct problems that may arise 

in the future. 

The bicycling program is designed to avoid or minimize impacts anticipated to the 

Refuges’ resources and visitors. The Refuges’ have requested Section 7 consultation with 

USFWS and NOAA-Fisheries on the Draft CCP/EA (USFWS 2008) and its effects on any 

of the special status species/designated critical habitat occurring on the Refuges 

including: palmate-bracted bird’s beak, hairy Orcutt grass, Greene’s tuctoria, Hoover’s 

spurge, Conservancy fairy shrimp, vernal pool fairy shrimp, vernal pool tadpole shrimp, 

giant garter snake, western yellow-billed cuckoo, winter-run Chinook salmon, spring-run 

Chinook salmon, Central Valley steelhead, fall-run Chinook salmon, and late fall-run 

Chinook salmon. 

Anticipated Impacts of Uses on future lands within the approved boundary: The 

following conditions must be met before allowing existing uses to occur on newly acquired 

lands: (1) There is no indirect, direct, or cumulative threat anticipated to human health or 

safety; (2) There is no indirect, direct, or cumulative threat anticipated to natural or 

cultural resources; (3) The use is consistent with management of existing Sacramento and 

Colusa Refuge lands and would contribute to achieving the Refuges’ goals. In particular, 

existing Refuge regulations would not be compromised; (4) The newly acquired lands 

represent a meaningful unit within which to manage the activity; and (5) There are no 

anticipated conflicts with priority public uses. 

Public Review and Comment: Public review and comments will be solicited in 

conjunction with distribution of the Draft CCP/EA for the Sacramento, Delevan, Colusa, 

and Sutter Refuges (USFWS 2008). 

Determination: 

_____ Use is Not Compatible 

Use is Compatible with the Following Stipulations 

Stipulations necessary to ensure compatibility: 

 Bicycling is allowed only on the entrance roads and auto tour routes on Sacramento 

and Colusa Refuges from May through August. 

 Access to the Refuges is allowed from one hour before sunrise to one hour after 

sunset. 

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 A special use permit is required of 10 or more riders, prior to the use occurring. 

 Off road cycling is prohibited. 

 Bicyclists are required to stay on their bicycle on the auto tour routes unless in the 

designated park and stretch areas. 

 Regulatory and directional signs clearly mark designated routes of travel and 

areas closed to the public. 

Maps and public use information are available at the Refuge Headquarters, kiosks, and 

the Complex’s website http://sacramentovalleyrefuges.fws.gov. 

 Refuge biologists and visitor services staff conduct regular surveys of public 

activities on the Refuges. The data is analyzed and used by the refuge manager to 

develop future modifications if necessary to ensure compatibility bicycling. 

 Routine law enforcement patrols are conducted throughout the year. 

Justification: While not listed as priority wildlife-dependent recreational use under the 

National Wildlife Refuge Improvement Act, as amended, bicycling is believed to be a 

compatible public use under the stipulations outlined in this compatibility determination. 

Primary reasons for this determination include the following: wildlife observation can be 

an element of bicycling and impacts associated with this activity is not believed to exceed 

impacts already caused by other public use activities, during the months of May through 

August. 

The stipulations outlined above should minimize potential impacts relative to 

wildlife/human interactions. Based upon impacts described in the Draft Comprehensive 

Conservation Plan and Environmental Assessment (USFWS 2008), it is determined that 

bicycling within the Sacramento and Colusa National Wildlife Refuges as described 

herein, will not materially interfere with or detract from the purposes for which the 

Refuges were established or the mission of the Refuge System. In our opinion, 

implementing the bicycling to facilitate wildlife-dependent recreation and its associated 

stipulations will not conflict with the national policy to maintain the biological diversity, 

integrity, and environmental health of the Refuges. 

Mandatory Re-Evaluation Date (2018): 

_____ Mandatory 15-year Re-Evaluation, Date will be provided in Final EA/CCP (for 

priority public uses) 

Mandatory 10-year Re-Evaluation (for all uses other than priority public uses) 

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 X 
 X 

NEPA Compliance for Refuge Use Decision (check one below): 

_____ Categorical Exclusion without Environmental Action Statement 

_____ Categorical Exclusion and Environmental Action Statement 

Environmental Assessment and Finding of No Significant Impact 

_____ Environmental Impact Statement and Record of Decision 

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References 

Cessford, G. R. 1995. Off-road mountain biking: A profile of participants and their 

recreation setting and experience preferences. Department of Conservation 

Science and Research Series, 93. 

Hammitt, W. E., and D. N. Cole. 1998. Wildland Recreation: Ecology and Management. 

2nded. New York: John Wiley and Sons. 

Hill, D., D. Hockin, D. Price, G. Tucker, R. Morris, and J. Treweek. 1997. Bird 

disturbance: improving the quality and utility of disturbance research. Journal of 

Applied Ecology 34:275-288. 

Hockin, D., M. Ounsted, M. Gorman, D. Hill, V. Keller, and M. A. Barker. 1992. 

Examination of the effects of disturbance on birds with reference to its importance 

in ecological assessments. Journal of Environmental Management 36:253-286. 

Klein, M. L. 1993. Waterbird behavioral responses to human disturbances. Wildl. Soc. 

Bull. 21:31-39. 

Klein, M. L., S. R. Humphrey, and H. F. Percival. 1995. Effects of ecotourism on 

distribution of waterbirds in a wildlife refuge. Conservation Biology 9:1454-1465. 

Knight, R. L., and D. N. Cole. 1991. Effects of Recreational Activity on Wildlife in 

Wildlands. Transactions of the 56th North American Wildlife & Natural Resources 

Conference. Pp: 238-247. 

Knight, R.L., and K. J. Gutzwiller, eds. 1995. Wildlife and Recreationists: Coexistence 

through Management and Research.Washington, D.C.: Island Press. 

Taylor, A. R. and R. L. Knight. 2003. "Wildlife Responses to Recreation and Associated 

Visitor Perceptions," Ecological Applications, (2003), 13(4):951-963. 

U.S. Fish and Wildlife Service. 2008. Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges Draft Comprehensive Conservation Plan and Environmental 

Assessment. Region 8. Sacramento, CA. 

Whittaker D., and R. L. Knight. 1998. Understanding wildlife responses to humans. 

Wildlife Society Bulletin. 26:312–317. 

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Refuge Determination 

Prepared by: ____________________________________ 

(Signature) 

____________ 

(Date) 

Wildlife Refuge Manager/ 

Project Leader 

Approval: ____________________________________ 

(Signature) 

____________ 

(Date) 

Concurrence 

Refuge Supervisor: ____________________________________ 

(Signature) 

____________ 

(Date) 

Assistant Regional 

Director, Refuges: ____________________________________ 

(Signature) 

____________ 

(Date) 

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COMPATIBILITY DETERMINATION 

(June 2008) 

Use: Commercial Photography 

Refuge Name: Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges, 

located in Glenn, Colusa, and Sutter Counties, California. 

Establishing and Acquisition Authority(ies): 

Sacramento National Wildlife Refuge (Refuge) was established in 1937. Legal authorities 

include: Executive Order 7562, February 27, 1937, Migratory Bird Conservation Act of 

1929 (16 U.S.C. 715d), Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as 

amended, the Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 

Statute 884), and the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Delevan Refuge was established in 1962. Legal authority includes: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d). 

Colusa Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884), and 

the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Sutter Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), and the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884). 

Refuge Purpose(s): 

Sacramento Refuge purposes include: 

“... as a refuge and breeding ground for migratory birds and other wildlife...” 

Executive Order 7562, February 27, 1937. 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, 

(2) the protection of natural resources, (3) the conservation of endangered species 

or threatened species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use 

B-10
... real ... property. Such acceptance may be accomplished under the terms and 

conditions of restrictive covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge 

Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection 

of fish and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the 

United States Fish and Wildlife Service, in performing its activities and services. 

Such acceptance may be subject to the terms of any restrictive or affirmative 

covenant, or condition of servitude ...” 16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 

1956). 

Delevan Refuge purpose includes: 

 “... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

Colusa Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

Sutter Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

National Wildlife Refuge System Mission: “To administer a national network of lands 

and waters for the conservation, management, and where appropriate, restoration of the 

fish, wildlife, and plant resources and their habitats within the United States for the 

B-11
benefit of present and future generations of Americans.” (National Wildlife Refuge 

System Administration Act of 1966, as amended [16 U.S.C. 668dd-ee]). 

Description of Use: The National Wildlife Refuge System Improvement Act of 1997 

identifies wildlife photography as well as hunting, fishing, wildlife observation, 

interpretation, and environmental education as priority wildlife dependent public uses for 

Refuges. As one of the six priority public uses of the Refuge System, wildlife photography 

is to be encouraged when compatible with the purposes of the Refuge. 

The guiding principles of the System’s wildlife photography program are to: 

• Provide safe, enjoyable, and accessible wildlife viewing opportunities and facilities. 

• Promote visitor understanding of, and increase visitor appreciation for, America’s 

natural resources. 

• Provide opportunities for quality recreational and educational experiences 

consistent with criteria describing quality found in 605 FW 1.6. 

• Minimize conflicts with visitors participating in other compatible wildlifedependent recreation activities 

Commercial photography is a visual recording (motion or still) by firms or individuals 

(other than news media representatives) who intend to distribute their photographic 

product for money or other consideration. This includes the creation of educational, 

entertainment, or commercial enterprises as well as advertising audio-visuals created for 

the purpose of paid product or services publicity, and commercially oriented photo 

contests (Service Manual 605 FW 5). These uses are identified and discussed in detail in 

the Draft Comprehensive Conservation (CCP) and Environmental Assessment (EA) 

(USFWS 2008) which are incorporated by reference. 

The photography objective of the Draft Comprehensive Conservation Plan (CCP) 

(USFWS 2008) states that the Refuges will provide 80 photography blind annual visits 

and 10,000 annual photography visits by 2023. This includes photographic opportunities 

from the auto tours, walking trails, and photography blinds. A portion of the hunt area 

(2,275 acres) is open for photography from February through June on Sacramento, 

Colusa, and Sutter Refuges. The in-ground, concrete hunting blinds in this area on 

Sacramento Refuge are available for photographic use from February through June with 

no user fees or reservations required. 

The best time of year for photography occurs from November through February when a 

variety of waterfowl is present. The auto tour routes and walking trails on Sacramento 

and Colusa Refuges provide excellent photographic opportunities. The viewing blind on 

the Discovery Trail at Colusa Refuge will be replaced with a universally accessible blind 

and boardwalk. 

There are two photography blinds on Sacramento Refuge and one on Colusa Refuge. A 

universally accessible photography blind will be constructed at Delevan Refuge with 

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access via Four Mile Road. The photography blinds may be reserved only one day each 

week, on Wednesdays through Sundays. The current fee for photo blind use is $10 per 

visit. Photographers may request up to three total reservations during October through 

March and unlimited visits during the spring and summer. Photographers may be placed 

on a waiting list if the blind or day requested is filled. Photographers also complete an 

evaluation that reports photographed species, time spent, and comments. Photographers 

must be in the blind at least one hour before sunrise. They must park in the designated 

parking area and proceed directly to the assigned blind on foot. The route from the 

parking area to the blind is marked by stakes with reflective tape. The route is designed 

to minimize disturbance; therefore, deviation from the staked route is not allowed. 

Photographers may leave the blind at any time, but once the blind has been vacated, 

returning to the blind is not permitted. 

The blinds are approximately 300 yards within the wetlands. They are approximately 4.5' 

x 6' wide and 5' high. They have adjustable camera size openings in three sides. The blinds 

accommodate one person comfortably; however, two people at a time are allowed. There is 

one chair in each blind. Islands or tree snags and islands have been placed to encourage 

birds to perch or rest about 40 feet from the blind. Photography Blind 2 on Sacramento 

Refuge will be replaced with a universally accessible blind and boardwalk. 

Availability of Resources: The following funding/annual costs (based on FY 2007 costs) 

would be required to administer and manage commercial photography activities as 

described above: 

Costs 

Monthly costs to monitor a large scale commercial operation (e.g. motion 

picture filming, etc.) on an as needed basis: 

Vehicle rental $ 500 

One temporary GS-5 Park Ranger $ 2,400 

TOTAL $ 2,900 

Additional funds would be required to operate and maintain the commercial photography 

program. User fees are collected for issuing special use permits (SUP) to recreational and 

commercial photographers. The standard fee for commercial photography is $100 per 

year. This category applies to any photography that result in images that are intended for 

sale, or where the photographer is otherwise paid for the work by salary or contract. A 

permit and fee (other than the daily Refuge entrance fee at the Sacramento Refuge and 

photo blind use fee if appropriate) is not required when the photographer is utilizing areas 

and facilities that are open to the general public. If any special attention (such as 

transportation, access to restricted areas, food, lodging, or guide service) is provided by 

the refuge staff, these costs (see table above) will be added to the standard fee for issuing 

a SUP (USFWS 1992). 

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Anticipated Impacts of Use: Once considered “non-consumptive”, it is now recognized 

that wildlife photography can negatively impact wildlife by altering wildlife behavior, 

reproduction, distribution, and habitat (Purdy et al. 1987, Knight and Cole 1995). 

Of the wildlife observation techniques, photographers tend to have the largest 

disturbance impacts (Klein 1993, Morton 1995, Dobb 1998). While wildlife observers 

frequently stop to view species, wildlife photographers are more likely to approach 

wildlife (Klein 1993). Even slow approach by photographers tends to have behavioral 

consequences to wildlife species (Klein 1993). Other impacts include the potential for 

photographers to remain close to wildlife for extended periods of time, in an attempt to 

habituate the wildlife subject to their presence (Dobb 1998) and the tendency of casual 

photographers, with low-power lenses, to get much closer to their subjects than other 

activities would require (Morton 1995), including wandering off trails. This usually results 

in increased disturbance to wildlife and habitat, including trampling of plants. Klein (1993) 

recommended that refuges provide observation and photography blinds to reduce 

disturbance of waterbirds when approached by visitors. 

Disturbance of wildlife is the primary concern regarding this use. Disturbance to wildlife, 

such as the flushing of feeding, resting, or nesting birds, is inherent to these activities. 

There is some temporary disturbance to wildlife due to human activities on trails (hiking, 

bird watching), however, the disturbance is generally localized and will not adversely 

impact overall populations. Increased facilities and visitation would cause some 

displacement of habitat and increase some disturbance to wildlife, although this is 

expected to be minor given the size of the Refuges and by avoiding or minimizing 

intrusion into important wildlife habitat. 

The commercial photography program is designed to avoid or minimize impacts 

anticipated to Refuge resources and Refuge visitors. The Refuges’ have requested Section 

7 consultation with USFWS and NOAA-Fisheries on the Draft CCP/EA (USFWS 2008) 

and its effects on any of the special status species/designated critical habitat occurring on 

the Refuges including: palmate-bracted bird’s beak, hairy Orcutt grass, Greene’s tuctoria, 

Hoover’s spurge, Conservancy fairy shrimp, vernal pool fairy shrimp, vernal pool tadpole 

shrimp, giant garter snake, western yellow-billed cuckoo, winter-run Chinook salmon, 

spring-run Chinook salmon, Central Valley steelhead, fall-run Chinook salmon, and late 

fall-run Chinook salmon. 

Anticipated Impacts of Uses on future lands within the approved boundary: The 

following conditions must be met before allowing existing uses to occur on newly acquired 

lands: (1) There is no indirect, direct, or cumulative threat anticipated to human health or 

safety; (2) There is no indirect, direct, or cumulative threat anticipated to natural or 

cultural resources; (3) The use is consistent with management of existing Sacramento, 

Delevan, Colusa, and Sutter Refuge lands and would contribute to achieving the Refuges’ 

goals. In particular, existing Refuge regulations would not be compromised; (4) The newly 

B-14
 X 

acquired lands represent a meaningful unit within which to manage the activity; and (5) 

There are no anticipated conflicts with priority public uses. 

Public Review and Comment: Public review and comments will be solicited in 

conjunction with distribution of the Draft CCP/EA for the Sacramento, Delevan, Colusa, 

and Sutter Refuges (USFWS 2008). 

Determination: 

_____ Use is Not Compatible 

Use is Compatible with the Following Stipulations 

Stipulations necessary to ensure compatibility: 

 Refuge visitors are required to remain in vehicles while on the auto tour routes 

except at designated park and stretch locations. 

 Access to the Refuges is allowed from one hour before sunrise to one hour after 

sunset. 

 Visitors, including commercial photographers, are required to obtain a Refuge Day 

Pass (currently $3 per vehicle) or Refuge Commercial Day Pass (currently $20 per 

commercial vehicle) for public use activities on Sacramento Refuge unless in 

possession of a Refuge Annual Pass, Federal Duck Stamp, valid Golden Eagle, Age 

or Access Passport, National Parks Pass with Hologram, or America the Beautiful 

Pass. 

 Two photography blinds on Sacramento Refuge and a blind on Colusa Refuge are 

available by reservation from October through March. A universally accessible 

blind will be constructed at Delevan Refuge and be available by reservation. The 

photography blinds may be reserved only one day each week, on Wednesdays 

through Sundays. The current fee for photo blind use is $10 per visit. 

Photographers may request up to three total reservations during October through 

March and unlimited visits during the spring and summer. 

 Commercial wildlife photographers must obtain a special use permit if the request 

includes access to closed areas or other special considerations (e.g. access to the 

Refuges after normal public visitation hours, setting up temporary photography 

blinds, etc.) (16 USC 460I-6d, Refuge Manual 8 RM 16). A standard fee of $100 per 

year for commercial photographers will be charged for issuing the SUP (USFWS 

1992). Unless otherwise stated on the permit, in addition to the permit fee, a daily 

Refuge entrance fee of $3 per vehicle is charged on Sacramento Refuge. Areas 

used will be closely monitored to evaluate the impacts on the resource; if adverse 

B-15
impacts appear, the activity may be moved to secondary locations or curtailed 

entirely. Specific conditions may apply depending upon the requested activity and 

will be addressed through the SUP. 

 All commercial photography operations that involve models, sets, props, lights, or 

similar equipment which will result in damage to the resource or which will unduly 

conflict with normal visitor use require an audio-visual production permit. 

Photography that includes commercial products for sale, filming motion pictures, 

documentaries or commercials, and similar related activities also requires an 

audio-visual production permit. All advertising photography requires an audiovisual production permit. Advertisements must not imply endorsement by the 

Service. No fee is charged for the permit. A bond or cash deposit is required when 

an audio-visual production permit is issued. The purpose of the bond is to assure 

that the area is left in its original condition. A performance bond issued by a 

bonding company, a cash deposit or certified check may be used for this purpose. 

Bonds or deposits will be required in amounts equal to the estimated cost to the 

Service of clean-up or restoration that would be required if the permittee failed to 

perform. Should the permittee actually fail to perform all or any part of the 

necessary clean-up or restoration, the refuge manager will have the required work 

done, assess the charge, deduct it from the bond or cash deposit and return the 

balance, if any, to the permittee. A Certificate of Insurance also is required naming 

the Service as certificate holder with the filming company assuming all liability for 

losses and damages (Refuge Manual 8 RM 16). Areas used will be closely 

monitored to evaluate the impacts on the resource; if adverse impacts appear, the 

activity may be moved to secondary locations or curtailed entirely. Specific 

conditions may apply depending upon the requested activity and will be addressed 

through the audio-visual production permit. 

 News gathering organizations are exempt from formal permits and bonding 

requirements. 

Justification: It is determined that commercial photography within the Sacramento, 

Delevan, Colusa, and Sutter National Wildlife Refuges as described herein, will not 

materially interfere with or detract from the purposes for which the Refuges were 

established or the mission of the Refuge System. In our opinion, allowing commercial 

photography with associated stipulations will not conflict with the national policy to 

maintain the biological diversity, integrity, and environmental health of the Refuges. 

B-16
 

 

Mandatory Re-Evaluation Date (2018): 

_____ Mandatory 15-year Re-Evaluation, Date will be provided in Final EA/CCP (for 

priority public uses) 

X Mandatory 10-year Re-Evaluation (for all uses other than priority public uses) 

NEPA Compliance for Refuge Use Decision (check one below): 

_____ Categorical Exclusion without Environmental Action Statement 

_____ Categorical Exclusion and Environmental Action Statement 

X Environmental Assessment and Finding of No Significant Impact 

_____ Environmental Impact Statement and Record of Decision 

References 

Dobb, E. 1998. Reality check: the debate behind the lens. Audubon: Jan.-Feb. 

Klein, M. L. 1993. Waterbird behavioral responses to human disturbances. Wildl. Soc. 

Bull. 21:31-39. 

Knight, R. L. and D. N. Cole. 1995. Wildlife responses to recreationists. Pages 71-79 in R. 

L. Knight and K. J. Gutzwiller, ed. Wildlife and Recreationists: coexistence 

through management and research. Island Press, Washington, D. C. 372 pp. 

Morton, J. M. 1995. Management of human disturbance and its effects on waterfowl. 

Pages F59-F86 in W. R. Whitman, T. Strange, L. Widjeskog, R. Whittemore, P. 

Kehoe, and L. Roberts (eds.). Waterfowl habitat restoration, enhancement and 

management in the Atlantic Flyway. Third Ed. Environmental Manage. Comm., 

Atlantic Flyway Council Techn. Sect., and Delaware Div. Fish and Wildl., Dover, 

DE. 1114 pp. 

Purdy, K. G., G. R. Goft, D. J. Decker, G. A. Pomerantz, and N. A. Connelly. 1987. A guide 

to managing human activity on National Wildlife Refuges. Office of Information 

Transfer, U.S. Fish and Wildlife Service, Ft. Collins, CO. 57 pp. 

U.S. Fish and Wildlife Service. 1992. Standardized fee schedule for special use permits. 

March 16, 1992 memo from Assistant Regional Director, Refuges and Wildlife, 

Portland, OR. 5 pp. 

B-17
U.S. Fish and Wildlife Service. 2008. Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges Draft Comprehensive Conservation Plan and Environmental 

Assessment. Region 8. Sacramento, CA. 

B-18
Refuge Determination 

Prepared by: ____________________________________ ____________

 (Signature) (Date)

Wildlife Refuge Manager/ 

Project Leader 

Approval: ____________________________________ ____________

 (Signature) (Date)

Concurrence 

Refuge Supervisor: ____________________________________ ____________

 (Signature) (Date)

Assistant Regional 

Director, Refuges: ____________________________________ ____________

 (Signature) (Date)

B-19
COMPATIBILITY DETERMINATION 

(June 2008) 

Use: Environmental Education and Interpretation 

Refuge Name: Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges, 

located in Glenn, Colusa, and Sutter Counties, California. 

Establishing and Acquisition Authority(ies): 

Sacramento National Wildlife Refuge (Refuge) was established in 1937. Legal authorities 

include: Executive Order 7562, February 27, 1937, Migratory Bird Conservation Act of 

1929 (16 U.S.C. 715d), Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as 

amended, the Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 

Statute 884), and the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Delevan Refuge was established in 1962. Legal authority includes: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d). 

Colusa Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884), and 

the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Sutter Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), and the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884). 

Refuge Purpose(s): 

Sacramento Refuge purposes include: 

“... as a refuge and breeding ground for migratory birds and other wildlife...” 

Executive Order 7562, February 27, 1937. 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, 

(2) the protection of natural resources, (3) the conservation of endangered species 

or threatened species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use 

B-20
... real ... property. Such acceptance may be accomplished under the terms and 

conditions of restrictive covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge 

Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection 

of fish and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the 

United States Fish and Wildlife Service, in performing its activities and services. 

Such acceptance may be subject to the terms of any restrictive or affirmative 

covenant, or condition of servitude ...” 16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 

1956). 

Delevan Refuge purposes include: 

 “... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

Colusa Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

Sutter Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

National Wildlife Refuge System Mission: “To administer a national network of lands 

and waters for the conservation, management, and where appropriate, restoration of the 

fish, wildlife, and plant resources and their habitats within the United States for the 

B-21
benefit of present and future generations of Americans.” (National Wildlife Refuge 

System Administration Act of 1966, as amended [16 U.S.C. 668dd-ee]). 

Description of Use: The National Wildlife Refuge System Improvement Act of 1997 

identifies environmental education and interpretation as well as hunting, fishing, wildlife 

observation, and photography as priority wildlife-dependent public uses for Refuges. As 

two of the six priority public uses of the Refuge System, these uses are to be encouraged 

when compatible with the purposes of the Refuges. Environmental education and 

interpretation are considered simultaneously in this compatibility determination. Many 

elements of environmental education and interpretation are also similar to opportunities 

provided in the wildlife observation and photography program programs. These uses are 

identified and discussed in detail in the Draft Comprehensive Conservation Plan (CCP) 

and Environmental Assessment (EA) (USFWS 2008a) which are incorporated by 

reference. 

The guiding principles of the Refuge System’s environmental education programs (605 

FW 6 of the Service Manual) are to: 

• Teach awareness, understanding, and appreciation of our natural and cultural 

resources and conservation history. 

• Allow program participants to demonstrate learning through refuge-specific 

stewardship tasks and projects that they can carry over into their everyday lives. 

• Establish partnerships to support environmental education both on- and off-site. 

• Support local, State, and national educational standards through environmental 

education on refuges. 

• Assist refuge staff, volunteers, and other partners in obtaining the knowledge, 

skills, and abilities to support environmental education. 

• Provide appropriate materials, equipment, facilities, and study locations to support 

environmental education. 

• Give refuges a way to serve as role models in the community for environmental 

stewardship. 

• Minimize conflicts with visitors participating in other compatible wildlifedependent recreation activities. 

The guiding principles of the Refuge System’s interpretive programs(605 FW 7 of the 

Service Manual) are to: 

• Promote visitor understanding of, and increase appreciation for, America’s natural 

and cultural resources and conservation history by providing safe, informative, 

enjoyable, and accessible interpretive opportunities, products, and facilities; 

• Develop a sense of stewardship leading to actions and attitudes that reflect interest 

and respect for wildlife resources, cultural resources, and the environment; 

• Provide quality interpretive experiences that help people understand and 

appreciate the individual refuge and its role in the Refuge System; 

• Provide opportunities for quality recreational and interpretive experiences 

consistent with criteria describing quality found in 605 FW 1.6; 

B-22
• Assist refuge staff, volunteers, and community support groups in attaining 

knowledge, skills, and abilities in support of interpretation; and 

• Minimize conflicts with visitors participating in other compatible wildlifedependent recreational activities. 

Environmental education and interpretation conducted on portions of the Refuges open to 

the general public do not require a special use permit. These areas are open one hour 

before sunrise to one hour after sunset on all Refuges. 

Environmental Education 

Environmental education is comprised of teacher or leader-conducted activities that are 

intended to actively involve students or others in hands-on activities. These activities are 

designed to promote discovery and fact-finding, develop problem-solving skills, and lead 

to personal involvement and action. The Service focuses on kindergarten through twelfth 

grade students. 

The Environmental Education Guide for the Complex describes the activities, facilities 

and resources available. The environmental education program was restructured in 2005 

to increase the involvement of teachers or leaders in conducting their pre-selected 

activities. The program offers several ways for the classes to experience the Complex. 

Specifically at the Sacramento Refuge, they are welcomed by visitor services staff and 

have access to the diorama, Discovery Room and refuge videos/DVDs. For the remainder 

of their visit, the teachers or leaders guide their group through their pre-planned tour. 

Although the Refuges are open to the public from one hour before sunrise to one hour 

after sunset daily, we require groups to make reservations two weeks in advance to 

ensure that they will have the best possible experience and that needed resource 

materials are available. They may call, fax or visit the Complex’s website to make 

reservations. 

For an even more comprehensive environmental education experience, there is the fully 

equipped backpack or Discovery Pack to teach as many as five activities along the 

Wetlands Walk. The Pack contains dip nets, field guides, plant mounts, bug boxes, lenses, 

and other written materials. A teacher’s guide can be sent, upon request, prior to the visit. 

Binoculars and waterfowl guides are available on loan. The Environmental Education 

Guide and the Complex’s website list many other resources available. 

The environmental education program will be greatly expanded in the future with the 

development of the Wetlands Resource Center near the Refuge Headquarters. The 

Wetlands Resource Center would accommodate 5,000 teachers, students, and adults 

annually. The Wetlands Resource Center would be located on the east side of Logan 

Creek between the existing headquarters and easement buildings. A wetland could be 

created south of the Center for habitat viewing and environmental education activities. A 

foot bridge would be constructed over Logan Creek so that the current parking area and 

B-23
Wetlands Walk may be used. The Center could be a one-story building with a covered 

viewing porch at roof height. Large picture windows would accommodate views to the 

south and west. Part of the entry area would descend below the pond surface to allow 

visitors to view aquatic organisms and soil profiles. An auditorium would provide seating 

for up to 100 and include a surround-sound system, High Definition (HD) television, and 

retracting screens for projectors, videos, and DVDs. Separate laboratory rooms would 

provide a secluded work area, storage and sinks. Computer work stations with 

internet/satellite access and a resource library would be available for students and 

teachers. 

Interpretation 

Interpretation involves participants of all ages who learn about the complex issues 

confronting fish and wildlife resource management as they voluntarily engage in 

stimulating and enjoyable activities. First-hand experience with the environment is 

emphasized although presentations, audiovisual media, and exhibits are often necessary 

components of the interpretive program. The interpretation visits would significantly 

expand and enhanced with the development of the Wetlands Resource Center to 

accommodate up to 20,000 visits annually. 

In 2007, the Service declared that “connecting people with nature” is among the agencies 

highest national priorities (USFWS 2008b). A connection with nature, whether it’s hiking, 

fishing, camping, hunting, or simply playing outside, helps children develop positive 

attitudes and behaviors towards the environment. Positive interactions with the 

environment can lead to a life-long interest in enjoying and preserving nature. People’s 

interest in nature is crucial to the Service mission of conserving, protecting, and 

enhancing fish, wildlife, plants, and their habitats. 

When Service employees were asked to describe a childhood experience where they felt a 

connection with nature, the answers ranged from memories of riding on the laps of loved 

ones while mowing the lawn, to family vacations along a lake, beach, or forest, to hiking, 

climbing trees, and discovering insects, frogs, and birds. Many employees credit these 

memorable moments for placing them in the career that they are in today. Those 

experiences were the spark that led to a lifetime of stewardship and conservation. The 

Service wants to capture that spark and share it with the next generation of 

conservationists. The Connecting People with Nature Program goals for Region 8 include 

1) Rekindle the spark, 2) Share the spark and 3) Ignite the spark. The Refuges are 

currently beginning to implement these goals by developing “Sense of Wonder Zones” or 

naturalized play areas for family-oriented activities on the Sacramento and Colusa 

Refuges where people of all ages can reconnect with nature. The Refuges will also create 

interpretive geocaching opportunities on the Sacramento and Colusa Refuges. 

Refuge brochures pertaining to information on the Complex, Watchable Wildlife, and 

hunting have been developed and revised over the years. The Wetlands Walk Guide and 

the birding trail guide were completed in 2006. Varieties of videos/DVDs are also available 

B-24
for viewing upon request. The Sacramento Valley Refuge: An Unfinished Symphony and 

America’s National Wildlife Refuge System: Where Wildlife Comes First, are the most 

popular videos. The Unfinished Symphony was written and filmed on location in 2003 as 

part of the Refuge System Centennial Celebration. 

A bookstore in the Sacramento Refuge visitor center (Refuge Headquarters) was created 

in 1990 via cooperative agreement with the San Francisco Bay Wildlife Society. Additional 

shelving was added in 1996 increasing the sales to a consistent $14,000 annually. The 

cooperative agreement was terminated with San Francisco Wildlife Society in 2001 and a 

new cooperative agreement was signed with Altacal Audubon Society of Chico, CA in 

2002. 

Refuge related information is provided at annual local festivals or during special events, 

such as the State Fair, International Migratory Bird Day, Snow Goose Festival, National 

Wildlife Refuge Week, Pacific Flyway Decoy Association, Coleman National Fish 

Hatchery Salmon Festival, Chico Endangered Species Fair, California Waterfowl 

Association (CWA) Art Camp, CWA Marsh Madness, Orland’s Community Expo, 

Willow’s Business Expo and Colusa’s Farm Day. During 2005, approximately 13,000 

individuals attended the presentations and saw exhibits at these events. 

B-25
 

Availability of Resources: The following funding/annual costs (based on FY 2007 costs) 

would be required to administer and manage environmental education and interpretation 

activities as described above: 

One-Time Costs Annual Costs 

New Construction 

Construct Wetland Resource 

Center (Sacramento) 

$5,984,000 

Obtain equipment and supplies for 

Wetland Resource Center 

(Sacramento) 

$ 184,800 

Improve entrance road and visitor 

parking area including railroad 

crossing device (Sacramento) 

$ 540,000 

Construct accessible restroom 

(Sacramento) 

$ 227,000 

Repair visitor entrance road and 

parking areas (Sacramento) 

$ 60,800 

Replace domestic well and water 

lines at headquarters 

(Sacramento) 

$ 190,000 

Predicted Maintenance of Facilities 

Regular maintenance of Wetland 

Resource Center, restrooms, etc. 

$ 20,000 

Equipment, vehicles, and supplies 

(e.g. brochures, etc.) 

$ 22,000 

New Staffing 

One full-time (1.0 FTE) GS-7/9 

interpretive specialist 

$ 64,430 

One full-time (1.0 FTE) WG-3 

maintenance worker 

$ 42,209 

TOTAL $7,186,600 $148,639 

Additional funds would be required to fully implement the environmental education and 

interpretation programs. Additional visitor services staff and volunteers would be needed. 

Funding will be sought through the Service budget process. Other sources will be sought 

through strengthened partnerships, grants, and additional refuge operations funding to 

support a safe and quality program as described above. 

Anticipated Impacts of Use: Disturbance of wildlife is the primary concern regarding 

these uses. Disturbance to wildlife, such as the flushing of feeding, resting, or nesting 

birds, is inherent to these activities. There is some temporary disturbance to wildlife due 

to human activities on trails (hiking, bird watching) however, the disturbance is generally 

localized and will not adversely impact overall populations. Increased facilities and 

B-26
visitation would cause some displacement of habitat and increase some disturbance to 

wildlife, although this is expected to be minor given the size of the Refuges and by 

avoiding or minimizing intrusion into important wildlife habitat. 

Individual animals may be disturbed by human contact to varying degrees. Human 

activities on trails can result in direct effects on wildlife through harassment, a form of 

disturbance that can cause physiological effects, behavioral modifications, or death (Smith 

and Hunt 1995). Many studies have shown that birds can be impacted from human 

activities on trails when they are disturbed and flushed from feeding, resting, or nesting 

areas. Flushing, especially repetitive flushing, can strongly impact habitat use patterns of 

many bird species. Flushing from an area can cause birds to expend more energy, be 

deterred from using desirable habitat, affect resting or feeding patterns, and increase 

exposure to predation or cause birds to abandon sites with repeated disturbance (Smith 

and Hunt 1995). Migratory birds were observed to be more sensitive than resident species 

to disturbance (Klein 1989). 

Herons and shorebirds were observed to be the most easily disturbed (when compared to 

gulls, terns and ducks) by human activity and flushed to distant areas away from people 

(Burger 1981). A reduced number of shorebirds were found near people who were walking 

or jogging, and about 50 percent of flushed birds flew elsewhere (Burger 1981). In 

addition, the foraging time of sanderlings decreased and avoidance (e.g., running, 

flushing) increased as the number of humans within 100 meters increased (Burger and 

Gochfeld 1991). Nest predation for songbirds (Miller et al. 1998), raptors (Glinski 1976), 

colonial nesting species (Buckley and Buckley 1976), and waterfowl (Boyle and Samson 

1985) tends to increase in areas more frequently visited by people. In addition, for many 

passerine species, primary song occurrence and consistency can be impacted by a single 

visitor (Gutzwiller et al. 1994). In areas where primary song was affected by disturbance, 

birds appeared to be reluctant to establish nesting territories (Reijnen and Foppen 1994). 

Depending on the species (especially migrants vs. residents), some birds may habituate to 

some types of recreation disturbance and either are not disturbed or will immediately 

return after the initial disturbance (Hockin et al. 1992; Burger et al. 1995; Knight and 

Temple 1995; Madsen 1995; Fox and Madsen 1997). Rodgers and Smith (1997) calculated 

buffer distances that minimize disturbance to foraging and loafing birds based on 

experimental flushing distances for 16 species of waders and shorebirds. They 

recommended 100 meters as an adequate buffer against pedestrian traffic, however, they 

suggest this distance may be reduced if physical barriers (e.g., vegetation screening) are 

provided, noise levels are reduced, and traffic is directed tangentially rather than directly 

toward birds. Screening may not effectively buffer noise impacts, thus visitors should be 

educated on the effects of noise and noise restrictions should be enforced (Burger 1981, 

1986; Klein 1993; Bowles 1995; Burger and Gochfeld 1998). Seasonally restricting or 

prohibiting recreation activity may be necessary during spring and fall migration to 

alleviate disturbance to migratory birds (Burger 1981, 1986; Boyle and Samson 1985; 

Klein et al. 1995; Hill et al. 1997). 

B-27
Education helps make visitors aware that their actions can have negative impacts on 

birds, and will increase the likelihood that visitors will abide by restrictions on their 

actions. For example, Klein (1993) demonstrated that visitors who had spoken with refuge 

staff or volunteers were less likely to disturb birds. Increased surveillance and imposed 

fines may also help reduce visitor caused disturbance (Knight and Gutzwiller 1995). 

Monitoring is recommended to adjust management techniques over time, particularly 

because it is often difficult to generalize about the impacts of specific types of recreation 

in different environments. Local and site-specific knowledge is necessary to determine 

effects on birds and to develop effective management strategies (Hockin et al. 1992; Klein 

et al. 1995; Hill et al. 1997). Informed management decisions coupled with sufficient public 

education could do much to mitigate disturbance effects of wildlife-dependent recreations 

(Purdy et al 1987). 

Environmental education and interpretation activities generally support the Refuges 

purposes and impacts can largely be minimized (Goff et al. 1988). The minor resource 

impacts attributed to these activities are generally outweighed by the benefits gained by 

educating present and future generations about refuge resources. Environmental 

education is a public use management tool used to develop a resource protection ethic 

within society. While it targets school age children, it is not limited to this group. This tool 

allows us to educate refuge visitors about endangered and threatened species 

management, wildlife management and ecological principles and communities. A 

secondary benefit of environmental education is that it instills an ‘ownership’ or 

‘stewardship’ ethic in visitors and most likely reduces vandalism, littering and poaching. It 

also strengthens Service visibility in the local community. 

The disturbance by environmental education activities is considered to be of minimal 

impact because: (1) the total number of students permitted through the reservation 

system is limited to 100 per day; (2) students and teachers will be instructed in trail 

etiquette and the best ways to view wildlife with minimal disturbance; (3) education 

groups will be required to have a sufficient number of adults to supervise the group; (4) 

trail design will provide adequate cover for wildlife; and (5) observation areas and scopes 

are provided to view wildlife at a distance which reduces disturbance. 

Education staff coordinates with biologists regarding activities associated with restoration 

or monitoring projects to ensure that impacts to both wildlife and habitat are minimal. As 

with any restoration and monitoring activities conducted by refuge personnel, these 

activities conducted by students would be at a time and place where the least amount of 

disturbance would occur. 

The environmental education and interpretation programs are designed to avoid or 

minimize impacts anticipated to the Refuges’ resources and visitors. The Refuges’ have 

requested Section 7 consultation with USFWS and NOAA-Fisheries on the Draft 

CCP/EA (USFWS 2008a) and its effects on any of the special status species/designated 

critical habitat occurring on the Refuges including: palmate-bracted bird’s beak, hairy 

Orcutt grass, Greene’s tuctoria, Hoover’s spurge, Conservancy fairy shrimp, vernal pool 

B-28
 

 

fairy shrimp, vernal pool tadpole shrimp, giant garter snake, western yellow-billed 

cuckoo, winter-run Chinook salmon, spring-run Chinook salmon, Central Valley 

steelhead, fall-run Chinook salmon, and late fall-run Chinook salmon. 

Anticipated Impacts of Uses on future lands within the approved boundary: The 

following conditions must be met before allowing existing uses to occur on newly acquired 

lands: (1) There is no indirect, direct, or cumulative threat anticipated to human health or 

safety; (2) There is no indirect, direct, or cumulative threat anticipated to natural or 

cultural resources; (3) The use is consistent with management of existing Sacramento, 

Delevan, Colusa, and Sutter Refuge lands and would contribute to achieving the Refuges’ 

goals. In particular, existing Refuge regulations would not be compromised; (4) The newly 

acquired lands represent a meaningful unit within which to manage the activity; and (5) 

There are no anticipated conflicts with priority public uses. 

Public Review and Comment: Public review and comments will be solicited in 

conjunction with distribution of the Draft CCP/EA for the Sacramento, Delevan, Colusa, 

and Sutter Refuges (USFWS 2008a). 

Determination: 

 Use is Not Compatible 

X Use is Compatible with the Following Stipulations 

Stipulations necessary to ensure compatibility: 

 Participants in the Refuges’ environmental education and interpretation programs 

are restricted to established trails, the visitor center, the Wetland Resource 

Center, and other designated sites. 

 All groups using the Refuges for environmental education are required to make 

reservations two-weeks in advance. They may call, fax, or visit the Complex’s 

website to make reservations. This reservation process, allows refuge staff to 

manage the number and location of visitors for each day. Currently, educational 

groups are not charged a fee or required to have a special use permit. A daily limit 

of 100 students participating in the education program will be maintained through 

this reservation system. Efforts are made to spread out use by large groups, 

reducing disturbance to wildlife and over-crowding of the Refuges’ facilities during 

times of peak demand. 

 Trail etiquette including ways to reduce wildlife disturbance is discussed with 

teachers during orientation workshops and with students upon arrival during their 

welcome session. On the Refuges, the teacher(s) is responsible for ensuring that 

students follow required trail etiquette. 

B-29
 

 

 Refuge biologists and visitor services staff conduct regular surveys of public 

activities on the Refuges. The data is analyzed and used by the refuge manager to 

develop future modifications if necessary to ensure compatibility of environmental 

education programs. 

 Educational groups are required to have a sufficient number of adults to supervise 

their groups, a minimum of 1 adult per 12 students. 

Justification: These wildlife-dependent uses are priority public uses of the National 

Wildlife Refuge System. Providing opportunities for environmental education and 

interpretation, would contribute toward fulfilling provisions of the National Wildlife 

Refuge System Administration Act, as amended in 1997, and one of the goals of the 

Sacramento, Delevan, Colusa, and Sutter Refuges (Goal 3, Chapter 4, CCP). 

Environmental education and interpretation would provide an excellent forum for 

allowing public access and increasing understanding of Refuge resources. The stipulations 

outlined above should minimize potential impacts relative to wildlife/human interactions. 

Based upon impacts described in the Draft Comprehensive Conservation Plan and 

Environmental Assessment (USFWS 2008a), it is determined that environmental 

education and interpretation within the Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges as described herein, will not materially interfere with or detract from the 

purposes for which the Refuges were established or the mission of the Refuge System. In 

our opinion, implementing the visitor services plan and associated stipulations will not 

conflict with the national policy to maintain the biological diversity, integrity, and 

environmental health of the Refuges. 

Mandatory Re-Evaluation Date (2023): 

X Mandatory 15-year Re-Evaluation, Date will be provided in Final EA/CCP (for 

priority public uses) 

_____ Mandatory 10-year Re-Evaluation (for all uses other than priority public uses) 

NEPA Compliance for Refuge Use Decision (check one below): 

_____ Categorical Exclusion without Environmental Action Statement 

_____ Categorical Exclusion and Environmental Action Statement 

X Environmental Assessment and Finding of No Significant Impact 

_____ Environmental Impact Statement and Record of Decision 

B-30
References 

Bowles A. E. 1995. Response of wildlife to noise. Pages 109-156. in R.L. Knight and D.N. 

Cole, editors. Wildlife and recreationists: coexistence through management and 

research. Washington, D.C., Island Press. 

Boyle, S. A. and F. B. Samson. 1985. Effects of non-consumptive recreation on wildlife: a 

review. Wildl. Soc. Bull. 13:110-116. 

Buckley, P. A. and F. G. Buckley. 1976. Guidelines for protection and management of 

colonially nesting waterbirds. North Atlantic Regional Office, National Park 

Service, Boston, MA. 52 pp. 

Burger, J. 1981. The effect of human activity on birds at a coastal bay. Biol. Cons. 21:231­

241. 

Burger, J. 1986. The effect of human activity on shorebirds in two coastal bays in 

northeastern United States. Biological Conservation 13:123-130. 

Burger, J. and M. Gochfeld. 1991. Human distance and birds: tolerance and response 

distances of resident and migrant species in India. Environ. Conserv. 18:158-165. 

Burger, J., and M. Gochfeld. 1998. Effects of ecotourists on bird behavior at Loxahatchee 

National Wildlife Refuge, Florida. Environmental Conservation 25:13-21. 

Burger, J., M. Gochfeld, and L. J. Niles. 1995. Ecotourism and birds in coastal New 

Jersey: Contrasting responses of birds, tourists, and managers. Environmental 

Conservation 22:56-65. 

Fox, A. D., and J. Madsen. 1997. Behavioural and distributional effects of hunting 

disturbance on waterbirds in Europe: implications for refuge design. The Journal 

of Applied Ecology 34:1-13. 

Glinski, R. L. 1976. Birdwatching etiquette: the need for a developing philosophy. Am. 

Bird 30(3):655-657. 

Goff, G.R., D.J. Decker and G. Pomerantz. 1988. A diagnostic tool for analyzing visitor 

impacts on wildlife refuges: A basis for a systematic approach to visitor 

management. Trans. Northeast Sect. Wildl. Soc. 45:82. 

Gutzwiller, K. J., R. T. Wiedenmann, K. L. Clements, and S. H. Anderson. 1994. Effects 

on human intrusion on song occurrence and singing consistency in subalpine birds. 

Auk 111:28-37. 

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Hill, D., D. Hockin, D. Price, G. Tucker, R. Morris, and J. Treweek. 1997. Bird 

disturbance: improving the quality and utility of disturbance research. Journal of 

Applied Ecology 34:275-288. 

Hockin, D., M. Ounsted, M. Gorman, D. Hill, V. Keller, and M. A. Barker. 1992. 

Examination of the effects of disturbance on birds with reference to its importance 

in ecological assessments. Journal of Environmental Management 36:253-286. 

Klein, M. 1989. Effects of high levels of human visitation on foraging waterbirds at J. N. 

"Ding" Darling National Wildlife Refuge, Sanibel Florida. Masters thesis. 

Gainesville, Florida: University of Florida. 

Klein, M. L. 1993. Waterbird behavioral responses to human disturbances. Wildl. Soc. 

Bull. 21:31-39. 

Klein, M. L., S. R. Humphrey, and H. F. Percival. 1995. Effects of ecotourism on 

distribution of waterbirds in a wildlife refuge. Conservation Biology 9:1454-1465. 

Knight, R.L., and K. J. Gutzwiller, ed. 1995. Wildlife and Recreationists: coexistence 

through management and research. Island Press, Washington, D. C. 372 pp. 

Knight, R. L. and S. A. Temple. 1995. Origin of wildlife responses to recreationists. In 

Wildlife and recreation: coexistence through management and research. R. L. 

Knight and K. J. Gutzwiller, eds. Island Press, Washington, D. C., pp 81-91. 

Madsen, J. 1995. Impacts of disturbance on migratory waterfowl. Ibis 137 Supplemental: 

S67-S74. 

Miller, S. G., R. L. Knight, and C. K. Miller. 1998. Influence of recreational trails on 

breeding bird communities. Ecol. Appl. 8:162-169. 

Purdy, K. G., G. R. Goft, D. J. Decker, G. A. Pomerantz, and N. A. Connelly. 1987. A guide 

to managing human activity on National Wildlife Refuges. Office of Information 

Transfer, U.S. Fish and Wildlife Service, Ft. Collins, CO. 57 pp. 

Reijnen, R. and R. Foppen. 1994. The effects of car traffic on breeding bird populations in 

woodland. I. Evidence of reduced habitat quality for willow warbler (Pylloscopus 

trochilus) breeding close to a highway. J. Appl. Ecol 31:85-94. 

Rodgers, J. A., and H. T. Smith. 1997. Buffer zone distances to protect foraging and 

loafing waterbirds from human disturbance in Florida. Wildlife Society Bulletin 

25:139-145. 

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Smith, L. and J. D. Hunt. 1995. Nature tourism: impacts and management. Pp. 203-219 in 

Knight, R. L.; Gutzwiller, K. J. (Wildlife and recreationists: coexistence through 

management and research, eds.). Island Press, Washington, D. C. 

U.S. Fish and Wildlife Service. 2008a. Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges Draft Comprehensive Conservation Plan and Environmental 

Assessment. Region 8. Sacramento, CA. 

U.S. Fish and Wildlife Service. 2008b. Connecting People with Nature Action Plan, 

Sharing the Spark. California Nevada Region 8. Sacramento, CA. 42 pp. 

B-33
 

 

 

 

Refuge Determination 

Prepared by: ____________________________________ 

(Signature) 

____________ 

(Date) 

Wildlife Refuge Manager/ 

Project Leader 

Approval: ____________________________________ 

(Signature) 

____________ 

(Date) 

Concurrence 

Refuge Supervisor: ____________________________________ 

(Signature) 

____________ 

(Date) 

Assistant Regional 

Director, Refuges: ____________________________________ 

(Signature) 

____________ 

(Date) 

B-34
COMPATIBILITY DETERMINATION 

(June 2008) 

Use: Grazing 

Refuge Name: Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges, 

located in Glenn, Colusa, and Sutter Counties, California. 

Establishing and Acquisition Authorities: 

Sacramento National Wildlife Refuge (Refuge) was established in 1937. Legal authorities 

include: Executive Order 7562, February 27, 1937, Migratory Bird Conservation Act of 

1929 (16 U.S.C. 715d), Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as 

amended, the Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 

Statute 884), and the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Delevan Refuge was established in 1962. Legal authority includes: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d). 

Colusa Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884), and 

the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Sutter Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), and the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884). 

Refuge Purpose(s): 

Sacramento Refuge purposes include: 

“... as a refuge and breeding ground for migratory birds and other wildlife...” 

Executive Order 7562, February 27, 1937. 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, 

(2) the protection of natural resources, (3) the conservation of endangered species 

or threatened species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use 

B-35
... real ... property. Such acceptance may be accomplished under the terms and 

conditions of restrictive covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge 

Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection 

of fish and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the 

United States Fish and Wildlife Service, in performing its activities and services. 

Such acceptance may be subject to the terms of any restrictive or affirmative 

covenant, or condition of servitude ...” 16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 

1956). 

Delevan Refuge purposes include: 

 “... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

Colusa Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

Sutter Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

National Wildlife Refuge System Mission: “To administer a national network of lands 

and waters for the conservation, management, and where appropriate, restoration of the 

fish, wildlife, and plant resources and their habitats within the United States for the 

B-36
benefit of present and future generations of Americans.” (National Wildlife Refuge 

System Administration Act of 1966, as amended [16 U.S.C. 668dd-ee]). 

Description of Use: Livestock grazing is conducted annually for a specified period (i.e., 

seasonally) to manage vegetation for the benefit of native plants and wildlife habitat on 

Sacramento, Delevan, Colusa, and Sutter Refuges, where appropriate. Grazing is 

administered with a livestock cooperator under a Special Use Permit (SUP). The SUP 

states provisions for habitat objectives, expected wildlife benefits, shared staffing, facility 

maintenance, pest management, remedies, operating rules and laws, and reporting 

requirements. An annual grazing plan identifies the refuge tract to be grazed and 

specifies: vegetation and habitat type, grazing objective (primary target weed and/or 

primary native species or taxa), prescribed expected tract conditions (vegetation height), 

date by which expected conditions are to be met, livestock turn-in/turn-out dates and 

Animal Unit Months (AUM). 

The specific dates are determined by the refuge manager through consultation with the 

refuge biologist and cooperator to develop a strategy that meets target tract objectives. 

Each year the needs for vegetation management, including grazing, are evaluated during 

the annual review of the habitat management plan. The plan has built-in flexibility due to 

the uncertainties of annual and seasonal precipitation, flooding, and temperatures, and 

their consequent affect on vegetation growth. This flexibility insures that expected 

conditions are met and that refuge vegetation is neither over-grazed nor under-grazed— 

both conditions result in degraded habitat. Included in the annual habitat management 

plan is a project plan, which also specifies by refuge tract: identified facilities and 

maintenance projects, materials, shared responsibilities, and special management 

problems and considerations. This is a refuge management economic activity and its 

utilization helps the Refuges achieve the purposes for which they were created and the 

mission of the Refuge System. The proposed grazing program is described in the Draft 

Comprehensive Conservation Plan (CCP) and associated Environmental Assessment 

(EA), which are incorporated by reference (USFWS 2008). 

Grazing is used as a management tool to improve habitat conditions on the Refuges. 

Privately owned livestock (sheep, goats, or cattle) will graze on the Refuges to improve 

vegetative composition by reducing exotic weed species. Grazing will be timed to reduce 

undesirable vegetation and will be conducted in grassland habitats (March 1 through 

November 1) and in seasonal wetland habitats (May 1 through October 1). 

Livestock will be kept in areas that have undesirable vegetative composition and in 

numbers that can have an impact on the undesirable vegetation. If sheep were used, a 

herder and dogs would be allowed to stay in a small trailer on the Refuge to tend the 

animals. 

B-37
Of the management tools available to be used to control exotic weeds (herbicides, mowing, 

burning, discing, grazing) in grassland habitats, grazing is often the most practical and 

cost efficient. 

Availability of Resources: The following funding/annual costs (based on FY 2007 costs) 

would be required to administer and manage grazing activities as described above: 

Annual Costs 

Administration $1,000 

Facilities maintenance $5,000 

TOTAL $6,000 

Monitoring is addressed in the annual habitat management plans. The Refuges may 

charge user fees; however, in-kind services have been used to the advantage of the Refuge 

and are determined annually during annual grazing plan meetings. Refuge operational 

funds are currently available through the Service budget process to administer this 

program. 

Anticipated Impacts of Use: Grazing by native wildlife species has long occurred in the 

California landscape where it has shaped its botanical and zoological resources (Edwards 

1992; Edwards 1996). Currently, livestock grazing is an important method of vegetation 

management (Barry 2003; Griggs 2000). Beneficial effects to Refuge habitat, wildlife and 

native plants would occur as a result of a well managed livestock grazing program. 

Primary benefits associated with the grazing program include: a reduction in the 

accumulation of dead plant material; reduction in non-native invasive weeds (Thomsen et 

al. 1993); increases in native plants, including special status species, from reduced 

competition for sunlight, water and nutrients with non-native annual grasses (Coppoletta 

and Moritsch 2001; Davis and Sherman 1992; Menke 1992; Muir and Moseley 1994); 

increases primary production and resultant increases in plant biomass (McNaughton 

1985); and increases in flowering, with consequent increases in macro-invertebrate 

populations, including native pollinators of native plants, and prey items for refuge 

wildlife such as migratory birds. Grazing would provide optimal shorebird foraging 

habitat (Colwell and Dodd 1995; Knopf and Rupert 1995) and would provide short, 

nutritious grasses for grazing migratory waterfowl (Buchsbaum et al. 1986), and local 

deer. Aquatic invertebrates, insects, and special status species would benefit from grazed 

herbaceous habitats (Bratton 1990; Bratton and Fryer 1990; Panzer 1988; Germano et al. 

2001; Knopf and Rupert 1995). Primary burrowing mammals such as California ground 

squirrel would increase with grazing and this would result in increases of secondary 

burrowing animals such as burrowing owls and various snake taxa. Primary, long-term 

benefits include continued annual native plant production, control of non-native invasive 

plant species, and, seasonal use of refuge habitat by migratory birds and resident deer. 

Within grassland habitats on the Refuges, invasive weeds include yellow star-thistle 

(Centaurea solstitialis), black mustard (Brassica nigra), Mediterranean annual grasses, 

B-38
perennial pepperweed (Lepidium latifolium), and others. Yellow star-thistle is a noxious 

weed in grassland habitats on the Refuges. Yellow star-thistle reduces the values of 

grassland areas to many native wildlife species. Properly timed grazing will reduce yellow 

star-thistle biomass and seed productions (Thomson et al 1996, Thomson et al 1993). At 

some sites on the Refuges, grazing will be used to reduce the seed production of yellow 

star-thistle and other weeds prior to native grass restoration efforts, thereby reducing 

competition and improving success of the restoration efforts. 

Refuge wetlands are intensively managed to provide optimal habitat for large 

concentrations of wintering waterfowl. Discing is often used as a tool to set back 

succession within wetland habitats, which have become dominated by perennial species. 

Bermuda grass (Cynodon dactylon) and knotgrass (Paspalum distichum) have become 

dominant in some management units, and out-compete more desirable annual plants. 

Bermuda grass and knotgrass form thick mattes, which reduces the effectiveness of 

discing. Fire is an alternative tool to reduce plant biomass and is often used prior to 

discing. However, Bermuda grass and knotgrass often remain green throughout the 

summer and in many years cannot be burned. By reducing biomass of Bermuda grass and 

knotgrass, grazing can improve the effectiveness of subsequent discing. 

The grazing program could also impact the Refuges’ wildlife and habitat. Impacts to some 

nesting waterfowl and songbirds could occur (Kirsch 1969; Krueper 1993). Grazing in 

grasslands will reduce tall grass cover, which is used by nesting mallards, cinnamon teal, 

gadwall, northern harriers, American bitterns and ring-necked pheasants. Pheasants use 

grasslands with tall vegetation throughout the year and may be impacted by grazing. At 

locations where native grass restoration is planned, the short-term impacts of grazing to 

ground nesting birds and pheasants will be reversed as native grasses are established. 

Mammals, which burrow through thatch such as California meadow vole would likely 

decrease with grazing. However, these impacts would be short-term because the program 

would stipulate seasonal grazing. Songbirds, harriers and larger mammals, such as blacktailed jackrabbit, would move to other areas of the Refuges, which would provide cover 

outside the grazed areas. Seasonal grazing would improve plant species composition and 

structure so that short-term impacts to wildlife and habitat would be mitigated by longterm benefits to the Refuges’ vegetation, native plants, and overall wildlife habitat quality. 

Therefore, the long-term benefits to habitat, migratory birds, resident deer, and native 

plants would mitigate the short-term, localized impacts to local ground-nesting birds and 

some small mammals. 

Potential impacts of grazing activities on the Refuges’ resources will be minimized 

because sufficient restrictions would be included as part of the annual grazing plan and 

grazing activities will be monitored by the refuge manager and biologist. The refuge 

manager and biologist ensure the grazing plan and associated projects contribute to the 

enhancement, protection, conservation, and management of native Refuge wildlife 

populations and their habitats thereby helping the Refuges fulfill the purposes for which 

B-39
 X 

they were established, the mission of the National Wildlife Refuge System, and the need 

to maintain ecological integrity, diversity, and environmental health. 

The grazing program is designed to avoid or minimize impacts anticipated to the Refuges’ 

resources and visitors. The Refuges’ have requested Section 7 consultation with USFWS 

and NOAA-Fisheries on the Draft CCP/EA (USFWS 2008) and its effects on any of the 

special status species/designated critical habitat occurring on the Refuge including: 

palmate-bracted bird’s beak, hairy Orcutt grass, Greene’s tuctoria, Hoover’s spurge, 

Conservancy fairy shrimp, vernal pool fairy shrimp, vernal pool tadpole shrimp, giant 

garter snake, western yellow-billed cuckoo, winter-run Chinook salmon, spring-run 

Chinook salmon, Central Valley steelhead, fall-run Chinook salmon, and late fall-run 

Chinook salmon. 

Anticipated Impacts of Uses on future lands within the approved boundary: The 

following conditions must be met before allowing existing uses to occur on newly acquired 

lands: (1) There is no indirect, direct, or cumulative threat anticipated to human health or 

safety; (2) There is no indirect, direct, or cumulative threat anticipated to natural or 

cultural resources; (3) The use is consistent with management of existing Refuge lands 

and would contribute to achieving the Refuges’ goals. In particular, existing Refuge 

regulations would not be compromised; (4) The newly acquired lands represent a 

meaningful unit within which to manage the activity; and (5) There are no anticipated 

conflicts with priority public uses. 

Public Review and Comment: Public review and comments will be solicited in 

conjunction with distribution of the Draft CCP/EA for the Sacramento, Delevan, Colusa, 

and Sutter Refuges (USFWS 2008). 

Determination: 

_____ Use is Not Compatible 

Use is Compatible with the Following Stipulations 

Stipulations necessary to ensure compatibility: 

 The criteria for evaluating need for vegetation management, including grazing, are 

determined during the annual review of the habitat management plans. 

 Grazing is conducted in accordance with the SUPs which include special conditions 

that specifies timing of grazing, location(s) of grazing, stocking densities, types of 

livestock permitted, access locations, predator management restrictions, and 

personnel and equipment allowed. The specific conditions will vary annually due to 

differences in objectives, habitat conditions, and weather. 

B-40
 

 

 Grazing is not allowed in sensitive natural areas or cultural resource sites. 

 Grazing will comply with the Section 7 consultations with USFWS and NOAAFisheries. 

Justification: The grazing program as described is determined to be compatible. Based 

upon impacts described in the Draft Comprehensive Conservation Plan and 

Environmental Assessment (USFWS 2008), it is determined that grazing within the 

Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges, as described herein, 

will not materially interfere with or detract from the purposes for which the Refuges were 

established or the mission of the Refuge System. Refuge livestock grazing will directly 

benefit and support refuge goals, objectives and management plans and activities. Fish, 

wildlife, plants and their habitat will improve through vegetation management which will 

result in short-term and long-term reductions of non-native invasive plant species, 

increases in native plants, increases in biomass, improved foraging conditions for 

migratory birds and local deer herds, and long-term improved nesting conditions for some 

species. Consequently, the livestock grazing program would increase or maintain 

biological integrity, diversity and environmental health. The wildlife-dependent, priority 

public uses (hunting, fishing, wildlife observation, photography, environmental education 

and interpretation) would also benefit as a result of increased biodiversity and wildlife and 

native plant populations from improved habitat conditions associated with the grazing 

program. In our opinion, grazing will not conflict with the national policy to maintain the 

biological diversity, integrity, and environmental health of the Refuges. 

Mandatory Re-Evaluation Date (2018): 

_____ Mandatory 15-year Re-Evaluation, Date will be provided in Final EA/CCP (for 

priority public uses) 

X Mandatory 10-year Re-Evaluation (for all uses other than priority public uses) 

NEPA Compliance for Refuge Use Decision (check one below): 

_____ Categorical Exclusion without Environmental Action Statement 

_____ Categorical Exclusion and Environmental Action Statement 

X Environmental Assessment and Finding of No Significant Impact 

_____ Environmental Impact Statement and Record of Decision 

B-41
References 

Barry, S. 2003. Using planned grazing to manage for native grasslands. Pages 1–10, in 

Section 14, Grazing. Techniques and Strategies for Using Native Crass and 

Graminoids in Revegetation and Restoration. California Native Grass Association. 

Buchsbaum, R., J. Wilson, and I. Valiela. 1986. Digestibility of plant constituents by 

Canada geese and Atlantic brant. Ecology 67:386–393. 

Bratton, J.H. 1990. Seasonal pools: An overlooked invertebrate habitat. British Wildlife 

2:22–29. 

Bratton, J.H. and G. Fryer. 1990. The distribution and ecology of Chirocephalus 

diaphanus Prévost (Branchiopoda: Anostraca) in Britain. Journal of Natural 

History 24:955–964. 

Colwell, M. A. and S.L. Dodd. 1995. Waterbird communities and habitat relationships in 

coastal pastures of northern California. Conservation Biology 9:827–834. 

Coppoletta, M. and B. Moritsch. 2001. Taking steps toward long-term preservation of the 

Sonoma spineflower. Fremontia 29(2):23–25. 

Davis, L.H. and R.J. Sherman. 1992. Ecological study of the rare Chorizanthe valida 

(Polygonaceae) at Point Reyes National Seashore, California. Madroño 39 (4):271– 

280. 

Edwards, S.W. 1992. Observations on the prehistory and ecology of grazing in California. 

Fremontia 20(1):3–11. 

Edwards, S.W. 1996. A rancholabrean-age, latest Pleistocene bestiary for California 

botany. The Four Seasons 10(2):5–34. 

Germano, D.J., G.B. Rathbun and L.R. Saslaw. 2001. Managing exotic grasses and 

conserving declining species. Wildlife Society Bulletin 29(2):551–559. 

Griggs, F.T. 2000. Vina Plains Preserve: eighteen years of adaptive management. 

Fremontia 27(4) and 18(1): 48–51. 

Kirsch, L.M. 1969. Waterfowl production in relation to grazing. Journal of Wildlife 

Management 33:821-828. 

Krueper, D.J. 1993. Effects of land use practices on western riparian ecosystems. Pages 

321–330 in D.M. Finch and P.W. Stangel (editors), Status and Management of 

B-42
Neotropical Migratory Birds. U.S. Forest Service, General Technical Report RM229, Fort Collins, CO. 

Knopf, F.L. and J.R. Rupert. 1995. Habits and habitats of mountain plovers in California. 

The Condor 97:743–751. 

McNaughton, S J. 1985. Ecology of a grazing ecosystem: The Serengeti. Ecological 

Monographs 55:259–294. 

Menke, J.W. 1992. Grazing and fire management for native perennial grass restoration in 

California grasslands. Fremontia 20(2):22–25. 

Muir, P.S. and R.K. Moseley. 1994. Responses of Primula alcalina, a threatened species 

of alkaline seeps, to site and grazing. Natural Areas Journal 14:269–279. 

Panzer, R. 1988. Managing prairie remnants for insect conservation. Natural Areas 

Journal 8(2):83–90. 

Thomsen, C.D., W.A. Williams, M. Vayssiéres, F.L. Bell, and M.R. George. 1993. 

Controlled grazing on annual grassland decreases yellow starthistle. California 

Agriculture 47:36–40. 

Thomsen, C.D., W.A. Williams, and M. Vayssiéres. 1996. Yellow star-thistle management 

with grazing, mowing, and comptetive plantings. In J.E. Lovich, J. Randall and 

M.D. Kelly (eds). Proceedings of the California Exotic Plant Council Symposium. 

Vol. 2: 1996. pp. 65-71. 

U.S. Fish and Wildlife Service. 2008. Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges Draft Comprehensive Conservation Plan and Environmental 

Assessment. Region 8. Sacramento, CA. 

B-43
Refuge Determination 

Prepared by: ____________________________________ ____________

 (Signature) (Date)

Wildlife Refuge Manager/ 

Project Leader 

Approval: ____________________________________ ____________

 (Signature) (Date)

Concurrence 

Refuge Supervisor: ____________________________________ ____________ 

 (Signature) (Date)

Assistant Regional 

Director, Refuges: ____________________________________ ____________ 

 (Signature) (Date)

B-44
COMPATIBILITY DETERMINATION 

(June 2008) 

Use: Hunting 

Refuge Name: Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges, 

located in Glenn, Colusa, and Sutter Counties, California. 

Establishing and Acquisition Authority(ies): 

Sacramento National Wildlife Refuge (Refuge) was established in 1937. Legal authorities 

include: Executive Order 7562, February 27, 1937, Migratory Bird Conservation Act of 

1929 (16 U.S.C. 715d), Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as 

amended, the Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 

Statute 884), and the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Delevan Refuge was established in 1962. Legal authority includes: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d). 

Colusa Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884), and 

the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Sutter Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), and the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884). 

Refuge Purpose(s): 

Sacramento Refuge purposes include: 

“... as a refuge and breeding ground for migratory birds and other wildlife...” 

Executive Order 7562, February 27, 1937. 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, 

(2) the protection of natural resources, (3) the conservation of endangered species 

or threatened species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use 

B-45
... real ... property. Such acceptance may be accomplished under the terms and 

conditions of restrictive covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge 

Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection 

of fish and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the 

United States Fish and Wildlife Service, in performing its activities and services. 

Such acceptance may be subject to the terms of any restrictive or affirmative 

covenant, or condition of servitude ...” 16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 

1956). 

Delevan Refuge purposes include: 

 “... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

Colusa Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

Sutter Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

National Wildlife Refuge System Mission: “To administer a national network of lands 

and waters for the conservation, management, and where appropriate, restoration of the 

fish, wildlife, and plant resources and their habitats within the United States for the 

B-46
benefit of present and future generations of Americans.” (National Wildlife Refuge 

System Administration Act of 1966, as amended [16 U.S.C. 668dd-ee]). 

Description of Use: Hunting is identified in the National Wildlife Refuge System 

Improvement Act of 1997 (16 U.S.C. 668dd-ee) as a priority use for refuges when it is 

compatible with the refuge purposes and mission of the Refuge System. As a result, the 

Service is proposing to allow waterfowl, coot, common moorhen, pheasant, and snipe 

hunting on approximately 8,525 acres of Sacramento, Delevan, Colusa, and Sutter 

Refuges. The Proposed Action (Alternative C) analyzed in the Draft Comprehensive 

Conservation Plan (CCP) and Environmental Assessment (EA) (USFWS 2008a) and the 

Hunt Plan (USFWS 2008b), which are incorporated by reference, contain maps and 

Refuge descriptions where hunting will be allowed. The hunting program will provide 

high quality, safe, and cost-effective hunting opportunities, and will be carried out 

consistent with State regulations. The guiding principles of the Refuge System’s hunting 

programs (Service Manual 605 FW 2) are to: 

• Manage wildlife populations consistent with Refuge System-specific management 

plans approved after 1997 and, to the extent practicable, State fish and wildlife 

conservation plans; 

• Promote visitor understanding of and increase visitor appreciation for America’s 

natural resources; 

• Provide opportunities for quality recreational and educational experiences 

consistent with criteria describing quality found in 605 FW 1.6; 

• Encourage participation in this tradition deeply rooted in America’s natural 

heritage and conservation history; and 

• Minimize conflicts with visitors participating in other compatible wildlifedependent recreational activities. 

The Hunt Plan (USFWS 2008b) was developed to provide safe hunting opportunities, 

while minimizing conflicts with other priority wildlife-dependent recreational uses. The 

Refuges’ hunting program will comply with the Code of Federal Regulations Title 50, 32.1 

and be managed in accordance with Service Manual 605 FW2, Hunting. 

Hunting will be permitted in accordance with State and Federal regulations and seasons 

(Table 1 gives an example of annual State hunt seasons for areas within the Refuges) to 

ensure that it will not interfere with the conservation of fish and wildlife and their 

habitats. Therefore, the sport hunting of migratory birds and upland game birds on the 

Refuges is in compliance with State regulations and seasons, the National Wildlife Refuge 

System Administration Act of 1966 as amended by the National Wildlife Refuge System 

Improvement Act of 1997 (16 U.S.C. 668dd-ee), and the Refuge Recreation Act of 1962 (16 

U.S.C. 460k). 

B-47
 

Table 1. Sacramento, Delevan, Colusa, and Sutter Refuges, Hunting Season Bag 

Limit Summary for 2006-2007 

Species Dates Daily Bag Limits 

Waterfowl – Ducks Third Saturday in October 

extending for 100 

consecutive days 

Up to 7 ducks; see 

below; possession 

double the bag limit* 

Waterfowl – Geese October - concurrent with 

duck season 

Up to 4 geese any 

species; possession 

double the bag limit 

American Coot and 

Common Moorhen 

October - concurrent with 

duck season 

25/day, 25 in 

possession, either all of 

one species or a 

mixture of these 

species 

Snipe Third Saturday in October 

extending for 107 days 

8/day; possession 

double the bag limit 

Pheasants – General Second Saturday in 

November extending for 44 

days 

2 – males first two 

days; 

3 males thereafter; 

possession double the 

bag limit 

*Duck Bag Limits: 7 ducks/ but not more than 2 hen mallards, 1 pintail, 1 canvasback, 2 

redhead, 3 scaup, throughout the season 

Limited spring turkey hunting opportunities on Sacramento, Delevan, and Colusa 

Refuges could be allowed based on sufficient wild turkey populations, habitat conditions, 

and the development of a turkey hunt management plan as well as appropriate National 

Environmental Policy Act compliance. 

The hunting program is administered by the Service in cooperation with the California 

Department of Fish and Game (CDFG). The Service manages the Refuges’ land, habitat 

and facilities; and the CDFG selects and processes the Refuge hunters and operates the 

check stations. A valid California hunting license, including appropriate stamps, is 

required for taking any bird. Entry permits are issued at the check stations, which are 

used to track daily hunter quotas, hunter refill, and bird species harvest. 

Hunting is permitted on designated portions of Sacramento, Delevan, Colusa and Sutter 

Refuges (Figures 11-14 in the CCP). Hunting of waterfowl, coot, common moorhen, snipe, 

and pheasant is permitted on Saturdays, Sundays, and Wednesdays during hunting 

seasons established by the California Fish and Game Commission. Pheasants may only be 

hunted in the free roam areas, except for the Special Monday Pheasant Hunt, which is 

held the first Monday after the opening day of pheasant season. On this day, the entire 

hunt areas are opened to pheasant hunting, including the spaced blind areas. 

B-48
Hunting areas are divided into designated areas— free roam, spaced hunt blind, spaced 

hunt site (island), or assigned pond (Figures 11-14 in the CCP). The overall harvest 

success, as measured by the number of birds per hunter per day, has remained relatively 

constant (approximately 2.0 birds per hunter) since the hunting programs were 

established in 1963. This consistency has occurred despite rather significant fluctuations 

in total birds harvested annually for the Complex and trends on individual Refuges. 

Harvest data indicate that ducks make up 95 percent of the hunter bag. The top six 

species of ducks harvested are mallard (22.3 percent), gadwall (18.5 percent), greenwinged teal (14.5 percent), northern shoveler (13.5 percent), American wigeon (12.6 

percent), and northern pintail (7.5 percent). Geese harvested include snow (53.8 percent), 

white-fronted (30.2 percent), and Ross’s (13.4 percent). The majority of the goose harvest 

occurs on Sacramento and Delevan Refuges. 

The Refuges have approximately 22,000 annual hunting visits, including up to 500 annual 

visits by hunters with disabilities. Hunters must report take of waterfowl and pheasants 

to the check station located at Sacramento Refuge south of Road 68, at Delevan Refuge 

off of Four Mile Road, at Colusa Refuge south of Abel Road, and at Sutter Refuge south 

of Hughes Road (Figures 11-14 in the CCP). Field checks by refuge law enforcement 

officers will be planned, conducted, and coordinated with staff and other agencies to 

maintain compliance with regulations and assess species and number harvested. Dogs will 

be required to be kept on a leash, except for hunting dogs engaged in authorized hunting 

activities and under the immediate control of a licensed hunter. 

The Refuge Hunting Program Working Group was established in 1991 to exchange ideas 

and information regarding the Complex’s hunting program. The Disabled Access Working 

Group was established in 1999 to discuss disabled hunting access issues on the Complex. 

In 2006, the groups were combined to form the Complex Hunting Program Working 

Group. The State game wardens and Federal law enforcement officers also attend the 

Working Group meeting. 

With the number of waterfowl hunters declining in California, it is important to offer 

opportunities for new hunters to experience quality refuge hunting. In the early 1990s, 

the Service began hosting a one-day, in-season junior waterfowl hunt on Sacramento and 

Delevan Refuges. The spaced hunt site areas were reserved for junior hunters (age 16 and 

younger). These hunts resulted in up to 145 junior hunt visits annually. In the late 1990s, 

post season youth only hunts (age 15 and younger) began on Sacramento and Colusa 

Refuges and were later added to Delevan Refuge. These hunts have resulted in up to 372 

annual junior hunter visits. Many local partners (i.e. California Waterfowl Association, 

Willows Rotary, Willows Kiwanis, and National Wild Turkey Federation) have also 

assisted by providing free morning beverages, barbecue lunches, raffles, and educational 

displays and activities. 

B-49
Sacramento Refuge

Hunting is allowed on 3,566 acres south of Road 68 (Table 2). 

Table 2. Hunt area acreage and hunter quotas for Sacramento Refuge 

Spaced 

Blind Area 

Assigned 

Pond Area 

(# parties) 

Free Roam 

Area 

Pheasant 

Only 

Acres dry 220 48 336 127 

Acres flooded 1,233 428 1,146 

Total acres 1,453 476 1,482 127 

Number of blinds 37 

Number of assigned 

ponds 

9 

Maximum adult hunter 

quota 

148 36 (9) 75 

Wetland acre/hunter or 

hunt site 

33.3 47.5 15.3 

Sacramento Refuge has spaced blinds, assigned ponds, and free roam areas that consist of 

managed wetland, watergrass, permanent pond, grassland, and vernal pool/alkali meadow 

habitats. Blinds are in-ground, concrete pits spaced 250-400 yards apart. Hunters must 

remain within 100 feet of their assigned blind. Free roam and assigned pond hunters 

move unrestricted within the signed hunting area boundary. Directional signs guide 

hunters to their respective hunting areas, while additional reflective stakes direct hunters 

to their assigned blind. The hunting areas are accessible by foot only from four parking 

areas. 

Pheasant and snipe may be hunted on waterfowl hunt days in the free roam and pheasant 

only areas. Pheasant may also be hunted on the first Monday of the season in free roam, 

spaced blind, and assigned pond areas. Maximum quota for this day is 100 hunters. 

Hunter quotas are based on acres of available wetland habitat and are adjusted depending 

upon water conditions. Fully-flooded conditions provide up to 37 blinds (up to four people 

per blind), nine assigned ponds (up to four people per pond), and up to 75 free roam 

hunters (15.3 wetland acres/hunter). In addition to quotas, hunter distribution is 

influenced by habitat management, pond size, daily weather conditions, and waterfowl 

flight patterns. 

Sacramento Refuge has three spaced blinds (Blinds 5D, 23D, and 27D) designated for 

hunters with mobility impairments. These sites may be accessed by motor vehicle or allterrain-vehicle (ATV) from the parking areas. Additionally, a parking area to access 

Blinds 23D and 27D and a designated accessible boat launch in the free roam area (Tract 

38) is available. In 2006-07, there were 212 visits by 62 individual hunters with disabilities. 

B-50
Delevan Refuge

Hunting is allowed on 1,922 acres within the south half of Delevan Refuge (Table 3). 

Table 3. Hunt area acreage and hunter quotas for Delevan Refuge. 

Spaced 

Hunt Area 

Assigned 

Pond Area 

(# parties) 

Free Roam 

Area 

Acres dry 22 0 192 

Acres flooded 746 129 *833 

Total acres 768 129 1,025 

Number of blinds 26 

Number of assigned 

ponds 

3 

Maximum adult 

hunter quota 

104 12 (3) **58 

Wetland acre/hunter 

or hunt site 

28.7 43.0 14.4 

* Does not include acres for T41.2 when it gets flooded in December-January. 

**Increased to 62 during December-January when T41.2 is flooded. 

Delevan Refuge has spaced hunt sites, assigned pond, and free roam areas that consist of 

managed wetland, watergrass, permanent pond, grassland, and vernal pool/alkali meadow 

habitats. Hunt sites consist of a dirt island (approximately 10’x20’) surrounded by cattail 

or bulrush. Hunters must remain within 100 feet of their assigned hunt site. Free roam 

and assigned pond hunters move unrestricted within the signed hunting area boundary. 

Directional signs guide hunters to their respective hunting areas, while additional 

reflective stakes direct hunters to their assigned hunt site. The hunting areas are 

accessible by foot only from three parking areas. 

Pheasant and snipe may be hunted on waterfowl hunt days in the free roam areas. 

Pheasant may also be hunted on the first Monday of the season in free roam, spaced hunt 

sites, and assigned pond areas. Maximum quota for this day is 50 hunters. 

Hunter quotas are based on acres of available wetland habitat and will be adjusted 

depending upon water conditions. Fully-flooded conditions provide up to 26 hunt sites (up 

to four people per hunt site), three assigned ponds (up to four people per pond) and up to 

58 free roam hunters (14.4 wetland acres/hunter). In addition to quotas, hunter 

distribution is influenced by habitat management, pond size, daily weather conditions, and 

waterfowl flight patterns. 

Delevan Refuge has three spaced blinds (Blinds 13D, 29D, and 30D) designated for 

disabled hunters. These blinds may be accessed by motor vehicle or ATV from the 

parking areas. A floating pontoon blind is located in T34.3 as a free roam hunting 

opportunity. Additionally, there are designated accessible boat launches in the free roam 

B-51
area of Tract 33 and Tract 34.3. In 2006-07, there were 223 visits by 53 individual hunters 

with disabilities. 

Colusa Refuge

Hunting is allowed on 1,921 acres south of Abel Road (Table 4). 

Table 4. Hunt area acreage and hunter quotas for Colusa Refuge. 

Assigned 

Pond Area 

(# parties) 

Free Roam 

Area -

Westside 

Free Roam 

Area -

Eastside 

Acres dry 1 488 126 

Acres flooded 386 292 491 

Total acres 387 780 617 

Number of assigned 

ponds 

10 

Maximum adult 

hunter quota 

30 (15) 14 36 

Wetland 

acres/hunter or hunt 

site 

25.7 20.8 13.6 

Colusa Refuge has assigned pond and free roam areas that consist of managed wetland, 

watergrass, permanent pond, grassland, and vernal pool/alkali meadow habitats. Free 

roam and assigned pond hunters move unrestricted within the signed hunting area 

boundary. Directional signs guide hunters to their respective hunting areas. The hunting 

areas are accessible by foot only from four parking areas. Disabled hunters may access 

Pool 2 (P2) from the disabled parking area via a boat ramp or access a blind in the 

northeast corner. In 2006-07, P2 had 236 hunter visits and hunters reported using the P2 

blind on 10 days resulting in 22 visits. 

Pheasant and snipe may be hunted on waterfowl hunt days in the free roam areas only. 

Pheasant may also be hunted on the first Monday of the season in free roam and assigned 

pond areas. Maximum quota for this day is 10 hunters on the east side and 35 hunters on 

the westside. 

Hunter quotas are based on acres of available wetland habitat and are adjusted depending 

upon water conditions. Fully-flooded conditions provide up to 10 assigned ponds (two 

adult hunters per party) and up to 50 free roam hunters. Assigned ponds T24.4- 5, T24.7­

10, and T19.1-2 allow one party per pond, Pool 1 allows up to 4 parties per pond. P2 allows 

up to three parties: 2 disabled and one party, which must have a junior hunter. In addition 

to quotas, hunter distribution is influenced by habitat management, pond size, daily 

weather conditions and waterfowl flight patterns. 

B-52
The eastside free roam area has 1 hunter per 13.6 wetland acres at its maximum quota of 

36 hunters. The westside free roam area has 1 hunter per 20.8 wetland acres at its 

maximum quota of 14. The westside free roam area is not in as strong a flight path and 

thus the hunter density allowed is lower. 

Sutter Refuge

Currently hunting is allowed on 1,116 acres on the south half of Sutter Refuge (Table 5). 

Table 5. Hunt area acreage and hunter quotas for Sutter Refuge. 

Assigned 

Pond Area 

(# parties) 

Free Roam 

Area 

Pheasant 

Only Area 

Acres dry 0 0 125 

Acres flooded 540 265 

Total acres 540 265 125 

Number of 

assigned ponds 

10 

Maximum adult 

hunter quota 

44 (22) 20 10 

Wetland 

acres/hunter or 

hunt site 

24.5 13.2 

Sutter Refuge has assigned pond and free roam areas that primarily consist of managed 

wetland, watergrass, and grassland habitats. Free roam and assigned pond hunters move 

unrestricted within the signed hunting area boundary. Directional signs guide hunters to 

their respective hunting areas. The hunting areas are accessible by foot only from two 

parking areas. In addition, there is a designated boat launch with a parking area available 

to hunters with disabilities, in the southeast corner of assigned pond T17. There was 

minimal visitation by hunters with disabilities. 

Pheasant and snipe can be hunted in the free roam and pheasant only areas on the Refuge 

on waterfowl hunt days. 

Hunter quotas are based on acres of available wetland habitat and are adjusted depending 

upon water conditions. Fully-flooded conditions provide up to 10 assigned ponds and up to 

20 free roam hunters. Assigned ponds T10 and T12.1-.3 allow one party per pond; T12.4, 

T14.1 and T14.2 allow up to two parties each and T15-17 allow up to four parties each, 

including two adult disabled hunting parties in T17. A hunting party may include up to 

two adults. A disabled hunting party must include at least one disabled hunter. In addition 

to quotas, hunter distribution is influenced by habitat management, pond size, daily 

weather conditions, and waterfowl flight patterns. 

B-53
The free roam area has 1 hunter per 13.2 wetland acres at its maximum quota of 20 

hunters. Tract 18 will remain as a pheasant hunting only area and will have a quota up to 

10 hunters. 

Availability of Resources: The following funding/annual costs (based on FY 2007 costs) 

would be required to administer and manage hunting activities as described above: 

One-Time Costs Annual Costs 

Install electric line for hunter 

check station (Delevan) 

$172,000 

Replace hunter access bridges 

with culverts (Sacramento and 

Delevan) 

$20,000 

Printing (brochures, signs, 

posters, etc) 

$3,000 

Law Enforcement (permit 

compliance, access control, 

protection) 

$22,000 

Maintenance (check stations, 

blinds, disking, mowing, etc.) 

$33,000 

Personnel Services (managerial, 

biological, clerical, etc.) 

$27,000 

New Staffing 

One full-time (1.0 FTE) GS-5 

office automation clerk 

$25,514 

TOTAL $192,000 $110,514 

Funds are currently available to operate and maintain the hunt program. Funding is 

acquired through the Service budget process and as a reimbursement via a cooperative 

agreement with the CDFG. To defray expenses connected with the operation and 

maintenance of the hunting program, the CDFG is authorized to charge and retain a fee 

from each adult hunter. Hunter fees are determined annually in advance of the hunting 

season by the California Fish and Game Commission. At present, the Refuge entry permit 

fees are: one-day $14.75, two-day $25.45, or a season pass with a one-time, base fee of 

$117.85. These fees are adjusted annually, as required under Fish and Game Code Section 

713. Holders of valid junior hunting licenses and non-shooters are exempt from these fees. 

Anticipated Impacts of Use: Direct effects of hunting include mortality, wounding, and 

disturbance (De Long 2002). Hunting can alter behavior (i.e. foraging time), population 

structure, and distribution patterns of wildlife (Owens 1977, Raveling 1979, WhiteRobinson 1982, Thomas 1983, Bartelt 1987, Madsen 1985, and Cole and Knight 1990). 

There also appears to be an inverse relationship between the numbers of birds using an 

area and hunting intensity (DeLong 2002). In Connecticut, lesser scaup were observed to 

forage less in areas that were heavily hunted (Cronan 1957). In California, the numbers of 

B-54
northern pintails on Sacramento Refuge non-hunt areas increased after the first week of 

hunting and remained high until the season was over in early January (Heitmeyer and 

Raveling 1988). Following the close of the hunting season, ducks generally increased their 

use of the hunt area; however, use was lower than before the hunting season began. 

Human disturbance associated with hunting includes loud noises and rapid movements, 

such as those produced by shotguns and boats powered by outboard motors. This 

disturbance, especially when repeated over a period of time, compels waterfowl to change 

food habits, feed only at night, lose weight, or desert feeding areas (Madsen 1995, Wolder 

1993). 

These impacts can be reduced by the presence of adjacent sanctuary areas where hunting 

does not occur, and birds can feed and rest relatively undisturbed. Sanctuaries or nonhunt areas have been identified as the most common solution to disturbance problems 

caused from hunting (Havera et. al 1992). Prolonged and extensive disturbances may 

cause large numbers of waterfowl to leave disturbed areas and migrate elsewhere 

(Madsen 1995, Paulus 1984). In Denmark, hunting disturbance effects were 

experimentally tested by establishing two sanctuaries (Madsen 1995). Over a 5-year 

period, these sanctuaries became two of the most important staging areas for coastal 

waterfowl. Numbers of dabbling ducks and geese increased 4 to 20 fold within the 

sanctuary (Madsen 1995). Thus, sanctuary and non-hunt areas are very important to 

minimize disturbance to waterfowl populations to ensure their continued use of the 

Refuges. 

Intermittent hunting can be a means of minimizing disturbance, especially if rest periods 

in between hunting events are weeks rather than days (Fox and Madsen 1997). It is 

common for Refuges to manage hunt programs with non-hunt days. At Sacramento 

Refuge, 3-16 percent of pintails were located on hunted units during non-hunt days, but 

were almost entirely absent in those same units on hunt days (Wolder 1993). In addition, 

northern pintails, American wigeon, and northern shovelers decreased time spent feeding 

on days when hunting occurred on public shooting areas, as compared to non-hunt days 

(Heitmeyer and Raveling 1988). The intermittent hunting program of three hunt days per 

week at Sacramento Refuge resulted in lower pintail densities on hunt areas during nonhunt days than non-hunt areas (Wolder 1993). However, intermittent hunting may not 

always greatly reduce hunting impacts. 

The impacts addressed here are discussed in detail in the Environmental Assessment 

(EA) (Appendix A) for the Draft Comprehensive Conservation Plan (CCP) (USFWS 

2008a) which is incorporated by reference. Biological conflicts will be minimized by 

following proper zoning and regulations. Refuge seasons will be designated to minimize 

negative impacts to wildlife. 

Hunting is a highly regulated activity, and generally takes place at specific times and 

seasons (fall and winter) when the game animals are less vulnerable, reducing the 

magnitude of disturbance to the Refuges’ wildlife. Managed and regulated hunting will 

B-55
not reduce species populations to levels where other wildlife-dependent uses will be 

affected. 

The use of retrieving dogs would be permitted and encouraged in all areas open to 

waterfowl hunting. These dogs would be required to be under control at all times. Any 

hunter who allows his/her dog to disturb wildlife is not well received by other hunters who 

do not want waterfowl disturbed on the ponds that they are hunting. Law enforcement 

officers will enforce regulations requiring owners to maintain control over their dogs 

while on the Refuges. Although the use of dogs is not a form of wildlife-dependent 

recreation; they do in this case support a wildlife dependent use. Implementing the 

prescribed restrictions outlined in the Stipulations section should alleviate any substantial 

impacts. 

Hunting is an appropriate wildlife management tool that can be used to manage wildlife 

populations. Some wildlife disturbance will occur during the hunting seasons. Proper 

zoning, regulations, and Refuge seasons will be designated to minimize any negative 

impacts to wildlife populations using the Refuges. Harvesting these species, or any other 

hunted species, would not result in a substantial decrease in biological diversity on the 

Refuges. 

Conflicts between hunting and other public uses will be minimized by the following: 

• Physically separate non-hunting and hunting acres to spatially divide the activities. 

• Hunting will be limited to occur only on Wednesdays, Saturdays, and Sundays during 

hunting seasons established by the California Fish and Game Commission. 

• Boundary and hunting area signs will be maintained to clearly define the designated 

hunting areas. 

• Allow vehicle traffic only on designated roads and parking areas. 

• Parking areas will be signed and gated to allow only pedestrian access. 

• The hunting program will be highly regulated and managed in strict accordance with 

all applicable Federal laws (Code of Federal Regulations, Title 50 subchapter C) and 

to the extent practicable, consistent with applicable State laws. 

• Field checks by refuge law enforcement officers will be planned and coordinated with 

staff and other agencies to maintain compliance with regulations and assess species 

and number harvested. 

• Provide information about the Refuges’ hunting program through signs, kiosks, 

brochures, and Complex’s website (http://sacramentovalleyrefuges.fws.gov). 

• No camping or tents are allowed on the Refuges. 

Wildlife populations on the Refuges are able to sustain hunting and support other wildlifedependent priority uses. To manage the populations to support hunting, the Refuges 

adopt harvest regulations set by the State within Federal framework guidelines. 

By its very nature, hunting has very few positive effects on the target species while the 

activity is occurring. However, in our opinion, hunting has given many people a deeper 

B-56
appreciation of wildlife and a better understanding of the importance of conserving their 

habitat, which has ultimately contributed to the Refuge System mission. Furthermore, 

despite the potential impacts of hunting, a goal of the Sacramento, Delevan, Colusa, and 

Sutter Refuges is to provide visitors of all ages an opportunity to enjoy wildlife-dependent 

recreation. Of key concern is to offer a safe and quality program and to ensure adverse 

impacts remain at an acceptable level. 

Recreational hunting will remove individual animals, but does not negatively affect 

wildlife populations. To assure that populations are sustainable, the California Fish and 

Game Commission, in consultation with the CDFG, annually review the population 

censuses to establish season lengths and harvest levels. Each year the refuge staff 

conducts habitat management reviews of each unit on the Complex to evaluate wildlife 

population levels, habitat conditions and public use activities. The areas closed to various 

hunting activities provide adequate sanctuaries for wildlife. 

The Service believes that there will be minimal conflicts between hunters and the other 

wildlife-dependent recreational uses. The uses are not occurring on the same area at the 

same time. 

The hunting program has been designed to avoid or minimize impacts anticipated to 

Refuge resources and Refuge visitors. The Refuges have requested Section 7 consultation 

with USFWS and NOAA-Fisheries on the Draft CCP/EA (USFWS 2008a) and its effects 

on any of the special status species/designated critical habitat occurring on the Refuges 

including: palmate-bracted bird’s beak, hairy Orcutt grass, Greene’s tuctoria, Hoover’s 

spurge, Conservancy fairy shrimp, vernal pool fairy shrimp, vernal pool tadpole shrimp, 

giant garter snake, western yellow-billed cuckoo, winter-run Chinook salmon, spring-run 

Chinook salmon, Central Valley steelhead, fall-run Chinook salmon, and late fall-run 

Chinook salmon. 

Anticipated Impacts of Uses on future lands within the approved boundary: The 

following conditions must be met before allowing existing uses to occur on newly acquired 

lands: (1) There is no indirect, direct, or cumulative threat anticipated to human health or 

safety; (2) There is no indirect, direct, or cumulative threat anticipated to natural or 

cultural resources; (3) The use is consistent with management of existing Sacramento, 

Delevan, Colusa, and Sutter Refuge lands and would contribute to achieving the Refuges’ 

goals. In particular, existing Refuge regulations would not be compromised; (4) The newly 

acquired lands represent a meaningful unit within which to manage the activity; and (5) 

There are no anticipated conflicts with priority public uses. 

Public Review and Comment: Public review and comments will be solicited in 

conjunction with distribution of the Draft CCP/EA for the Sacramento, Delevan, Colusa, 

and Sutter Refuges (USFWS 2008a). 

B-57
Determination: 

_____ Use is Not Compatible 

X Use is Compatible with the Following Stipulations 

Stipulations necessary to ensure compatibility: 

 Refuge Specific Regulations. 

o Hunting of Migratory Game Birds: We allow the hunting of geese, ducks, 

coots, moorhens, and snipe on designated areas of the refuge subject to the 

following conditions [for Sacramento Refuge (see regulations 1-13 below), 

Delevan Refuge (see regulations 1-13 below), Colusa Refuge (see 

regulations 4-13 below), and Sutter Refuge (see regulations 4-13 below)]: 

1. You must unload firearms while transporting them between parking 

areas and spaced blind areas. 

2. We do not allow snipe hunting in the spaced blind area. 

3. We restrict hunters to the spaced blind unit to within 100 feet (30 m) 

of their assigned hunt site except for retrieving downed birds, 

placing decoys, or traveling to and from the parking area. 

4. You may possess only approved nontoxic shot while in the field. 

5. You may possess no more than 25 shells while in the field. 

6. Access to the hunt area is by foot traffic only. We do not allow 

bicycles and other conveyances. Mobility-impaired hunters should 

consult the refuge manager for allowed conveyances. 

7. No person may build or maintain fires, except in portable gas stoves. 

8. You may enter or exit only at designated locations. 

9. Vehicles may stop only at designated parking areas. We prohibit the 

dropping of passengers or equipment or stopping between 

designated parking areas. 

10. We require dogs to be kept on a leash, except for hunting dogs 

engaged in authorized hunting activities and under the immediate 

control of a licensed hunter (see 50 CFR 26.21(b).* 

11. We do not allow cutting or removal of vegetation for blind 

construction or for making trails.* 

12. We allow only electric motors on boats used by hunters with 

disabilities.* 

13. Consumption or possession of an open container of alcohol within 

public areas on the Refuges is prohibited.* 

*Indicates a new regulation. 

o Upland Game Hunting: We allow hunting of pheasant on designated areas 

of the refuge subject to the following conditions [for Sacramento Refuge 

B-58
(see regulations 1-9 below), Delevan Refuge (see regulations 1-9 below), 

Colusa Refuge (see regulations 2-9 below), and Sutter Refuge (see 

regulations 2-9 below)]: 

1. We do not allow pheasant hunting in the spaced blind and assigned 

pond areas except during a special 1 day only pheasant hunt on the 

first Monday after the opening of the State pheasant hunting season. 

2. You may possess only approved nontoxic shot while in the field. 

3. Access to the hunt area is by foot traffic only. We do not allow 

bicycles and other conveyances. Mobility-impaired hunters should 

consult the refuge manager for allowed conveyances. 

4. You may possess no more than 25 shells while in the field. 

5. No person may build or maintain fires, except in portable gas stoves. 

6. You may enter or exit only at designated locations. 

7. Vehicles may stop only at designated parking areas. We prohibit the 

dropping of passengers or equipment or stopping between 

designated parking areas. 

8. We require dogs to be kept on a leash, except for hunting dogs 

engaged in authorized hunting activities and under the immediate 

control of a licensed hunter.* 

9. Consumption or possession of an open container of alcohol within 

public areas is prohibited.* 

*Indicates a new regulation. 

 All hunting activities and operations will be reviewed annually to ensure compliance 

with all applicable laws, regulations, and policies. 

 Population censuses will be reviewed annually with the CDFG to ensure that harvest 

from hunting is not unacceptably impacting the targeted populations. The program 

will be modified accordingly. 

 Each year the Refuge staff will conduct habitat management reviews of each unit to 

evaluate wildlife population levels, habitat conditions and public use activities. 

 Refuge specific hunting information will be available via signs, information panels, 

brochures and the website (http://sacramentovalleyrefuges.fws.gov). 

 Refuge law enforcement officers will patrol, monitor, and collect data on hunting 

activities in the field to assure that it does not interfere with wildlife resources and 

other wildlife dependent uses on a weekly basis. The program will be modified 

accordingly. 

 Dog training on the Refuges will not be allowed. 

 Harvest will be recorded at each of the Refuges’ check stations. 

Justification: Hunting is a wildlife-dependent recreational use listed in the National 

Wildlife Refuge System Improvement Act. Providing a quality hunting program 

contributes to achieving one of the Refuges’ goals (Goal 3, Objective 3.1, Chapter 4 of the 

CCP). By facilitating this use on the Refuges, we will increase the visitors’ knowledge and 

B-59
 

 

appreciation of fish and wildlife, which may lead to increased public stewardship of 

wildlife and their habitats on the Refuges. Increased public stewardship will support and 

complement the Service’s actions in achieving the Refuges’ purposes and the mission of 

the National Wildlife Refuge System. Approximately 15,448 acres will be closed to 

hunting and 11,152 acres will be closed to all public use to ensure an adequate amount of 

high-quality feeding and resting habitat (USFWS 2008a). 

Based upon impacts described in the Hunt Plan and the Draft Comprehensive 

Conservation Plan and Environmental Assessment (USFWS 2008a,b), it is determined 

that hunting within the Sacramento, Delevan, Colusa, and Sutter National Wildlife 

Refuges, as described herein, will not materially interfere with or detract from the 

purposes for which the Refuges were established or the mission of the Refuge System. In 

our opinion, implementing the Hunt Plan and associated stipulations will not conflict with 

the national policy to maintain the biological diversity, integrity, and environmental health 

of the Refuges. 

Mandatory Re-Evaluation Date (2023): 

X Mandatory 15-year Re-Evaluation, Date will be provided in Final EA/CCP (for 

priority public uses) 

_____ Mandatory 10-year Re-Evaluation (for all uses other than priority public uses) 

NEPA Compliance for Refuge Use Decision (check one below): 

_____ Categorical Exclusion without Environmental Action Statement 

_____ Categorical Exclusion and Environmental Action Statement 

X Environmental Assessment and Finding of No Significant Impact 

_____ Environmental Impact Statement and Record of Decision 

B-60
References 

Bartelt, G. A. 1987. Effects of disturbance and hunting on the behavior of Canada goose 

family groups in east central Wisconsin. J. Wildl. Manage. 51:517-522. 

Cole, D. N. and R. L. Knight. 1990. Impacts of recreation on biodiversity in wilderness. 

Utah State University, Logan, Utah. 

Cronan, J. M. 1957. Food and feeding habits of the scaups in Connecticut waters. Auk 

74(4):459-468. 

DeLong, A. 2002. Managing Visitor Use and Disturbance of Waterbirds. A Literature 

Review of Impacts and Mitigation Measures. 

Fox, A. D. and J. Madsen. 1997. Behavioral and distributional effects of hunting 

disturbance on waterbirds in Europe: implications for refuge design. J. Appl. Ecol. 

34:1-13. 

Havera, S. P., L. R. Boens, M. M. Georgi, and R. T. Shealy. 1992. Human disturbance of 

waterfowl on Keokuk Pool, Mississippi River. Wildl. Soc. Bull. 20:290-298. 

Heitmeyer, M. E. and D. G. Raveling. 1988. Winter resource use by three species of 

dabbling ducks in California. Dept. Wildlife and Fisheries Biology, Univ. of Calif., 

Davis. Final Report to Delta Waterfowl and Wetlands Research Center, Portage 

La Prairie, Manitoba, Canada. 200 pp. 

Madsen, J. 1985. Impact of disturbance on field utilization o f pink-footed geese in West 

Jutland, Denmark. Biol. Conserv. 33:53-63. 

Madsen, J. 1995. Impacts of disturbance on migratory waterfowl. Ibis 137:S67-S74. 

Owens, N. W. 1977. Responses of wintering brant geese to human disturbance. Wildfowl 

28:5-14. 

Paulus, S.L. 1984. Activity budgets of nonbreeding gadwalls in Louisiana. J. Wildl. 

Manage. 48:371-380. 

Raveling, D. G. 1979. The annual cycle of body composition of Canada geese with special 

reference to control of reproduction. Auk 96:234-252. 

Thomas, V. G. 1983. Spring migration: the prelude to goose reproduction and a review of 

its implication. In Fourth Western Hemispheric Waterfowl and Waterbird 

Symposium, ed., H. Boyd. 73-81. Ottawa, Canada: Canadian Wildlife Service. 

B-61
U.S. Fish and Wildlife Service. 2008a. Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges Draft Comprehensive Conservation Plan and Environmental 

Assessment. Region 8. Sacramento, CA. 

U.S. Fish and Wildlife Service. 2008b. Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges Hunt Plan. Region 8. Sacramento, CA. 

White-Robinson, R. 1982. Inland and salt marsh feeding of wintering brent geese in 

Essex. Wildfowl 33:113-118. 

Wolder, M. 1993. Disturbance of wintering northern pintails at Sacramento National 

Wildlife Refuge, California. M. S. Thesis, Humboldt State Univ., Arcata. 62 pp. 

B-62
 

 

 

 

Refuge Determination 

Prepared by: ____________________________________ 

(Signature) 

____________ 

(Date) 

Wildlife Refuge Manager/ 

Project Leader 

Approval: ____________________________________ 

(Signature) 

____________ 

(Date) 

Concurrence 

Refuge Supervisor: ____________________________________ 

(Signature) 

____________ 

(Date) 

Assistant Regional 

Director, Refuges: ____________________________________ 

(Signature) 

____________ 

(Date) 

B-63
COMPATIBILITY DETERMINATION 

(June 2008) 

Use: Mosquito Monitoring and Control 

Refuge Names: Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges, 

located in Glenn, Colusa, and Sutter counties, California. 

Establishing and Acquisition Authorities: 

Sacramento National Wildlife Refuge (Refuge) was established in 1937. Legal authorities 

include: Executive Order 7562, February 27, 1937, Migratory Bird Conservation Act of 

1929 (16 U.S.C. 715d), Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as 

amended, the Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 

Statute 884), and the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Delevan Refuge was established in 1962. Legal authority includes: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d). 

Colusa Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884), and 

the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Sutter Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), and the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884). 

Refuge Purpose(s): 

Sacramento Refuge purposes include: 

“... as a refuge and breeding ground for migratory birds and other wildlife...” 

Executive Order 7562, February 27, 1937 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, 

(2) the protection of natural resources, (3) the conservation of endangered species 

or threatened species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use 

B-64
... real ... property. Such acceptance may be accomplished under the terms and 

conditions of restrictive covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge 

Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection 

of fish and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the 

United States Fish and Wildlife Service, in performing its activities and services. 

Such acceptance may be subject to the terms of any restrictive or affirmative 

covenant, or condition of servitude ...” 16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 

1956). 

Delevan Refuge purposes include: 

 “... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

Colusa Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

Sutter Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

National Wildlife Refuge System Mission: “To administer a national network of lands 

and waters for the conservation, management, and where appropriate, restoration of the 

fish, wildlife, and plant resources and their habitats within the United States for the 

B-65
benefit of present and future generations of Americans” (National Wildlife Refuge 

System Administration Act of 1996, as amended [16 U.S.C. 668dd-ee]). 

Description of Use: The proposed use is the implementation of mosquito monitoring and 

control activities requested and conducted by local mosquito control districts (Districts) 

within the Sacramento, Delevan, Colusa, and Sutter Refuges. These Districts include 

Glenn County Mosquito and Vector Control District (MVCD), Colusa Mosquito 

Abatement District, and Sutter-Yuba MVCD. This is not a wildlife-dependent public use. 

This represents an update of a compatibility determination approved in August 1994 

(USFWS 1994). 

The Districts have verbally informed the wildlife refuge manager of their desire to 

conduct mosquito monitoring and, if necessary, control activities in order to protect the 

public from any mosquito borne diseases. While mosquitoes are considered a nuisance 

because of their biting, some species are known vectors of serious diseases in California. 

There are primarily five mosquito species of concern potentially produced or harbored on 

the Refuges: Aedes melanimon, Aedes nigromaculis, Aedes vexans, Culex tarsalis, and 

Anopheles freeborni. 

The main diseases of concern for mosquito control programs in northern California are 

Western Equine Encephalitis (WEE), St. Louis Encephalitis (SLE), California 

Encephalitis, West Nile Virus (WNV), and malaria (USFWS 2008b). Culex tarsalis is the 

main vector identified in the transmission of these diseases, with the exception of malaria, 

which is vectored by Anopheles freeborni mosquitoes. The other mosquito species listed 

above can also potentially transmit WEE, SLE, and WNV, but are less competent vectors 

compared to C. tarsalis. WEE and SLE have caused significant outbreaks of human 

disease (CA Dept. of Health Services 2003). Public concern over human health issues 

related to mosquito-borne disease has intensified on the west coast with the advance of 

WNV across the United States, and its detection in California in 2003. 

Guidelines to address mosquito management have been developed for implementation on 

refuges in the Pacific Region (USFWS 2003), as well as similar guidance developed at the 

national level for the National Wildlife Refuge System (USFWS 2005a). At the local level, 

the Sacramento Refuge Complex (Complex) has a Draft Integrated Pest Management 

Plan for Mosquito Control (IPM Plan), initially developed in 1999, and updated to 

incorporate the above current regional and national policies. The proposed use would 

apply the principles in the IPM Plan incorporated herein by reference (USFWS 2008b). 

The purposes of this IPM plan are to: 1) describe Refuge habitats and their role in the 

production or harborage of mosquitoes; 2) describe the use of approved mosquito control 

methods and materials in an IPM program that is consistent with the goals of the 

Complex, Department of Interior (DOI) and Service policy, and minimizes public health 

risk from Refuge-produced or harbored mosquitoes; 3) provide long-term planning to 

meet the Service's goal of using IPM to minimize effects of mosquito control on trust 

B-66
resources to the greatest extent possible; and 4) provide long-term planning to meet the 

Service's goals of reducing overall pesticide use on DOI trust resources to the greatest 

extent possible and using the least toxic options when pesticide use is deemed necessary. 

The IPM Plan outlines a risk-based, hierarchical approach to mosquito management 

adapted from national guidance (Figure 1). This approach uses an understanding of 

mosquito biology and ecology whereby intervention measures depend on continuous 

monitoring of mosquito populations. 

The IPM approach ensures legitimate human, fish, and wildlife health concerns are 

addressed. It incorporates a combination of best management practices (BMPs) in 

managed wetlands (Kwasny et al. 2004), biological controls, and a select group of 

pesticides if warranted. Treatment thresholds (i.e. adult and larval mosquito population 

levels, and disease activity) and appropriate corresponding responses are identified 

(USFWS 2008b). Under this program, if mosquito population monitoring and disease 

surveillance indicate that human health thresholds are exceeded, the use of larvicides, 

pupicides, and/or adulticides may become necessary. In some cases, emergency actions 

may be required that are not addressed by this compatibility determination. 

Mosquito monitoring and control is currently authorized on the Complex through Special 

Use Permits (SUP) and approved Pesticide Use Proposals (PUP), both of which are 

issued to the Districts on an annual basis. In addition, the Districts have received a copy 

of the most current IPM Plan. The SUP identifies permitted dates, access points and 

conditions, monitoring and data reporting requirements, treatment thresholds, approved 

PUPs, treatment notification requirements, and sensitive areas to be avoided. The SUP 

makes specific reference to the IPM Plan for many of these items. The PUPs identify 

specific mosquito control products approved for use on the Refuges, and include details on 

target pests, products applied, application dates, rates, methods, number of applications, 

site description, sensitive habitats and best management practices to avoid them. Because 

the U.S. Fish and Wildlife Service (Service) uses insecticides, herbicides and fungicides on 

national wildlife refuges a formal pesticide use review process is employed to ensure that 

all chemical pesticides approved for use have been reviewed for their potential impacts to 

groundwater, surface water and terrestrial and aquatic non-target vegetation and wildlife, 

including threatened and endangered species. Pesticides approved for use must be shown 

to pose the lowest toxicity-related threat to non-target terrestrial and aquatic ecosystems, 

while addressing the specific pest control objectives. Depending on the product, PUPs are 

reviewed and approved at the wildlife refuge manager, Regional Office, or Washington 

Office level. 

Refuge and District staff meet annually to evaluate past and proposed mosquito 

management activities and to coordinate all necessary permitting and implementation 

planning required to conduct mosquito monitoring and control on the Complex for the 

upcoming year. During these meetings, Refuge and District staffs discuss ways to further 

minimize pesticide use on the Refuges, use the least toxic materials practicable, and 

identify research needs. As part of this coordination process, refuge staff provides District 

B-67
personnel with habitat management data and maps for the Refuges that identify planned 

habitat types, water management schedules, and locations of sensitive areas and species. 

District personnel are responsible for monitoring mosquitoes and are required to provide 

refuge staff with timely data collected on mosquito population trends and disease activity 

on the Refuge. 

Mosquito monitoring and control is discussed in Chapter 3 of the Comprehensive 

Conservation Plan (CCP) and Environmental Assessment (EA) (USFWS 2008a) which 

are incorporated by reference. It is also detailed in the Draft IPM Plan (which is included 

as Appendix F of the CCP), which is also incorporated by reference (USFWS 2008b). 

Availability of Resources: The following funding/annual costs (based on FY 2007 costs) 

would be required to administer and manage activities as described above: 

ANNUAL COSTS 

Administration (Evaluation of 

applications, permit compliance, and 

monitoring) 

$5,000 

TOTAL $5,000 

Refuge operational funds are currently available through the Service budget process to 

administer this program. 

Anticipated Impacts of Use: One of the major objectives of the Refuges is to provide 

high quality feeding areas for migratory birds and other wildlife; there is concern that 

mosquito control treatments may be interfering with that objective by reducing the 

existing food base. Effects on non-target organisms (i.e., those other than mosquitoes) can 

be loss of biomass, loss of diversity, interference with normal ecological relationships, 

bioaccumulation, or other unknown effects. Another concern is that rare insects and/or 

insects that may function as important pollinators for rare plants may be impacted by 

mosquito control treatments. Use of non-native biological controls such as mosquitofish 

may alter ecological relationships of native species. 

Significant bioaccumulation has not been associated with any of the chemical treatments 

proposed in the IPM Plan. In a study conducted on Colusa and Sutter Refuges, 

researchers found no reductions in total abundance or biomass of aquatic macroinvertebrates in the treated (i.e., application of pyrethrin, permethrin, or malathion) or 

control fields (Lawler et al. 1997). Adult midges and some other flying insects experienced 

apparent short-term decreases, rebounding to pre-application levels within 24 hours. 

While this study provided encouraging information about adulticide use there are still 

some questions about their effects on refuge resources. This study focused on the effects 

of a single adulticide treatment. During most years, Colusa and Sutter Refuges, and the 

Butte Sink Wildlife Management Area receive multiple adulticide treatments, often 

weekly during the fall flood-up season. Effects of multiple applications may have 

B-68
cumulative effects not detected in the 1997 study. In addition, effects on smaller common 

invertebrates (i.e. cladocera, copepods) were not studied, but should be included in future 

research efforts, given their lower acute toxicity tolerances (Johnson and Finley 1980). 

Some of these questions are being addressed in a current research effort being conducted 

on Colusa Refuge by USFWS-Sacramento Contaminants Division and University of 

California-Davis. As results of this investigation become available, they will factor into the 

IPM process. Sub-lethal effects on non-target species have also not been studied in detail. 

Mosquito monitoring includes regular visits by District personnel to sample mosquito 

larvae (dip counts) and adults (landing counts) in wetlands and adjacent areas. Mosquito 

monitoring will cause direct and indirect disturbance effects. Disturbance would include 

altering wildlife behavior and habitat use, and entering a number of wetland areas to 

collect mosquito samples. However, most of these effects would be short-term. The 

sampling interval would typically be once a week during May through October. Longterm effects would be eliminated/reduced because sufficient restrictions would be 

included as part of the SUP, and District activities would be monitored by refuge staff. 

Refuge staff would ensure that mosquito monitoring does not detract from the purposes 

of the Refuges, the mission of the National Wildlife Refuge System, and the need to 

maintain ecological integrity. Additionally, SUP conditions would include conditions to 

further ensure that impacts to wildlife and habitats are avoided and minimized. 

Mosquito control will have minimal impact to public use activities on the Refuges. Using 

the approach identified in this determination and the IPM Plan, mosquito control will 

utilize the least toxic and the least amount of insecticide required to achieve mosquito 

control and public health protection objectives. Adulticide treatments will occur in 

evenings or early mornings when adult mosquitoes are active and refuge personnel and 

visitors are not present. 

The Refuges have requested Section 7 consultation with USFWS and NOAA-Fisheries on 

the Draft CCP/EA (USFWS 2008) and its effects on any of the special status species/ 

designated critical habitat occurring on the Refuges including: palmate-bracted bird’s 

beak, hairy orcutt grass, Greene’s tuctoria, Hoover’s spurge, Conservancy fairy shrimp, 

vernal pool fairy shrimp, vernal pool tadpole shrimp, giant garter snake, western yellowbilled cuckoo, winter-run Chinook salmon, spring-run Chinook salmon, Central Valley 

steelhead, fall-run Chinook salmon, and late fall-run Chinook salmon. 

Following the IPM approach, including the implementation of adequate monitoring, will 

lessen potential short-term, long-term, and cumulative impacts of mosquito control 

activities to acceptable levels. The annual PUP and SUP processes would continue to be 

used by the Complex staff. 

Anticipated Impacts of Uses on future lands within the approved boundary: The 

following conditions must be met before allowing existing uses to occur on newly acquired 

lands: (1) There is no indirect, direct, or cumulative threat anticipated to human health or 

B-69
safety; (2) There is no indirect, direct, or cumulative threat anticipated to natural or 

cultural resources; (3) The use is consistent with management of existing Sacramento, 

Delevan, Colusa, and Sutter Refuge lands and would contribute to achieving the Refuges’ 

goals. In particular, existing Refuge regulations would not be compromised; (4) The newly 

acquired lands represent a meaningful unit within which to manage the activity; and (5) 

There are no anticipated conflicts with priority public uses. 

Public Review and Comment: Public review and comments will be solicited in 

conjunction with distribution of the Draft CCP/EA for the Sacramento, Delevan, Colusa, 

and Sutter Refuges (USFWS 2008a). 

Determination: 

_____ Use is Not Compatible 

 X Use is Compatible with the Following Stipulations 

Stipulations necessary to ensure compatibility: 

1. All mosquito control activities proposed by the Districts are evaluated and authorized 

through an annual SUP, supported by the risk-based, hierarchical approach outlined 

in the IPM Plan (Figure 1). 

2. The application of any mosquito control products are conducted in accordance with 

approved PUPs, which is referenced in the SUP. 

3. The implementation of mosquito monitoring and control are conducted in accordance 

with Section 7 of the Endangered Species Act. The Refuges provide the Districts a 

map of sensitive areas and identifies measures to avoid them. 

4. Districts are required to notify the wildlife refuge manager prior to any treatments or 

expected series of treatments, which can only occur after mosquito populations and 

virus activity levels exceed treatment thresholds as documented by monitoring data. 

5. An annual report summarizing the mosquito control activities is provided to the 

wildlife refuge manager each year. 

6. The Refuges will monitor District activities on the Refuges to ensure compliance with 

the Stipulations presented here and any additional conditions specified in the SUP, to 

ensure any impacts remain at an acceptable level. 

Justification: Mosquito-borne disease issues are a real threat in the northern Central 

Valley. Mosquito management activities are controlled by a process that involves 

incorporating USFWS National and Regional Mosquito Guidance, the local IPM Plan, 

annual PUPs and SUPs, which would contribute towards a compatible program consistent 

with purposes of the Refuges and Refuge System mission. Appropriate safeguards are 

incorporated into the planning efforts to ensure that the level of mosquito control is 

commensurate with the associated public health risk. In particular, the above stipulations 

and those within the PUPs and SUPs will help to avoid or minimize any impacts to fish, 

B-70
wildlife, plants and their habitats along with the Refuges’ ability to maintain the biological 

integrity, diversity, and environmental health of the Refuges. Any additional terms and 

conditions included in the SUP will be based, at least in part, on the results of monitoring 

efforts. If monitoring demonstrates an unacceptable impact to the Refuges’ resources, 

this use will be reevaluated. Based upon impacts described in the IPM Plan, Draft 

Comprehensive Conservation Plan and Environmental Assessment (USFWS 2008a), it is 

determined that mosquito management activities within the Sacramento, Delevan, Colusa, 

and Sutter National Wildlife Refuges, as described herein, will not materially interfere 

with or detract from the purposes for which the Refuges were established or the mission 

of the Refuge System. In our opinion, these mosquito management activities will not 

conflict with the national policy to maintain the biological diversity, integrity, and 

environmental health of the Refuges. 

Refuge staff has also worked with local Districts on mosquito control at other Refuges 

within the Complex, in a manner consistent with this compatibility determination 

(USFWS 2005b). 

This compatibility determination may need to be reevaluated in the event that a national 

policy for management of mosquitoes on National Wildlife Refuges is finalized. 

Mandatory Re-Evaluation Date (2018): 

 Mandatory 15-year Re-Evaluation, Date will be provided in Final EA/CCP (for 

priority public uses) 

X Mandatory 10-year Re-Evaluation (for all uses other than priority public uses) 

NEPA Compliance for Refuge Use Decision (check one below): 

_____ Categorical Exclusion without Environmental Action Statement 

_____ Categorical Exclusion and Environmental Action Statement 

X Environmental Assessment and Finding of No Significant Impact 

_____ Environmental Impact Statement and Record of Decision 

B-71
B-72

Which thresholds met?

Documented historical 

mosquito production that 

regularly results in 

exceeded treatment

Treatment/action 

thresholds exceeded? 

Documented historical 

health threat/emergency? 

 

Yes 

Districts monitor disease activity (mosquito pools, 

sentinel chicken flocks, wild birds, human cases) and 

mosquito population indices (larval dips, light traps, 

landing counts) from May through October 

Yes No 

Apply appropriate site-specific 

mosquito management BMPs; plus 

allow site-specific larvacidal 

control, using BTI or Methoprene; if 

pupae concentrated limited use of 

GB-1111 

Apply appropriate site-specific 

mosquito management BMPs; 

plus allow site-specific adult 

control in areas confirmed to 

exceed thresholds;

Adults 

Post-treatment monitoring shows mosquito population 

indices to be below treatment thresholds?

Apply appropriate sitespecific non-pesticide 

mosquito management 

BMPs (Table 3) 

Yes 

No 

No action required other 

than periodic monitoring 

Yes 

Larvae/Pupae

No 

Figure 1. Decision-making process regarding mosquito control on an individual refuge at the Sacramento NWR Complex, 

adapted from Interim Guidance for Mosquito Management on National Wildlife Refuges, Table 1 (2005).No 
References 

California Department of Health Services. 2003. California mosquito-borne virus 

surveillance and response plan. 

Johnson, W. W., and M. T. Finley. 1980. Handbook of acute toxicity of chemicals to fish 

and aquatic invertebrates. U. S. Dept. of Int., Fish and Wildl. Serv. Res. Pub. 137, 

98pp. 

Kwasny, D.C., M. A. Wolder, and C.R. Isola. 2004. Technical guide to best management 

practices for mosquito control in managed wetlands. Central Valley Joint Venture 

pub., 35pp. 

Lawler, S.P., T. Jensen, and D.A. Dritz. 1997. Mosquito Management on National Wildlife 

Refuges Ecosystems Effects Study: Phase II – California. Effects of ultra low volume 

applications of pyrethrin, malathion, and permethrin on macro-invertebrates in the 

Sacramento National Wildlife Refuge Complex. Technical Report prepared for the 

U.S. Fish and Wildlife Service – Cooperative Agreement No. 14-48-0001-94582. 

U.S. Fish and Wildlife Service. 1994. Mosquito and Other Vector Management 

Compatibility Determination for Sacramento River Refuge. 

U.S. Fish and Wildlife Service. 2003. Draft Mosquito Management Guidelines for the 

National Wildlife Refuge System Pacific Region. Portland, OR. 

U.S. Fish and Wildlife Service. 2004a. Draft Integrated Pest Management Plan for 

Mosquito Control at the Sacramento National Wildlife Refuge Complex. Revised May 

2004. Willows, California 

U.S. Fish and Wildlife Service. 2004b. Environmental Effects of Mosquito Control “white 

paper.” U.S. Fish and Wildlife Service, Region 1. 

U.S. Fish and Wildlife Service. 2005a. Interim Mosquito Guidance 2005 – National 

Wildlife Refuge System Mosquito Management Guidelines 2005. April 2005. 20pp. 

U.S. Fish and Wildlife Service. 2005b. Sacramento River National Wildlife National 

Wildlife Refuge Final Comprehensive Conservation Plan. California/Nevada 

Operations Office. Sacramento, CA. 

U.S. Fish and Wildlife Service. 2008a. Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges Draft Comprehensive Conservation Plan and Environmental 

Assessment. Region 8. Sacramento, CA. 

U.S. Fish and Wildlife Service. 2008b. Draft Integrated Pest Management Plan for 

Sacramento National Wildlife Refuge Complex. Region 8. Sacramento, CA. 

B-73
Refuge Determination 

Prepared by: ____________________________________ ____________ 

 (Signature) (Date) 

Wildlife Refuge Manager/ 

Project Leader 

Approval: ____________________________________ ____________ 

 (Signature) (Date) 

Concurrence 

Refuge Supervisor: ____________________________________ ____________ 

 (Signature) (Date) 

Assistant Regional 

Director, Refuges: ____________________________________ ____________ 

 (Signature) (Date) 

B-74
COMPATIBILITY DETERMINATION 

(June 2008) 

Use: Plant Material Gathering 

Refuge Name: Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges, 

located in Glenn, Colusa, and Sutter Counties, California. 

Establishing and Acquisition Authority(ies): 

Sacramento National Wildlife Refuge (Refuge) was established in 1937. Legal authorities 

include: Executive Order 7562, February 27, 1937, Migratory Bird Conservation Act of 

1929 (16 U.S.C. 715d), Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as 

amended, the Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 

Statute 884), and the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Delevan Refuge was established in 1962. Legal authority includes: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d). 

Colusa Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884), and 

the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Sutter Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), and the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884). 

Refuge Purpose(s): 

Sacramento Refuge purposes include: 

“... as a refuge and breeding ground for migratory birds and other wildlife...” 

Executive Order 7562, February 27, 1937. 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. ¤ 1534 (Endangered Species Act 

of 1973). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, 

(2) the protection of natural resources, (3) the conservation of endangered species 

or threatened species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use 

B-75
... real ... property. Such acceptance may be accomplished under the terms and 

conditions of restrictive covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge 

Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection 

of fish and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the 

United States Fish and Wildlife Service, in performing its activities and services. 

Such acceptance may be subject to the terms of any restrictive or affirmative 

covenant, or condition of servitude ...” 16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 

1956). 

Delevan Refuge purposes include: 

 “... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

Colusa Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

Sutter Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

National Wildlife Refuge System Mission: “To administer a national network of lands 

and waters for the conservation, management, and where appropriate, restoration of the 

fish, wildlife, and plant resources and their habitats within the United States for the 

B-76
benefit of present and future generations of Americans.” (National Wildlife Refuge 

System Administration Act of 1966, as amended [16 U.S.C. 668dd-ee]). 

Description of Use: Gathering of plants in and around Sacramento, Delevan, Colusa, and 

Sutter Refuges by Native Americans has occurred historically and continues to be a 

periodic use today. Plants are gathered for a variety of uses; for food, medicinal uses, 

ceremonial uses, and for artistic purposes such as basket weaving. Plants gathered for 

traditional uses may include: tule (Schoenoplectus acutus), cattail (Typha spp.), and other 

common species. The amount of plant material being harvested is traditionally small and 

is not expected to increase. The use of Refuge lands for plant gathering is important to 

Native American cultural groups. 

In addition, native plant seeds may also be collected and propagated for use in habitat 

restoration activities on the Complex. Species may include salt grass (Distichlis spicata), 

gumweed (Grindelia camporum) and other common species. 

A Special Use Permit (SUP) will be issued for all plant gathering/collection activities. 

SUPs will contain specific terms and conditions that the gatherer(s) must follow relative 

to activity, location, duration, seasonality, etc. to ensure continued compatibility. All 

Refuge rules and regulations must be followed unless otherwise provided in writing by 

Refuge management. 

The proposed program is described in the Draft Comprehensive Conservation Plan (CCP) 

and associated Environmental Assessment (EA), which are incorporated by reference 

(USFWS 2008). 

Availability of Resources: The following funding/annual costs (based on FY 2007 costs) 

would be required to administer and manage plant gathering activities as described 

above: 

Annual Costs 

Administration $1,000 

TOTAL $1,000 

Anticipated Impacts of Use: Anticipated impacts to habitat and wildlife associated with 

plant gathering on the Refuges are expected to be minimal. The amount of plant material 

being harvested is very minor (<1 percent of any Refuge unit) and will have an 

insignificant impact on habitat. Cuttings from perennial plant species are typically 

requested, which result in no plant mortality. In addition, cuttings are usually harvested 

from areas that are identified for thinning. No rare or sensitive species will be gathered. 

The level of disturbance to wildlife is also minor and long-term effects would be negligible 

because conditions of SUPs would ensure that impacts, such as disturbance to wildlife and 

habitats, are avoided or minimized. Areas used will be closely monitored to evaluate the 

B-77
 

impacts on the resource; if adverse impacts appear, the activity may be moved to 

secondary locations or eliminated entirely. 

While the activity of gathering may have short-term impacts on individual plants and 

wildlife, no adverse long-term impacts on wildlife or plant populations are anticipated. 

This activity should not result in short- or long-term impacts that adversely affect the 

purposes of the Refuges or the mission of the National Wildlife Refuge System. 

Plant gathering on the Refuges has been designed to avoid or minimize impacts 

anticipated to the Refuges’ resources and visitors. The Refuges have requested Section 7 

consultation with USFWS and NOAA-Fisheries on the Draft CCP/EA (USFWS 2008) 

and its effects on any of the special status species/designated critical habitat occurring on 

the Refuges including: palmate-bracted bird’s beak, hairy Orcutt grass, Greene’s tuctoria, 

Hoover’s spurge, Conservancy fairy shrimp, vernal pool fairy shrimp, vernal pool tadpole 

shrimp, giant garter snake, western yellow-billed cuckoo, winter-run Chinook salmon, 

spring-run Chinook salmon, Central Valley steelhead, fall-run Chinook salmon, and late 

fall-run Chinook salmon. 

Anticipated Impacts of Uses on future lands within the approved boundary: The 

following conditions must be met before allowing existing uses to occur on newly acquired 

lands: (1) There is no indirect, direct, or cumulative threat anticipated to human health or 

safety; (2) There is no indirect, direct, or cumulative threat anticipated to natural or 

cultural resources; (3) The use is consistent with management of existing Sacramento, 

Delevan, Colusa, and Sutter Refuge lands and would contribute to achieving the Refuges’ 

goals. In particular, existing Refuge regulations would not be compromised; (4) The newly 

acquired lands represent a meaningful unit within which to manage the activity; and (5) 

There are no anticipated conflicts with priority public uses. 

Public Review and Comment: Public review and comments will be solicited in 

conjunction with distribution of the Draft CCP/EA for the Sacramento, Delevan, Colusa, 

and Sutter Refuges. 

Determination: 

_____ Use is Not Compatible 

Use is Compatible with the Following Stipulations 

Stipulations necessary to ensure compatibility: 

 Access to the Refuges is allowed from one hour before sunrise to one hour after 

sunset. 

 A special use permit (SUP) will be issued for all plant gathering activities. SUPs 

B-78

 X 
 

 

 

will contain specific terms and conditions that the gatherer(s) must follow relative 

to activity, location, duration, seasonality, etc. to ensure continued compatibility. 

All Refuge rules and regulations must be followed unless otherwise excepted in 

writing by Refuge management. 

 Areas used will be closely monitored to evaluate the impacts on the resource; if 

adverse impacts appear, the activity may be moved to secondary locations or 

eliminated. 

Justification: Though plant gathering is not a wildlife-dependent recreational use, it is an 

activity that contributes to environmental education and awareness. The stipulations 

outlined above should minimize potential impacts relative to wildlife/human interactions. 

Based upon impacts described in the Draft Comprehensive Conservation Plan and 

Environmental Assessment (USFWS 2008), it is determined that plant gathering within 

the Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges as described 

herein, will not materially interfere with or detract from the purposes for which the 

Refuges were established or the mission of the Refuge System. In our opinion, 

implementing the plant gathering and associated stipulations will not conflict with the 

national policy to maintain the biological diversity, integrity, and environmental health of 

the Refuges. 

Mandatory Re-Evaluation Date (2018): 

Mandatory 15-year Re-Evaluation, Date will be provided in Final EA/CCP (for 

priority public uses) 

X Mandatory 10-year Re-Evaluation (for all uses other than priority public uses) 

NEPA Compliance for Refuge Use Decision (check one below): 

_____ Categorical Exclusion without Environmental Action Statement 

_____ Categorical Exclusion and Environmental Action Statement 

X Environmental Assessment and Finding of No Significant Impact 

_____ Environmental Impact Statement and Record of Decision 

B-79
References 

U.S. Fish and Wildlife Service. 2008. Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges Draft Comprehensive Conservation Plan and Environmental 

Assessment. Region 8. Sacramento, CA. 

B-80
Refuge Determination 

Prepared by: ____________________________________ ____________

 (Signature) (Date)

Wildlife Refuge Manager/ 

Project Leader 

Approval: ____________________________________ ____________

 (Signature) (Date)

Concurrence 

Refuge Supervisor: ____________________________________ ____________

 (Signature) (Date)

Assistant Regional 

Director, Refuges: ____________________________________ ____________

 (Signature) (Date)

B-81
COMPATIBILITY DETERMINATION 

(June 2008) 

Use: Research 

Refuge Name: Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges, 

located in Glenn, Colusa, and Sutter Counties, California. 

Establishing and Acquisition Authority(ies): 

Sacramento National Wildlife Refuge (Refuge) was established in 1937. Legal authorities 

include: Executive Order 7562, February 27, 1937, Migratory Bird Conservation Act of 

1929 (16 U.S.C. 715d), Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as 

amended, the Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 

Statute 884), and the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Delevan Refuge was established in 1962. Legal authority includes: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d). 

Colusa Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884), and 

the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Sutter Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), and the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884). 

Refuge Purpose(s): 

Sacramento Refuge purposes include: 

“... as a refuge and breeding ground for migratory birds and other wildlife...” 

Executive Order 7562, February 27, 1937 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, 

(2) the protection of natural resources, (3) the conservation of endangered species 

or threatened species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use 

B-82
... real ... property. Such acceptance may be accomplished under the terms and 

conditions of restrictive covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge 

Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection 

of fish and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the 

United States Fish and Wildlife Service, in performing its activities and services. 

Such acceptance may be subject to the terms of any restrictive or affirmative 

covenant, or condition of servitude ...” 16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 

1956). 

Delevan Refuge purposes include: 

 “... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

Colusa Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

Sutter Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

National Wildlife Refuge System Mission: “To administer a national network of lands 

and waters for the conservation, management, and where appropriate, restoration of the 

fish, wildlife, and plant resources and their habitats within the United States for the 

B-83
benefit of present and future generations of Americans.” (National Wildlife Refuge 

System Administration Act of 1966, as amended [16 U.S.C. 668dd-ee]). 

Description of Use: Two provisions of the National Wildlife Refuge Improvement Act are 

to “maintain biological integrity, diversity and environmental health” and to conduct 

“inventory and monitoring.” Research investigations are designed to address these 

provisions by answering specific management questions. These include, but are not 

limited to, evaluation of vegetation and wildlife response to habitat management 

techniques, wildlife and plant population monitoring, documentation of seasonal wildlife 

movements and habitat use, wildlife disease investigations, and development of invasive 

species management techniques. Pertinent results from research investigations are 

incorporated into management plans and actions, and help strengthen the decisionmaking process. The proposed research program is discussed in detail as part of the 

Proposed Action in the Draft Comprehensive Conservation Plan (CCP) and associated 

Environmental Assessment (EA), which are incorporated by reference (USFWS 2008). 

Sacramento Refuge Complex receives numerous requests each year to conduct scientific 

research at the Refuges. The Refuges issue Special Use Permits (SUP) for approved 

research and monitoring projects. SUPs would only be issued for monitoring and 

investigations, which contribute to the enhancement, protection, preservation, and 

management of native Refuge plant and wildlife populations and their habitats. Research 

applicants are required to submit a proposal that outlines: (1) objectives of the study; (2) 

justification for the study; (3) detailed methodology and schedule; (4) potential impacts on 

Refuge wildlife or habitat, including disturbance (short and long term), injury, or 

mortality (this includes a description of measures the researcher will take to reduce 

disturbance or impacts); (5) research personnel required; (6) costs to Refuge, if any; and 

(7) progress reports and end products (i.e., reports, thesis, dissertations, publications). 

Research proposals are reviewed by refuge staff, and if approved, a SUP is issued by the 

wildlife refuge manager to formally authorize any project. 

Evaluation criteria will include, but not be limited to, the following: 

 Research that will contribute to specific Refuge management issues will be given 

higher priority over other research requests. 

 Research that will conflict with other ongoing research, monitoring, or 

management programs will not be granted. 

 Research projects that can be accomplished off-Refuge are less likely to be 

approved. 

 Research, which causes undue disturbance or is intrusive will likely not be granted. 

Level and type of disturbance will be carefully evaluated when considering a 

request. Suggestions may be made to adjust the location, timing, scope, number of 

B-84
permittees, study methods, number of study sites, etc. 

 If staffing or logistics make it impossible for the Refuge to monitor researcher 

activity in a sensitive area, the research request may be denied. 

 The length of the project will be considered and agreed upon before approval. 

Projects will be reviewed annually. 

Availability of Resources: The following funding/annual costs (based on FY 2007 costs) 

would be required to administer and manage research activities as described above: 

Annual Costs 

Administration 

(Evaluation of applications, management 

of permits, and monitoring of research 

projects) 

$5,000 

TOTAL $5,000 

Refuge operational funds are currently available through the Service budget process to 

administer this program. 

Anticipated Impacts of Use: Conducting management-oriented research will benefit 

Refuge fish, wildlife, plant populations, and their habitat. Monitoring and research 

investigations will be designed to answer habitat or population management questions, 

thereby contribute to adaptive management of the Complex. An expected short-term 

effect of monitoring and research investigations is that Refuge management activities 

would be modified to improve habitat and wildlife populations, as a result of new 

information. Expected long-term and cumulative effects include a growing body of 

science-based data and knowledge from which to draw upon to implement the best Refuge 

management possible. Natural resources inventory, monitoring and research are 

necessary tools towards maintaining biological integrity and diversity and environmental 

health. Information gained from well-thought out research will improve habitat and 

wildlife populations. 

Some negative direct and indirect effects would occur through disturbance, which is 

expected with some research activities, especially where researchers are entering 

sanctuaries. Researcher disturbance would include altering wildlife behavior, going off 

designated trails, collecting soil and plant samples, or trapping and handling wildlife. 

However, most of these effects would be short-term because only the minimum of samples 

(e.g., water, soils, vegetative litter, plants, macroinvertebrates) required for identification 

and/or experimentation and statistical analysis would be permitted and captured and 

marked wildlife would be released. Long-term effects would be negligible because Refuge 

evaluation of research proposals and conditions of SUPs would ensure that impacts, such 

as disturbance, to wildlife and habitats are avoided or minimized. Refuge staff would 

B-85
 

ensure research projects contribute to the enhancement, protection, preservation, and 

management of native Refuge wildlife populations and their habitats thereby helping the 

Refuge fulfill the purposes for which it was established and the mission of the National 

Wildlife Refuge System. 

The Refuges have requested Section 7 consultation with USFWS and NOAA-Fisheries on 

the Draft CCP/EA (USFWS 2008) and its effects on any of the special status 

species/designated critical habitat occurring on the Refuges including: palmate-bracted 

bird’s beak, hairy Orcutt grass, Greene’s tuctoria, Hoover’s spurge, Conservancy fairy 

shrimp, vernal pool fairy shrimp, vernal pool tadpole shrimp, giant garter snake, western 

yellow-billed cuckoo, winter-run Chinook salmon, spring-run Chinook salmon, Central 

Valley steelhead, fall-run Chinook salmon, and late fall-run Chinook salmon. 

Anticipated Impacts of Uses on future lands within the approved boundary: The 

following conditions must be met before allowing existing uses to occur on newly acquired 

lands: (1) There is no indirect, direct, or cumulative threat anticipated to human health or 

safety; (2) There is no indirect, direct, or cumulative threat anticipated to natural or 

cultural resources; (3) The use is consistent with management of existing Sacramento, 

Delevan, Colusa, and Sutter Refuge lands and would contribute to achieving the Refuges’ 

goals. In particular, existing Refuge regulations would not be compromised; (4) The newly 

acquired lands represent a meaningful unit within which to manage the activity; and (5) 

There are no anticipated conflicts with priority public uses. 

Public Review and Comment: Public review and comments will be solicited in 

conjunction with distribution of the Draft CCP/EA for the Sacramento, Delevan, Colusa, 

and Sutter Refuges (USFWS 2008). 

Determination: This program as described is determined to be compatible. Potential 

impacts of research activities on Refuge resources will be minimized because sufficient 

restrictions and safeguards would be included in the SUP and research activities will be 

monitored by the refuge manager and biologist. The refuge manager and biologist would 

ensure that proposed monitoring and research investigations would contribute to the 

enhancement, protection, conservation, and management of native Refuge wildlife 

populations and their habitats thereby helping the Refuges fulfill the purposes for which 

they were established, the mission of the National Wildlife Refuge System, and the need 

to maintain ecological integrity, diversity, and environmental health. 

_____ Use is Not Compatible 

Use is Compatible with the Following Stipulations 

Stipulations necessary to ensure compatibility: 

The criteria for evaluating a research proposal, outlined in the Description of Use section 

above, will be used when determining whether a proposed study will be approved on the 

B-86

 X 
Refuges. If proposed research methods are evaluated and determined to have potential 

adverse impacts on Refuge wildlife or habitat, then the Refuges would determine the 

utility and need of such research to conservation and management of Refuge wildlife and 

habitat. If the need was demonstrated by the research permittee and accepted by the 

Refuges, then measures to minimize potential impacts (e.g., reduce the numbers of 

researchers entering an area, restrict research in specified areas) would be developed and 

included as part of the study design and on the SUP. SUPs will contain specific terms and 

conditions that the researcher(s) must follow relative to activity, location, duration, 

seasonality, etc. to ensure continued compatibility. All Refuge rules and regulations must 

be followed unless otherwise accepted in writing by Refuge management. 

Refuge staff will monitor researcher activities for potential impacts to the Refuges and for 

compliance with conditions on the SUPs. Research activities will be modified to avoid 

harm to sensitive wildlife and habitat when unforeseen impacts arise. The refuge manager 

may determine that previously approved research and SUPs be terminated due to 

observed impacts. The refuge manager will also have the ability to cancel a SUP if the 

researcher is out of compliance with the conditions of the SUP. 

Justification: This program as described is determined to be compatible. Based upon 

impacts described in the Draft Comprehensive Conservation Plan and Environmental 

Assessment (USFWS 2008), it is determined that research within the Sacramento, 

Delevan, Colusa, and Sutter National Wildlife Refuges, as described herein, will not 

materially interfere with or detract from the purposes for which the Refuges were 

established or the mission of the Refuge System. In fact, well-designed research 

investigations will directly benefit and support refuge goals, objectives and management 

plans and activities. Fish, wildlife, plants and their habitat will improve through the 

application of knowledge gained from monitoring and research. Biological integrity, 

diversity and environmental health would benefit from scientific research conducted on 

natural resources at the Refuges. The wildlife-dependent, priority public uses (wildlife 

viewing and photography, environmental education and interpretation, fishing and 

hunting) would also benefit as a result of increased biodiversity and wildlife and native 

plant populations from improved restoration and management plans and activities 

associated with monitoring and research investigations which address specific restoration 

and management questions. 

B-87
Mandatory Re-Evaluation Date (2018): 

 Mandatory 15-year Re-Evaluation, Date will be provided in Final EA/CCP (for 

priority public uses) 

X Mandatory 10-year Re-Evaluation (for all uses other than priority public uses) 

NEPA Compliance for Refuge Use Decision (check one below): 

_____ Categorical Exclusion without Environmental Action Statement 

_____ Categorical Exclusion and Environmental Action Statement 

X Environmental Assessment and Finding of No Significant Impact 

_____ Environmental Impact Statement and Record of Decision 

References 

U.S. Fish and Wildlife Service. 2008. Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges Draft Comprehensive Conservation Plan and Environmental 

Assessment. Region 8. Sacramento, CA. 

B-88
Refuge Determination 

Prepared by: ____________________________________ ____________ 

 (Signature) (Date) 

Wildlife Refuge Manager/ 

Project Leader 

Approval: ____________________________________ ____________ 

 (Signature) (Date) 

Concurrence 

Refuge Supervisor: ____________________________________ ____________ 

 (Signature) (Date) 

Assistant Regional 

Director, Refuges: ____________________________________ ____________ 

 (Signature) (Date) 

B-89
COMPATIBILITY DETERMINATION 

(June 2008) 

Use: Wildlife Observation and Photography 

Refuge Name: Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges, 

located in Glenn, Colusa, and Sutter Counties, California. 

Establishing and Acquisition Authority(ies): 

Sacramento National Wildlife Refuge (Refuge) was established in 1937. Legal authorities 

include: Executive Order 7562, February 27, 1937, Migratory Bird Conservation Act of 

1929 (16 U.S.C. 715d), Refuge Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as 

amended, the Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 

Statute 884), and the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Delevan Refuge was established in 1962. Legal authority includes: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d). 

Colusa Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884), and 

the Fish and Wildlife Act of 1956 (16 U.S.C. 742). 

Sutter Refuge was established in 1945. Legal authorities include: Migratory Bird 

Conservation Act of 1929 (16 U.S.C. 715d), Lea Act of 1948 (16 U.S.C. 695), and the 

Endangered Species Act of 1973 as amended (16 U.S.C. 1531-1543: 87 Statute 884). 

Refuge Purpose(s): 

Sacramento Refuge purposes include: 

“... as a refuge and breeding ground for migratory birds and other wildlife...” 

Executive Order 7562, February 27, 1937. 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. ¤ 1534 (Endangered Species Act 

of 1973). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, 

(2) the protection of natural resources, (3) the conservation of endangered species 

or threatened species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use 

B-90
... real ... property. Such acceptance may be accomplished under the terms and 

conditions of restrictive covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge 

Recreation Act of 1962 (16 U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection 

of fish and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the 

United States Fish and Wildlife Service, in performing its activities and services. 

Such acceptance may be subject to the terms of any restrictive or affirmative 

covenant, or condition of servitude ...” 16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 

1956). 

Delevan Refuge purposes include: 

 “... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

Colusa Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

Sutter Refuge purposes include: 

“... for use as an inviolate sanctuary, or for any other management purpose, for 

migratory birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 

16 U.S.C. 695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or 

threatened species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 

1973). 

National Wildlife Refuge System Mission: “To administer a national network of lands 

and waters for the conservation, management, and where appropriate, restoration of the 

fish, wildlife, and plant resources and their habitats within the United States for the 

B-91
benefit of present and future generations of Americans.” (National Wildlife Refuge 

System Administration Act of 1966, as amended [16 U.S.C. 668dd-ee]). 

Description of Use: The National Wildlife Refuge System Improvement Act of 1997 

identifies wildlife observation and photography as well as hunting, fishing, interpretation, 

and environmental education as priority wildlife-dependent public uses for refuges. As 

two of the six priority public uses of the Refuge System, these uses are to be encouraged 

when compatible with the purposes of the refuges. Wildlife observation and photography 

are considered simultaneously in this compatibility determination. Many elements of the 

wildlife observation and photography programs are also similar to opportunities provided 

in the environmental education and interpretation programs. These uses are described in 

the Draft Comprehensive Conservation Plan (CCP) and Environmental Assessment (EA) 

(USFWS 2008) and are incorporated by reference. 

The guiding principles of the Refuge System’s wildlife observation and wildlife 

photography programs (Service Manual 605 FW 4 and 5) are to: 

 

• Provide safe, enjoyable, and accessible wildlife viewing opportunities and facilities. 

• Promote visitor understanding of, and increase visitor appreciation for, America’s 

natural resources. 

• Provide opportunities for quality recreational and educational experiences 

consistent with criteria describing quality found in Service Manual 605 FW 1.6. 

• Minimize conflicts with visitors participating in other compatible wildlifedependent recreation activities. 

Wildlife observation and photography conducted on portions of the Refuges open to the 

general public do not require a special use permit (SUP). These areas are open one hour 

before sunrise to one hour after sunset on all Refuges. 

Wildlife Observation

The wildlife observation objective of the Draft CCP states that the Refuges will provide 

100,000 wildlife observation annual visits by 2023. A portion of the hunt area (2,275 acres) 

will be open for wildlife observation from February through June on Sacramento, Colusa, 

and Sutter Refuges. 

Sacramento Refuge is open to the public for wildlife observation and photography daily 

along the auto tour route and trails from one hour before sunrise to one hour after sunset 

year-round. The six-mile auto tour route meanders along marshes and riparian areas of 

Logan Creek. There are two park and stretch areas on the auto tour route where visitors 

are encouraged to get out of their vehicles to view wildlife. At the first park-and-stretch 

area halfway along the auto tour route, there is a three-tier wildlife viewing platform with 

two spotting scopes. The two-mile walking trail also meanders along marshes and riparian 

areas of Logan Creek. Using the Wetlands Walk Guide, groups may stroll by the fourteen 

B-92
stops for an hour long adventure. If time is limited, visitors may take alternate trail 

shortcut routes. 

Delevan Refuge is open to the public for wildlife observation and photography along 

perimeter roads only. A primitive off-refuge parking area is currently available for 

visitors along Maxwell Road on the southern boundary of the Refuge. Construction of a 

viewing platform and other improvements to this site are planned. An additional parking 

area and viewing platform along Four Mile Road is also planned. 

On Colusa Refuge, visitors enjoy wildlife viewing and photography as they drive the 

three-mile, graveled auto tour route adjacent to wetlands. A one-mile walking trail is 

located along a lush riparian slough. The auto tour route and trail are open one hour 

before sunrise to one hour after sunset year-round. The walking trail will be upgraded to 

provide for universal access and the wildlife viewing blind will be replaced with a 

universally accessible blind and boardwalk. 

Roads adjacent to Sutter Refuge provide the public with opportunities for wildlife 

observation throughout the year. In addition, scheduled guided tours on the southern 

portion of the Refuge will be conducted during February through June when staff and 

funding are available. In addition, a walking trail utilizing the existing roads will be 

constructed. 

Photography 

The photography objective of the Draft CCP states that the Refuges will provide 80 

photography blind annual visits and 10,000 annual photography visits by 2023. This 

includes photographic opportunities from the auto tours, walking trails, and photography 

blinds. A portion of the hunt area (2,275 acres) is open for photography from February 

through June on Sacramento, Colusa, and Sutter Refuges. The in-ground, concrete 

hunting blinds in this area on Sacramento Refuge are available for photographic use from 

February through June with no user fees or reservations required. 

The best time of year for photography occurs from November through February when a 

variety of waterfowl is present. The auto tour routes and walking trails on Sacramento 

and Colusa Refuges provide excellent photographic opportunities. The viewing blind on 

the Discovery Trail at Colusa Refuge will be replaced with a universally accessible blind 

and boardwalk. 

There are two photography blinds on Sacramento Refuge (Blinds 1 and 2) and one on 

Colusa Refuge (Blind 3). A universally accessible photography blind will be constructed at 

Delevan Refuge (Blind 4). The blinds are approximately 300 yards within the wetlands. 

They are approximately 4.5' x 6' wide and 5' high. They have adjustable camera size 

openings in three sides. The blinds accommodate one person comfortably; however, two 

people at a time are allowed. There is one chair in each blind. Islands or tree snags and 

islands have been placed to encourage birds to perch or rest about 40 feet from the blind. 

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Photography Blind 2 on Sacramento Refuge will be replaced with a universally accessible 

blind and boardwalk. 

Photography blind use will be limited to one day (Wednesdays through Sundays) each 

week from October through March. Limiting use promotes continued bird use of the 

surrounding areas, and thereby improving the potential for good photography 

opportunities.

Lottery:

Photographers may apply through a lottery system, for up to three reservations annually. 

Photographers will be assigned up to three reservations in an August lottery. Then, 

depending on availability, reservations will be assigned by a first-come, first-serve 

process. 

Lottery Process: 

• The lottery is held in August (applications must be received between August 1-31). 

• Photographers may select up to 10 date/blind combinations in priority order [e.g. 

Choice 1: Dec. 17, 2008 – Blind 1, Choice 2: Dec. 17 – Blind 3, Choice 3: Nov. 12 – 

Blind 1, etc.], including the option to be on a blind waiting list (indicate which week 

or month and blind is desired). 

• All reservation applications are randomly drawn and assigned a number, which 

indicates the order in which the reservations will be processed. 

• The reservations are then processed in numerical order by reserving the remaining 

highest priority of date/blind choice available for all of the reservation applicants. 

• After all of the applicants have received one reservation, the blind assignment 

continues until all applicants receive their next priority date of choice. 

First come, first serve process: 

Photographers that missed the lottery will fill any remaining dates by a first-come, firstserve process. 

Waiting list: 

In addition, there is a blind waiting list that is used to refill blinds when there are 

reservation cancellations. 

Fees:

The photography blind fee has two required components: 

• Purchase of a Refuge entrance pass (Refuge Day Pass or Refuge Annual Pass is 

required by all photographers who do not possess either a Federal Duck Stamp, 

Golden Eagle, Golden Age, Golden Access or America the Beautiful Pass). 

• A non-refundable $15 fee per photography blind visit. 

For photographers participating in the lottery, the fee is due by October 1. 

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For photographers participating in the first come, first serve or in the waiting list, the 

reservations are confirmed when the photography blind fee is paid prior to the visit. 

Some of the photography blinds may also be available for use from April through June 

when habitat is suitable. Inquiries about availability should be directed to Sacramento 

National Wildlife Refuge Complex, 752 County Road 99W, Willows, CA 95988 (530/934­

2801). 

Photographers also complete a blind evaluation that reports photographed species, time 

spent, and comments. Photographers must be in the blind at least one hour before 

sunrise. They must park in the designated parking area and proceed directly to the 

assigned blind on foot. Stakes with reflective tape mark the route from the parking area 

to the blind. The route is designed to minimize disturbance; therefore, deviation from the 

staked route is not allowed. Photographers may leave the blind at any time, but once the 

blind has been vacated, returning to the blind is not permitted. 

Availability of Resources: The following funding/annual costs (based on FY 2007 costs) 

would be required to administer and manage wildlife observation and photography 

activities as described above: 

One-Time Costs Annual Costs 

New Construction 

Improve Maxwell Road parking 

area including viewing platform 

(Delevan) 

$102,200 

Obtain Wayside Exhibit 

materials for viewing platform 

(Delevan) 

$ 94,600 

Construct parking area and 

viewing platform along 4-Mile 

Road (Delevan) 

$ 80,000 

Construct universally accessible 

photography blind including 

boardwalk (Sacramento) 

$ 33,100 

Construct universally accessible 

photography blind including 

boardwalk (Delevan) 

$ 18,000 

Replace wildlife observation 

blind with an accessible blind and 

boardwalk (Colusa) 

$ 75,000 

Predicted Maintenance of Facilities 

Modifications in hunt areas for 

spring-summer use (e.g. signs, 

parking lot modifications, etc.) 

$ 30,000 

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(Sacramento, Colusa and Sutter) 

Renovate existing trails for 

universal access (Sacramento) 

$116,000 

Renovate existing trail for 

universal access (Colusa) 

$ 75,000 

Regular maintenance of kiosks, 

auto tours, viewing platforms, 

photography blinds, trails, 

restrooms, etc. 

$ 20,000 

Equipment, vehicles, and 

supplies (e.g. brochures, etc.) 

$ 22,000 

New Staffing 

One full-time (1.0 FTE) WG-6 

tractor operator 

$ 54,431 

One full-time (1.0 FTE) WG-8 

maintenance worker 

$ 62,895 

TOTAL $623,900 $159,326 

Additional funds would be required to operate and maintain the programs. Funding will 

be sought through the Service budget process. User fees are collected for photography 

blind use, commercial photography activities and for issuing special use permits (SUPs). 

Other sources will be sought through strengthened partnerships, grants, and additional 

refuge operations funding to support a safe and quality program as described above. 

User fees are collected for issuing SUPs for access to closed areas or other special 

considerations (e.g. access to the Refuges after normal public visitation hours, setting up 

temporary photography blinds, etc.) (16 USC 460I-6d, Refuge Manual 8 RM 16). The 

standard fee for noncommercial photography and wildlife observation is $50 per year. The 

standard fee for commercial photography is $100 per year. This category applies to any 

photography that result in images that are intended for sale, or where the photographer is 

otherwise paid for the work by salary or contract. The standard fee for commercial tours 

is $150. A SUP and fee (other than daily Refuge entrance fees at the Sacramento Refuge 

and photo blind use fees, if appropriate) is not required when the use is conducted in areas 

and facilities that are open to the general public. If any special attention (such as 

transportation, access to restricted areas, food, lodging, or guide service) is provided by 

the refuge staff, these costs will be added to the standard fee for the SUP (USFWS 1992). 

Anticipated Impacts of Use: Once considered “non-consumptive”, it is now recognized 

that wildlife observation and wildlife photography can negatively impact wildlife by 

altering wildlife behavior, reproduction, distribution, and habitat (Purdy et al. 1987, 

Knight and Cole 1995). 

Purdy et al. (1987) and Pomerantz et al. (1988) described six categories of impacts to 

wildlife as a result of visitor activities. They are: 

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1) Direct mortality: immediate, on-site death of an animal; 

2) Indirect mortality: eventual, premature death of an animal caused by an event or 

agent that predisposed the animal to death; 

3) Lowered productivity: reduced fecundity rate, nesting success, or reduced survival 

rate of young before dispersal from nest or birth site; 

4) Reduced use of refuge: wildlife not using the refuge as frequently or in the manner 

they normally would in the absence of visitor activity; 

5) Reduced use of preferred habitat on the refuge: wildlife use is relegated to less 

suitable habitat on the refuge due to visitor activity; and 

6) Aberrant behavior/stress: wildlife demonstrating unusual behavior or signs of stress 

likely to result in reduced reproductive or survival rates. 

Individual animals may be disturbed by human contact to varying degrees. Human 

activities on trails can result in direct effects on wildlife through harassment, a form of 

disturbance that can cause physiological effects, behavioral modifications, or death (Smith 

and Hunt 1995). Many studies have shown that birds can be impacted from human 

activities on trails when they are disturbed and flushed from feeding, resting, or nesting 

areas. Flushing, especially repetitive flushing, can strongly impact habitat use patterns of 

many bird species. Flushing from an area can cause birds to expend more energy, be 

deterred from using desirable habitat, affect resting or feeding patterns, and increase 

exposure to predation or cause birds to abandon sites with repeated disturbance (Smith 

and Hunt 1995). Migratory birds were observed to be more sensitive than resident species 

to disturbance (Klein 1989). 

Herons and shorebirds were observed to be the most easily disturbed (when compared to 

gulls, terns and ducks) by human activity and flushed to distant areas away from people 

(Burger 1981). A reduced number of shorebirds were found near people who were walking 

or jogging, and about 50 percent of flushed birds flew elsewhere (Burger 1981). In 

addition, the foraging time of sanderlings decreased and avoidance (e.g., running, 

flushing) increased as the number of humans within 100 meters increased (Burger and 

Gochfeld 1991). Nest predation for songbirds (Miller et al. 1998), raptors (Glinski 1976), 

colonial nesting species (Buckley and Buckley 1976), and waterfowl (Boyle and Samson 

1985) tends to increase in areas more frequently visited by people. In addition, for many 

passerine species, primary song occurrence and consistency can be impacted by a single 

visitor (Gutzwiller et al. 1994). In areas where primary song was affected by disturbance, 

birds appeared to be reluctant to establish nesting territories (Reijnen and Foppen 1994). 

Depending on the species (especially migrants vs. residents), some birds may habituate to 

some types of recreation disturbance and either are not disturbed or will immediately 

return after the initial disturbance (Hockin et al. 1992; Burger et al. 1995; Knight and 

Temple 1995; Madsen 1995; Fox and Madsen 1997). Rodgers and Smith (1997) calculated 

buffer distances that minimize disturbance to foraging and loafing birds based on 

experimental flushing distances for 16 species of waders and shorebirds. They 

recommended 100 meters as an adequate buffer against pedestrian traffic, however, they 

B-97
suggest this distance may be reduced if physical barriers (e.g., vegetation screening) are 

provided, noise levels are reduced, and traffic is directed tangentially rather than directly 

toward birds. Screening may not effectively buffer noise impacts, thus visitors should be 

educated on the effects of noise and noise restrictions should be enforced (Burger 1981, 

1986; Klein 1993; Bowles 1995; Burger and Gochfeld 1998). Seasonally restricting or 

prohibiting recreation activity may be necessary during spring and fall migration to 

alleviate disturbance to migratory birds (Burger 1981, 1986; Boyle and Samson 1985; 

Klein et al. 1995; Hill et al. 1997). 

Of the wildlife observation techniques, wildlife photographers tend to have the largest 

disturbance impacts (Klein 1993, Morton 1995, Dobb 1998). While wildlife observers 

frequently stop to view species, wildlife photographers are more likely to approach 

wildlife (Klein 1993). Even slow approach by wildlife photographers tends to have 

behavioral consequences to wildlife species (Klein 1993). Other impacts include the 

potential for photographers to remain close to wildlife for extended periods of time, in an 

attempt to habituate the wildlife subject to their presence (Dobb 1998) and the tendency 

of casual photographers, with low-power lenses, to get much closer to their subjects than 

other activities would require (Morton 1995), including wandering off trails. This usually 

results in increased disturbance to wildlife and habitat, including trampling of plants. 

Klein (1993) recommended that refuges provide observation and photography blinds to 

reduce disturbance of waterbirds when approached by visitors. 

Education helps make visitors aware that their actions can have negative impacts on 

birds, and will increase the likelihood that visitors will abide by restrictions on their 

actions. For example, Klein (1993) demonstrated that visitors who had spoken with refuge 

staff or volunteers were less likely to disturb birds. Increased surveillance and imposed 

fines may also help reduce visitor caused disturbance (Knight and Gutzwiller 1995). 

Monitoring is recommended to adjust management techniques over time, particularly 

because it is often difficult to generalize about the impacts of specific types of recreation 

in different environments. Local and site-specific knowledge is necessary to determine 

effects on birds and to develop effective management strategies (Hockin et al. 1992; Klein 

et al. 1995; Hill et al. 1997). 

The construction and maintenance of boardwalks/trails and parking lots will have minor 

impacts on soils and vegetation around the trails. This could include an increased potential 

for erosion, soil compaction (Liddle 1975), reduced seed emergence (Cole and Landres 

1995), alteration of vegetative structure and composition, and sediment loading (Cole and 

Marion 1988). However, the construction of boardwalks will concentrate the foot traffic, 

allowing the vegetation surrounding them to remain undisturbed. 

Disturbance of wildlife is the primary concern regarding these uses. Disturbance to 

wildlife, such as the flushing of feeding, resting, or nesting birds, is inherent to these 

activities. There is some temporary disturbance to wildlife due to human activities on 

trails (hiking, bird watching) however, the disturbance is generally localized and will not 

B-98
 X 

adversely impact overall populations. Increased facilities and visitation would cause some 

displacement of habitat and increase some disturbance to wildlife, although this is 

expected to be minor given the size of the Refuges and by avoiding or minimizing 

intrusion into important wildlife habitat. 

The wildlife observation and photography programs are designed to avoid or minimize 

impacts anticipated to the Refuges’ resources and visitors. The Refuges have requested 

Section 7 consultation with USFWS and NOAA-Fisheries on the Draft CCP/EA (USFWS 

2008) and its effects on any of the special status species/designated critical habitat 

occurring on the Refuges including: palmate-bracted bird’s beak, hairy Orcutt grass, 

Greene’s tuctoria, Hoover’s spurge, Conservancy fairy shrimp, vernal pool fairy shrimp, 

vernal pool tadpole shrimp, giant garter snake, western yellow-billed cuckoo, winter-run 

Chinook salmon, spring-run Chinook salmon, Central Valley steelhead, fall-run Chinook 

salmon, and late fall-run Chinook salmon. 

Anticipated Impacts of Uses on future lands within the approved boundary: The 

following conditions must be met before allowing existing uses to occur on newly acquired 

lands: (1) There is no indirect, direct, or cumulative threat anticipated to human health or 

safety; (2) There is no indirect, direct, or cumulative threat anticipated to natural or 

cultural resources; (3) The use is consistent with management of existing Sacramento, 

Delevan, Colusa, and Sutter Refuge lands and would contribute to achieving the Refuges’ 

goals. In particular, existing Refuge regulations would not be compromised; (4) The newly 

acquired lands represent a meaningful unit within which to manage the activity; and (5) 

There are no anticipated conflicts with priority public uses. 

Public Review and Comment: Public review and comments will be solicited in 

conjunction with distribution of the Draft CCP/EA for the Sacramento, Delevan, Colusa, 

and Sutter Refuges (USFWS 2008). 

Determination: 

_____ Use is Not Compatible 

Use is Compatible with the Following Stipulations 

Stipulations necessary to ensure compatibility: 

 Adequate areas are designated as wildlife sanctuary with no or limited public use 

activities to provide high quality habitat for feeding, resting, and nesting. 

 Regulations and wildlife friendly behavior (e.g., requirements to stay on designated 

trails, dogs must be kept on leash, etc.) are described in brochures and posted at 

the visitor center. 

B-99
 Refuge visitors are required to remain in vehicles while on the auto tour routes 

except at designated park and stretch locations. 

 Visitor Services Assistants routinely monitor the auto tour route and walking trail 

on Sacramento Refuge for refuge regulation compliance. 

 Refuge biologists and public use specialists conduct regular surveys of public 

activities on the Refuges. The data is analyzed and used by the refuge manager to 

develop future modifications if necessary to ensure compatibility of the wildlife 

observation and photography programs. 

 Access to the Refuges is allowed from one hour before sunrise to one hour after 

sunset. 

 Regulatory and directional signs clearly mark designated routes of travel and 

areas closed to the public. 

 Visitors are required to obtain a Refuge Day Pass (currently $3 per vehicle) or 

Refuge Commercial Day Pass (currently $20 per commercial vehicle) for public use 

activities on Sacramento Refuge unless in possession of a Refuge Annual Pass, 

Federal Duck Stamp, valid Golden Eagle, Age or Access Passport, National Parks 

Pass with Hologram, or America the Beautiful Pass. 

 Maps and public use information are available at the Refuge Headquarters, kiosks, 

and the Complex’s website http://sacramentovalleyrefuges.fws.gov. 

 Two photography blinds on Sacramento Refuge and a blind on Colusa Refuge are 

available by reservation from October through March. A universally accessible 

blind will be constructed at Delevan Refuge and be available by reservation. The 

photography blinds may be reserved only one day each week, on Wednesdays 

through Sundays. The current fee for photo blind use is $10 per visit. 

Photographers may request up to three total reservations during October through 

March and unlimited visits during the spring and summer if habitat conditions 

allow. 

 Visitors must obtain a special use permit if the request includes access to closed 

areas of the Refuges or other special considerations (e.g. access to the Refuges 

after normal public visitation hours, setting up temporary photography blinds, etc.) 

(16 USC 460I-6d, Refuge Manual 8 RM 16). A standard fee of $50 per year for 

noncommercial photography and wildlife observation will be charged for issuing 

the SUP. The standard fee for commercial photographers is $100 per year. The 

standard fee for commercial tours is $150 (USFWS 1992). Unless otherwise stated 

on the permit, in addition to the permit fee, a daily Refuge entrance fee of $3 per 

vehicle or $20 per commercial vehicle is charged on Sacramento Refuge. Areas 

B-100
 

 

used will be closely monitored to evaluate the impacts on the resource; if adverse 

impacts appear, the activity may be moved to secondary locations or curtailed 

entirely. Specific conditions may apply depending upon the requested activity and 

will be addressed through the SUP. 

 Additional requirements for commercial photography activities are covered in the 

Compatibility Determination for Commercial Photography for Sacramento, 

Delevan, Colusa, and Sutter National Wildlife Refuges. 

Justification: These wildlife-dependent uses are priority public uses of the National 

Wildlife Refuge System. Providing opportunities for wildlife observation and photography 

would contribute toward fulfilling provisions of the National Wildlife Refuge System 

Administration Act, as amended in 1997, and one of the goals of the Sacramento Refuge 

(Goal 3, Chapter 4, CCP). Wildlife observation and photography provide an excellent 

forum for allowing public access and increasing understanding of the Refuges’ resources. 

The stipulations outlined above should minimize potential impacts relative to 

wildlife/human interactions. Based upon impacts described in the Draft Comprehensive 

Conservation Plan and Environmental Assessment (USFWS 2008), it is determined that 

wildlife observation and photography within the Sacramento, Delevan, Colusa, and Sutter 

National Wildlife Refuges as described herein, will not materially interfere with or detract 

from the purposes for which the Refuges were established or the mission of the Refuge 

System. In our opinion, implementing the wildlife observation and photography programs 

and associated stipulations will not conflict with the national policy to maintain the 

biological diversity, integrity, and environmental health of the Refuges. 

Mandatory Re-Evaluation Date (2023): 

X Mandatory 15-year Re-Evaluation, Date will be provided in Final EA/CCP (for 

priority public uses) 

_____ Mandatory 10-year Re-Evaluation (for all uses other than priority public uses) 

NEPA Compliance for Refuge Use Decision (check one below): 

_____ Categorical Exclusion without Environmental Action Statement 

_____ Categorical Exclusion and Environmental Action Statement 

X Environmental Assessment and Finding of No Significant Impact 

_____ Environmental Impact Statement and Record of Decision 

B-101
References 

Bowles A. E. 1995. Response of wildlife to noise. Pages 109-156. in R.L. Knight and D.N. 

Cole, editors. Wildlife and recreationists: coexistence through management and 

research. Washington, D.C., Island Press. 

Boyle, S. A. and F. B. Samson. 1985. Effects of non-consumptive recreation on wildlife: a 

review. Wildl. Soc. Bull. 13:110-116. 

Buckley, P. A. and F. G. Buckley. 1976. Guidelines for protection and management of 

colonially nesting waterbirds. North Atlantic Regional Office, National Park 

Service, Boston, MA. 52pp. 

Burger, J. 1981. The effect of human activity on birds at a coastal bay. Biol. Cons. 21:231­

241. 

Burger, J. 1986. The effect of human activity on shorebirds in two coastal bays in 

northeastern United States. Biological Conservation 13:123-130. 

Burger, J. and M. Gochfeld. 1991. Human distance and birds: tolerance and response 

distances of resident and migrant species in India. Environ. Conserv. 18:158-165. 

Burger, J., and M. Gochfeld. 1998. Effects of ecotourists on bird behavior at Loxahatchee 

National Wildlife Refuge, Florida. Environmental Conservation 25:13-21. 

Burger, J., M. Gochfeld, and L. J. Niles. 1995. Ecotourism and birds in coastal New 

Jersey: Contrasting responses of birds, tourists, and managers. Environmental 

Conservation 22:56-65. 

Cole, D. N. and P. B. Landres. 1995. Indirect effects of recreation on wildlife. Pages 183­

201 in R. L. Knight and K. J. Gutzwiller, ed. Wildlife and Recreationists: 

coexistence through management and research, Island Press, Washington, D. C. 

372pp. 

Cole, D. N. and J. L. Marion. 1988. Recreation impacts in some riparian forests of the 

eastern United States. Env. Manage. 12:99-107. 

Dobb, E. 1998. Reality check: the debate behind the lens. Audubon: Jan.-Feb. 

Fox, A. D., and J.Madsen. 1997. Behavioural and distributional effects of hunting 

disturbance on waterbirds in Europe: implications for refuge design. The Journal 

of Applied Ecology 34:1-13. 

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Glinski, R. L. 1976. Birdwatching etiquette: the need for a developing philosophy. Am. 

Bird 30(3):655-657. 

Gutzwiller, K. J., R. T. Wiedenmann, K. L. Clements, and S. H. Anderson. 1994. Effects 

on human intrusion on song occurrence and singing consistency in subalpine birds. 

Auk 111:28-37. 

Hill, D., D. Hockin, D. Price, G. Tucker, R. Morris, and J. Treweek. 1997. Bird 

disturbance: improving the quality and utility of disturbance research. Journal of 

Applied Ecology 34:275-288. 

Hockin, D., M. Ounsted, M. Gorman, D. Hill, V. Keller, and M. A. Barker. 1992. 

Examination of the effects of disturbance on birds with reference to its importance 

in ecological assessments. Journal of Environmental Management 36:253-286. 

Klein, M. 1989. Effects of high levels of human visitation on foraging waterbirds at J. N. 

"Ding" Darling National Wildlife Refuge, Sanibel Florida. Masters thesis. 

Gainesville, Florida: University of Florida. 

Klein, M. L. 1993. Waterbird behavioral responses to human disturbances. Wildl. Soc. 

Bull. 21:31-39. 

Klein, M. L., S. R. Humphrey, and H. F. Percival. 1995. Effects of ecotourism on 

distribution of waterbirds in a wildlife refuge. Conservation Biology 9:1454-1465. 

Knight, R. L. and D. N. Cole. 1995. Wildlife responses to recreationists. Pages 71-79 in R. 

L. Knight and K. J. Gutzwiller, ed. Wildlife and Recreationists: coexistence 

through management and research. Island Press, Washington, D. C. 372pp. 

Knight, R.L., and K. J. Gutzwiller, ed. 1995. Wildlife and Recreationists: coexistence 

through management and research. Island Press, Washington, D. C. 372pp. 

Knight, R. L. and S. A. Temple. 1995. Origin of wildlife responses to recreationists. In 

Wildlife and recreation: coexistence through management and research. R. L. 

Knight and K. J. Gutzwiller, eds. Island Press, Washington, D. C., pp 81-91. 

Liddle, M. J. 1975. A selective review of the ecological effects on human trampling on 

natural ecosystems. Biol. Conserv. 7:17-36. 

Madsen, J. 1995. Impacts of disturbance on migratory waterfowl. Ibis 137 Supplemental: 

S67-S74 

Miller, S. G., R. L. Knight, and C. K. Miller. 1998. Influence of recreational trails on 

breeding bird communities. Ecol. Appl. 8:162-169. 

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Morton, J. M. 1995. Management of human disturbance and its effects on waterfowl. 

Pages F59-F86 in W. R. Whitman, T. Strange, L. Widjeskog, R. Whittemore, P. 

Kehoe, and L. Roberts (eds.). Waterfowl habitat restoration, enhancement and 

management in the Atlantic Flyway. Third Ed. Environmental Manage. Comm., 

Atlantic Flyway Council Techn. Sect., and Delaware Div. Fish and Wildl., Dover, 

DE. 1114pp. 

Pomerantz, G. A., D. J. Decker, G. R. Goff, and K. G. Purdy. 1988. Assessing impact of 

recreation on wildlife: a classification scheme. Wildl. Soc. Bull. 16:58-62. 

Purdy, K. G., G. R. Goft, D. J. Decker, G. A. Pomerantz, N. A. Connelly. 1987. A guide to 

managing human activity on National Wildlife Refuges. Office of Information 

Transfer, U.S. Fish and Wildlife Service, Ft. Collins, CO. 57pp. 

Reijnen, R. and R. Foppen. 1994. The effects of car traffic on breeding bird populations in 

woodland. I. Evidence of reduced habitat quality for willow warbler (Pylloscopus 

trochilus) breeding close to a highway. J. Appl. Ecol 31: 85-94. 

Rodgers, J. A., and H. T. Smith. 1997. Buffer zone distances to protect foraging and 

loafing waterbirds from human disturbance in Florida. Wildlife Society Bulletin 

25:139-145. 

Smith, L. and J. D. Hunt. 1995. Nature tourism: impacts and management. Pp. 203-219 in 

Knight, R. L.; Gutzwiller, K. J. (Wildlife and recreationists: coexistence through 

management and research, eds.). Island Press, Washington, D. C. 

U.S. Fish and Wildlife Service. 1992. Standardized fee schedule for special use permits. 

March 16, 1992 memo from Assistant Regional Director, Refuges and Wildlife, 

Portland, OR.5 pp. 

U.S. Fish and Wildlife Service. 2008. Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges Draft Comprehensive Conservation Plan and Environmental 

Assessment. Region 8. Sacramento, CA. 

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Refuge Determination 

Prepared by: ____________________________________ ____________

 (Signature) (Date)

Wildlife Refuge Manager/ 

Project Leader 

Approval: ____________________________________ ____________

 (Signature) (Date)

Concurrence 

Refuge Supervisor: ____________________________________ ____________

 (Signature) (Date)

Assistant Regional 

Director, Refuges: ____________________________________ ____________

 (Signature) (Date)

B-105
B-106
Appendix C. Hunt Plan 

Table of Contents 

I. Introduction .............................................................................................................................................. 1

II. Conformance with Statutory Authorities........................................................................................ 1

A. Refuge System Mission and Goals .................................................................................................... 1

B. Refuge Purposes .................................................................................................................................. 2

C. Refuge System Improvement Act ..................................................................................................... 3

D. Compatibility Determination ............................................................................................................. 4

E. Compliance with Endangered Species Act ...................................................................................... 4

F. Appropriate NEPA Documents......................................................................................................... 4

III. Statement of Objectives ...................................................................................................................... 5

IV. Assessment ............................................................................................................................................. 6

A. Are wildlife populations present in numbers sufficient to sustain optimum population levels 

for priority refuge objectives other than hunting?............................................................................... 6

B. Is there competition for habitat between target species and other wildlife? .............................. 6

C. Are there unacceptable levels of predation by target species on other wildlife forms? ............ 6

V. Description of Hunting Program ....................................................................................................... 6

A. Areas of the refuge that support populations of the target species.............................................. 6

1. Habitats.............................................................................................................................................. 7

2. Target Species .................................................................................................................................. 9

B. Areas to be opened to the public...................................................................................................... 10

1. Hunt Program Background Information.................................................................................... 10

2. Harvest Information ...................................................................................................................... 12

3. Refuge Hunting Area Descriptions ............................................................................................. 14

C. Species to be taken, hunting periods............................................................................................... 30

1. Hunting Season and Bag Limits Overview................................................................................. 30

2. Refuge Hunt Seasons and Bag Limits ........................................................................................ 31

D. Justification for a permit if one is required.................................................................................... 32

E. Procedures for consultation and coordination with State............................................................ 32

1. Check Station Operation ............................................................................................................... 32

F. Methods of control and enforcement (identify check stations) ................................................... 33

G. Funding and staffing requirements for the hunt. ......................................................................... 33

H. Consideration of providing opportunities for hunters with disabilities..................................... 34

VI. Measures Taken to Avoid Conflicts With Other Management Objectives ........................... 35

A. Biological Conflicts ............................................................................................................................ 35

B. Public Use Conflicts........................................................................................................................... 36

C. Administrative Conflicts ................................................................................................................... 36

VII. Conduct of the Hunt......................................................................................................................... 36

A. Refuge Specific Regulations............................................................................................................. 36

1. Hunting of Migratory Game Birds .............................................................................................. 36

2. Upland Game Hunting................................................................................................................... 37

B. Anticipated public reaction to the hunt........................................................................................... 38

C. Hunter application and registration procedures ........................................................................... 38

1. Reservation Application Procedures: .......................................................................................... 38

2. Lottery Draw Procedures: ............................................................................................................ 38

3. First-come, first-served Procedure: ............................................................................................ 39

D. Description of hunter selection process.......................................................................................... 39

1. Reservation Process....................................................................................................................... 39

2. Lottery Draw Process.................................................................................................................... 40

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3. First-come, first-served Process .................................................................................................. 41

4. Mobility Impaired Waiting............................................................................................................ 41

5. Hunt Site Waiting........................................................................................................................... 41

6. Free Roam Waiting........................................................................................................................ 42

7. MI Blind and Assigned Pond Refill ............................................................................................. 42

E. Media selection for announcing and publicizing the hunt............................................................ 42

1. Outreach Plan.................................................................................................................................. 43

F. Description of hunter orientation, including pre hunt scouting opportunities ......................... 44

G. Hunter requirements......................................................................................................................... 44

1. State determined age requirement.............................................................................................. 44

2. Allowable equipment...................................................................................................................... 44

3. Licensing and permits ................................................................................................................... 44

4. Reporting harvest........................................................................................................................... 45

5. Hunter training and safety............................................................................................................ 45

6. Other information........................................................................................................................... 45

VIII. Evaluation......................................................................................................................................... 45

A. Monitoring and reporting use levels and trends ........................................................................... 45

B. Surveying needs of the hunting visitor ........................................................................................... 46

C. Are we meeting program objectives?.............................................................................................. 46

D. Do we need to resolve any conflicts?............................................................................................... 46

References Cited ........................................................................................................................................ 48

Figures 

Figure 1. Sacramento Refuge Hunting Area Map ................................................................................. 18

Figure 2. Delevan Refuge Hunting Area Map........................................................................................ 22

Figure 3. Colusa Refuge Hunting Area Map .......................................................................................... 25

Figure 4. Sutter Refuge Hunting Area Map ........................................................................................... 28

Tables 

Table 1. Acreage and habitats of Refuges within the Sacramento, Delevan, Colusa, and Sutter 

National Wildlife Refuges. ........................................................................................................................... 7

Table 2. Primary Duck Species Harvested on the Sacramento Complex (2004-06 Season). ........... 13

Table 3. Primary Goose Species Harvested on the Sacramento Complex (2004-06 Season). .......... 14

Table 4. Hunt area acreage and hunter quotas for Sacramento Refuge............................................. 16

Table 5. Hunt area acreage and hunter quotas for Delevan Refuge. .................................................. 20

Table 6. Hunt area acreage and hunter quotas for Colusa Refuge...................................................... 24

Table 7. Hunt area acreage and hunter quotas for Sutter Refuge. ..................................................... 27

Table 8. Maximum Adult Hunter Quota in 2006-2007 Compared With Proposed Hunt Plan 

Changes. ....................................................................................................................................................... 29

Table 9. Sacramento, Delevan, Colusa, and Sutter Refuges, Hunting Season Bag Limit Summary

for 2006-2007. ............................................................................................................................................... 31

C-ii 
I. Introduction 

Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges (Refuges) are part of the 

Sacramento National Wildlife Refuge Complex (Complex) located approximately ninety miles 

north of the city of Sacramento, California. The Complex contains critically important habitats for 

a great diversity of wildlife, particularly migratory birds of the Pacific Flyway. Forty-four percent 

of the Pacific Flyway waterfowl population winters in the Sacramento Valley. An abundance and 

diversity of other migratory birds also winter or migrate through the area. A total of sixteen 

Federal and/or State listed threatened or endangered species occur on the Refuges. A variety of 

wetland and upland habitats on the Refuges supports these and many other species. 

The purpose of this Hunt Plan is to outline how the hunting program will be managed on the 

Refuges. The Hunt Plan documents how the Refuges will provide safe, quality hunting 

opportunities, while minimizing conflicts with other priority wildlife-dependent recreational uses 

(Service Manual, 605 FW 2). The Hunt Plan will discuss the following topics: compatibility, the 

effect of hunting on Refuge objectives, assessment of target species, description of the hunting 

areas, avoiding biological and public conflicts, and the procedures to conduct the daily hunt. 

II. Conformance with Statutory Authorities 

National Wildlife Refuges are guided by the mission and goals of the National Wildlife Refuge 

System and the purposes for which individual Refuges were established, as well as other policies, 

laws and international treaties. Relevant guidance includes the National Wildlife Refuge System 

Administration Act of 1966 (Administration Act), as amended by the National Wildlife Refuge 

System Improvement Act of 1997 (Improvement Act), the Refuge Recreation Act of 1962, and 

selected portions of the Code of Federal Regulations and Service Manual. The Refuge Recreation 

Act of 1962, as amended, authorized the Secretary of the Interior to administer refuges, 

hatcheries, and other conservation areas for recreational use when such uses did not interfere 

with the area’s primary purpose. 

A. Refuge System Mission and Goals 

The Administration Act, as amended by the Improvement Act, states: “The mission of the System 

is to administer a national network of lands and waters for the conservation, management, and 

where appropriate, restoration of the fish, wildlife, and plant resources and their habitats within 

the United States for the benefit of present and future generations of Americans.” 

The following Refuge System goals guide the development of comprehensive conservation plans 

(CCPs) and the administration, management, and growth of the Refuge System: 

• Conserve a diversity of fish, wildlife, and plants and their habitats, including species that 

are endangered or threatened with becoming endangered. 

• Develop and maintain a network of habitats for migratory birds, anadromous and 

interjurisdictional fish, and marine mammal populations that is strategically distributed 

and carefully managed to meet important life history needs of these species across their 

ranges. 

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• Conserve those ecosystems, plant communities, wetlands of national or international 

significance, and landscapes and seascapes that are unique, rare, declining, or 

underrepresented in existing protection efforts. 

• Provide and enhance opportunities to participate in compatible wildlife-dependent 

recreation (hunting, fishing, wildlife observation and photography, and environmental 

education and interpretation). 

• Foster understanding and instill appreciation of the diversity and interconnectedness of 

fish, wildlife, and plants and their habitats. 

B. Refuge Purposes 

The official purpose or purposes for a refuge are specified in or derived from the law, 

proclamation, executive order, agreement, public land order, donation document, or 

administrative memorandum establishing, authorizing, or expanding a refuge, refuge unit, or 

refuge subunit. The Service defines the purpose of a refuge when it is established or when new 

land is added to an existing refuge. 

The Refuge purposes are: 

Sacramento Refuge Purposes 

“... as a refuge and breeding ground for migratory birds and other wildlife...” Executive 

Order 7562, February. 27,1937. 

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory 

birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... to conserve (A) fish or wildlife which are listed as endangered species or threatened 

species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 1973). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, (2) the 

protection of natural resources, (3) the conservation of endangered species or threatened 

species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use ... real ... property. 

Such acceptance may be accomplished under the terms and conditions of restrictive 

covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge Recreation Act of 1962 (16 

U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection of fish 

and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the United States Fish 

and Wildlife Service, in performing its activities and services. Such acceptance may be 

subject to the terms of any restrictive or affirmative covenant, or condition of servitude ...” 

16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 1956). 

Delevan Refuge Purpose 

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory 

birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

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Colusa Refuge Purposes 

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory 

birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 16 U.S.C. 

695 (Lea Act of 1948). 

“... to conserve (A) fish or wildlife which are listed as endangered species or threatened 

species .... or (B) plants ...” 16 U.S.C. 1534 (Endangered Species Act of 1973). 

Sutter Refuge Purposes 

“... for use as an inviolate sanctuary, or for any other management purpose, for migratory 

birds.” 16 U.S.C. 715d (Migratory Bird Conservation Act of 1929). 

“... for the management and control of migratory waterfowl and other wildlife ...” 16 U.S.C. 

695 (Lea Act of 1948). 

“... suitable for (1) incidental fish and wildlife-oriented recreational development, (2) the 

protection of natural resources, (3) the conservation of endangered species or threatened 

species ...” 16 U.S.C. 460k-1 “... the Secretary ... may accept and use ... real ... property. 

Such acceptance may be accomplished under the terms and conditions of restrictive 

covenants imposed by donors ...” 16 U.S.C. 460k-2 (Refuge Recreation Act of 1962 (16 

U.S.C. 460k-460k-4), as amended). 

“... for the development, advancement, management, conservation, and protection of fish 

and wildlife resources ...” 16 U.S.C. 742f(a)(4) “... for the benefit of the United States Fish 

and Wildlife Service, in performing its activities and services. Such acceptance may be 

subject to the terms of any restrictive or affirmative covenant, or condition of servitude ...” 

16 U.S.C. 742f(b)(1) (Fish and Wildlife Act of 1956). 

In general, the Refuges’ purposes are to provide: 

• wetland habitat management for migratory birds; 

• habitat protection for endangered, threatened, or sensitive species; 

• priority wildlife-dependent recreation opportunities; 

• compatible, management-oriented research; and 

• crop depredation prevention. 

C. Refuge System Improvement Act 

The Improvement Act identified a new mission statement for the Refuge System; established six 

priority wildlife-dependent recreational uses (hunting, fishing, wildlife observation and 

photography, environmental education, and interpretation); emphasized conservation and 

enhancement of the quality and diversity of fish and wildlife habitat; stressed the importance of 

partnerships with Federal and State agencies, Tribes, organizations, industry, and the general 

public; mandated public involvement in decisions on the acquisition and management of refuges; 

and required, prior to acquisition of new refuge lands, identification of existing compatible 

wildlife-dependent uses that would be permitted to continue on an interim basis pending 

completion of comprehensive conservation planning. 

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The Improvement Act establishes the responsibilities of the Secretary of the Interior for 

managing and protecting the Refuge System; requires a CCP for each refuge by the year 2012; 

provides guidelines and directives for the administration and management of all areas in the 

Refuge System, including wildlife refuges, areas for the protection and conservation of fish and 

wildlife threatened with extinction, wildlife ranges, game ranges, wildlife management areas, and 

waterfowl production areas. 

D. Compatibility Determination 

The Improvement Act also establishes a formal process for determining compatibility of uses. 

Before any uses, including wildlife-dependent recreational uses, are allowed on refuges, Federal 

law requires that they be formally determined compatible. A compatible use is defined as a use 

that, in the sound professional judgment of the refuge manager, will not materially interfere with 

or detract from the fulfillment of the purposes of the refuge or mission of the Refuge System. 

Sound professional judgment is defined as a finding, determination, or decision that is consistent 

with the principles of sound fish and wildlife management and administration, available science 

and resources (funding, personnel, facilities, and other infrastructure), and applicable laws. The 

Service strives to provide wildlife-dependent recreational uses when compatible. If financial 

resources are not available to design, operate, and maintain a priority use, the refuge manager will 

take reasonable steps to obtain outside assistance from the State and other conservation interests. 

The Service has determined hunting of waterfowl, coot, common moorhen, snipe, and pheasant to 

be a compatible wildlife-dependent recreational use on the Complex (Hunting Compatibility 

Determination, Appendix C, Comprehensive Conservation Plan (CCP) (USFWS 2008a). Based 

upon biological impacts described in the Hunting Compatibility Determination (CD), Draft CCP 

and Environmental Assessment (USFWS 2008b), which are incorporated by reference, hunting 

within the Refuges is a compatible use and will not materially interfere with or detract from the 

purposes for which the Refuges were established. Stipulations within the Hunting CD to ensure 

compatibility include: Refuge-specific regulations; monitoring of hunting activities, habitat 

conditions, public use activities, and wildlife population levels; and routine law enforcement 

patrols. 

E. Compliance with Endangered Species Act 

The Refuges have requested Section 7 consultation with USFWS and NOAA-Fisheries on the 

Draft CCP/EA (USFWS 2008b) and its effects on any of the special status species/designated 

critical habitat occurring on the Refuges including: giant garter snake, winter-run Chinook 

salmon, spring-run Chinook salmon, Central Valley steelhead, western yellow billed cuckoo, fallrun Chinook salmon, late fall-run Chinook salmon, palmate-bracted bird’s beak, hairy Orcutt 

grass, Greene’s tuctoria, Hoover’s spurge, Conservancy fairy shrimp, vernal pool fairy shrimp, 

and vernal pool tadpole shrimp. 

F. Appropriate NEPA Documents 

See EA (Appendix A in CCP (USFWS 2008b)) 

C-4 
III. Statement of Objectives 

The Refuges’ management goals, objectives, and strategies (CCP, Chapter 4) are designed to 

achieve the Refuges purposes, which are listed previously in Section II, Conformance with 

Statutory Authorities. The Refuges’ hunting objective is to “implement a high quality hunting 

program including opportunities for approximately 22,000 annual hunting visits on 8,525 acres by 

2023” (Goal 3, Objective 3.1). 

The strategies for implementing the hunting objective (CCP, Chapter 4) and to create the Refuge 

hunting program were developed using the Refuge System’s guiding principles for hunting 

programs (Service Manual, 605, FW2): 

• Manage wildlife populations consistent with Refuge System-specific management plans 

approved after 1997 and, to the extent practicable, State fish and wildlife conservation plans; 

• Promote visitor understanding of, and increase visitor appreciation for, America’s natural 

resources; 

• Provide opportunities for quality recreational and educational experiences consistent with 

criteria describing quality found in 605 FW 1.6; 

• Encourage participation in this tradition deeply rooted in America’s natural heritage and 

conservation history; and 

• Minimize conflicts with visitors participating in other compatible wildlife-dependent 

recreational activities. 

The Refuge developed and manages the program in consultation with the California Department 

of Fish and Game (CDFG) and stakeholders input based on the following Service quality criteria 

(Service Manual, 605, FW2): 

• Promote safety of participants, other visitors, and facilities; 

• Promote compliance with applicable laws and regulations and responsible behavior; 

• Minimize or eliminate conflict with fish and wildlife population or habitat goals or objectives in 

an approved plan; 

• Minimize conflicts with other compatible wildlife-dependent recreation; 

• Minimize conflicts with neighboring landowners; 

• Promote accessibility and availability to a broad spectrum of the American people; 

• Promote resource stewardship and conservation; 

• Promote public understanding and increase public appreciation of America’s natural resources 

and our role in managing and conserving these resources; 

• Provide reliable/reasonable opportunities to experience wildlife; 

• Use facilities that are accessible to people and blend into the natural setting; and 

• Use visitor satisfaction to help define and evaluate programs. 

The hunting program will be conducted in a safe and cost-effective manner, and will be carried out 

consistent with State regulations. This Hunt Plan was developed to provide safe hunting 

opportunities, while minimizing conflicts with other priority wildlife-dependent recreational uses. 

Hunting will be permitted in accordance with State and Federal regulations and seasons to ensure 

that it will not interfere with the conservation of fish and wildlife and their habitats. Therefore, the 

sport hunting of waterfowl, coot, common moorhen, snipe, and pheasant on the Refuges is in 

compliance with State regulations and seasons, the National Wildlife Refuge System 

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Administration Act of 1966 as amended by the National Wildlife Refuge System Improvement Act 

of 1997 (16 U.S.C. 668dd-ee), and the Refuge Recreation Act of 1962 (16 U.S.C. 460k). 

IV. Assessment 

A. Are wildlife populations present in numbers sufficient to sustain optimum 

population levels for priority refuge objectives other than hunting? 

Yes, wildlife populations are present in sufficient numbers for priority Refuge objectives for 

wildlife management and for the other priority wildlife-dependent recreational uses (wildlife 

observation and photography, environmental education, and interpretation). The Refuges adopt 

harvest regulations set by the State, which uses concepts of density dependant compensatory 

mortality and adaptive harvest management to ensure sustained game species populations (See 

Section V. C. Species to be taken). 

The Refuges are evaluated to determine the best public use strategy for providing high quality 

wildlife-dependent public use opportunities. Approximately 8,525 acres on the Refuges is open to 

hunting of waterfowl, coot, common moorhen, snipe, and pheasant. Approximately 11,152 acres of 

the Refuges are closed to all public uses, including hunting. Approximately 6,571 acres provide 

opportunities for other wildlife-dependent opportunities (wildlife observation, photography, 

environmental education, and interpretation). In addition, approximately 2,275 acres in the 

hunting area will be open February-June for wildlife observation and photography. 

B. Is there competition for habitat between target species and other wildlife? 

Possibly; while each species occupies a unique niche, there is only a finite amount of space 

available to satisfy various habitat requirements of water, food, cover, breeding, and roosting 

areas. 

C. Are there unacceptable levels of predation by target species on other wildlife 

forms? 

No, target species (waterfowl, coot, common moorhen, snipe, and pheasant) generally do not prey 

on other species at unacceptable levels. 

V. Description of Hunting Program 

A. Areas of the refuge that support populations of the target species 

Target game species commonly occurring on the Refuges include waterfowl, coot, common 

moorhen, snipe, and pheasant. Descriptions of wetland, upland, vernal pool, and riparian habitats 

and their associated plant and wildlife species are described below, and in further detail in 

Chapter 3 of the CCP (USFWS 2008b). A list of animal and plant species occurring on the Refuges 

can be found in Appendix K of the CCP (USFWS 2008b). An overview of hunted target wildlife 

species is also described in Section 2. 

C-6 
1. Habitats 

The Refuges consist mostly of managed wetlands and uplands, with much smaller amounts of 

unmanaged wetlands (mostly vernal pools) and riparian forest (Table 1). The majority of the 

managed wetlands are seasonally flooded with 10-20 percent managed as summer wetlands 

(Figures 6-9 in the CCP). 

Table 1. Acreage and habitats of Refuges within the Sacramento, Delevan, Colusa, 

and Sutter National Wildlife Refuges. 

Acreage 

Refuge Total1 

Managed Wetlands2 Unmanaged 

Wetlands2 

Vernal 

Pool/Alkali 

Meadow2 Grasslands2, 5 

Riparian 

Forest2,6 

Other2,7 

SFW3 Summer 

Wetlands4 

Sacramento 10,819 6,305 781 163 2,941 139 117 373 

Delevan 5,877 3,939 661 13 461 464 46 290 

Colusa 4,686 2,957 390 119 619 438 15 148 

Sutter 2,591 1,708 173 45 0 226 403 36 

TOTAL 23,973 14,909 2,005 340 4,021 1,267 581 847 

1

 Official refuge acres. 

2

 Acres calculated with GIS from 2006-07 annual habitat management plans. 

3

 Includes irrigated and non-irrigated. 4 Includes semi-permanent and permanent wetlands. 

5 Includes annual and perennial grasslands 6

 Includes willow scrub, valley oak, and mixed riparian forest. 7

 Includes roads, facilities, and other miscellaneous areas. 

1.1. Wetlands 

The Central Valley has lost 90-95 percent of its original wetlands that existed in the late 1800’s, 

(Holland 1978, Gilmer et al. 1982, Frayer et al. 1989, Kempka and Kollasch 1990). Many of the 

original wetlands in the Sacramento Valley occurred along rivers and creeks, where over bank 

flooding during major rain events and runoff during the spring seasonally inundated large 

expanses of wetlands. In areas farther away, isolated vernal pools were also filled directly from 

precipitation, creating significant wetland landscapes. 

Most of the remaining wetlands in the Sacramento Valley are intensively managed, including 

those on the Sacramento Refuge Complex. Because of historic losses of wetlands, they are 

managed to maximize resources to support the annual abundance of migratory birds, endangered 

and threatened species, and other wetland-dependent wildlife. This has been accomplished 

through restoration and management of wetlands with delivered water for ponding (“managed 

wetlands”), while maintaining and restoring natural wetland habitats (vernal pools, vernal 

C-7 
pool/alkali meadow complex, riparian scrub and forests) when appropriate (Mensik and Paveglio 

2004). 

1.2. Seasonal Flooded Wetlands 

Seasonally-flooded wetlands (SFW) include both irrigated and non-irrigated wetlands and 

comprise the majority of the habitat on all four of the Refuges (Table 1). These wetlands are 

intensively managed, with the timing and depths of water controlled and vegetation species 

composition and density manipulated to meet resource management objectives. In general, they 

are wet from fall through spring and dry during the summer. SFW provide the greatest density 

and diversity of food and cover for waterfowl and other migratory wetland-dependant species. 

Consequently, it supports the greatest abundance and diversity of wildlife over the course of a 

year. Characteristic plants include emergent species such as cattail and hardstem, alkali and 

tuberous bulrush. Wildlife forage species include swamp timothy, smartweeds, and watergrass. 

The ratio of open water to emergent plants often determines the species that will use a particular 

area. For example, pintail, shoveler, wigeon, most geese, and shorebirds are species attracted to 

marshes, which have more open water and less emergent cover. When SFW are dry, bulrushes 

and other vegetation function as habitat for ground-nesting birds. 

Some SFW receive an irrigation during the spring or early summer. This results in a large volume 

of seed production, which is especially sought-after by waterfowl early and late in the season. 

Among other seasonal wetlands, watergrass dominated units play a role in providing alternate 

food resources in the early fall to help prevent crop depredation on private agricultural lands. 

1.3. Summer Wetlands 

Permanent and semi-permanent wetlands (often referred to as “permanent ponds” and “summer 

water,” respectively) provide wetland habitat during all or part of the summer, as well as most of 

the rest of the year (Table 1). These units provide nesting and brood habitat for waterfowl and 

other wetland-dependent species such as egrets, bitterns, ibis, grebes, coots, rails, and tricolored 

blackbirds. They are also important water sources for all wildlife when most seasonal marshes are 

dry. 

1.4. Vernal Pool/Alkali Meadow 

Vernal pools are depressions found on ancient soils with an impermeable layer (duripan) such as a 

hardpan or claypan, which perches rainwater above the water table. They are generally filled and 

maintained with rainwater in the winter and early spring, then evaporate as temperatures warm 

and north winds blow in late spring. While temporary wetlands such as vernal (spring) pools occur 

throughout the earth, those of California are unique. Thus, the flora and some of the fauna of 

vernal pools are unique to California (Holland and Jain 1988). Since vernal pools support a 

significant amount of endemic and rare flora and fauna, they add significantly to the biotic 

diversity of the Refuges (Thorp and Leong 1995; Eriksen and Belk 1999; Silveira 2000). As a 

result, vernal pools are a high conservation priority. 

These vernal pool-alkali meadow habitat complexes occur most commonly at Sacramento, 

Delevan, and Colusa Refuges (Table 1). They are a remnant of the original “Colusa Plains” 

identified by early settlers as the area west of the Sacramento River in the Colusa Basin. The 

C-8 
habitat was also referred to historically as “alkali gooseland,” as thousands of geese used to and 

continue to seek out these areas for grazing. Vernal pools and alkali meadows are technically 

wetlands, but have been historically considered part of the overall “uplands” habitat group. 

1.5. Grasslands 

True upland habitats are relatively uncommon on the Refuges (Table 1), and include annual and 

perennial grasslands. Perennial grasslands include some recently restored natives adapted to the 

less alkali soils, and introduced non-native species of tall wheatgrass and Harding grass or perlagrass. These introduced species are invasive and pose a threat to alkali meadow vegetation and 

the rare, endemic and native species that grow there. Upland cover provides nesting habitat for 

ducks, pheasants, meadowlarks, and other grassland species. During the winter and spring, short 

grass uplands provide green browse for geese, wigeon, and coots. Uplands also support significant 

populations of insects, rodents, and reptiles, which, in turn, are important forage items for raptors 

and other birds. 

1.6. Riparian Habitats 

Riparian habitats comprise a relatively small proportion of these four Refuges (Table 1). Narrow 

bands of Goodding’s black willow, and sometimes narrow-leaved willow, form willow scrub stands 

along Logan and Stone Corral Creeks, the Colusa Basin Drain, and several other water delivery 

and drainage canals of the Refuges. At Sacramento Refuge, a stand of mature cottonwoods, 

known locally as “Sherwood Forest,” forms a woodlot on the south half of the Refuge. At Colusa 

Refuge valley oak riparian forest occurs along Powell Slough, a small area along the Colusa Basin 

Drain. Mixed riparian forest occurs along the Sutter Bypass Canals at Sutter Refuge. 

Due to the dense canopy and understory, a large variety of Neotropical migrant bird species use 

this habitat, such as the yellow-billed cuckoo, yellow-rumped warbler, black-headed grosbeak, and 

spotted towhee. Because of their close proximity to water, riparian scrub and forest habitats 

attract a large array of “wetland-dependant” species such as the northwestern pond turtle, great 

blue heron, great egret, wood duck, common yellowthroat, song sparrow, beaver, and river otter. 

2. Target Species 

2.1. Migratory Game Birds 

The Central Valley of California has always been a major wintering area for Pacific Flyway 

waterfowl. Presently, peak wintering populations in the Central Valley occur during late 

November through January, when 3-4 million ducks and over a million geese have been surveyed 

in recent years (USFWS 1989-2007). For perspective, the four Refuges together have an average 

peak population of over one million ducks and 300,000 geese. In some years, populations can 

exceed 1.5 million ducks and 300,000 geese. The most common wintering duck species include 

northern pintail, mallard, American wigeon, green-winged teal, gadwall, northern shoveler, and 

ring-necked duck. The most common goose species include lesser snow, Ross’s, and Pacific and 

tule greater white-fronted geese. At certain times of the fall and winter, the majority of the 

Flyway’s population of Pacific greater white-fronted geese will be present on the four Refuges 

(USFWS, unpub. reports). In addition, the Sacramento, Delevan, and Colusa Refuges comprise 

the core wintering area for the tule greater white-fronted goose subspecies (Hobbs 1999). 

C-9 
Some waterfowl reproduction occurs on the Refuges throughout the spring and summer months. 

Species include mostly mallards, wood ducks, cinnamon teal, and gadwall, with fewer redheads, 

and ruddy ducks. A small number of Western Canada goose pairs will remain to nest as well. 

Depending on habitat conditions, an estimated 2,000-3,000 ducks are produced on the Refuges 

annually. 

Habitat use by waterfowl, coot, common moorhen, and snipe on the Refuges varies by species and 

includes many other factors such as water depth, ratio of open water to emergent vegetation, food 

availability, access to loafing sites, level of human disturbance, and tradition. Over 95 percent of 

waterfowl that occur on the Refuges are dabbling ducks and geese, which all prefer relatively 

shallow water. Species including pintail, wigeon, green-winged teal, and shoveler prefer more 

open water, whereas mallards and gadwall, will use wetlands with denser cover (Heitmeyer and 

Raveling 1988). Seasonal wetlands (including watergrass units) contain abundant seeds and other 

vegetative food items (leaves, stems, tubers, etc.) and invertebrates (insects, spiders, crustaceans, 

etc.). They are diverse in the amount and distribution of emergent vegetation (bulrushes, cattails) 

they provide, and also contain bare islands, levees, and open shorelines that provide excellent 

waterfowl loafing sites. Not surprisingly, the majority of wintering waterfowl select this habitat 

type above all other managed wetlands. Vernal pools are also heavily used, especially by mallard, 

wigeon, green-winged teal and shoveler, once they fill during the winter and spring (Bogiatto and 

Karnegis 2006; Silveira 1998). In addition, geese and wigeon will readily forage in alkali meadows 

and short grass uplands as soon as green browse is available in the fall (Silveira 1998, USFWS 

1989-2007). 

2.2. Upland Game Birds 

Upland game birds occupy various habitats on the Refuges. Ring-necked pheasant are resident 

species that use a variety of grassland, riparian, and wetland habitats throughout the year. 

Grasslands are used for nesting and foraging, and riparian forest and wetlands provide roosting 

sites and escape cover. 

B. Areas to be opened to the public 

1. Hunt Program Background Information 

The hunting program is administered by the Service in cooperation with the CDFG. The Service 

manages the Refuges’ land, habitat and facilities; and the CDFG selects and processes the Refuge 

hunters and operates the Refuge check stations. 

The hunting areas are physically separated from non-hunted lands and are opened to only 

migratory bird and upland game bird hunters. These hunting program parameters help minimize 

conflicts with visitors engaged in other priority wildlife-dependent recreational activities (i.e. 

wildlife observation, photography, environmental education, and interpretation). After the hunting 

season, designated portions of the hunt area (2,275 acres) will be open February-June for wildlife 

observation and photography (see Figures 11-14 in the CCP). 

Hunting of waterfowl, coot, common moorhen, snipe, and pheasant on Sacramento, Delevan, 

Colusa, and Sutter Refuges are highly regulated. Hunting takes place in designated areas and 

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occurs only on Wednesdays, Saturdays, and Sundays. Hunting areas are divided into free roam, 

spaced blind, spaced hunt site (island), or assigned pond (Figures 1-4). Pheasant and snipe may 

only be hunted in the free roam areas. A Special Monday Pheasant Hunt, which is held the first 

Monday after the opening day of the pheasant season on Sacramento, Delevan, and Colusa 

Refuges, opens the entire hunt areas to pheasant hunting, including the spaced blind and assigned 

pond areas. 

Initially the Refuges offered only free roam hunting opportunities. Free roam hunting allows 

unrestricted hunter movement, with variable hunting locations selected daily. Originally, a 10 acre 

per free roam hunter quota was established based on a similar existing State hunter quota. This 

hunter quota was based on a hunting area that was configured differently than the Refuges’ 

hunting areas; however, it was a starting point. Free roam was the most common type of hunting 

offered on the Refuges from the 1950s through the 1980s. 

Free roam hunting requires the hunter to have a knowledge and understanding (most often based 

on specific refuge experience) of the Refuge habitats and corresponding cover types, bird use, and 

flight patterns given certain weather conditions, in order to be successful. Often firing lines, where 

hunters lined up along a closed area boundary and pass shoot birds, would occur. Pass shooting 

birds is not encouraged, since it does not require calling or decoying skills and often leads to “sky 

busting” (shooting out of range) that often results in excessive crippling loss. In addition, the 

freedom to choose a hunting location can lead to hunter confrontations, as they try to “hold” a 

hunting spot that others may attempt to use. Refuge free roam hunters can sometimes have 

feelings of ownership, which has resulted in verbal aggression or other unethical behavior. 

It became evident that the Refuges needed to eliminate firing lines, crowding, and extreme 

competition among some hunters in order to provide a better quality hunting experience. In 

addition, due to the dynamic and ever-changing characteristics of the hunting program it was 

critical to adjust hunter quotas, procedures, and hunting area configuration to accommodate these 

changes in order to provide a quality hunting program. 

Over time, a 15 flooded acre per free roam hunter quota was adopted by the Refuges. In addition, 

in the late 1970s, the spaced blinds were established on a portion of the Sacramento Refuge hunt 

area. In the early 1990s, hunt sites (islands) were added on a portion of Delevan Refuge. The 

blinds and hunting sites were spaced 250-400 yards apart taking into account the shot distance 

and path of travel. Assigned pond areas were introduced on Colusa Refuge in 2004 and have been 

added to both Delevan and Sacramento Refuges since that time. Collectively, this “assigned 

hunting” provides an opportunity to hunt with less interference or competition from other 

hunters. It also allows for increased effectiveness of decoys and calls. 

Hunter quotas are currently based on acres of available wetland habitat and are adjusted 

depending upon water conditions. In addition to quotas, hunter distribution is influenced by 

habitat management, pond size, daily weather conditions, and waterfowl flight patterns. 

Hunters may retain their blind, hunt site or assigned pond (site) for the full day, even if they leave 

temporarily. The hunting sites also offer new, less frequent or less experienced hunters a better 

chance of having a quality hunting experience. The reserved sites, site descriptions, bird harvest 

averages and directional signs assist hunters in choosing, and then accessing their selected 

location. 

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With the number of waterfowl hunters declining in California, it is important to offer opportunities 

for new hunters to experience quality refuge hunting. In the early 1990s the Service began hosting 

a one-day, in-season junior waterfowl hunt on Sacramento and Delevan Refuges. The spaced hunt 

site areas were reserved for junior hunters (age 16 and younger). These hunts resulted in up to 

145 junior hunt visits annually. In the late 1990s, post season youth only hunts (age 15 and 

younger) began on Sacramento and Colusa Refuges and were later added to Delevan Refuge. 

These hunts have resulted in up to 372 annual youth hunter visits. Many local partners (i.e. 

California Waterfowl Association, Willows Rotary, Willows Kiwanis, and National Wild Turkey 

Federation) have also assisted by providing free morning beverages, barbecue lunches, raffles, 

and educational displays and activities. 

The Refuge Hunting Program Working Group was established in 1991 to exchange ideas and 

information regarding the Complex’s hunting program. The Disabled Access Working Group was 

established in 1999 to discuss disabled hunting access issues on the Complex. In 2006, the groups 

were combined to form the Complex Hunting Program Working Group. State game wardens and 

Federal law enforcement officers also routinely attend the annual Working Group meeting to 

provide information. 

2. Harvest Information 

The Refuges have approximately 22,000 annual hunting visits, including up to 500 annual visits by 

hunters with disabilities. The overall harvest success, as measured by the number of birds per 

hunter per day, has remained relatively constant (approximately 2.0 birds per hunter) since the 

hunting programs were established in the 1950s. This has occurred despite rather significant 

fluctuations in total birds harvested annually on the Complex, and trends on individual Refuges. 

Harvest data indicates that ducks make up 95 percent of the take. The top six species of ducks 

harvested are mallard (22.3 percent), gadwall (18.5 percent), green-winged teal (14.5 percent), 

northern shoveler (13.5 percent), American wigeon (12.6 percent), and northern pintail (7.5 

percent) (Table 2). Geese harvested include snow (53.8 percent), white-fronted (30.2 percent), and 

Ross’s (13.4 percent) (Table 3). The majority of the goose harvest occurs on Sacramento and 

Delevan Refuges. 

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Table 2. Primary Duck Species Harvested on the Sacramento Complex (2004-06 

Season). 

 Mallard Gadwall GWTeal Shoveler Wigeon Pintail 

Sacramento 

2006-07 2,992 3,324 2,029 3,294 2,015 1,688 

2005-06 3,053 2,184 2,094 2,340 1,770 1,519 

2004-05 3,392 2,237 1,995 1,794 1,373 1,112 

Average 3,146 2,582 2,039 2,476 1,719 1,440 

Delevan 

2006-07 2,991 4,332 2,518 3,959 2,304 1,553 

2005-06 4,037 3,001 2,504 2,200 2,257 1,412 

2004-05 3,319 2,854 2,117 1,776 1,808 655 

Average 3,449 3,396 2,380 2,645 2,123 1,207 

Colusa 

2006-07 1,287 2,774 1,770 1,468 868 720 

2005-06 2,912 1,736 1,538 716 814 678 

2004-05 2,625 2,067 1,639 734 1,248 381 

Average 2,275 2,192 1,649 973 977 593 

Sutter 

2006-07 2,182 564 1,138 792 1,481 665 

2005-06 1,558 227 587 176 613 263 

2004-05 1,875 1,469 1,026 299 1,469 249 

Average 1,872 753 917 422 1,188 392 

Average 

Total 10,742 8,923 6,985 6,516 6,077 3,632 

Percent of 

Grand Total1 22.3 18.5 14.5 13.5 12.6 7.5 

1

 The Grand Total includes other duck species that were harvested (48,233=Grand Total). 

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Table 3. Primary Goose Species Harvested on the Sacramento Complex (2004-06 

Season). 

Snow Ross’s White-front 

Sacramento 

2006-07 1,614 295 652 

2005-06 985 220 317 

2004-05 835 196 285 

Average 1,145 237 418 

Delevan 

2006-07 1,344 229 736 

2005-06 1,061 204 364 

2004-05 461 176 354 

Average 955 203 485 

Colusa 

2006-07 435 221 88 

2005-06 227 84 45 

2004-05 149 90 84 

Average 270 132 72 

Sutter 

2006-07 204 90 834 

2005-06 73 14 203 

2004-05 44 37 208 

Average 107 47 415 

Average Total 2,477 619 1,390 

Percent of Grand 

Total1 53.8 13.4 30.2 

1

 The Grand Total includes other goose species that were harvested (4,599=Grand Total). 

3. Refuge Hunting Area Descriptions 

The Refuges currently consist of 23,126 acres of wetland, alkali meadow/vernal pool, grassland, 

and riparian habitats (Table 1). Approximately 8,525 acres are open to hunting of waterfowl, coot, 

common moorhen, snipe, and pheasant (Figures 1-4). These acres are not open to other wildlifedependent recreational uses during the hunting season to allow for separation of the user groups 

spatially on the Refuges. 

It is important to note that the Refuges’ hunting program operations, procedures and hunting 

area designations (blind, hunt site, assigned pond and free roam) may change annually in order to 

provide a safe and quality Refuge hunting program. The Refuges’ maintain an open two-way 

communication (e.g. meetings, events, personal conversations, web site, electronic mail, postal 

mail and the telephone) with the CDFG and refuge hunters so that hunting program concerns, 

ideas, and comments can be discussed. 

3.1. Sacramento Refuge 

Sacramento Refuge is the headquarters for the Complex and is located in the northern 

Sacramento Valley of California. The Refuge is situated about 90 miles north of the metropolitan 

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area of Sacramento and six miles south of the town of Willows, population 6,000. The Refuge 

consists of 10,819 acres in Glenn and Colusa counties. 

The Refuge was established as a refuge for migratory birds and other wildlife. Major objectives 

are to: provide feeding and resting habitat for wintering waterfowl; provide habitat and manage 

for endangered, threatened, or sensitive species of concern; preserve a natural diversity and 

abundance of flora and fauna; provide an area for compatible, management-oriented research; 

alleviate crop depredation; and provide wildlife-dependent recreation such as wildlife observation, 

photography, interpretation, environmental education and hunting. 

The Refuge is divided into approximately 117 management units, and managed wetlands comprise 

about 65 percent of the total acreage (Table 1). The managed wetlands consist of summer 

wetlands (permanent and semi-permanent wetlands) and seasonally flooded wetlands (irrigated 

and non-irrigated seasonally flooded wetlands). The remaining acreage is comprised of 

unmanaged wetlands, alkali meadows, vernal pools, grasslands, riparian forests, and other 

habitats. 

The wetlands of the Central Valley are critical to waterfowl of the Pacific Flyway (USFWS et al. 

1986, 1998). Currently, about 44 percent of the Pacific Flyway waterfowl population winters in the 

Sacramento Valley. The Refuge typically supports wintering populations in excess of 680,000 

ducks and 178,000 geese. As wetlands of the Central Valley have been lost, the waterfowl resource 

has become increasingly dependent upon the refuges of the Sacramento Valley. To help support 

the abundance of waterfowl and other wetland-dependent wildlife, the Refuge Complex’s habitat 

management program is one of the most intensive in the National Wildlife Refuge System. 

In addition to wintering waterfowl and associated resident, migratory and breeding wildlife 

species, habitats of the Sacramento Refuge support eight federally-listed threatened, endangered, 

or candidate species. Sacramento Refuge is considered a priority 1 core area for recovery of 

vernal pool plants and animals (USFWS 2005). The Refuge manages the largest relatively intact 

remnant of vernal pool and vernal pool-alkali meadow complexes in the Colusa Basin. 

The visitor services program offers a six-mile auto tour route; a two-mile walking trail; 

environmental education activities, presentations, guided tours, videos/DVDs, a bookstore, and a 

wildlife exhibits at the visitor center; interpretive kiosks with brochures; two photography blinds; 

teacher assistance; a volunteer program; and waterfowl/pheasant hunting. The visitor center, auto 

tour route, and wetlands walking trail accommodate more than 86,000 annual visits. Waterfowl, 

coot, common moorhen, snipe, and pheasant hunting are permitted on Saturdays, Sundays, and 

Wednesdays and account for about 7,600 visits annually. Approximately 1,473 acres of the hunting 

area will be open February-June for wildlife observation and photography. 

Sacramento Refuge Hunting History 

In 1963, in cooperation with the CDFG, the Sacramento Refuge was opened to hunting. Slightly 

over 3,500 acres of the southern portion of the Refuge was opened to a maximum of 250 adult 

hunters. The initial fee was $2.50 per day per hunter. Hunters were largely dependent on a mail-in 

reservation system and a first come, first served system for obtaining a permit to hunt. Hunters 

leaving the area were usually quickly replaced by others waiting to hunt. As a result, the number 

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of hunters on any given day was sometimes twice the actual capacity allowed at any one time 

(quota). 

In 1978, the spaced blind program was initiated to improve the quality of the hunt and to meet 

regional and National Service policies. This involved the elimination of firing lines, crowding, and 

extreme competition among hunters. The blinds were either two in-ground, two-person, metal 

pits, or above-ground platforms that could accommodate up to four hunters. The blinds were 

spaced to improve hunter safety and to promote a hunting experience that emphasized decoys and 

calls. Hunters were only allowed to hunt waterfowl in the blind area and were required to hunt 

from within their assigned blinds until 1991. Since many of the metal blinds has become 

unavailable due to corrosion/leaking, the regulation was relaxed to allow hunting within 100 feet of 

the blind. During 1997-2003, concrete pit blinds were installed to replace all the metal pit and 

platform blinds. The first two replacement blinds, Blinds 9 and 13, were contributed by Safari 

Club International. 

In 1991, the Refuge eliminated the requirement that non-reservation hunters remain in the check 

station parking lot after receiving their sweat line number. In addition, an on-site lottery draw 

system for non-reservation numbers was implemented to reduce overnight camping and provide a 

more equitable system of hunter access. A new check station was constructed in 1999, and an 

information kiosk was installed near the check station in 2004. The first assigned pond, replacing 

Blind 55, was established in 2006. 

A Special Monday Pheasant Hunt was added to the hunt program in 1981. In addition, in 1991 an 

annual in-season, one-day Junior Waterfowl Hunt in the spaced blind area was implemented. 

Youth Hunts (either pre-season or post-season) were added beginning in 1996. 

In 1997, as the result of an accessibility evaluation, Blinds 23D and 27D were constructed for 

hunters with disabilities. 

Sacramento Current Hunting Conditions 

Hunting is allowed on 3,566 acres south of Road 68 (Table 4, Figure 1). 

Table 4. Hunt area acreage and hunter quotas for Sacramento Refuge. 

Spaced Blind 

Area 

Assigned 

Pond Area 

(# parties) 

Free Roam 

Area 

Pheasant 

Only 

Acres dry 220 48 336 127 

Acres flooded 1,233 428 1,146 

Total acres 1,453 476 1,482 127 

Number of blinds 37 

Number of assigned 

ponds 

9 

Maximum adult hunter 

quota 

148 36 (9) 75 

Wetland acre/hunter or 

hunt site 

33.3 47.5 15.3 

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Sacramento Refuge has spaced blind, assigned pond, and free roam areas (Figure 1) that consist 

of managed wetland, watergrass, permanent pond, grassland, and vernal pool/alkali meadow 

habitats. Blinds are in-ground, concrete pits spaced 250-400 yards apart. Hunters must remain 

within 100 feet of their assigned blind. Free roam and assigned pond hunters move unrestricted 

within the signed hunting area boundary. Directional signs guide hunters to their respective 

hunting areas, while additional reflective stakes direct hunters to their assigned blind. The 

hunting areas are accessible by foot only from four parking areas. 

Pheasant and snipe may be hunted on waterfowl hunt days in the free roam and pheasant only 

areas. Pheasant may also be hunted on the first Monday of the season in free roam, spaced blind, 

and assigned pond areas. Maximum quota for this day is 100 hunters. 

Hunter quotas are based on acres of available wetland habitat and are adjusted depending upon 

water conditions. Fully-flooded conditions provide up to 37 blinds (up to four people per blind), 

nine assigned ponds (up to four people per pond), and up to 75 free roam hunters (15.3 wetland 

acres/hunter) (Table 4). In addition to quotas, hunter distribution is influenced by habitat 

management, pond size, daily weather conditions, and waterfowl flight patterns. 

Sacramento Refuge has three spaced blinds (Blinds 5D, 23D, and 27D) designated for hunters 

with mobility impairments (Figure 1). These sites may be accessed by motor vehicle or an allterrain-vehicle (ATV) from the parking areas. Additionally, a parking area to access Blinds 23D 

and 27D and a designated accessible boat launch in the free roam area (Tract 38) is available 

(Figure 1). In 2006-07, there were 212 visits by 62 individual hunters with disabilities. 

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Figure 1. Sacramento Refuge Hunting Area Map 

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3.2. Delevan Refuge 

Delevan Refuge is situated about 80 miles north of the metropolitan area of Sacramento and four 

miles east of the town of Maxwell, population 1,500. The Refuge consists of 5,877 acres in Colusa 

County. 

Delevan Refuge was established in 1962 as a refuge and breeding ground for migratory birds and 

other wildlife. Major objectives are to provide feeding and resting habitat for wintering waterfowl; 

provide habitat and manage for endangered, threatened, or sensitive species of concern; preserve 

a natural diversity and abundance of flora and fauna; alleviate crop depredation; and provide 

public use activities such as hunting and wildlife observation. 

Delevan Refuge is divided into approximately 67 management units, and managed wetlands 

comprise about 78 percent of the total acreage. They consist of summer wetlands and seasonally 

flooded wetlands. The remaining acreage is comprised of unmanaged wetlands, alkali meadows, 

vernal pools, grasslands, riparian forest, and other habitats. The Refuge typically supports 

wintering populations in excess of 415,000 ducks and 150,000 geese. 

The Refuge supports one of the largest known populations of palmate-bracted birds-beak 

(Federal-listed endangered species) and significant breeding colonies of tricolored blackbirds. 

Some of the units on the Refuge form one of the largest relatively intact remnants of the vernal 

pool and vernal pool-alkali meadow habitats that remain in the Colusa Basin. 

A limited visitor services program on Delevan Refuge, offers wildlife observation and photography 

from adjacent county roads, including a primitive Watchable Wildlife site on Maxwell Road 

adjacent to the Refuge’s south boundary. Waterfowl, coot, common moorhen, snipe, and pheasant 

hunting are permitted on Saturdays, Sundays, and Wednesdays and account for about 6,900 visits 

annually. 

Delevan Refuge Hunting History 

In cooperation with the CDFG, the hunt program began in 1963 with the opening of 2,000 acres to 

free roam hunting. In 1989, a portion of the free roam area was converted to accommodate 26 

spaced hunting sites or islands. These sites could accommodate up to four hunters and were 

spaced to improve hunter safety and promote a hunting experience that emphasized decoys and 

calls. Hunters selecting such sites were required to remain within 100 feet of a marker stake 

designating the assigned hunting site, and were limited to waterfowl hunting only. A replacement 

hunter check station was completed in 1997, and a new hunter information kiosk was installed in 

2003. In 2004, assigned ponds were added, with Hunt Site 11 and 12A being the first to become 

assigned ponds, followed by Hunt Site 17 in 2005. 

The first Special Monday Pheasant Hunt was started in 1989, in conjunction with the new hunt 

sites. In 1991, the Delevan Refuge eliminated the sweat line system, and implemented an on-site 

lottery draw system for non-reservation hunters followed by a first-come first-served list. In 1992, 

an annual one-day Junior Waterfowl Hunt in the spaced hunt site area began. The first Youth 

Waterfowl Hunt was hosted “post-season” in January of 1998. 

In 1994, facilities for physically impaired hunters were provided by developing a new hunting 

blind easily accessible from the check station. After considering other areas that would not impact 

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the able-bodied hunt program and still be a quality hunting site for disabled hunters, the blind was 

constructed in Tract 27.2. The site was in a small pond close to the check station and was open to 

disabled hunters only. In 1997, as the result of an accessibility evaluation, Blind 13D was 

constructed as an additional disabled site, and the original disabled blind was renamed as Blind 

29D. Able-bodied hunters were allowed to refill both blinds after 3:00 p.m. 

In 1998, the Disabled Access Working Group (DAWG) requested that the Service construct Blind 

30D. The Service was concerned that if both Blinds 30D and 29D were filled with four hunters, a 

firing line might result. In 2001, the CDFG check station manager reported that Blind 30D was 

cutting off the natural flyway from the north closed area into the free roam area south of Blind 

30D. Since that time, the Service, Refuge Hunting Program Working Group, and DAWG have 

studied various proposals to locate an alternate site for Blind 30D. A flyer was distributed at the 

check stations, but no suggestions were received. The Service is now considering leaving Blind 

30D at the present location. Since Blinds 29D and 30D are located in small ponds, there is no refill 

by able-bodied hunters after 3:00 pm. 

In 2004, the Refuge introduced a floating pontoon blind in Tract 34.3 of the free roam area for 

mobility impaired hunters. The pontoon boat was purchased with a grant from Safari Club 

International and was modified to meet ADA standards. 

Delevan Current Hunting Conditions 

Hunting is allowed on 1,922 acres within the south half of Delevan Refuge (Table 5, Figure 2). 

Table 5. Hunt area acreage and hunter quotas for Delevan Refuge. 

Spaced Hunt 

Area 

Assigned 

Pond Area 

(# parties) 

Free Roam Area 

Acres dry 22 0 192 

Acres flooded 746 129 *833 

Total acres 768 129 1,025 

Number of blinds 26 

Number of assigned 

ponds 

3 

Maximum adult hunter 

quota 

104 12 (3) **58 

Wetland acre/hunter or 

hunt site 

28.7 43.0 14.4 

* Does not include acres for T41.2 when it gets flooded in December-January. 

**Increased to 62 during December-January when T41.2 is flooded. 

Delevan Refuge has spaced hunt sites, assigned pond, and free roam areas (Figure 2) that consist 

of managed wetland, watergrass, permanent pond, grassland, and vernal pool/alkali meadow 

habitats. Hunt sites consist of a dirt island (approximately 10’x20’) surrounded by cattail or 

bulrush. Hunters must remain within 100 feet of their assigned hunt site. Free roam and assigned 

pond hunters move unrestricted within the signed hunting area boundary. Directional signs guide 

hunters to their respective hunting areas, while additional reflective stakes direct hunters to their 

assigned hunt site. The hunting areas are accessible by foot only from three parking areas. 

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Pheasant and snipe may be hunted on waterfowl hunt days in the free roam area. Pheasant may 

also be hunted on the first Monday of the season in free roam, spaced hunt sites, and assigned 

pond areas. Maximum quota for the special Monday hunt is 50 hunters. 

Hunter quotas are based on acres of available wetland habitat and will be adjusted depending 

upon water conditions. Fully-flooded conditions provide up to 26 hunt sites (up to four people per 

hunt site), three assigned ponds (up to four people per pond) and up to 58 free roam hunters (14.4 

wetland acres/hunter) (Table 5). In addition to quotas, hunter distribution is influenced by habitat 

management, pond size, daily weather conditions, and waterfowl flight patterns. 

Delevan Refuge has three spaced blinds (Blinds 13D, 29D, and 30D) designated for disabled 

hunters (Figure 2). These blinds may be accessed by motor vehicle or ATV from the parking 

areas. A floating pontoon blind is located in Tract 34.3 as a free roam hunting opportunity. 

Additionally, there are designated accessible boat ramps in the free roam area of Tract 33 and 

Tract 34.3 (Figure 2). In 2006-07, there were 223 visits by 53 individual hunters with disabilities. 

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Figure 2. Delevan Refuge Hunting Area Map 

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3.3. Colusa Refuge 

Colusa Refuge is situated about 70 miles north of the metropolitan area of Sacramento and one 

mile southwest of the town of Colusa, population 5,500. The Refuge consists of 4,686 acres in 

Colusa County. 

Colusa Refuge was established in 1945 as a refuge and breeding ground for migratory birds and 

other wildlife and to reduce damage of agricultural crops caused by waterfowl. Major objectives 

are to provide feeding and resting habitat for wintering waterfowl; provide habitat and manage 

for endangered, threatened, or species of concern; preserve a natural diversity and abundance of 

flora and fauna; alleviate crop depredation; and provide public use activities such as hunting, 

wildlife observation, photography, environmental education, and interpretation. 

Colusa is divided into approximately 59 management units, and managed wetlands comprise about 

71 percent of the total acreage. They consist of summer wetlands and seasonally flooded wetlands. 

The remaining acreage is comprised of unmanaged wetlands, alkali meadows, vernal pools, 

grasslands, riparian, and other upland habitats. The Refuge typically supports wintering 

populations in excess of 218,000 ducks and 113,500 geese. 

The Refuge supports one of the largest known populations of giant garter snakes (Federal-listed 

threatened species), and palmate-bracted birds-beak (Federal-listed endangered species). Some of 

the units on the Refuge form one of the largest relatively intact remnants of the vernal pool and 

vernal pool-alkali meadow habitats that remain in the Colusa Basin. 

The visitor services program offers wildlife observation and photography from a three-mile auto 

tour route, one mile walking trail and one photography blind, and supports 16,300 annual visits. 

Waterfowl, coot, common moorhen, snipe, and pheasant hunting are permitted on Saturdays, 

Sundays, and Wednesdays and account for about 3,700 visits per year. Approximately 430 acres of 

the hunting area will be open February-June for wildlife observation and photography. 

Colusa Refuge Hunting History 

In cooperation with the CDFG, the Refuge was opened to free roam hunting in 1950. The hunt 

area acres have ranged from 1,100 in the 1960’s to the current 1,921 acres. The lottery draw was 

implemented in 1998. Also in 1998, a boat ramp and disabled parking area were constructed. The 

Colusa check station was relocated with the completion of a new building in 1999, and an 

information kiosk was installed in 2004. In 2004, eight assigned ponds were established on Colusa 

Refuge and in 2005; the first blind for disabled hunters was constructed in the northeast corner of 

Pool 2. The first Youth Hunt was hosted pre-season in October of 1996. Thereafter, Youth Hunts 

have been hosted during the weekend after the end of the waterfowl hunting season. 

Colusa Refuge Current Hunting Conditions 

Hunting is allowed on 1,921 acres south of Abel Road (Table 6, Figure 3). 

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Table 6. Hunt area acreage and hunter quotas for Colusa Refuge. 

Assigned 

Pond Area 

(# parties) 

Free Roam 

Area -

Westside 

Free Roam 

Area -

Eastside 

Acres dry 1 488 126 

Acres flooded 386 292 491 

Total acres 387 780 617 

Number of assigned 

ponds 

10 

Maximum adult 

hunter quota 

30 (15) 14 36 

Wetland acres/hunter 

or hunt site 

25.7 20.8 13.6 

Colusa Refuge has assigned pond and free roam areas (Figure 3) that consist of managed wetland, 

watergrass, permanent pond, grassland, and vernal pool/alkali meadow habitats. Free roam and 

assigned pond hunters move unrestricted within the signed hunting area boundary. Directional 

signs guide hunters to their respective hunting areas. The hunting areas are accessible by foot 

only from four parking areas. 

Disabled hunters may access Pool 2 from the disabled parking area via a boat ramp or access a 

blind in the northeast corner (Figure 3). In 2006-07, Pool 2 had 236 hunter visits and hunters 

reported using the accessible blind on 10 days resulting in 22 visits. 

Pheasant and snipe may be hunted on waterfowl hunt days in the free roam areas only. Pheasant 

may also be hunted on the first Monday of the season in free roam and assigned pond areas. 

Maximum quota for this day is 10 hunters on the east side and 35 hunters on the westside. 

Hunter quotas are based on acres of available wetland habitat and are adjusted depending upon 

water conditions. Fully-flooded conditions provide up to 10 assigned ponds (two adult hunters per 

party) and up to 50 free roam hunters (Table 6). Assigned ponds T24.4- 5, T24.7-10, and T19.1-2 

allow one party per pond, Pool 1 allows up to four parties per pond. Pool 2 allows up to three 

parties: two disabled and one party, which must have a junior hunter. In addition to quotas, hunter 

distribution is influenced by habitat management, pond size, daily weather conditions and 

waterfowl flight patterns. 

The eastside free roam area has one hunter per 13.6 wetland acres at its maximum quota of 36 

hunters (Table 6). The westside free roam area has one hunter per 20.8 wetland acres at its 

maximum quota of 14 (Table 6). The westside free roam area is not in as strong of a flight path and 

thus the hunter density allowed is lower. 

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Figure 3. Colusa Refuge Hunting Area Map 

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3.4. Sutter Refuge 

Sutter Refuge is situated about 50 miles north of the metropolitan area of Sacramento, 10 miles 

southwest of Yuba City, population approximately 60,000, and five miles south of Sutter, 

population approximately 2,900. The Refuge consists of 2,591 acres in Sutter County. 

The majority of the Sutter Refuge is located within the Sutter Bypass of the Sacramento River 

Flood Control Project; an area dedicated to flood water conveyance. The eastern levee of the 

Sutter Bypass is managed by the Department of Water Resources. The western levee is managed 

by Reclamation District 1660. Both levees are part of the Sutter Bypass Wildlife Area managed by 

the CDFG. The State of California Reclamation Board holds easements within the Bypass portion 

of the Refuge. The easements allow for the flowage of floodwaters over the land and for the 

removal of vegetation that may be impeding floodwaters. Copies of the specific easements are 

available for review at the Refuge Headquarters. 

Sutter Refuge was established in 1945 as a refuge and breeding ground for migratory birds and 

other wildlife, and to reduce damage of agricultural crops caused by waterfowl. Major objectives 

are to: provide feeding and resting habitat for wintering waterfowl; provide habitat and manage 

for endangered, threatened, or species of concern; preserve a natural diversity and abundance of 

flora and fauna; alleviate crop depredation; and provide public use activities such as hunting and 

wildlife observation. 

Sutter Refuge is divided into approximately 27 management units, and managed wetlands 

comprise about 73 percent of the total acreage. They consist of summer wetlands and seasonally 

flooded wetlands. The giant garter snake (Federal-listed threatened species) occurs on the Refuge 

primarily in the portion outside the Bypass. In recent years, the Refuge has supported large 

white-faced ibis nesting colonies (5,000-15,000 birds). The Refuge typically supports wintering 

populations in excess of 73,000 ducks and 100,000 geese. 

The remaining acres are in unmanaged wetlands, grasslands, riparian forest, and other habitats. 

The riparian habitat provides habitat for a variety of migratory songbirds, including the western 

yellow-billed cuckoo (Federal candidate species, State-listed threatened species), nesting 

Swainson’s hawks (State-listed species), and nesting rookeries for great blue herons and great 

egrets. 

A limited public use program offers hunting for waterfowl, coot, common moorhen, snipe, and 

pheasant on Saturdays, Sundays, and Wednesdays and accounts for approximately 2,100 visits 

annually. Approximately, 372 acres of the hunting area will be open February-June to wildlife 

observation and photography. 

Sutter Refuge Hunting History 

In cooperation with the CDFG, the hunt program began in 1953 when 1,350 acres were opened to 

free roam hunting. Since that time, the annual hunt program has varied from a complete closure in 

1978, to a maximum of 1,441 acres in 1987. The Refuge is located in the Sutter Bypass and 

consequently has suffered from flooding and resultant closures of the hunt program more 

frequently than any other Refuge on the Complex. A boat access ramp for disabled hunters was 

constructed in the southeast corner of Tract 17 in 1998. A new check station and information kiosk 

were constructed in 2006. 

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Sutter Refuge Current Hunting Conditions 

Currently hunting is allowed on 1,116 acres on the south half of Sutter Refuge (Table 7, 

Figure 4). 

Table 7. Hunt area acreage and hunter quotas for Sutter Refuge. 

Assigned 

Pond Area 

(# parties) 

Free Roam 

Area 

Pheasant 

Only Area 

Acres dry 0 0 125 

Acres flooded 540 *265 

Total acres 540 265 125 

Number of 

assigned ponds 

10 

Maximum adult 

hunter quota 

44 (22) 20 10 

Wetland 

acres/hunter or 

hunt site 

24.5 13.2 

Sutter Refuge has assigned pond and free roam areas (Figure 4) that primarily consist of 

managed wetland, watergrass, and grassland habitats. Free roam and assigned pond hunters 

move unrestricted within the signed hunting area boundary. Directional signs guide hunters to 

their respective hunting areas. The hunting areas are accessible by foot only from two parking 

areas. In addition, there is a designated boat launch with a parking area available to hunters with 

disabilities, in the southeast corner of assigned pond T17 (Figure 4). There has been minimal 

visitation by hunters with disabilities. 

Pheasant and snipe can be hunted in the free roam and pheasant only areas on the Refuge on 

waterfowl hunt days. 

Hunter quotas are based on acres of available wetland habitat and are adjusted depending upon 

water conditions. Fully-flooded conditions provide up to 10 assigned ponds and up to 20 free roam 

hunters (Table 7). Assigned ponds T10 and T12.1-.3 allow one party per pond; T12.4, T14.1 and 

T14.2 allow up to two parties each and T15-17 allow up to four parties each, including two adult 

disabled hunting parties in T17. A hunting party may include up to two adults. A disabled hunting 

party must include at least one disabled hunter. In addition to quotas, hunter distribution is 

influenced by habitat management, pond size, daily weather conditions, and waterfowl flight 

patterns. 

The free roam area has one hunter per 13.2 wetland acres at its maximum quota of 20 hunters 

(Table 7). Tract 18 will remain as a pheasant hunting only area and will have a quota up to 10 

hunters (Table 7). 

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Figure 4. Sutter Refuge Hunting Area Map 

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3.5. Summary of Hunter Quota Changes 

Below is a table that compares the 2006-07 hunting conditions with the hunting conditions 

proposed in this plan. 

Table 8. Maximum Adult Hunter Quota in 2006-2007 Compared With Proposed Hunt 

Plan Changes. 

2006-07 Proposed 2006-07 Proposed 2006-07 Proposed 2006-07 Proposed 

Spaced 

Blinds 

(# blinds) 

Spaced 

Blinds 

(# blinds) 

Assigned 

Ponds 

(# ponds) 

Assigned 

Ponds 

(# ponds) 

Free 

Roam 

Free 

Roam Total Total 

Sacramento 

Maximum 180 (45) 148 (37) 4 (1) 36 (9) 75 75 259 259 

Adult 

hunter 

quota 

Delevan 

Maximum 104 (26) 104 (26) 12 (3) 12 (3) 62 62 178 178 

Adult 

hunter 

quota 

Colusa 

Maximum 26 (8) 30 (10) 54 50 80 80 

Adult 

hunter 

quota 

Sutter 

Maximum 44 (10) 70 20 70 64 

Adult 

hunter 

quota 

Total 284 252 42 122 261 207 587 581 

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C. Species to be taken, hunting periods 

1. Hunting Season and Bag Limits Overview 

Waterfowl populations throughout the United States are managed through an administrative 

process known as flyways, of which there are four (Pacific, Central, Mississippi and Atlantic). The 

review of the policies, processes and procedures for waterfowl hunting are covered in a number of 

documents identified below. 

The National Environmental Policy Act (NEPA) considerations by the Service for hunted 

migratory game bird species are addressed by the programmatic document, ‘‘Final Supplemental 

Environmental Impact Statement: Issuance of Annual Regulations Permitting the Sport Hunting 

of Migratory Birds (FSES 88– 14),’’ filed with the Environmental Protection Agency on June 9, 

1988. The Service published a Notice of Availability in the Federal Register on June 16, 1988 (53 

FR 22582), and the Record of Decision on August 18, 1988 (53 FR 31341). Annual NEPA 

considerations for waterfowl hunting frameworks are covered under a separate Environmental 

Assessment and Finding of No Significant Impact. Further, in a notice published in the 

September 8, 2005 Federal Register (70 FR 53776), the Service announced its intent to develop a 

new Supplemental Environmental Impact Statement for the migratory bird hunting program. 

Public scoping meetings were held in the spring of 2006, as announced in a March 9, 2006 Federal 

Register notice (71 FR 12216). 

Because the Migratory Bird Treaty Act stipulates that all hunting seasons for migratory game 

birds are closed unless specifically opened by the Secretary of the Interior, the Service annually 

promulgates regulations in Title 50 of the Code of Federal Regulations (50 CFR Part 20) 

establishing the Migratory Bird Hunting Frameworks. The frameworks are essentially 

permissive in that hunting of migratory birds would not be permitted without them. Thus, in 

effect, Federal annual regulations both allow and limit the hunting of migratory birds. 

The Migratory Bird Hunting Frameworks provide season dates, bag limits, and other options for 

the States to select that should result in the level of harvest determined to be appropriate based 

upon Service-prepared annual biological assessments detailing the status of migratory game bird 

populations. In North America, the process for establishing waterfowl hunting regulations is 

conducted annually. In the United States, the process involves a number of scheduled meetings 

(Flyway Study Committees, Flyway Councils, Service Regulations Committee, etc.) in which 

information regarding the status of waterfowl populations and their habitats is presented to 

individuals within the agencies responsible for setting hunting regulations. In addition, public 

hearings are held and the proposed regulations are published in the Federal Register to allow 

public comment. 

For waterfowl, these annual assessments include the Breeding Population and Habitat Survey, 

which is conducted throughout portions of the United States and Canada, and is used to establish 

a Waterfowl Population Status Report annually. In addition, the number of waterfowl hunters and 

resulting harvest are closely monitored through both the Harvest Information Program (HIP) 

and Parts Survey (Wing Bee). Since 1995, such information has been used to support the adaptive 

harvest management (AHM) process for setting duck-hunting regulations. Under AHM, a number 

of decision-making protocols render the choice (package) of pre-determined regulations 

(appropriate levels of harvest) which comprise the framework offered to the States that year. 

California’s Fish and Game Commission then selects season dates, bag limits, shooting hours and 

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other options from the Pacific Flyway package. Their selections can be more restrictive, but can 

not be more liberal than AHM allows. Thus, the level of hunting opportunity afforded each State 

increases or decreases each year in accordance with the annual status of waterfowl populations. 

Each National Wildlife Refuge considers the cumulative impacts to hunted migratory species 

through the Migratory Bird Frameworks published annually in the Service’s regulations on 

Migratory Bird Hunting. Season dates and bag limits for National Wildlife Refuges open to 

hunting are never longer or larger than the State regulations. In fact, based upon the findings of 

an environmental assessment developed when a refuge opens a new hunting activity, season dates 

and bag limits may be more restrictive than the State allows. 

2. Refuge Hunt Seasons and Bag Limits 

Hunting will be permitted in accordance with State and Federal regulations (Table 9 gives an 

example of annual State hunt seasons for areas within the Refuges) to ensure that it will not 

interfere with the conservation of fish and wildlife and their habitats. Therefore, the sport hunting 

of migratory and upland game birds on the Refuges is in compliance with State regulations and 

seasons, the National Wildlife Refuge System Administration Act of 1966 as amended by the 

National Wildlife Refuge System Improvement Act of 1997 (16 U.S.C. 668dd-ee), and the Refuge 

Recreation Act of 1962 (16 U.S.C. 460k). 

Table 9. Sacramento, Delevan, Colusa, and Sutter Refuges, Hunting Season Bag 

Limit Summary for 2006-2007. 

Species Dates Daily Bag Limits 

Waterfowl – Ducks Third Saturday in October 

extending for 100 consecutive 

days 

Up to 7 ducks; see below; 

possession double the bag 

limit* 

Waterfowl – Geese October - concurrent with duck 

season 

Up to 4 geese any 

species; possession 

double the bag limit 

American Coot and 

Common Moorhen 

October - concurrent with duck 

season 

25/day, 25 in possession, 

either all of one species or 

a mixture of these species 

Snipe Third Saturday in October 

extending for 107 days 

8/day; possession double 

the bag limit 

Pheasants – General Second Saturday in November 

extending for 44 days 

2 – males first two days; 

3 males thereafter; 

possession double the bag 

limit 

*Duck Bag Limits: 7 ducks/ but not more than 2 hen mallards, 1 pintail, 1 canvasback, 2 redhead, 3 

scaup, throughout the season 

The Draft CCP (USFWS 2008b) identifies that limited spring turkey hunting opportunities on 

Sacramento, Delevan, and Colusa Refuges could be allowed based on sufficient wild turkey 

populations, habitat conditions, and the development of a turkey hunt management plan, as well as 

the appropriate National Environmental Policy Act compliance. 

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In order to promote interest in hunting and hunter recruitment, the Refuges will continue to 

coordinate in-season Junior Hunts and pre-season or post-season Youth Waterfowl Hunts in 

coordination with the CDFG and the California Waterfowl Association. 

D. Justification for a permit if one is required 

A valid California hunting license, including appropriate stamps, is required of all hunters. 

Permits are needed to track daily hunter quotas, hunter refill, and species harvested on the 

Refuges. To defray expenses connected with the operation and maintenance of the hunting 

program, the CDFG is authorized to charge and retain a fee from each adult hunter. Hunter fees 

are determined annually in advance of the hunting season by the California Fish and Game 

Commission. At present, the Refuge entry permit fees are: one-day $14.75, two-day $25.45, or a 

season pass with a one-time, base fee of $117.85. These fees are adjusted annually, as required 

under Fish and Game Code Section 713. Holders of valid junior hunting licenses and non-shooters 

are exempt from these fees. 

E. Procedures for consultation and coordination with State 

A Standard Agreement and a Cooperative Hunting Agreement enables the Service to administer 

the hunt program in cooperation with the CDFG. The Cooperative Agreement is renegotiated 

every 2-3 years. In general, the Service will manage the Refuges’ land, habitat and facilities; and 

the State will manage the hunter selection and processing. Both agencies participate in enforcing 

applicable Federal and State laws and Refuge regulations. Additionally, annual pre and postseason meetings are held with the CDFG to discuss and coordinate the Refuges’ hunting program 

procedures and operations. 

To assure that hunted bird populations are sustainable, the California Fish and Game 

Commission, in consultation with the CDFG, annually reviews the population censuses to establish 

season lengths and harvest levels. In addition, refuge staff conducts habitat management reviews 

of each unit on the Complex to evaluate wildlife population levels, habitat conditions and public use 

activities. This information is shared and discussed with the CDFG. 

Sometimes Delevan, Colusa, and Sutter Refuges need to be closed due to flood water events. The 

Service and the CDFG coordinate using the Procedures for Monitoring Flood Waters and Hunt 

Area Operations. The guidelines list notification contacts, timelines for decision-making, and 

suggested procedures for determining a closure. The Service also uses the Department of Water 

Resources, Division of Flood Management website to monitor flood stage forecasts in order to 

help determine a closure. 

1. Check Station Operation 

The CDFG provides annual training for check station staff that outlines check station procedures, 

operations, and changes. The Service hunting program coordinator attends this meeting. The 

CDFG, in coordination with the Service, provides and updates an in-depth Check Station 

Operations Manual for the Refuges. The Manual covers such topics as entry procedures to fill 

hunter quotas, checking lottery entries and generating a computer list, lottery and hunt day 

procedures, blind and free roam waiting, mobility impaired hunter access and blind filling, 

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morning hunter orientation, boat blind operations and checklist, procedures for monitoring flood 

waters, and hunt day closing. The kiosks and check station alcoves provide the most current 

California waterfowl and upland game hunting on State and Federal areas booklet, hunting 

related brochures, hunting area maps, Refuge hunting results, blind averages, waterfowl surveys, 

and litter bags. 

F. Methods of control and enforcement (identify check stations) 

The hunting program is managed in strict accordance with all applicable Federal laws (Code of 

Federal Regulations, Title 50 subchapter C) and to the extent practicable, consistent with 

applicable State laws. 

• Hunters are required to obtain a valid daily entry permit to access and exit the hunting area. 

The permit must be returned with the recorded bird harvest no later than within l 1⁄2 hours 

after sunset. 

• Hunters must report their harvest at the check stations located at Sacramento Refuge south 

of Road 68, at Delevan Refuge east of Four Mile Road, at Colusa Refuge north of Ware Road, 

and at Sutter Refuge south of Hughes Road. 

• Hunting visits, hunter quotas, and bird harvest will be monitored through entry permits 

issued at the check stations. 

• Boundary, spaced blind, assigned pond, hunt site and free roam area signs will be maintained. 

• Parking areas will be signed and gated to allow only pedestrian access. 

• Information in the hunting kiosks will be maintained and updated. 

• The CDFG State Area Manager is responsible for the check station operations and 

enforcement of the Operations Manual on each Refuge. 

• The CDFG State Area Manager supervises the State check station day and night shift staff. 

• The Service and State will coordinate monitoring and closing hunting areas during flood water 

events by following the Procedures for Monitoring Flood Waters and Hunt Area Operations. 

• Field checks by refuge law enforcement officers will be planned and coordinated with staff and 

other agencies to maintain compliance with regulations and assess species and number 

harvested. 

• Coordinated and frequent law enforcement patrols by refuge officers, special agents, game 

wardens, and deputy sheriffs will be conducted. 

G. Funding and staffing requirements for the hunt. 

The majority of the funding for the hunt program activities conducted by refuge personnel is 

provided from the Complex’s annual budget with a smaller portion coming from a reimbursement 

via an agreement with the CDFG. One of the purposes of the Cooperative Agreement with the 

CDFG is to reimburse the Service for some of the operation and maintenance costs directly 

attributable to the administration of the hunting programs. The CDFG enters into this 

Agreement pursuant to the authority granted to the California Fish and Game Commission by the 

California Legislature under the provisions of sections 1528, 1530, and 10680 of the California Fish 

and Game Code. The Service is required to collect these funds pursuant to an audit by the 

Department of the Interior’s Office of Inspector General. The CDFG has been conducting the 

public hunting program on these Refuges and collecting fees from hunters since the early 1950s. 

The Service is currently reimbursed with a payment that is based on the hunting season length. 

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In order to monitor and conduct the hunt program for the Complex, the estimated annual Service 

costs (printing, law enforcement, maintenance, other personnel services, etc.) are approximately 

$85,000 per year. 

The following one-time and annual costs (FY 2006) would be required: 

One-Time Costs Annual Costs 

Install electric line to hunter check 

station (Delevan) 

$172,000 

Replace hunter access bridges with 

culverts (Sacramento and Delevan) 

$20,000 

Printing (brochures, signs, posters, 

etc) 3% 

$3,000 

Law Enforcement (permit 

compliance, access control, 

protection) 26% 

$22,000 

Maintenance (check stations, blinds, 

discing, mowing, etc.) 39% 

$33,000 

Personnel Services (managerial, 

biological, clerical, etc.) 32% 

$27,000 

TOTAL $192,000 $ 85,000 

H. Consideration of providing opportunities for hunters with disabilities 

The Service, including the Office of Diversity and Civil Rights, strongly supports the Americans 

with Disabilities Act and Rehabilitation Act of 1967. Requirements that priority wildlifedependent activities are to be managed in ways that promote integrated access for persons with 

disabilities, to the maximum extent possible where feasible and safe, are priority Refuge 

objectives. The Refuges will keep integration central, avoid exclusivity and continue encouraging 

persons with disabilities to hunt wherever they are individually capable of hunting. Hunters with 

disabilities participate in the Complex Hunting Program Working Group that meets annually to 

discuss, evaluate and improve Refuge hunting facilities and procedures. 

Both the terms “disabled” which is used by the Service, and “mobility impaired” used by the 

CDFG, are used interchangeably. A mobility impaired (MI) hunter is defined by the CDFG as a 

person who has been issued a Department of Motor Vehicles (DMV) MI license plate or 

permanent parking placard identification card or a MI veteran license plate, or a valid MI persons 

motor vehicle hunting license. A blue plastic MI parking placard may not be substituted for the 

required identification card, which bears the name of the MI person. MI hunters must provide the 

registration certificate for the DMV issued MI license plates. 

The Refuges provide the following facilities for hunters with disabilities: 

• Sacramento Refuge has three spaced blind sites (Blinds 5D, 23D, and 27D) designated for 

hunters with mobility impairments. These sites may be accessed by motor vehicle or ATV. 

There is also a designated boat launch in the free roam area of Tract 38 for disabled hunter 

use. 

• Delevan Refuge has three spaced blind sites (Blinds 13D, 29D, and 30D) designated for 

hunters with mobility impairments. These sites may be accessed by motor vehicle or ATV. 

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There is also a designated boat launch in Tract 33, and a designated boat launch and pontoon 

blind in Tract 34.3 of the free roam area for disabled hunter use. 

• Colusa Refuge has a disabled access parking area that is available to disabled hunters 

assigned to Pool 2. There is a gravel boat ramp at the disabled parking area that allows for 

launching small boats and an accessible hunting blind. 

• Sutter Refuge has a designated boat launch available to disabled hunters in the southeast 

corner of Tract 17. 

• Mobility impaired hunters may use ATV's to access designated blinds and hunting sites on 

Sacramento and Delevan Refuges. A helmet must be worn while driving the ATV. A driver 

must provide proof of completion of ATV safety training. 

• MI hunters who wish to use their non-motorized boats or boats with electric motors may gain 

entry to the free roam areas (except Colusa) by using accessible boat ramps through the 

standard reservation and lottery draw systems. 

• MI hunters must abide by and sign the Safety and Operations Checklist when using the 

pontoon blind. 

• If a non-hunting MI person is a member of a hunting party and the party would like to use a 

MI hunting blind, it is up to the discretion of the area manager. 

• MI hunters desiring special accommodations should use the MI hunting application and 

processing procedures. The MI hunter who wants to hunt without any accommodations, and 

does not need assistance, may enter the hunting area under the standard procedures. 

VI. Measures Taken to Avoid Conflicts With Other Management 

Objectives 

The impacts addressed here are discussed in detail in the Environmental Assessment (Appendix 

A) for the CCP (USFWS 2008b) which is incorporated by reference. 

A. Biological Conflicts 

Biological conflicts will be minimized by the following: 

• Proper zoning and regulations will be designated to minimize negative impacts to wildlife. 

• The number of hunters will be limited by designated hunter quotas at each of the Refuges. 

• Check stations will process the hunters’ entry to and exit from the hunting areas. 

• Federally approved non-toxic shot will be used for all hunting to help minimize the possibility 

of lead poisoning. 

• No hunting will be allowed during the breeding season. Hunting will be allowed only during 

designated seasons for waterfowl and upland game birds. 

• The hunting area is flooded-up beginning approximately 21⁄2 months prior to the hunting 

season to allow bird use. 

• The areas closed to hunting activities (11,152 acres of sanctuary, 15,448 acres closed to 

hunting) will provide adequate sanctuaries for wildlife. 

• Law enforcement presence will help minimize excessive harvest and other infractions (illegal 

use of lead shot, take of non-game species, littering, etc.). 

• Firearms are permitted on the Refuges for public hunting under the provisions of 50 CFR 

Part 32. Persons may carry unloaded firearms on the Refuges that are dismantled or cased in 

vehicles (50 CFR 27.42). 

C-35 
• Section 7 consultations with USFWS and NOAA-Fisheries will be completed to determine 

effect of the CCP (USFWS 2008b) on special status species/designated critical habitat 

occurring on the Refuges. 

• The Refuges will provide information in kiosks about how to prevent the spread of invasive 

terrestrial and aquatic plant species. 

B. Public Use Conflicts 

Conflicts between hunting and other public uses will be minimized by the following: 

• Physically separate non-hunting and hunting acres will be provided to spatially divide the 

activities. 

• Hunting will be limited to Wednesdays, Saturdays, and Sundays during the established 

seasons. 

• Boundary and hunting area signs will be maintained to clearly define the designated hunting 

areas. 

• Vehicle traffic will be allowed only on designated roads and parking areas. 

• Parking areas will be signed and gated to allow only pedestrian hunter access to hunting 

areas. 

• The hunting program will be managed in strict accordance with all applicable Federal laws (50 

CFR Subchapter C) and to the extent practicable, consistent with applicable State laws. 

• Field checks by refuge law enforcement officers will be planned and coordinated with staff and 

other agencies to maintain compliance with regulations and assess species and number 

harvested. 

• Information about the Refuge hunting program will be provided through signs, kiosks, 

brochures, and the Complex’s website (http://sacramentovalleyrefuges.fws.gov) 

• No camping or tents will be allowed on the Refuges. 

C. Administrative Conflicts 

There are no administrative conflicts with this proposal at this time. As the program expands (i.e. 

permit system), there may be conflicts associated with the cost of the program. 

VII. Conduct of the Hunt 

A. Refuge Specific Regulations 

The following are the special regulations for Migratory Game Bird Hunting and Upland Game 

Hunting on the Sacramento, Delevan, Colusa, and Sutter Refuges. The regulations are noticed in 

the Federal Register and are incorporated into 50 CFR 32.24, California Refuge-specific 

regulations. 

1. Hunting of Migratory Game Birds 

We allow the hunting of geese, ducks, coots, moorhens, and snipe on designated areas of the 

refuge subject to the following conditions [for Sacramento Refuge (see regulations 1-13 below), 

Delevan Refuge (see regulations 1-13 below), Colusa Refuge (see regulations 4-13 below), and 

Sutter Refuge (see regulations 4-13 below)]: 

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1. You must unload firearms while transporting them between parking areas and spaced 

blind areas. 

2. We do not allow snipe hunting in the spaced blind area. 

3. We restrict hunters in the assigned blind unit to within 100 feet (30 m) of their assigned 

hunt site, except for retrieving downed birds, placing decoys, or traveling to and from the 

parking area. 

4. You may possess only approved non-toxic shot while in the field. 

5. You may possess no more than 25 shells while in the field. 

6. Access to the hunt area is by foot traffic only. We do not allow bicycles and other 

conveyances. Mobility-impaired hunters should consult the refuge manager for allowed 

conveyances. 

7. No person may build or maintain fires, except in portable gas stoves. 

8. You may enter or exit only at designated locations. 

9. Vehicles may stop only at designated parking areas. We prohibit the dropping off of 

passengers or equipment or stopping between designated parking areas. 

10. We require dogs to be kept on a leash, except for hunting dogs engaged in authorized 

hunting activities and under the immediate control of a licensed hunter.* 

11. We do not allow cutting or removal of vegetation for blind construction or for making 

trails.* 

12. We allow only electric motors on boats used by hunters with disabilities.* 

13. Consumption or possession of an open container of alcohol within public areas on the 

Refuges is prohibited.* 

(* Indicates a new regulation.) 

2. Upland Game Hunting 

We allow hunting of pheasant on designated areas of the Refuge subject to the following 

conditions: [for Sacramento Refuge (see regulations 1-9 below), Delevan Refuge (see regulations 

1-9 below), Colusa Refuge (see regulations 2-9 below), and Sutter Refuge (see regulations 2-9 

below)]: 

1. We do not allow pheasant hunting in the spaced blind and assigned pond areas except 

during a special 1-day pheasant-only hunt on the first Monday after the opening of the 

State pheasant hunting season. 

2. You may possess only approved nontoxic shot while in the field. 

3. Access to the hunt area is by foot traffic only. We do not allow bicycles and other 

conveyances. Mobility-impaired hunters should consult with the refuge manager for 

allowed conveyances. 

4. You may possess no more than 25 shells while in the field. 

5. No person may build or maintain fires, except in portable gas stoves. 

6. You may enter or exit only at designated locations. 

7. Vehicles may stop only at designated parking areas. We prohibit the dropping off of 

passengers or equipment or stopping between designated parking areas. 

8. We require dogs to be kept on a leash, except for hunting dogs engaged in authorized 

hunting activities and under the immediate control of a licensed hunter.* 

9. Consumption or possession of an open container of alcohol within public areas on the 

Refuges is prohibited.* 

(* Indicates a new regulation.) 

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B. Anticipated public reaction to the hunt 

Hunting is a traditional use in the Sacramento Valley. Hunting on the Refuges has been occurring 

since 1950. Most hunters would support the hunting program on Sacramento, Delevan, Colusa, 

and Sutter Refuges. During the comment periods and public scoping sessions for the CCP in 2005, 

a variety of opinions were heard. The majority of the comments received supported the hunting 

program on the Refuges (see Chapter 2 of the CCP). Anti-hunting individuals and organizations 

also voiced their objection to any hunting on the Refuges. 

The Draft CCP’s goal states that the Refuges will provide opportunities for approximately 22,000 

annual hunting visits on 8,525 acres (Chapter 4, Goal 3.1). A total of 157,000 annual visits are 

estimated for all wildlife-dependent recreational uses (includes 22,000 hunting visits (Chapter 4, 

Goal 3.1), 100,000 wildlife observation visits (Chapter 4, Goal 3.2), 10,000 photography visits 

(Chapter 4, Goal 3.3), 5,000 environmental education visits (Chapter 4, Goal 3.4), and 20,000 

interpretation visits (Chapter 4, Goal 3.5)). 

C. Hunter application and registration procedures 

Hunters may gain entry to hunt on the Refuges through the CDFG reservation system, an on-site 

lottery drawing, or sign-up on a first-come, first-served list on each Refuge. These systems 

establish the order of entry and permit sales. 

1. Reservation Application Procedures: 

• Resident, junior and non-resident licensed hunters may apply. 

• Reservation applicants may purchase a one-day ($1.25), five-day ($6.25), or season-long 

application. 

• Hunters may apply as many times per season as desired, but no more than once for each area 

for each shoot day. 

• Application forms are available through the CDFG offices and licensed agents. 

• The reservation application needs to be received 17 days prior to the requested hunt date. 

• On Sacramento and Delevan Refuges, each reservation assures entry for up to four 

individuals, whether adult hunters, junior hunters, or non-shooters. 

• On Colusa and Sutter Refuges, each reservation assures entry for up to two persons with 

adult licenses. Each adult (18 years of age or older) may be accompanied by up to two junior 

license holders, or two non-shooters, or one of each. 

2. Lottery Draw Procedures: 

The Refuges will hold an on-site, lottery drawing for non-reservation hunters. 

• Non-reservation hunters may enter a lottery drawing on only one Refuge each hunt date. This 

applies to all members of the hunting party. 

• Hunters who enter more than one lottery on a single shoot day shall not be issued a permit for 

that day, or will be ejected for that day if a permit has been issued, and may be denied entry to 

all the CDFG-operated areas for the remainder of the hunting season. 

• A maximum of three additional names may be placed on the back of the card. This includes 

C-38 
adult hunters, junior hunters (no more than two juniors per adult) and non-shooters. 

• A lottery draw fee is not required at this time. 

3. First-come, first-served Procedure: 

Hunters arriving at the Refuge check station after the lottery drawing may sign-up on a firstcome, first-served list (FC, FS). 

• A FC, FS fee is not required at this time. 

D. Description of hunter selection process 

The hunter selection process is a prioritized, three-tier system. The daily hunter quotas are filled 

through the check station in the following sequence: first the reservation card holders are 

processed, then the lottery card holders, and then first-come, first-served hunters. Refilling the 

hunting area quotas is accomplished using a waiting list. 

1. Reservation Process 

The reservations are numbered in the order in which they are randomly drawn by the computer at 

the CDFG License and Revenue Branch. Reservations will be mailed at least 7 days prior to the 

hunt day for which it is valid. Waterfowl reservations drawing results are also posted on the 

CDFG website (www.dfg.ca.gov). 

• Applicants must enter at the appropriate check station on the assigned hunt date. 

• On Sacramento Refuge, the reservation is valid from 2 1⁄2 to 1 1⁄2 hours before shoot time. On 

Delevan, Colusa, and Sutter Refuges the reservation is valid from 2 to 1 hour before shoot 

time. 

• Mobility impaired (MI) hunters will be processed before other hunters in numerical sequence. 

• If any reservation card holder is not present when a card number is called, they will be 

allowed to enter upon arrival, or until the end of the reservation period. 

• A MI reservation holder may choose any available MI blind, hunting site, assigned pond (hunt 

site), enter free roam, or elect to be placed on a "MI Waiting” list in order to remain eligible to 

hunt. 

• Reservation holders may choose any available non-MI hunt site or enter free roam. If these 

options are refused, the hunter may be placed on a waiting list in order to remain eligible to 

hunt (See Section 5 and 6, Waiting, below). 

• Guests of the reservation holder need not have a lottery number to be eligible. Once formed, 

the party cannot add or substitute other individuals. The party may not split between the blind 

and free roam areas. 

• If the reservation holder chooses a blind site or assigned pond and has a guest who has not 

arrived yet, the holder may request to have this person join him/her at his/her assigned blind 

site or assigned pond. The name must be given at the time of processing. This does not affect 

the quota. 

• If the reservation holder chooses free roam, all hunters in the party must be present at the 

time of processing. Once the free roam hunting party has been processed and the next 

reservation number is called, additional hunters cannot be added to the card, as this would 

affect the free roam quota. 

C-39 
2. Lottery Draw Process 

The CDFG will open the Refuge hunting area gates and check stations at 6:00 p.m. on Tuesdays 

and Fridays. The lottery will take place at 8:00 p.m. On Saturdays, hunters may enter the lottery 

for Sunday between 9:00 a.m. and 8:00 p.m. Lottery entry cards will be available at the check 

stations. 

• After reservations and prior to calling lottery card holders, the CDFG State Area Manager 

may issue any vacant MI hunt sites to MI hunters in the "lottery line”. 

• A MI lottery card holder may choose any available MI blind, hunt site, assigned pond, enter 

free roam or elect to be placed on a "MI waiting" in order to remain eligible to hunt. (See 

waiting list below.) 

• If a MI hunter selects a non-mobility impaired blind site, they must turn in their lottery 

number and drop down to the bottom of the first-come (sweat line) list and will then be 

processed in order of their number. 

• The remaining lottery card holders may choose any available non-MI hunt site, enter free 

roam, or elect to be placed on a waiting list in order to remain eligible to hunt. (See Section 5 

and 6, Waiting below). 

• Hunters obtain a lottery card at the check station and fill out both halves. Only one hunter’s 

name may appear on the front of a card. Hunting license number and vehicle license number 

must be written on the front. 

• MI hunters wishing to use the MI hunting areas must mark the MI box. 

• Hunter’s names and hunting license numbers (actual license is not required at this time) are 

required on the back of the card. Hunters on the back of the card do not have to be present. 

• Hunters who want to sign up other hunters but do not have their license numbers at the time 

may add license numbers any time before the draw. 

• Any names recorded without hunting license numbers at time of the draw will not be eligible 

to hunt. 

• Hunter’s name may be placed on the front or back of only one Refuge lottery card per hunt 

day. 

• A card number will be assigned to each card in the top right corner. It will take the place of 

individuals’ name for the purpose of assigning lottery numbers. 

• The right half of the lottery card will be filed at the check station. The hunter will keep the left 

half. 

• Hunters may leave the area once the lottery card is filled out and turned in. They do not have 

to be present during the draw. 

• On Tuesdays, Fridays, and Saturdays at 8:00 p.m., the total number of cards that have been 

issued are entered into the computer. The computer will randomly select the order of each 

card number. 

• The card numbers (plastic tokens) are placed on a numbered board in the check station. The 

position of each card number designates the lottery number. The spaces between each card 

number are determined by the additional number of hunters that have been entered on the 

cards. Non-shooters are not counted in the quota. 

• Lottery numbers determine the order that the hunters will be called the next morning. Only 

one lottery number will be issued per party. All names on a card must enter as a party. Once a 

party is formed, the party must hunt together. No splitting between blind and free roam 

areas. 

• It is the hunter’s responsibility to check the board to determine what their lottery number is 

before lottery numbers are called. Hunters will be called in sequence of their lottery number. 

C-40 
• If a lottery cardholder does not appear on the morning of the hunt, the other hunters on the 

back of the card are still eligible to hunt. 

• Hunters must be present when their number is called, and will be eliminated from the list if 

they are not present. 

• Waiting list numbers will become invalid at the end of refill time on Saturday, even if there 

was no opportunity to hunt. 

3. First-come, first-served Process 

Hunters arriving after the lottery drawing at 8:00 p.m. will be issued a first-come, first-served 

(FC, FS) number. This is also known as the “sweat line”. 

• FC, FS hunters will be processed after the last lottery card number. 

• Each hunter must be physically present to sign-up. 

• A FC, FS hunter may choose any available blind, hunt site, assigned pond or enter free roam. 

If these options are refused, the hunter may be placed on a waiting list in order to remain 

eligible to hunt. 

• Saturday FC, FS numbers will be invalid at the end of shoot time on Saturday, even if there 

was no opportunity to hunt. 

4. Mobility Impaired Waiting 

If there are no vacant or desirable mobility impaired blinds, pontoon boat or mobility pond 

(Colusa Pool 2), hunters may be placed on the MI “blind waiting” or “pond waiting” list. 

• The letters "MI" are placed after the name to indicate that the hunter has been placed on the 

“Mobility Impaired Waiting” list. This process begins the order of the “Mobility Impaired 

Waiting” list. 

• As spaces become available for a refill, hunters on the “Mobility Impaired Waiting” list are 

called in numerical order and offered the available hunt site. 

• The first name on the “Mobility Impaired Waiting” list will be given first option when refilling. 

• Hunters must be present when their number is called. If a hunter does not respond within a 

reasonable amount of time, their name is omitted and the next number is called. 

5. Hunt Site Waiting 

The hunter entry process utilizing the reservation, lottery draw, and FC, FS systems continues 

until all hunters have had an opportunity to obtain a permit or the daily hunter quota for the area 

is reached, whichever comes first. 

• If a hunter requests a particular hunting blind, site, pond (hunt sites) that is not available, or if 

they are filled, the hunter may request that they be placed on the waiting list. The hunter still 

retains their number and place in line. 

• The letter "W" is placed after the name to indicate that the hunter has been placed on the 

“Hunt Site Waiting” list. This process begins the order of the “Hunt Site Waiting” list. 

• As hunt sites become available for a refill, hunters on the “Hunt Site Waiting” list are called in 

numerical order and offered the available hunt site. 

C-41 
• The first name on the “Hunt Site Waiting” list will be given first option when refilling a hunt 

site each time there is a refill opportunity. Proceed through the “Hunt Site Waiting” list until 

it is filled. If not filled, continue to call hunters from remaining lottery and first-come lists. 

• Hunters must be present when their number is called. If a hunter does not respond within a 

reasonable amount of time, their name is omitted and the next number is called. 

• Hunters that have not been offered an opportunity to hunt must wait until their number is 

called before they will be added to the wait list. 

6. Free Roam Waiting 

If a hunter wishes to hunt free roam and it is at capacity when his number is called, the hunters 

name may be placed on “Free Roam Waiting” list. By doing so, the hunter gives up the option to 

take any assigned hunt site that may become available. 

• The letters "FR" are placed after the name to indicate that the hunter has been placed on the 

“Free Roam Waiting” list. This process begins the order of the “Free Roam Waiting” list. 

• As free roam spaces become available for refill, hunters on the “Free Roam Waiting” list are 

called in numerical order and offered the available space. 

• The first name on the “Free Roam Waiting” list will be given first option. 

• Hunters must be present when their number is called. If a hunter does not respond within a 

reasonable amount of time, their name is omitted and the next number is called. 

• Hunters that have not been offered an opportunity to hunt must wait until their number is 

called before they will be added to the “Free Roam Waiting” list. 

7. MI Blind and Assigned Pond Refill 

Unfilled sites that are vacant at 3:00 p.m. and if no MI hunters appear at 3:00 p.m. the following 

procedures will be in effect: 

• Sacramento Refuge – Blinds 5D, 23D and 27D may be refilled with able-bodied hunters at 

3:00p.m. 

• Delevan Refuge - Blinds 29D and 30D will not be refilled once vacated by the initial mobility 

impaired hunting party. Blind 13D may be refilled with able-bodied hunters at 3:00p.m. 

• Colusa Refuge – The blind may be filled or refilled by the mobility-impaired hunters in Pool 2 

at anytime before 3:00p.m. since it is part of the free roam area. 

E. Media selection for announcing and publicizing the hunt. 

The Complex has a standard list of local media contacts for news releases. The Service will utilize 

the Complex’s website, kiosks, brochures, and flyers to provide current and accurate information 

regarding the Refuges’ hunt program. A draft news release regarding the hunting program is 

attached. An Outreach Plan is also included below. 

C-42 
1. Outreach Plan 

1.1. Issue 

The Service intends to continue to manage designated areas for migratory bird and upland game 

bird hunting on Sacramento, Delevan, Colusa, and Sutter Refuges. 

1.2. Basic facts about the issue 

• The objective for the Refuges is to implement a high quality hunting program including 

opportunities for approximately 22,000 annual hunting visits on 8,525 acres by 2023, taking 

into account season length and climatic conditions. 

• Hunting of waterfowl, coot, common moorhen, snipe, and pheasant will be allowed in 

accordance with State and Refuge-specific hunting regulations during the legal hunting 

seasons and shooting times. 

• Hunting is allowed on limited designated areas of the Refuges, during the designated hunting 

seasons. 

• Hunting will be permitted in accordance with State and Federal regulations and seasons to 

ensure that it will not interfere with the conservation of fish and wildlife and their habitats. 

• Method of enforcement and control will take place through boundary and hunting signs, 

information kiosks, check stations, and routine patrol by the CDFG game wardens and refuge 

law enforcement officers. 

• Biological conflicts will be minimized by use of federally approved non-toxic shot and providing 

sanctuary areas that are strategically dispersed on the Refuges. 

• Measures taken to avoid Biological and Public Use conflicts are discussed under Section VI. 

• Hunters are required to enter and exit through a staffed check station where hunter quotas 

are filled and bird harvest is recorded. 

• The number of hunters using the Refuges is limited through daily hunter quotas and only 

during three days each week. 

1.3. Communication goals: 

Continue to: 

• Solicit input from partners and keep lines of communication open. 

• Participate or host the pre and post hunt meetings with the State. 

• Solicit input from the Sacramento Refuge Complex Hunting Program Working Group. 

• Host the annual Brush Up Day, including the hunter forum. 

• Participate in CWA’s annual hunter forum. 

• Ensure accurate public information and provide news releases. 

• Utilize the Complex’s website (http://sacramentovalleyrefuges.fws.gov), kiosks, brochures and 

flyers to provide current and accurate information. 

1.4. Message 

A quality and safe hunting program is managed and maintained on the Sacramento, Delevan, 

Colusa, and Sutter Refuges with input and assistance from many partners. 

C-43 
1.5. Interested parties 

State fish and wildlife agencies; tribes; nongovernmental organizations; conservation groups; 

hunting, fishing, and wildlife observation groups; educators; farmers and ranchers; other Federal 

agencies; members of Congress; State and county representatives; news media; and many 

members of the public. 

F. Description of hunter orientation, including pre hunt scouting opportunities 

Maps and hunting information will be provided on the Complex’s website, in the California State 

hunting regulations, and in the Refuges’ kiosks. The hunting areas of the Refuges are not open 

year-round, therefore pre-hunt scouting will not be allowed. 

A morning orientation announcement will be provided at the check station by the CDFG State 

Area Manager over a loud speaker system approximately 20 minutes before reservation process 

time. The following topics are included: a welcome to the Refuge, purchase of season pass and 

stamps, cash only, shooting hours, daily bag limits, species, and closures, 25 shell limit, steel or 

federally approved non-toxic shot, 100 foot of the blind or hunt site restriction (Sacramento and 

Delevan Refuges only), possession of alcohol while in the field is not allowed, bicycles are not 

allowed, pull carts are allowed, hunters must enter and exit at designated locations, stopping 

between designated parking areas to drop off passengers or equipment is not allowed and is a 

citable offense, trailers are allowed in the check station parking area only and must be removed at 

the end of the hunt day on Wednesdays and Sundays, observe all regulatory signs, MI boat access, 

parking and registration, and available harvest information in the kiosk. 

G. Hunter requirements 

1. State determined age requirement 

• Junior and youth hunters, 15 years of age or younger, must be accompanied by an adult. 

• Minor hunter, 16-17 years of age, may hunt alone but may not accompany a junior and youth 

hunter or non-shooter. 

• Adult hunter, 18 years of age or older, may accompany a junior, youth, or minor. 

2. Allowable equipment 

• Method of take: Federally approved non-toxic shot required for all species. No shot shell 

larger than 12 gauge and no shot size larger than “T” is permitted. Shotguns only are allowed. 

No rifles, pistols, or archery equipment may be used or possessed on the Refuges. 

• Dogs are required to be kept on a leash, except for hunting dogs engaged in authorized 

hunting activities and under the immediate control of a licensed hunter. 

• Hunters must remove from the field all personal property, including decoys, at the end of each 

day. 

3. Licensing and permits 

• A State hunting license is required for taking any bird. Hunters must carry licenses and be 

prepared to show them upon request. 

C-44 
• Federal Duck Stamps are required for hunters 16 and older to take migratory waterfowl. 

• State Duck Stamps are required for all hunters, except junior hunters, to take migratory 

waterfowl. 

• Upland Game Bird Stamps are required for all hunters, except junior hunters, to take 

pheasants. 

4. Reporting harvest 

• Hunters are required to obtain a valid daily entry permit at the check station to access and 

exit the hunting area. The permit must be returned before leaving the hunting area with the 

recorded bird harvest. 

• The total daily bird harvest is recorded by the check stations. 

• The daily blind harvest averages and/or Refuge bird harvest totals are posted on the Complex 

and State websites, Refuge telephone information line, and in the hunting kiosks. 

• The season totals are recorded in the States Operations Report for each Refuge. The reports 

are discussed at the post hunting season coordination meeting with the State and Service. 

5. Hunter training and safety 

The Refuge Systems’ guiding principles for hunting programs is to provide quality recreational 

experiences. The Service’s criteria for quality are to promote safety for participants, visitors, and 

facilities (see Section III). 

• Hunters are required to successfully complete a hunter education course in order to purchase 

a State hunting license. 

• The Refuge-specific regulations 1-3, 6, 8, 10, and 12 (see Section VII A) are enforced to 

address hunter safety. 

6. Other information 

• Waterfowl and upland game bird hunting: trained retrieving dogs are allowed and encouraged. 

• Falconry is not allowed. 

• Dog trials are not allowed. 

VIII. Evaluation 

A. Monitoring and reporting use levels and trends 

Each Refuge has a single entry point with a staffed check station. All hunters are required to 

enter and exit through the check station. Hunters are also required to record their birds 

harvested. Therefore, accurate, in-depth monitoring including daily hunting visits and bird 

harvest can be recorded at the Refuge check stations. 

Hunter use levels, trends, and needs will be evaluated through hunters’ harvest, contact in the 

field, comments during the annual Working Group meeting, agencies, public meetings, e-mails and 

letters. The visitor use will be recorded annually in the Refuge Annual Performance Plan. 

C-45 
B. Surveying needs of the hunting visitor 

Hunting visitor needs will be surveyed through hunter contacts in the field, discussions during the 

annual Working Group meeting, pre and post meetings with the State, public meetings, e-mails 

and letters. 

C. Are we meeting program objectives? 

The hunting program objective to “provide high quality hunting opportunities on 8,525 acres by 

2023,” taking into account season length and climatic conditions, will be met through the CCP 

strategies (Chapter 4, Goal 3). Monitoring will determine if we are meeting program objectives. 

D. Do we need to resolve any conflicts? 

Not at this time. The hunting program and outreach plans are written to minimize future conflicts. 

C-46 
 

U.S. FISH & WILDLIFE SERVICE 

Sacramento NWR Complex 

752 County Road 99 W 

Willows, CA 95988 

FOR IMMEDIATE RELEASE 

Contact: Denise Dachner 

530/934-2801 

Sacramento, Delevan, Colusa, and Sutter 

National Wildlife Refuges 

Open to Hunting

The Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges (Refuges) will 

provide opportunities for migratory and upland game bird hunting on 8,525 acres 

beginning on XXXX. Take of waterfowl, coot, common moorhen, snipe, and pheasant 

will be allowed in accordance with the State of California and Refuge-specific hunting 

regulations during the legal hunting seasons. Brochures and posted public use signs will 

assist hunters in determining the Refuges’ hunting areas. For further information and 

Refuge-specific hunting regulations see http://sacramentovalleyrefuges.fws.gov or call 

530-934-2801. 

The U.S. Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting and 

enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service 

manages the 94-million-acre National Wildlife Refuge System, which encompasses more than 545 national wildlife 

refuges, thousands of small wetlands and other special management areas. It also operates 70 national fish 

hatcheries, 64 fishery resource offices and 78 ecological services field stations. The agency enforces Federal wildlife 

laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant 

fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign governments with their 

conservation efforts. It also oversees the Federal Aid program that distributes hundreds of millions of dollars in 

excise taxes on fishing and hunting equipment to state fish and wildlife agencies. 08/08 

 - FWS - 

For more information about the U.S. Fish and Wildlife Service, 

visit our home page at http://www.fws.gov 

C-47 
 

References Cited 

Bogiatto, R. J. and J.D. Karnegis. 2006 The use of eastern Sacramento Valley vernal pools by 

ducks. California Fish and Game 92(3):125–141. 

Eriksen, C. and D. Belk 1999. Fairy Shrimps of California’s Puddles, Pools, and Playas. Mad 

River Press, Inc., Eureka, California. 

Frayer, W.E., D.D. Peters, and H.R. Pywell. 1989. Wetlands of the California Central Valley: 

Status and Trends 1939 to mid–1980’s. U. S. Fish and Wildlife Service, Region 1, Portland, 

OR. 29 pp. 

Gilmer, D. S., M. R. Miller, R. D. Bauer, and J. R. LeDonne. 1982. California’s Central Valley 

Wintering Waterfowl: Concerns and Challenges. Trans. 47th N. Am. Wildl. and Nat. Res. 

Conf. pp. 441-452. 

Heitmeyer, M. E., and D. G. Raveling. 1988. Winter resource use by three species of dabbling 

ducks in California. Final report to Delta Waterfowl and Wetlands Research Center, 

Portage La Prairie, Manitoba, Canada. 

Hobbs, J. H. 1999. Fall and winter distribution and habitat use of the tule greater white-fronted 

goose (Anser albifrons gambelli) in the Sacramento Valley, California. M. S. Thesis, Cal. 

State Univ., Sacramento. 84 pp. 

Holland, R.F. 1978. The Geographic and Edaphic Distribution of Vernal Pools in the Great 

Central Valley, California. Special Publication No. 4. California Native Plant Society, 

Sacramento, CA. 12 pp. + 2 maps. 

Holland, R.F. and S. Jain. 1988. Vernal pools. Pages 515–533 in M. Barbour and J. Major 

(Editors). Terrestrial Vegetation of California. Special Publication No. 9. California Native 

Plant Society, Sacramento, CA. 

Kempka, R.G. and R.P. Kollasch. 1990. Recommendations for using remote sensing to evaluate 

waterfowl habitat in California. Pages 188–196 in: Yosemite Centennial Symposium and 

Proceedings of the 17th Natural Areas Conference. Concord, CA. 

Mensik, J.G. and F.L. Paveglio. 2004. Biological integrity, diversity, and environmental health 

policy and the attainment of refuge purposes: a Sacramento National Wildlife Refuge case 

study. Natural Resources Journal 44(4): 1161–1183. 

Silveira, J. G. 1998. Avian uses of vernal pools and implications for conservation practice. Pages 

92-106 in: C. W. Witham, E. T. Bauder, D. Belk, W. R. Ferren Jr., and R. Ornduff (Eds.). 

Ecology, Conservation, and Management of Vernal Pool Ecosystems – Proceedings from a 

1996 conference. California Native Plant Society, Sacramento, CA. 

Silveira, J.G. 2000. Alkali vernal pools at Sacramento National Wildlife Refuge. Fremontia 27(4) 

and 28(1):10–18. 

C-48 
Thorpe, R. W. and J. M. Leong. 1995. Native bee pollinators of vernal pool plants. Fremontia 

23(2):3-7. 

U. S. Fish and Wildlife Service. 1989-2007. Regular wildlife surveys, 1989-2007. Sacramento 

National Wildlife Refuge files, Willows, CA. 

U. S. Fish and Wildlife Service and Canadian Wildlife Service. 1986. North American Waterfowl 

Management Plan. U. S. Dept. of Int. Rep., Washington, D. C. 19 pp. 

U. S. Fish and Wildlife Service, Canadian Wildlife Service, and Mexican National Institute of 

Ecology. 1998. Expanding the vision: 1998 Update -North American Waterfowl 

Management Plan. U. S. Dept. of Int. Rep., Washington, D. C. 34 pp. 

U. S. Fish and Wildlife Service. 2008a. Compatibility Determination for Hunting on Sacramento, 

Delevan, Colusa, and Sutter National Wildlife Refuges. Region 8. Sacramento, CA. 

U. S. Fish and Wildlife Service. 2008b. Sacramento, Delevan, Colusa, and Sutter National Wildlife 

Refuges Draft Comprehensive Conservation Plan and Environmental Assessment. Region 

8. Sacramento, CA. 

Wolder, M. A. 1993. Disturbance of wintering northern pintails at Sacramento National Wildlife 

Refuge. M. S. Thesis, Humboldt State Univ. 62pp. 

C-49 
C-50 
Appendix D. Visitor Services Plan 

Table of Contents 

Summary...........................................................................................................................................3

Introduction .....................................................................................................................................3

Brief History.................................................................................................................................5

Significant Features.....................................................................................................................5

Primary Refuge Resource Management Goals .......................................................................5

Local Setting....................................................................................................................................6

Community Description ..............................................................................................................6

Local Economy.........................................................................................................................6

Demographics...........................................................................................................................7

Visitor Data ...................................................................................................................................8

Travel Links................................................................................................................................10

Visitor Services Opportunities (off-refuge) ............................................................................11

Visitor Services Standards..........................................................................................................12

Welcome and Orient Visitors....................................................................................................13

Provide Quality Hunting Opportunities..................................................................................13

Hunting Objective..................................................................................................................13

Provide Quality Fishing Opportunities ...................................................................................19

Provide Quality Wildlife Observation......................................................................................19

Wildlife Observation Objective ............................................................................................19

Provide Quality Photographic Opportunities.........................................................................21

Wildlife Photography Objective...........................................................................................22

Develop and Implement Quality Environmental Education Programs.............................25

Environmental Education Objective...................................................................................25

Provide Quality Interpretations of Key Resources...............................................................27

Interpretation Objective .......................................................................................................28

Manage for Other Recreational Use Opportunities ..............................................................31

Communicate Key Issues with Off-Site Audiences...............................................................31

Build Volunteer Programs and Partnerships with Refuge Support Groups.....................31

Volunteer Objective...............................................................................................................32

Partnerships Goal ..................................................................................................................33

Partnership Objective ...........................................................................................................33

Other Applicable Visitor Services Programs: ........................................................................35

Youth Conservation Corps........................................................................................................35

YCC Objectives ......................................................................................................................35

Refuge Law Enforcement.........................................................................................................36

Law Enforcement Objective ................................................................................................36

Fee Programs .............................................................................................................................37

Cooperating Association/Friends Groups...............................................................................38

Other ............................................................................................................................................38

Implementing the Plan................................................................................................................38

Essential Staffing Needs...........................................................................................................38

Table of Projects, Costs.............................................................................................................39

Partnership Funding and Resources ......................................................................................39

Compatibility Determinations...................................................................................................39

NEPA Document/Decision Document.....................................................................................39

ESA Section 7 Consultations .....................................................................................................39

Literature Cited ............................................................................................................................39

D-i 
Figures 

Figure 1. Sacramento Refuge Complex ........................................................................................4

Figure 2. Sacramento Refuge – Visitor Services .......................................................................14

Figure 3. Delevan Refuge – Visitor Services..............................................................................15

Figure 4. Colusa Refuge – Visitor Services ................................................................................16

Figure 5. Sutter Refuge – Visitor Services.................................................................................17

Tables 

Table 1. Refuge Visitation Trends FY 2002-2006 ......................................................................10

D-ii 
Summary 

The purpose of the Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges (Refuges) 

(Figure 1) visitor services program is to foster understanding and instill appreciation of the fish, 

wildlife, and plants and their conservation by providing the public with safe, high quality, 

appropriate, and compatible wildlife-dependent recreational and educational programs and 

activities. In 1997, Congress passed the National Wildlife Refuge Improvement Act (Improvement 

Act) which clearly states, that on national wildlife refuges, wildlife comes first. The Improvement 

Act also identified six priority wildlife-dependent public use activities and programs that are 

compatible with the mission of the National Wildlife Refuge System. These uses include hunting, 

fishing, wildlife observation, wildlife photography, environmental education, and interpretation. 

This Visitor Services Plan (VSP) was prepared based upon these guidelines. With the adoption 

and implementation of the Comprehensive Conservation Plan (CCP) (USFWS 2008a) and this 

step-down plan, all visitor service activities and programs on the Refuges would be in conformance 

with national guidelines and would insure that all visitor activities are compatible with the Refuges 

overarching wildlife mission and purposes. 

The purpose of the VSP is to establish priorities and identify improvements, which will guide the 

Refuges visitor service program over the next fifteen years. A visitor services goal, objectives, and 

strategies have been identified within the Chapter 4 of the CCP for Sacramento, Delevan, Colusa, 

and Sutter Refuges (USFWS 2008a). A Hunt Plan, which is a step-down plan from this VSP, has 

also been prepared (Appendix C of the CCP). This VSP addresses compatible wildlife-dependent 

recreational uses on the Refuges including hunting, wildlife observation, photography, 

environmental education, and interpretation (Appendix B of the CCP). Bicycling, a form of nonwildlife dependant recreation, in designated areas has also been determined to be compatible 

(Appendix B of the CCP). The VSP also addresses the volunteer, Youth Conservation Corps 

(YCC) programs and the partnership and resource protection goals from Chapter 4 of the CCP 

(USFWS 2008a). 

Introduction 

The U. S. Fish and Wildlife Service (Service) manages the Sacramento National Wildlife 

Refuge Complex (Complex) located in the Sacramento Valley of California (Figure 1) 

approximately ninety miles north of the city of Sacramento. Five national wildlife refuges 

(Sacramento, Delevan, Colusa, Sutter, and Sacramento River) and three wildlife management 

areas (North Central Valley, Willow Creek – Lurline, and Butte Sink) are included in the 

Complex. The Complex contains critically important habitats for a great diversity of wildlife, 

particularly migratory birds of the Pacific Flyway. A variety of wetland and upland habitats on 

the Refuges supports these and many other species. 

D-3
Figure 1. Sacramento Refuge Complex

D-4
Brief History 

In 1937, when Sacramento National Wildlife Refuge was established, managers and biologists 

worked to transform many of the Refuge's dry, alkaline lands into productive managed marshes. 

Some of the areas were used for growing grain crops to attract waterfowl away from those on 

private lands. Three additional Refuges were created in the 1940s through the 1980s, forming the 

Sacramento National Wildlife Refuge Complex. These Refuges, including Delevan, Colusa, and 

Sutter, were established to provide wintering habitat for waterfowl and in some cases to reduce 

crop damage. They consist of approximately 23,000 acres of wetland, grassland, and riparian 

habitats. Seasonal marshes, the Refuges most common habitat type, are drained during spring 

and remain dry over the summer to encourage plant growth on the moist, exposed soil. Reflooding in the fall makes seeds and plants available for wildlife. Water management, prescribed 

burns, disking, and mowing are some of the techniques used to manage wetland habitats. 

The fifth refuge, Sacramento River Refuge, was established in 1989 to help protect and restore 

riparian habitat along the Sacramento River as it meanders through the Sacramento Valley from 

Red Bluff to Colusa. The Sacramento River Refuge Final CCP (USFWS 2005a) was completed in 

2005 and a separate VSP will be completed for this Refuge. 

The Complex’s three wildlife management areas: North Central Valley, Willow Creek – Lurline, 

and Butte Sink, except where noted in the CCP, are closed to the public and therefore are not 

included in this VSP. 

For more information, see Chapter 1 of the CCP (USFWS 2008a). 

Significant Features 

Sacramento, Delevan, Colusa, and Sutter Refuges provide a significant amount of the wintering 

habitat that supports waterfowl and many other migratory birds in the Sacramento Valley. Fortyfour percent of the Pacific Flyway waterfowl population winters in the Sacramento Valley. An 

abundance and diversity of other migratory birds also winters or migrates through the area. The 

Refuges currently support nearly 300 species of birds. A total of sixteen Federal and/or State 

listed threatened or endangered species occur on the Refuges. 

Primary Refuge Resource Management Goals 

The CCP (USFWS 2008a) contains the primary goals that will define the management direction of 

the Refuges for the next 15 years. In addition, as part of the CCP, the Refuges developed 

objectives and strategies that, together, will help achieve the goals. 

The five goals of the Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges are 

outlined below. The objectives and strategies can be found in Chapter 4 of the CCP (USFWS 

2008a). 

Goal 1: Wildlife and Habitat Goal 

Conserve, manage, restore, and enhance habitats and associated plant and wildlife species, with an 

emphasis on supporting an abundance and natural diversity of wintering and migrating waterfowl, 

shorebirds, birds of prey, and songbirds. 

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Goal 2: Threatened and Endangered Species Goal 

Conserve, manage, restore, and enhance threatened and endangered species and their habitats 

including vernal pool plants and invertebrates, and giant garter snakes. 

Goal 3: Visitor Services Goal 

Provide visitors of all ages and abilities with quality wildlife-dependent recreation (hunting, 

wildlife observation, photography, environmental education, and interpretation), and volunteer 

opportunities to enhance public appreciation, understanding, and enjoyment of fish, wildlife, 

habitats, and cultural resources. 

Goal 4: Partnership Goal 

Promote partnerships to preserve, restore, and enhance a diverse, healthy, and productive 

ecosystem in which the Refuges play a key role. 

Goal 5: Resource Protection Goal 

Adequately protect and maintain all natural and cultural resources, staff and visitors, equipment, 

facilities, and other property on the Refuges. 

Local Setting 

Community Description 

Sacramento Refuge is the headquarters of the Sacramento Refuge Complex and is located in the 

Sacramento Valley of north-central California (Figure 1). The Refuge is situated about 90 miles 

north of the metropolitan area of Sacramento and six miles south of the town of Willows, 

population 6,000. The Refuge consists of 10,819 acres in Glenn and Colusa counties. 

Delevan Refuge is located about 80 miles north of the metropolitan area of Sacramento and four 

miles east of the town of Maxwell, population 1,500 (Figure 1). The Refuge consists of 5,877 acres 

in Colusa County. 

Colusa Refuge is situated about 70 miles north of the metropolitan area of Sacramento and one 

mile southwest of the town of Colusa, population 5,500 (Figure 1). The Refuge consists of 4,686 

acres in Colusa County. 

Sutter Refuge is situated about 50 miles north of the metropolitan area of Sacramento, 10 miles 

southwest of Yuba City, population approximately 60,000, and five miles south of Sutter, 

California (Figure 1). The Refuge consists of 2,591 acres in Sutter County. 

For additional information, see Chapter 3 of the CCP (USFWS 2008a). 

Local Economy 

Agriculture is the dominant economic enterprise in the northern Sacramento Valley and provides 

nearly 20 percent of the jobs in the Central Valley. The diversity of crops grown in the 

Sacramento Valley reflects the diversity of soils, climate, cultural and economic factors. Glenn 

County’s major crops include rice, almonds, prunes, and corn; Colusa County’s include rice, 

tomatoes, and almonds; and Sutter County’s include rice, plums, peaches, walnuts, and tomatoes. 

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Countywide agricultural production values are $280.9 million for Glenn County, $346 million for 

Colusa County, and $343 million for Sutter County (California Department of Finance 2002). 

The 2005-2025 County-Level Economic Forecast (California Department of Transportation 2005) 

reported that Glenn County’s per capita income is $21,210, and the average salary per worker is 

$30,780. Colusa County’s per capita income is $27,690, and the average salary per worker is 

$31,450. Sutter County’s per capita income is $26,940, and the average salary per worker is 

$32,150. 

For additional information, see Chapter 3 of the CCP (USFWS 2008a). 

Demographics 

In the first 150 years of statehood, California grew from fewer than 100,000 citizens in 1850 to 

almost 34 million in 2000 (California Department of Finance 2002). Between 1950 and 2000 alone, 

California’s population increased by 200 percent (California Department of Finance 2002). If 

California continues to add nearly 500,000 persons each year, by 2012, the population could easily 

exceed 40 million. The 50-million mark will be passed sometime between 2030 and 2040 if current 

growth rates persist (California Department of Finance 2002). 

The Central Valley has been one of the fastest growing areas in California during the last few 

decades. As of July 1997, the Central Valley had seventeen percent of the State’s population 

(Munroe and Jackman 1999). 

In 2005, Glenn County’s population was 28,197 and is expected to increase to 32,000 residents by 

2020 (California Department of Finance 2005). The racial makeup of the county was 71.8 percent 

white, 29.6 percent Hispanic, 3.4 percent Asian, 2.1 percent Native American, 0.6 percent African 

American, with the remaining percentage from other races (percentage total can be greater than 

100 percent because Hispanics can be counted in multiple races, US Census Bureau 2000). The 

estimated median family income was $32,107. 

Colusa County is home to 20,800 residents and is projected to increase to 26,000 residents by 2020 

(California Department of Finance 2005). The racial makeup of the county was 64.3 percent white, 

46.5 percent Hispanic, 2.3 percent Native American, 1.2 percent Asian, 0.5 percent African 

American, with the remaining percentage from other races (percentage total can be greater than 

100 percent because Hispanics can be counted in multiple races, US Census Bureau 2000). The 

estimated median family income was $35,062. 

Sutter County’s population was 88,945 people and is expected to increase to 112,000 people by 

2020 (California Department of Finance 2005). The racial makeup of the county was 67.5 percent 

white, 22.2 percent Hispanic, 11.3 percent Asian, 1.9 percent African American, 1.6 percent Native 

American, with the remaining percentage from other races (percentage total can be greater than 

100 percent because Hispanics can be counted in multiple races, US Census Bureau 2000). The 

estimated median family income was $38,375. 

The Sacramento River Public Recreation Access Study (EDAW 2003) was conducted to assess 

existing and potential public recreation uses, accesses, needs, and opportunities along the 

Sacramento River between Red Bluff and Colusa. This study indicates a substantial public 

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interest in recreational activities of boating, fishing, and hunting. Additionally, other uses such as 

bird watching, wildlife viewing, and other nature observation activities are expected to increase 65 

percent over the next 40 years. EDAW (2003) depicts a profile of the potential local refuge visitor 

as predominately Caucasian, 31-50 years of age with some college education/trade school 

education. As the population in the region grows, demand for recreation activities will increase. 

Planning will need to strike a balance between recreation use and conservation goals. 

The report “Banking on Nature 2006: The Economic Benefits to Local Communities of National 

Wildlife Refuge Visitation” (USFWS 2007) detailed the findings from 80 national wildlife refuges, 

including Sacramento Refuge. The Banking on Nature 2006 study included money spent for food 

and refreshments, lodging at motels, cabins, lodges or campgrounds, and transportation when it 

calculated the total economic activity related to refuge recreational use. Sacramento Refuge had 

over 137,430 visits in 2006. Refuge visitors enjoyed a variety of activities, including wildlife 

viewing, hiking, and migratory bird hunting. Non-residents accounted for about 127,408 or 93 

percent of recreation visits and almost all of the visits were for non-consumptive recreations 

(129,257). Sacramento Refuge generated an estimated $2.4 million in total economic activity 

related to refuge recreational use with associated employment of 25 jobs, $773,500 in employment 

income and $391,100 in total tax revenue. Total expenditures were $1.8 million with non-residents 

accounting for $1.7 million or 96 percent of total expenditures. Expenditures on hunting accounted 

for 57 percent of all expenditures, and non-consumptive activities accounted for 43 percent. 

Sacramento Refuge generated $2.78 of recreation-related benefits for every $1 of budget 

expenditure during 2006. 

For additional information, see Chapter 3 of the CCP (USFWS 2008a). 

Visitor Data 

The Complex utilizes a variety of methods for estimating the number of annual wildlife-dependent 

visits. The types of estimation methods used are direct observation, traffic counters, hunter 

permits, surveys, and estimation based on professional judgment. From these estimates, the 

numbers of visitors and visits are used to manage and improve the Refuges’ visitor services 

program. 

The National Wildlife Refuge System Visitation Estimation Workbook (USFWS 2005b) provides 

basic principles and definitions that have been used to describe the Refuge visitation estimation 

program. 

Refuge recreational or educational activities that are allowed and monitored include wildlife 

observation, environmental education, interpretation, photography, and hunting. Wildlife 

observation has been more specifically reported as auto tour and hiking trail visits. 

A Refuge visitor (visitor) is a person that participates in at least one of the wildlife-dependent 

activities (e.g. wildlife viewing, hunting, environmental education, interpretation, or photography). 

Visitors do not include staff, volunteers, researchers, contractors, special use permittees, or 

people who are traveling through the refuge to reach another non-refuge location. A single visitor 

may make several visits to the refuge during the year by participating in one or more activities. 

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A visitor is not the same as a Refuge visit (visit). A single visitor can make several visits to the 

Refuge on a single day by participating in several different activities. The total amount of visits on 

a given day is a count of only individuals. The amount of time for each individual visit is not 

accounted for; whether it be minutes to hours. 

It should be noted that there is not a 100 percent accurate method of counting all visitors or visits. 

Therefore, the numbers of visitors or visits reported are only estimates. The Refuge strives for 

consistency and quality of estimation monitoring methods to improve the accuracy of the 

information collected. Unfortunately, the reporting systems Refuge Management Information 

System (RMIS) and the Refuge Annual Performance Plan (RAPP) change annually, making it 

more difficult to accurately compare annual visitation. 

Table 1 depicts the number of Refuge visitors and visits for some of the primary wildlifedependent Refuge activities over the last five years. The environmental education, interpretation 

and photography blind visits were collected from reservation forms. Hunting visit information was 

collected from hunting permits and professional estimations of hunting activities (e.g. a hunter in 

the free roam area may hunt several species during waterfowl and pheasant season). The auto 

tour and hiking trail visits are a percentage of the vehicle counts that are recorded by a traffic 

counter at the Refuge entrance. The vehicle counts are multiplied by three due to a Refuge survey 

that documented an average of three people per vehicle. It should be noted that the 2002-2004 

data is based on RMIS reports and 2005-06 is based on RAPP. The data management systems are 

not directly comparable, since they each used a different reporting methodology to determine 

activity visits. The annual visitors are comparable, since the same formula was used. On 

Sacramento and Colusa Refuges, the formula is: Annual Visitors = Vehicle Counts X 3 + 

Interpretation + EE + Hunting + Photo Blind Visitors. On Delevan and Sutter Refuges, the 

annual visitors equal the hunting visits. 

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Table 1. Refuge Visitation Trends FY 2002-2006 

2002 2003 2004 2005 2006 Five Year 

Average 

Sacramento 

Annual Visitors 67,619 75,528 71,617 89,138 86,165 78,103 

Auto Tour Visits 48,345 53,842 51,646 73,149 60,616 57,520 

Hiking Trail Visits 8,566 8,418 8,064 9,443 8,735 8,645 

Hunting Visits 8,203 7,052 6,851 7,386 7,683 7,435 

Environmental 

Education Visits 2,851 3,027 2,799 3,032 2,528 2,847 

Interpretation Visits 807 1,065 630 125 150 555 

Photo Blind Visits 20 33 39 34 33 32 

Delevan 

Annual Visitors 6,073 5,660 5,881 5,678 6,386 5,936 

Hunting Visits 6,073 5,660 5,881 5,678 6,386 5,936 

Colusa 

Annual Visitors 24,308 31,135 26,364 20,426 16,284 25,311 

Auto Tour Visits 16,246 21,847 18,084 16,547 13,027 17,150 

Hiking Trail Visits 4,185 5,610 4,496 4,127 3,256 4,335 

Hunting Visits 3,877 3,678 3,784 3,879 3,910 3,826 

Environmental 

Education Visits 168 60 65 39 24 71 

Interpretation Visits 0 0 88 0 0 18 

Photo Blind Visits NA NA NA NA 12 12 

Sutter 

Annual Visitors 3,058 1,241 2,620 2,870 2,152 2,388 

Hunting Visits 3,058 1,241 2,620 2,870 2,152 2,388 

TOTAL ANNUAL 

VISITORS 96,924 108,135 101,869 118,112 110,999 107,208 

Travel Links 

Major transportation routes in the vicinity of the Refuge include Interstate 5, State highways 99, 

45, 162 and 20, and county route 99W. Many small paved county roads provide for local 

transportation, offering service access to local agricultural activities. These, and the large 

interstate and highways, provide access to Refuge visitor contact stations and parking lots. There 

are no alternative transportation systems that provide access to the Refuges. 

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Visitor Services Opportunities (off-refuge) 

Sacramento River National Wildlife Refuge 

Established in 1989, the fifth Refuge in the Complex, Sacramento River Refuge, is composed of 27 

units along a 77-mile stretch of the Sacramento River between Red Bluff and Princeton. As of 

2006, Refuge lands comprise approximately 10,000 acres of riparian habitat, wetlands, uplands, 

and intensively managed walnut, almond, and prune orchards. 

Sacramento River Refuge has 18 units that are open to public access offering wildlife observation, 

photography, interpretation, and environmental educational opportunities. In addition, hunting 

and fishing are allowed on selected units of the Refuge. Gravel bars also continue to be open for 

hunting, fishing, and camping. 

Mendocino National Forest 

The Mendocino National Forest straddles the eastern spur of the Coastal Mountain Range in 

northwestern California, just a three-hour drive north of San Francisco and Sacramento. Some 65 

miles long and 35 miles across, the Forest's 913,306 federally owned acres of mountains and 

canyons offer a variety of recreational opportunities: camping, hiking, backpacking, boating, 

fishing, hunting, nature study, photography, and off-highway vehicle travel. The Forest’s office is 

located in Willows. 

California Department of Fish and Game 

Located approximately 60 miles north of Sacramento, the 9,100 acre Gray Lodge Wildlife Area’s 

(WA) diversity and location along the Pacific Flyway make this a heaven for wildlife. Wildlife 

viewing is available all year. In the fall and winter, a vast number of migratory waterfowl fill the 

sanctuary with lively chatter and incredible sights. For the more avid photographers and viewers, 

two viewing hides are available. Hunters enjoy many species of wildlife they may take during the 

regulated hunting seasons. Fishing is also a highlight in the spring and summer. Educational 

programs, informative exhibits, a self-guided nature trail and seasonal guided tours are used by 

thousands of visitors every year. 

Upper Butte Basin WA includes Howard Slough, Little Dry Creek, and Llano Seco units 

encompassing 9,376 acres. The WA provides local recreational opportunities including hunting, 

wildlife observation, and photography. 

Sacramento River WA consists of 3,737 acres of riparian woodland, meadows, and gravel bars. 

Most areas are accessible only by boat and provide local recreation opportunities including 

hunting, fishing, wildlife observation, and photography. 

Oroville WA is located west of Oroville adjacent to the Feather River. It consists of 11,870 acres of 

riparian forest, bordered by 12 miles of river channels. Local recreation opportunities include 

fishing, camping, hunting, and wildlife observation. 

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Other Areas 

The Bureau of Land Management, Army Corps of Engineers (Black Butte Lake), California State 

Parks, and various city and county agencies all provide additional recreation opportunities near 

the Refuges. 

Visitor Services Standards 

The Service Manual (605 FW 1-7) provides Service policies, strategies, and requirements for 

management of wildlife-dependent recreation programs within the National Wildlife Refuge 

System (Refuge System). 

The Service Manual (605 FW 1, Section 1.6) states: the Refuge System provides a unique 

opportunity to ensure that we approach our compatible wildlife-dependent recreation programs 

from the perspective of the Refuge System mission and goals. We believe wildlife-dependent 

recreation that comports well with the following criteria will continue to meet the needs and 

desires of refuge visitors. To ensure continued visitor satisfaction with our wildlife-dependent 

recreation programs, we incorporate public input using visitor satisfaction surveys or other 

instruments, including input during the development of a CCP or VSP, that help us define and 

evaluate wildlife-dependent recreation programs at each refuge. We develop our wildlifedependent recreation programs in consultation with State fish and wildlife agencies and 

stakeholder input based on the following criteria: 

• Promotes safety of participants, other visitors, and facilities; 

• Promotes compliance with applicable laws and regulations and responsible behavior; 

• Minimizes or eliminates conflict with fish and wildlife population or habitat goals or 

objectives in an approved plan; 

• Minimizes or eliminates conflicts with other compatible wildlife-dependent recreation; 

• Minimizes conflicts with neighboring landowners; 

• Promotes accessibility and availability to a broad spectrum of the American people; 

• Promotes resource stewardship and conservation; 

• Promotes public understanding and increases public appreciation of America’s natural 

resources and our role in managing and conserving these resources; 

• Provides reliable/reasonable opportunities to experience wildlife; 

• Uses facilities that are accessible to people and blend into the natural setting; and 

• Uses visitor satisfaction to help define and evaluate programs. 

In 2007, the Service declared that “connecting people with nature” is among the agencies highest 

national priorities (USFWS 2008b). A connection with nature, whether it’s hiking, fishing, 

camping, hunting, or simply playing outside, helps children develop positive attitudes and 

behaviors towards the environment. Positive interactions with the environment can lead to a lifelong interest in enjoying and preserving nature. People’s interest in nature is crucial to the 

Service mission of conserving, protecting, and enhancing fish, wildlife, plants, and their habitats. 

When U.S. Fish and Wildlife Service employees were asked to describe a childhood experience 

where they felt a connection with nature, the answers ranged from memories of riding on the laps 

of loved ones while mowing the lawn, to family vacations along a lake, beach, or forest, to hiking, 

climbing trees, and discovering insects, frogs, and birds. Many employees credit these memorable 

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moments for placing them in the career that they are in today. Those experiences were the spark 

that led to a lifetime of stewardship and conservation. The Service wants to capture that spark and 

share it with the next generation of conservationists. The Connecting People with Nature 

Program goals for Region 8 include 1) rekindle the spark, 2) share the spark and 3) ignite the 

spark. Currently, these goals are being implemented on the Refuges. 

Welcome and Orient Visitors 

We will assure that our Refuges are welcoming, safe, and accessible. We will provide visitors with 

clear information so they can easily determine where they can go, what they can do, and how to 

safely and ethically engage in recreational and educational activities. Facilities will meet the 

quality criteria defined in 605 FW 1, Section 1.6 of the Service Manual. We will treat visitors with 

courtesy and in a professional manner. 

Our Visitors Services goal, as stated in the CCP (USFWS 2008a), is to: 

Provide visitors of all ages and abilities with quality wildlife-dependent recreation (hunting, 

wildlife observation, photography, environmental education, and interpretation), and 

volunteer opportunities to enhance public appreciation, understanding, and enjoyment of 

fish, wildlife, habitats, and cultural resources. 

Provide Quality Hunting Opportunities 

Hunting is a wildlife-dependent recreational use and, when compatible, an appropriate use of 

resources in the Refuge System. Hunting programs will meet the quality criteria defined in the 

Visitor Services Standards above and, to the extent practicable, be carried out consistent with 

State laws, regulations, and management plans. 

Hunting Objective 

Implement a high quality hunting program including opportunities for approximately 22,000 

annual hunting visits on 8,525 acres by 2023, depending on season length and climatic conditions. 

Rationale: Hunting is identified in the Improvement Act as a priority public use that can be 

allowed when compatible with other Refuge purposes. As a result, the Refuge proposes waterfowl, 

coot, common moorhen, snipe, and pheasant hunting, all of which are currently hunted on the 

Refuges. The hunting program will be conducted in a safe and cost-effective manner and will be 

carried out consistent with State regulations. The Hunting Plan (Appendix C of the CCP) was 

developed to provide safe hunting opportunities, while minimizing conflicts with other priority 

wildlife-dependent recreational uses. Other visitor uses occur on different areas, thereby 

minimizing potential conflicts with hunters (Figures 2-5, or 11-14 from the CCP). The Refuge 

hunting program complies with the Code of Federal Regulations Title 50, 32.1 and is managed in 

accordance with Service Manual 605 FW 2, Hunting. 

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Figure 2. Sacramento Refuge – Visitor Services 

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Figure 3. Delevan Refuge – Visitor Services

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Figure 4. Colusa Refuge – Visitor Services

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Figure 5. Sutter Refuge – Visitor Services

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Hunting Strategies: 

1. Implement the Hunting Plan for the Refuges. 

2. Coordinate hunt program operations with California Fish and Game Department (CDFG) 

including the annual pre and post hunting meetings. 

3. Add hunt program changes to CDFG regulations and 50 CFR annually. 

4. Provide the Complex’s hunting brochure at the hunter check station, interpretive kiosks, 

and the visitor center. 

5. Disseminate hunting information packet at the Complex visitor center. 

6. Provide and update hunting information on the Complex’s 24-hour telephone information 

line and on the website. 

7. Continue to coordinate the Junior and Youth Waterfowl Hunts on Sacramento, Delevan, 

and Colusa Refuges with California Waterfowl Association and CDFG. 

8. Monitor hunting visits and bird harvest every hunt day. 

9. Work with the Complex’s Refuge Hunting Program Working Group to develop and 

improve the Refuge hunting program, including access and facilities for hunters with 

disabilities. 

10. Work cooperatively with CDFG wardens to enforce State Fish and Game hunting laws and 

Refuge-specific regulations to provide a quality experience for all visitors. 

11. Maintain hunter check stations and kiosks to effectively process hunters and provide 

hunter-related information. 

12. Convert a portion of the free roam area to assigned ponds at Sutter and Colusa Refuges 

and convert some spaced blinds to assigned ponds at Sacramento Refuge. 

13. Consider allowing limited spring turkey hunting opportunities on Sacramento, Delevan, 

and Colusa Refuges based on sufficient populations, habitat conditions, and the 

development of a turkey hunt management plan, as well as appropriate National 

Environmental Policy Act compliance. 

14. Hire one full-time clerk position to implement the hunting program and support other 

Refuge programs. 

Current Program 

See Chapter 3 of the CCP (USFWS 2008a). 

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Proposed Change 

See Hunt Plan (Appendix C of the CCP) (USFWS 2008a). 

Monitoring and Evaluation 

See Hunt Plan (Appendix C of the CCP) (USFWS 2008a). 

Provide Quality Fishing Opportunities 

Fishing is a wildlife-dependent recreational use and, when compatible, an appropriate use of 

resources in the Refuge System. Fishing programs will meet the quality criteria defined in the 

Visitor Services Standards above and, to the extent practicable, be carried out consistent with 

State laws, regulations, and management plans. 

Current Program 

Currently there is no public fishing access on Sacramento, Delevan, Colusa, and Sutter Refuges. 

Proposed Change 

None. 

Monitoring and Evaluation 

None. 

Provide Quality Wildlife Observation 

Visitors of all ages and abilities will have an opportunity to observe key wildlife and habitat on the 

Refuges when it is compatible with the refuges’ purpose(s). Viewing wildlife in natural or managed 

environments should foster a connection between visitors and natural resources. The wildlife 

observation program will meet the quality criteria defined above. 

Wildlife Observation Objective 

Provide quality opportunities for 100,000 wildlife viewing annual visits on 8,575 acres by 2023. 

Rationale: Wildlife observation is identified in the Improvement Act as a priority public use that 

can be allowed when compatible with other Refuge purposes. As a result, the Refuges’ encourage 

first-hand opportunities to observe wildlife in their habitats. This activity will be managed to 

ensure that people have opportunities to observe wildlife in ways that minimize wildlife 

disturbance and damage to Refuge habitats. Wildlife viewing will be managed to foster a 

connection between visitors and natural resources. This Visitor Services Plan was developed to 

provide guidance for the Refuges’ public use program. The wildlife observation program will be 

managed in accordance with Service Manual 605 FW 4, Wildlife Observation. 

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Wildlife Observation Strategies: 

1. Maintain and enhance auto tour routes on Sacramento and Colusa Refuges to provide 

viewing opportunities of wildlife and their habitats. 

2. Expand the hours on all Refuges to one hour before sunrise to one hour after sunset. 

3. Maintain the wildlife viewing facilities on Sacramento, Delevan, and Colusa Refuges. 

4. Upgrade walking trails on Sacramento and Colusa Refuges to provide for universal access. 

5. Construct a walking trail on Sutter Refuge and provide guided tours from April-June. 

6. Continue to plan and integrate universal access, facilities and programs to provide and 

enhance a quality wildlife observation program, including replacement of the wildlife 

observation blind at Colusa with an accessible blind and boardwalk. 

7. Open selected portions of the hunt area (2,275 acres) and modify parking areas to provide 

wildlife observation from February through June (post waterfowl season) on Sacramento, 

Colusa, and Sutter Refuges. 

8. Add wildlife-viewing platforms along Maxwell Road and Four Mile Road on Delevan 

Refuge. 

9. Install a remote camera on an eagle nest or a view of the Butte Sink WMA to facilitate 

viewing via the Complex’s website and the Refuge Headquarters. 

10. Increase the Refuge Day and Annual Pass fees. 

11. Hire a full-time tractor operator and maintenance worker to implement the wildlife 

observation and support other Refuge programs. 

Current Program 

Sacramento Refuge is open to the public for wildlife observation daily along the auto tour route 

and trails from sunrise to sunset year-round. The visitor center, auto tour route, and wetlands 

walking trail currently accommodate approximately 66,165 annual visits (Table 1). The six-mile 

auto tour route meanders along marshes and riparian areas of Logan Creek. There are two park 

and stretch areas on the auto tour route where visitors are encouraged to get out of their vehicles 

to view wildlife. At the first park-and-stretch area halfway along the auto tour route, there is a 

three-tier wildlife-viewing platform with two spotting scopes. The two-mile walking trail also 

meanders along marshes and riparian areas of Logan Creek. Using the new Wetlands Walk 

Guide, groups may stroll by the fourteen stops for an hour-long adventure. If time is limited, 

visitors may take alternate trail shortcut routes. Binoculars are loaned to visitors using the auto 

tour and walking trail on Sacramento Refuge to enhance their viewing opportunities. 

Delevan Refuge is open to the public for wildlife observation and photography along perimeter 

roads only. A primitive off-Refuge parking area is currently available for visitors along the 

Maxwell Road on the southern boundary of the Refuge. 

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On Colusa Refuge, visitors enjoy wildlife viewing as they drive the three-mile, graveled auto tour 

route adjacent wetlands. A universally accessible wildlife viewing platform is located at the 

beginning of the auto tour route. A one-mile walking trail is located along a lush riparian slough. 

The auto tour route and trail are open sunrise to sunset year-round. The Refuge receives an 

average of 21,485 annual auto tour and hiking trail visits (Table 1). 

Roads adjacent to Sutter Refuge provide the public with opportunities for wildlife observation 

throughout the year. 

Proposed Change 

The Refuges will be open from one hour before sunrise to one hour after sunset. 

A portion of the hunt area (2,275 acres) will be open for photography from February through June 

on Sacramento, Colusa, and Sutter Refuges. Visitors would utilize the existing directional blind, 

directional assigned pond and free roam boundary signs to access the areas. Boundary closed 

signs would be added and taken down seasonally. 

A primitive parking area along the Maxwell Road on Delevan Refuge is currently available for 

visitors. Construction of a viewing platform and other improvements to this site are planned. An 

additional parking area and viewing platform along Four Mile Road is also planned. 

The walking trail on Colusa Refuge will be upgraded to provide for universal access and the 

wildlife viewing blind will be replaced with a universally accessible blind and boardwalk. 

Scheduled guided tours on the southern portion of the Sutter Refuge will be conducted during 

February through June when staff and funding are available. In addition, a walking trail utilizing 

the existing roads will be available. 

Monitoring and Evaluation 

Vehicle counters on Sacramento and Colusa Refuges assist in monitoring the number of visitors 

monthly. Visitors are also encouraged by Refuge staff to sign their name and address in a 

registration book located in the visitor center. This information helps determine visitor group size 

and travel distance. Visitor Service Assistants (VSA) staff the visitor center seven days a week 

November through February. During this time, the VSAs engage visitors in conversations that 

help evaluate the wildlife viewing facilities and program. Walking trail use is periodically observed 

for use and effectiveness. In addition, our questions and comments from our website visitors help 

assess our wildlife-viewing program. 

Provide Quality Photographic Opportunities 

Visitors of all ages and abilities will have an opportunity to photograph key wildlife and habitat on 

the refuges when it is compatible with the refuges’ purpose(s). Photographing wildlife in natural 

or managed environments should foster a connection between visitors and natural resources. The 

photography program will meet the quality criteria defined in the Visitor Services Standards 

above. 

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Wildlife Photography Objective 

Provide quality opportunities for 80 photography blind visits and 10,000 wildlife photography 

annual visits on 8,758 acres by 2023. 

Rationale: Wildlife photography is identified in the Improvement Act as a priority public use that 

can be allowed when compatible with other Refuge purposes. As a result, the Refuges’ encourage 

first-hand opportunities to observe and photograph wildlife in their habitats. This activity will be 

managed to ensure that people have opportunities to photograph wildlife in ways that minimize 

wildlife disturbance and damage to Refuge habitats. Wildlife photography will be managed to 

foster a connection between visitors and natural resources. The wildlife photography program will 

be managed in accordance with Service Manual 605 FW 5, Wildlife Photography. 

Wildlife Photography Strategies: 

1. Maintain and enhance auto tour routes on Sacramento and Colusa Refuges to provide 

photographic opportunities from a vehicle. 

2. Maintain two wildlife photography blinds on Sacramento Refuge and one wildlife 

photography blind on Colusa Refuge. 

3. Construct and maintain a universally accessible photography blind on Delevan Refuge. 

Replace one of the Sacramento Refuge wildlife photography blinds with a universally 

accessible blind. 

4. Open selected portions of the hunt area (2,275 acres) and modify parking areas to provide 

wildlife photography from February through June (post waterfowl season) on Sacramento, 

Colusa, and Sutter Refuges. 

5. Update photographer guidelines, maps, and photography blind reports annually. 

6. Evaluate photography blind reports and implement changes annually. 

7. Maintain the Complex’s website to provide information about current photographer 

guidelines and facilities. 

8. Offer photography workshops and guided field trips on Sacramento Refuge utilizing the 

Wetlands Resource Center. 

Current Program 

The auto tour and walking trail on both Sacramento and Colusa Refuges provide excellent 

photographic opportunities. Sacramento Refuge receives an average of 32 annual photo blind 

visits and Colusa Refuge receives an average of 12 annual photo blind visits (Table 1). The best 

time of year for photography occurs from November through February, when a variety of 

waterfowl and shorebirds are present. 

Additionally, there are two photography blinds on Sacramento Refuge and one on Colusa Refuge. 

The blinds may be reserved one day each week only on Wednesdays through Sundays for a small 

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fee (currently $10). Limiting use promotes continued bird use of the surrounding areas, and 

thereby improving the potential for good photography opportunities. They are typically available 

October through March depending on habitat conditions. When habitat conditions are suitable, the 

blinds are available for use during the spring and summer months. Photographers may request up 

to three reservations each season and may be placed on a waiting list if the blind or day requested 

is filled. Photographers also complete an evaluation that reports photographed species, time 

spent, and comments. 

Photographers must be in the blind at least one hour before sunrise. They must park in the 

designated parking area and proceed directly to the assigned blind on foot. Stakes with reflective 

tape mark the route from the parking area to the blind. The route is designed to minimize 

disturbance; therefore, deviation from the staked route is not allowed. Photographers may leave 

the blind at any time, but once the blind has been vacated, returning to the blind is not permitted. 

The blinds are approximately 300 yards within the wetlands, see map. They are 42' x 6' wide and 

5' high. They have adjustable camera size openings in three sides. The blinds accommodate one 

person comfortably; however, two people at a time are allowed. There is one chair in each blind. 

Tree snags and islands have been placed to encourage birds to perch or rest about 40 feet from the 

blind. 

Proposed Change 

The Refuges will be open from one hour before sunrise to one hour after sunset. 

A portion of the hunt area (2,275 acres) will be open for photography from February through June

on Sacramento, Colusa, and Sutter Refuges. Visitors would utilize the existing directional blind, 

directional assigned pond and free roam boundary signs to access the areas. Boundary closed 

signs would be added and taken down seasonally. The in-ground, concrete hunting blinds on 

Sacramento Refuge will be available for photographic use from February through June with no 

user fees or reservations required. 

Photography Blind 2 on Sacramento Refuge will be replaced with a universally accessible blind 

and boardwalk. A universally accessible photography blind will be constructed at Delevan Refuge 

with access via Four Mile Road. The viewing blind at Colusa Refuge will also be replaced with a 

universally accessible blind and boardwalk. 

Lottery:

Photographers may apply through a lottery system, for up to three reservations annually. 

Photographers will be assigned up to three reservations in an August lottery. Then, depending on 

availability, reservations will be assigned by a first-come, first-serve process. 

Lottery Process: 

• The lottery is held in August (applications must be received between August 1-31). 

• Photographers may select up to 10 date/blind combinations in priority order [e.g. Choice 1: 

Dec. 17, 2008 – Blind 1, Choice 2: Dec. 17 – Blind 3, Choice 3: Nov. 12 – Blind 1, etc.], 

including the option to be on a blind waiting list (indicate which week or month and blind is 

desired). 

D-23 
• All reservation applications are randomly drawn and assigned a number, which indicates the 

order in which the reservations will be processed. 

• The reservations are then processed in numerical order by reserving the remaining highest 

priority of date/blind choice available for all of the reservation applicants. 

• After all of the applicants have received one reservation, the blind assignment continues 

until all applicants receive their next priority date of choice. 

First come, first serve process: 

Photographers that missed the lottery will fill any remaining dates by a first-come, first-serve 

process. 

Waiting list: 

In addition, a blind waiting list that is used to refill blinds when there are reservation 

cancellations. 

Fees:

The photography blind fee has two required components: 

• Purchase of a Refuge entrance pass (Refuge Day Pass or Refuge Annual Pass is required 

by all photographers who do not possess either a federal duck stamp, Golden Eagle, 

Golden Age, Golden Access or America the Beautiful Pass). 

• A non-refundable $15 fee per photography blind visit. 

For photographers participating in the lottery, the fee is due by October 1. 

For photographers participating in the first come, first serve or in the waiting list, the 

reservations are confirmed when the photography blind fee is paid prior to the visit. 

Some of the photography blinds may also be available for use from April through June when 

habitat is suitable. Inquiries about availability should be directed to Sacramento National Wildlife 

Refuge Complex, 752 County Road 99W, Willows, CA 95988 (530/934-2801). 

Photographers also complete a blind evaluation that reports photographed species, time spent, 

and comments. Photographers must be in the blind at least one hour before sunrise. They must 

park in the designated parking area and proceed directly to the assigned blind on foot. Stakes 

with reflective tape mark the route from the parking area to the blind. The route is designed to 

minimize disturbance; therefore, deviation from the staked route is not allowed. Photographers 

may leave the blind at any time, but once the blind has been vacated, returning to the blind is not 

permitted. 

Monitoring and Evaluation 

The photography blind reservation process assists in monitoring the number of visits by each 

photographer and the day of the visit. The photographer completes photography blind reports for 

each visit. The forms request comments regarding name and number of bird species 

photographed, other wildlife observed/photographed, time of entrance and egress from the blind, 

and other suggestions and observations. The comments assist in our photography blind 

management decisions. 

D-24 
Develop and Implement Quality Environmental Education Programs 

Through curriculum-based environmental education (EE) packages based on National and State 

education standards, we will advance public awareness, understanding, appreciation, and 

knowledge of key fish, wildlife, plant, and resource issues. Each Refuge will assist its potential to 

work with schools to provide an appropriate level of EE. We may support EE using facilities, 

equipment, educational materials, teacher workshops, programs and study sites that are safe, 

accessible, and conducive to learning. EE programs will meet the quality criteria defined in the 

Visitor Services Standards above. 

Environmental Education Objective 

Develop an environmental education program by 2023 to serve 5,000 students annually. Develop 

an environmental education program that promotes in-depth studies of the ecological principles 

that are associated with wetland and riparian ecosystems, and the Refuges’ natural, cultural, and 

historical resources. The education activities will be designed to develop awareness and 

understanding for refuge resources and management activities. 

Rationale: Environmental education is identified in the Improvement Act as a priority public use 

that can be allowed when compatible with other Refuge purposes. As a result, the Refuge 

encourages environmental education as a process of building knowledge in students. The Refuge 

staff will work with schools (K-12) to integrate environmental concepts and concerns into 

structured educational activities. These Refuge-lead or educator-conducted activities are intended 

to actively involve students or others in first-hand activities that promote discovery and factfinding, develop problem-solving skills, and lead to personal involvement and action. Refuge staff 

will promote environmental education that: is aligned to the current Federal, State and local 

standards; is curriculum-based that meets the goals of school districts adopted instructional 

standards; and provides interdisciplinary opportunities that link the natural world with all subject 

areas. The environmental education program will be managed in accordance with Service Manual 

605 FW 6 Environmental Education. 

Environmental Education Strategies: 

1. Construct and operate a Wetlands Resource Center at Sacramento Refuge. 

2. Schedule and plan 100 school group field trips annually utilizing the Wetlands Resource 

Center and the visitor facilities at Colusa Refuge. 

3. Offer the Discovery Pack containing environmental education activities and on-site 

information for use on walking trails on Sacramento and Colusa Refuges. 

4. Annually assist schools who wish to implement an in-depth study of wetlands and riparian 

habitats on Sacramento Refuge utilizing the Wetlands Resource Center. 

5. Facilitate after school programs involving activities such as habitat restoration, wetland 

analysis, and student mentor workshops. 

6. Develop a partnership with the Girl Scouts: Linking Girls to the Land to assist habitat 

restoration projects. 

D-25 
7. Facilitate two annual resource-training workshops (e.g. Project Wild or Project Wet) 

about the Refuges’ environmental education program for educators. 

8. Annually disseminate current environmental education program guidelines and activities 

offered to teachers. 

9. Maintain the Complex’s website to promote current educational opportunities, provide 

reservation form, and update guidelines. 

10. Update and provide Environmental Education Guide brochure. 

11. Utilize interpretive specialists, interns, and volunteers to facilitate the environmental 

education program. 

12. Hire one full-time interpretive specialist to implement environmental education activities 

and the visitor services program. 

13. Hire one full-time custodian/maintenance worker to maintain visitor service facilities. 

Current Program 

The Environmental Education Guide for the Complex describes the activities, facilities and 

resources available. The environmental education program was restructured in 2005 to increase 

the involvement of teachers or leaders in conducting their pre-selected activities. The program 

offers several ways for the classes to experience the Refuge Complex. Specifically at the 

Sacramento Refuge, they are welcomed by visitor services staff and have access to the diorama, 

Discovery Room and Refuge videos. For the remainder of their visit, the teachers or leaders guide 

their group through their pre-planned tour using the two-mile walking trail, kiosk area and sixmile auto tour. Sacramento Refuge receives an average of 2,847 annual environmental education 

visits (Table 1). On Colusa Refuge, students use the new visitor facilities including restrooms, 

welcome kiosk, viewing platform. Colusa Refuge receives an average of 71 annual environmental 

education visits (Table 1). 

Participants in the Refuge’s environmental education and interpretation programs are restricted 

to established trails, the visitor center, the Wetland Resource Center, and other designated sites. 

All groups using the Refuge for environmental education are required to make reservations twoweeks in advance. They may call, fax, or visit the Complex’s website to make reservations by a 

first-come, first serve system. This reservation process, allows refuge staff to manage the number 

and location of visitors for each day. A daily limit of up to one school participating in the education 

program is maintained through this reservation system. Efforts are made to spread out use by 

large groups, reducing disturbance to wildlife and over-crowding of the Refuges’ facilities during 

times of peak demand. Educational groups are required to have a sufficient number of adults to 

supervise their groups, a minimum of one adult per 12 students. Currently, educational groups are 

not charged a fee or required to have a special use permit (SUP). 

The Field Trip/Event Reservation Application allows the Refuges and groups to help plan their 

visit. Groups can request teacher’s packets, discovery packs, scavenger hunt directions, a bird 

D-26
coloring book, bird mounts and videos for classroom use. The application also provides some 

activity time guidelines (e.g., 45 minutes to drive the auto tour, 1 1/2 hours to have lunch and drive 

the auto tour, 20 minutes to 1 1⁄2 hours on wetlands walk depending on the trail section, and videos 

are about 20 minutes). 

For an even more comprehensive environmental education experience, the fully equipped 

backpack or Discovery Pack provides items to teach as many as five activities along the Wetlands 

Walk. The Pack contains dip nets, field guides, plant mounts, bug boxes, lenses, and other written 

materials. A teacher’s guide can be sent, upon request, prior to the visit. Binoculars and waterfowl 

guides are available on loan. The Environmental Education Guide and the Complex’s website list 

many other resources available. 

The Wetlands Walk trail is posted with “Short Cut” signs for school groups that are under a time 

constraint. Trail etiquette, including talk softly, move slowly, stay on the trail and leave only foot 

prints behind, is discussed with teachers during orientation workshops and with students upon 

arrival during their welcome session. On the Refuges, the teacher(s) is responsible for ensuring 

that students follow required trail etiquette. 

Proposed Change 

A Wetland Resource Center would be constructed and more teacher workshops would be held. 

The site area for the Wetlands Resource Center would be located on the east side of Logan Creek 

between the existing headquarters and easement buildings. A wetland could be created south of 

the Center for habitat viewing and EE activities. A footbridge would be constructed over Logan 

Creek so that the current parking area and Wetlands Walk may be used. The Center could be a 

one-story building with a covered viewing porch at roof height. Large picture windows would 

accommodate views to the south and west. Part of the entry area would descend below the pond 

surface to allow visitors to view aquatic organisms and soil profiles. An auditorium would provide 

seating for up to 100 and include a surround-sound system, High Definition (HD) television, and 

retracting screens for projectors, videos, and DVDs. Separate laboratory rooms would provide a 

secluded work area, storage and sinks. Computer workstations with internet/satellite access and a 

resource library would be available for students and teachers. 

Monitoring and Evaluation 

The reservation and application process for scheduling a visit assists Refuge staff in monitoring 

the EE program. The application (available in paper copy and on the Refuge web site) records the 

name of the school and teacher, date and reason of visit, arrival and departure time, number of 

students/adults, grade level, items requested for loan, and EE activities. Each teacher completes a 

teacher evaluation form for each Refuge visit. The forms allow the teachers to evaluate the 

activities and facilities they utilized (i.e. videos, wetlands walk, auto tour, viewing platform, 

wetland scavenger hunt, discovery room and the discovery pack). These comments assist with 

managing the EE program. 

Provide Quality Interpretations of Key Resources 

We will communicate fish, wildlife, habitat, and other resource issues to visitors of all ages and 

abilities through effective interpretation. We will tailor core recreational uses when we determine 

they are both appropriate and compatible. We will allow uses that are either legally mandated or 

D-27
occur due to special circumstances. Interpretive programs will meet the quality criteria defined in 

the Visitor Services Standards above. 

Interpretation Objective 

Refuge staff will develop an interpretive program to provide 20,000 annual visits. The program 

will promote public awareness and support of the Refuge resources and management activities by 

2023. 

Rationale: Interpretation is identified in the Improvement Act as a priority public use that can be 

allowed when compatible with other Refuge purposes. As a result, the Refuges encourage 

interpretation as both an educational and recreational opportunity that is aimed at revealing 

relationships, examining systems, and exploring how the natural world and human activities are 

interconnected. Participants of all ages can voluntarily engage in stimulating and enjoyable 

activities as they learn about the issues confronting fish and wildlife resource management on the 

Refuges. First-hand experiences with the environment will be emphasized, although 

presentations, audiovisual media, and exhibits will be necessary components of the Refuges’ 

interpretive program. The Visitor Services Plan (Appendix D) was developed to provide guidance 

for the Refuges’ public use program. The interpretive program will be managed in accordance 

with Service Manual 605 FW 7, Interpretation. 

Effective outreach is an important component of the interpretive program. The Refuges will 

provide two-way communication between the Refuges and the public to establish a mutual 

understanding and promote involvement with the goal of improving joint stewardship of our 

natural resources. Outreach will be designed to identify and understand the issues and target 

audiences, craft messages, select the most effective delivery techniques, and evaluate 

effectiveness. Refuge outreach will follow the guidance of the National Outreach Strategy: A 

Master Plan for Communicating in the U.S. Fish and Wildlife Service (USFWS 1997). 

In 2007, the Service declared that “connecting people with nature” is among the agencies highest 

national priorities (USFWS 2008b). A connection with nature, whether it’s hiking, fishing, 

camping, hunting, or simply playing outside, helps children develop positive attitudes and 

behaviors towards the environment. Positive interactions with the environment can lead to a lifelong interest in enjoying and preserving nature. People’s interest in nature is crucial to the 

Service mission of conserving, protecting, and enhancing fish, wildlife, plants, and their habitats. 

Interpretation Strategies: 

1. Use the Complex’s visitor center to provide presentations and exhibits. 

2. Maintain interpretive kiosks, walking trails, auto tour routes, the visitor center, and 

Wetlands Resource Center for use by Refuge visitors. 

3. Lead at least 20 tour groups on the Refuges annually. 

4. Develop “Sense of Wonder Zones” or naturalized play areas for family-oriented activities 

on the Sacramento and Colusa Refuges where people of all ages can reconnect with nature. 

D-28
5. Create interpretive geocaching opportunities on the Sacramento and Colusa Refuges 

where people of all ages can increase their awareness of fish and wildlife resources and 

outdoor activities that the Refuges provide. 

6. Continue to participate in or provide information to local annual events (e.g. International 

Migratory Bird Day, National Wildlife Refuge Week, Snow Goose Festival, Pacific Flyway 

Decoy Association Wildlife Art Festival, California State Fair, International Sportsman’s 

Expo, Return of the Salmon Festival and California Junior Duck Stamp Contest/Judging). 

7. Participate in fire prevention education and outreach about the role of fire and its 

management uses. 

8. Write news releases for local and State newspapers and articles for magazines. Conduct 

television and radio interviews upon request. 

9. Maintain the Complex’s website. 

10. Maintain the Sacramento Refuge radio station (FM 93.1). 

11. Provide interpretive brochures at kiosks and in the visitor center. 

12. Maintain and upgrade the Discovery Room displays, videos, and activities. 

13. Manage and stock the bookstore to provide relevant books and miscellaneous items that 

relate to the Refuge Complex. 

14. Continue to coordinate and facilitate the California Junior Duck Stamp Contest and 

judging. 

15. Continue to host and facilitate California Waterfowl Association’s (CWA) Marsh Madness 

school events. 

16. Utilize interpretive specialists, interns, and volunteers to coordinate annual events on and 

off Refuge, manage the bookstore, and coordinate the California Junior Duck Stamp 

Program. 

17. Utilize interns to assist with Refuge programs (e.g. managing the visitor center on 

weekends, facilitating school groups). 

Current Program 

Interpretation involves participants of all ages who learn about the complex issues confronting 

fish and wildlife resource management as they voluntarily engage in stimulating and enjoyable 

activities. First-hand experience with the environment is emphasized although presentations, 

audiovisual media, and exhibits are often necessary components of the interpretive program. 

Refuge brochures pertaining to information on the Complex, Watchable Wildlife, and the hunting 

program have been developed and revised over the years. The Wetlands Walk Guide and the 

D-29
Northern Sacramento Valley birding trail guide were completed in 2006. A variety of videos is also 

available for viewing upon request. The Sacramento Valley Refuge: An Unfinished Symphony and 

America’s National Wildlife Refuge System: Where Wildlife Comes First, are the most popular 

videos. As part of the Refuge System Centennial Celebration, the Unfinished Symphony was 

written and filmed on location in 2003. 

A bookstore in the Sacramento Refuge Visitor Center (Headquarters Office) was created in 1990 

via cooperative agreement with the San Francisco Bay Wildlife Society. Additional shelving was 

added in 1996 increasing the sales to a consistent $14,000 annually. The cooperative agreement 

was terminated with San Francisco Wildlife Society in 2001 and a new cooperative agreement was 

signed with Altacal Audubon Society in Chico, CA in 2002. 

Refuge related information is provided at annual local festivals or during special events, such as 

the State Fair, International Migratory Bird Day, Snow Goose Festival, National Wildlife Refuge 

Week, Pacific Flyway Decoy Association, Coleman National Fish Hatchery Salmon Festival, 

Chico Endangered Species Fair, CWA Art Camp, and CWA Marsh Madness. During 2005, 

approximately 13,000 individuals attended the presentations and saw exhibits at these events. 

Sacramento Refuge receives an average of 555 annual interpretation visits and Colusa Refuge 

receives an average of 18 annual interpretation visits (Table 1). 

Proposed Change 

A Wetland Resource Center would be constructed and more teacher workshops would be held. 

The site area for the Wetlands Resource Center would be located on the east side of Logan Creek 

between the existing headquarters and easement buildings. A wetland could be created south of 

the Center for habitat viewing and EE activities. A footbridge would be constructed over Logan 

Creek so that the current parking area and Wetlands Walk may be used. The Center could be a 

one-story building with a covered viewing porch at roof height. Large picture windows would 

accommodate views to the south and west. Part of the entry area would descend below the pond 

surface to allow visitors to view aquatic organisms and soil profiles. An auditorium would provide 

seating for up to 100 and include a surround-sound system, High Definition (HD) television, and 

retracting screens for projectors, videos, and DVDs. Separate laboratory rooms would provide a 

secluded work area, storage and sinks. Computer workstations with internet/satellite access and a 

resource library would be available for students and teachers. 

“Connecting people with nature” is among the agencies highest national priorities (USFWS 

2008b). A connection with nature, whether it’s hiking, fishing, camping, hunting, or simply playing 

outside, helps children develop positive attitudes and behaviors towards the environment. Positive 

interactions with the environment can lead to a life-long interest in enjoying and preserving 

nature. The Refuges are currently beginning to implement these goals by developing “Sense of 

Wonder Zones” or naturalized play areas for family-oriented activities on the Sacramento and 

Colusa Refuges where people of all ages can reconnect with nature. The Refuges will also create 

interpretive geocaching opportunities on the Sacramento and Colusa Refuges. 

Monitoring and Evaluation 

The reservation and application process for scheduling a visit assists Refuge staff in monitoring 

the interpretation program. The application (available in paper copy and on the Complex’s 

D-30
website) records the name of the group, date and reason of visit, arrival and departure time, 

number of participants, age, items requested for loan, and activities. Annual on and off Refuge 

events are monitored by Refuge staff recording the event and number of participants on a 

calendar posted in the Visitor Services office. Refuge brochures and bookstore items are 

monitored in order to restock the inventory. The Junior Duck Stamp Contest including the 

judging is evaluated annually with California Waterfowl Association and other partners. 

Manage for Other Recreational Use Opportunities 

We may allow other recreational uses that support or enhance one of the wildlife-dependent 

recreational uses or minimally conflict with any of the wildlife-dependent recreational uses when 

we determine they are both appropriate and compatible. We will allow uses that are either legally 

mandated or occur due to special circumstances (605 FW 1). 

Bicycling is currently allowed on the auto tour route on Sacramento Refuge. 

Communicate Key Issues with Off-Site Audiences 

Effective outreach depends on open and continuing communication and collaboration between the 

refuge and its many publics. Effective outreach involves determining and understanding the 

issues, identifying audiences, listening to stakeholders, crafting messages, selecting the most 

effective delivery techniques, and evaluating effectiveness. If conducted successfully, the results 

we achieve will further refuge purposes and the Refuge System mission. 

Proposed Change 

Bicycling would be allowed on the entrance road and auto tour routes on Sacramento and Colusa 

Refuges from May through August (see Bicycling Compatibility Determination, Appendix B). 

Other non-wildlife dependent uses (i.e. field dog trials, horseback riding, camping, etc) would not 

be allowed on the Refuges. 

Monitoring and Evaluation 

Refuge biologists and visitor services staff conduct regular surveys of public activities including 

bicycling on the Refuges. The data is analyzed and used by the refuge manager to develop future 

modifications if necessary to ensure compatibility bicycling. 

Build Volunteer Programs and Partnerships with Refuge Support Groups 

Volunteer and Friends organizations fortify refuge staffs with their gifts of time, skills, and 

energy. They are integral to the future of the Refuge System. Where appropriate, refuge staff will 

initiate and nurture relationships with volunteers and Friends organizations and will continually 

support, monitor, and evaluate these groups with the goal of fortifying important refuge activities. 

The National Wildlife Refuge System Volunteer and Community Partnership Enhancement Act 

of 1998 strengthen the Refuge System’s role in developing effective partnerships with various 

community groups. Whether through volunteers, Friends organizations, or other important 

D-31
partnerships in the community, refuge personnel will seek to make the refuge an active 

community member, giving rise to a stronger Refuge System. 

Volunteer Objective 

Increase the number of volunteers to 120 in order to support a variety of Refuge programs by 

2023. 

Rationale: The National Wildlife Refuge System Volunteer and Partnership Enhancement Act of 

1998 (P.L. 105-242) strengthens the Refuge System’s role in developing relationships with 

volunteers. Volunteers possess knowledge, skills, and abilities that can enhance the scope of 

refuge operations. Volunteers enrich Refuge staff with their gift of time, skills, and energy. 

Refuge staff will initiate, support, and nurture relationships with volunteers so that they may 

continue to be an integral part of Refuge programs and management. The volunteer program will 

be managed in accordance with the Fish and Wildlife Service Manual, Part 150, Chapters 1-3, 

“Volunteer Services Program”, and Part 240 Chapter 9 “Occupational Safety and Health, 

Volunteer and Youth Program”. 

Volunteer Strategies: 

1. Utilize interpretative specialists and interns to coordinate the volunteer program. 

2. Recruit interns through the California Waterfowl Association, California State University 

Chico (CSU/Chico) internship program, and other universities. 

3. Recruit a variety of community groups and individuals (e.g. CSU/Chico, Butte College, 

Boy Scouts, Girl Scouts, Altacal Audubon Society). 

4. Host an annual volunteer recognition dinner. 

5. Facilitate volunteer training workshops. 

6. Host an annual workday (Brush Up Day) to clean up Refuges’ hunt areas. 

7. Utilize the Girl Scout Council to recruit volunteers. 

8. Provide Service volunteer uniform for all volunteers to wear when greeting the public or at 

special events. 

Current Program 

The Complex volunteer program consists of 69 individuals that assist with biological, 

environmental education, interpretive, wildlife observation, hunting, and maintenance events and 

activities. Additional individuals are signed up for one-time events such as Brush Up Day of the 

hunting areas and trail maintenance by Altacal Audubon Society. The Refuges support and 

participate in annual Eagle Scout and Girl Scout projects. 

D-32 
Proposed Change 

Volunteer recruitment would take place in order to increase the number of current volunteers 

from 69 to 120. 

Monitoring and Evaluation 

Volunteers are monitored through an application process that enables Refuge staff to match 

requested volunteer projects by Refuge staff with volunteer interests and expertise. Volunteers 

may participate in specific work projects, special events or on specific days/hours. Each volunteer 

records their hours daily within one of four categories: recreation, habitat & wildlife, maintenance 

or cultural resources. The volunteer program is evaluated by work project completion and 

volunteer satisfaction. 

Partnerships Goal 

Promote partnerships to preserve, restore, and enhance a diverse, healthy, and 

productive ecosystem in which the Refuges play a key role. 

Partnership Objective 

Maintain and enhance at least 25 partnerships among Federal, State, local agencies, 

organizations, schools, corporations, and private landowners to promote the understanding and 

conservation of the Refuges’ resources, activities, and management by 2023. 

Rationale: The Refuge System recognizes that strong citizen support benefits the System. These 

benefits include the involvement and insight of citizen groups in Refuge resource and 

management issues and decisions, a process that helps managers gain an understanding of public 

concerns. Partners support Refuge activities and programs, raise funds for projects, are 

advocates on behalf of wildlife and the Refuge System, and provide support on important wildlife 

and natural resource issues. In “Fulfilling the Promise”, the Service (USFWS 1999) identified the 

need to forge new and non-traditional alliances and strengthen existing partnerships with States, 

Tribes, non-profit organizations and academia to broaden citizen and community understanding 

and support for the National Wildlife Refuge System. 

A variety of people including, but not limited to, scientists, farmers, birders, hunters, 

photographers, and students have a great deal of interest in Sacramento Refuge Complex’s 

management, fish and wildlife species, and habitats. As opportunities, funding, and staff are 

available, new partnerships will be formed. 

Partnership Strategies: 

1. Maintain good relations and open communication with partners. 

2. Actively look for partnering opportunities with local and regional conservation groups, 

academic institutions, organizations, and other local, State and Federal agencies. 

3. Pursue opportunities to cost-share mutually beneficial projects with other organizations. 

D-33
4. Expand opportunities with local Chambers of Commerce to participate in local events and 

improve dissemination of public recreation literature about the Refuges. 

5. Stay actively involved in Federal, State, and local planning processes to protect Refuge 

resources and foster cooperative management of those resources. 

6. Work closely with Bureau of Reclamation and local irrigation district personnel on water 

delivery issues. 

7. Continue to participate in the Sacramento Valley Water Quality Coalition. 

8. Continue partnership with Altacal Audubon Society to operate the bookstore at 

Sacramento Refuge. 

9. Maintain active participation with the Central Valley Joint Venture. 

10. Maintain cooperative agreement with US Geological Survey to conduct managementoriented research and monitoring efforts. 

11. Continue partnerships with California Waterfowl Association, Ducks Unlimited, and other 

conservation non-governmental organizations. 

Current Program 

The Refuge is part of a mosaic of public and private land in the Sacramento Valley. The private 

lands include both farms and natural riparian habitat in the vicinity of the Complex. To maximize 

our conservation efforts the Complex encourages and supports the cooperative management 

approach by working with Federal, State, and county agencies, private landowners, neighbors, 

and citizens. 

Partnerships in habitat restoration and management, migratory bird studies, and visitor services 

program include but are not limited to the California Department of Fish and Game, Ducks 

Unlimited, Inc., California Waterfowl Association, Altacal Audubon Society, Girl Scouts and Boy 

Scouts of America, and local Chambers of Commerce. 

Proposed Change 

Maintain and enhance at least 25 partnerships among Federal, State, local agencies, 

organizations, schools, corporations, and private landowners to promote the understanding and 

conservation of the Refuges’ resources, activities, and management. 

D-34
Other Applicable Visitor Services Programs: 

Youth Conservation Corps 

The Youth Conservation Corps (YCC) is a well-balanced work-learn-earn program that develops 

an understanding and appreciation in participating youth of the Nation’s environment and 

heritage. The YCC program will be administered in accordance with Public Law 93-408 and an 

interagency Letter of Cooperation. It is administered by the Forest Service, the Service, and 

National Park Service. YCC offers gainful summer employment to youth 15-19 years of age, for 

approximately eight weeks. The organization and management of individual YCC projects will be 

governed by program objectives, budget limitations, and guidelines established by the Service in 

Fish and Wildlife Service Manual Part 141. Within these objectives, limitations and guidelines, 

individual program operations, public information and community relations concerning YCC will 

be the responsibility of the Host Site Supervisor. 

YCC Objectives 

The stated purpose of the YCC is to further the development and maintenance of the natural 

resources of the United States by America’s youth and, in so doing, to prepare them for the 

ultimate responsibility of maintaining and managing these resources for the American people. 

There are three equally important objectives as reflected in the law: 

1. Accomplish needed conservation work on public lands. 

2. Provide gainful employment for young males and females from all social, economic, 

ethnic, and racial classifications. 

3. Develop an understanding and appreciation in the participating youth of the Nation’s 

natural environment and heritage. 

The objectives are accomplished in a manner that provides the youth with an opportunity to 

acquire increased self-discipline. They learn work ethics, how to relate to peers and supervisors, 

and how to build lasting cultural bridges with youth from other backgrounds. 

Current Program 

A Youth Conservation Corps program, the first in over two decades, was implemented during the 

summer of 2005. It consisted of one crew leader and four crewmembers. In 2006, YCC consisted of 

one crew leader, one youth leader, and four crewmembers. During the eight-week program, 

enrollees complete maintenance, fence construction and painting projects. YCC contributes over 

1,000 work project hours annually. For every 8 hours of work, one hour of environmental 

education is provided as field trips, presentations, or discussions. 

Proposed Change 

None. 

D-35 
Refuge Law Enforcement 

Visitor safety is a key issue in providing quality compatible wildlife-dependent recreation 

programs. Visitor safety at refuges is a high priority when developing compatible wildlifedependent recreation programs. Refuge managers provide adequate law enforcement and supply 

visitors with information about specific hazards, including animal behavior; geographical, 

topographical, tidal, or flood hazards; inclement weather patterns; road and trail hazards; and 

other safety concerns. We also use environmental education and interpretive programs to alert 

visitors to safety issues. 

Refuge law enforcement ensures legal use of fish and wildlife resources on the Refuges, as 

prescribed by law. We use refuge law enforcement to obtain compliance with laws and regulations 

necessary for proper administration, management, and protection of facilities of the Refuge 

System. Refuge policy (605 FW 1-7) Guidelines for Wildlife-Dependent Recreation states that 

refuge law enforcement effort should be sufficient to protect human safety and wildlife 

populations, ensure compliance with regulations, and based on past experiences and current 

circumstances. 

Law Enforcement Objective 

Provide a safe environment for visitors, protect Refuges’ resources, and ensure compliance with 

regulations through effective law enforcement on each Refuge by 2008. 

Rationale: An increasing number of Refuge facilities and visitors necessitate an adequate level of 

safety and security through an enhanced law enforcement presence. Illegal activities, such as drug 

cultivation, poaching, vandalism, and vehicle stripping, are present on Refuge lands where there 

are public activities. Strict law enforcement and the support of partners are necessary to provide a 

safe environment for visitors and staff. In addition, a common belief among neighboring 

landowners is that public ownership, easements, or access could result in increased vandalism and 

theft of agricultural equipment, poaching, and disregard of private property rights. A wellplanned and coordinated program will be necessary to successfully address these concerns. 

Law Enforcement Strategies: 

1. Develop Memorandum of Understandings with various law enforcement agencies to 

improve coordination, improve safety and coordinate efforts in areas of special 

concern. 

2. Provide public education and signage as part of law enforcement programs and 

provide a sufficient level of law enforcement from various agencies to address these 

issues. 

3. Employ three full-time park rangers (refuge law enforcement officers), one full-time 

supervisory law enforcement officer, and supplement their duty schedule with dualfunction officers. 

4. Maintain a daily law enforcement presence to ensure that violations are deterred or 

successfully detected, investigated, and the violators are apprehended, charged, and 

prosecuted. 

D-36 
5. Have refuge officers work closely with CDFG game wardens and deputy sheriffs from 

Glenn, Colusa, and Sutter counties. 

6. Develop a Law Enforcement Plan for the Complex. 

7. Annually maintain boundary, closed area, and other public use signs. 

Current Program 

The Sacramento Refuge Complex has a law enforcement staff that consists of three full-time 

refuge officers and one dual-function officer. These officers are responsible for all law 

enforcement issues on Sacramento River, Sacramento, Delevan, Colusa, and Sutter Refuges, and 

on Butte Sink Wildlife Management Area. The dual-function officers conduct law enforcement as a 

“collateral duty” in addition to their primary responsibility, such as an assistant refuge manager. 

The refuge officers are responsible for coordinating their activities and cooperating with other 

local, State, and Federal law enforcement officials. 

Proposed Change 

Hire an additional full-time refuge law enforcement officer and supervisory law enforcement 

supervisor for the Complex. 

Fee Programs 

The Service is one of four Federal land management agencies (Fish and Wildlife Service, Bureau 

of Land Management, National Park Service, and Forest Service) directed by Congress in 1996, 

to implement or expand fee collection sites as part of a program to explore the feasibility to better 

offset costs to administer recreation on public lands. 

The fee demonstration program was a four-year effort to create innovative approaches and 

methods to charge and collect fees for recreation services provided on Service lands. An entrance 

fee program was implemented at Sacramento Refuge during the spring of 1998. This involved 

constructing a parking area, sidewalk, kiosk with interpretive panels, and automated fee machine. 

A survey was completed in 1998 to determine compliance and the number of people per vehicle. 

The survey revealed that there was a 90 percent compliance of visitors that paid before entering 

the Refuge. 

In 2004, Congress passed the Federal Lands Recreation Enhancement Act that allows the 

government to charge a fee for recreation use of public lands managed by the Service, Bureau of 

Reclamation, National Park Service, Bureau of Land Management, and Forest Service. 

Currently, there is an entrance fee program for Sacramento Refuge. A fee for vehicles is collected 

to pay for visitor facilities and wildlife habitat improvements. A $3 day pass, $12 Refuge Annual 

Pass or $20 commercial pass can be purchased on-site. Holders of a Federal Duck Stamp or 

Golden Eagle, Age, Access Passport, or America the Beautiful Pass enter free. 

D-37 
The entrance fee is waived for educational groups studying nature as part of a course of 

curriculum. Visitors pay a fee at an automated machine at the entrance to the Refuge. The 

machine is housed within an interpretive kiosk that depicts what to see and do, and brochures are 

available to assist the tourist in deciding if, when, and where they may visit. 

The entrance fee generates approximately $13,000 annually, which is used to hire two visitor 

services assistants for October-March. The assistants help with many daily tasks, staff the visitor 

center on weekends, facilitate school groups, update the website, provide hunt data, and answer 

the phone. 

Additionally, there are two photography blinds on Sacramento Refuge and one on Colusa Refuge. 

The blinds may be reserved one day each week only on Wednesdays through Sundays for $10 per 

use. They are available October through March depending on habitat conditions. 

Cooperating Association/Friends Groups 

A bookstore in the Sacramento Refuge Visitor Center (Headquarters Office) was created in 1990 

via cooperative agreement with the San Francisco Bay Wildlife Society. Additional shelving was 

added in 1996 increasing the sales to a consistent $14,000 annually. The cooperative agreement 

was terminated with San Francisco Wildlife Society in 2001 and a new cooperative agreement was 

signed with Altacal Audubon Society of Chico, CA in 2002. 

Other 

In “Fulfilling the Promise”, the Service (USFWS 1999) identified the need to forge new and nontraditional alliances and strengthen existing partnerships with States, Tribes, non-profit 

organizations and academia to broaden citizen and community understanding of and support for 

the National Wildlife Refuge System. The Service recognizes that strong citizen support benefits 

the Refuge System. Involving citizen groups in Refuge resource and management issues and 

decisions helps managers gain an understanding of public concerns. Partners yield support for 

Refuge activities and programs, raise funds for projects, are activists on behalf of wildlife and the 

Refuge System, and provide support on important wildlife and natural resource issues. 

A variety of people including, but not limited to, scientists, birders, hunters, farmers, outdoor 

enthusiasts and students are keenly interested in the management of Sacramento Refuge 

Complex, its fish and wildlife species, and its plants and habitats. This is illustrated by the number 

of visitors the Refuge receives and the partnerships that have already developed. We will continue 

to form new partnerships with interested organizations, local civic groups, community schools, 

Federal, State, and County governments, and other civic organizations. 

Implementing the Plan 

Essential Staffing Needs 

See Chapter 5 of the CCP. 

D-38
Table of Projects, Costs 

See Chapter 5 of the CCP. 

Partnership Funding and Resources 

See Chapter 5 of the CCP. 

Compatibility Determinations 

See Appendix B of CCP. 

NEPA Document/Decision Document 

See Appendix A of CCP. 

ESA Section 7 Consultations 

See Appendix L of CCP. 

Literature Cited 

California Department of Finance. 2002. Census 2000 California Profile. Sacramento, California. 

California Department of Finance. 2005. California Employment Development Department Labor 

Market Information website. http://www.labormarketinfo.edd.ca.gov/ 

California Department of Transportation. 2005. California 2005-2025 County-Level Economic 

Forecast. Office of Transportation Economics. Sacramento, CA. 243 pp. 

EDAW 2003. Sacramento River Public Recreation Access Study – Red Bluff to Colusa. Report 

prepared for The Nature Conservancy and CALFED. Prepared by EDAW, 2022 J Street, 

Sacramento, California. January 2003. 

Munroe, T. and W. Jackman. 1999. The State of the Great Central Valley of California – Assessing 

the Region via Indicators. Report prepared for the Great Valley Center. 56 pp. 

U. S. Census Bureau. 2000. Website for 2000 Census Data. www.census.gov. 

U. S. Fish and Wildlife Service. 1997. National Outreach Strategy: A Master Plan for 

Communicating in the U. S. Fish and Wildlife Service. 26 pp. 

U. S. Fish and Wildlife Service. 1999. Fulfilling the Promise; The National Wildlife Refuge 

System; Visions for Wildlife, Habitat, People, and Leadership. USFWS Division of 

Refuges, Washington D.C., 92 pp. 

D-39
U. S. Fish and Wildlife Service. 2005a. Sacramento River National Wildlife Refuges Final 

Comprehensive Conservation Plan. California Nevada Region. Sacramento, CA. 

U. S. Fish and Wildlife Service. 2005b. National Wildlife Refuge System Visitation Estimation 

Workbook. Arlington, VA. 80 pp. 

U. S. Fish and Wildlife Service. 2007. Banking on Nature 2006: The Economic Benefits to Local 

Communities of National Wildlife Refuge Visitation. E. Carver and J. Caudill. Division of 

Economics. Washington, D.C. 382 pp. 

U. S. Fish and Wildlife Service. 2008a. Sacramento, Delevan, Colusa, and Sutter National Wildlife 

Refuges Draft Comprehensive Conservation Plan. Region 8. Sacramento, CA. 

U. S. Fish and Wildlife Service. 2008b. Connecting People with Nature Action Plan Sharing the 

Spark. California Nevada Region. Sacramento, CA. 

D-40
Appendix E. Habitat Management Plan 

Sacramento, Delevan, Colusa, and Sutter Refuges’ management is determined, guided, 

and tracked by an annual habitat management planning process. The annual Habitat 

Management Plans identify individual management units within each Refuge. These units 

consist of tracts of land, which have common management constraints, conditions, and 

public use activities. The habitat management plan identifies physical attributes of the 

unit, habitat objectives, specifies management activities to make any necessary repairs or 

improvements; emphasizes positive results from previous years; and notes special 

management considerations (i.e. presence of special status species or other significant 

wildlife use). It also prioritizes management activities and projects based on the overall 

condition and functionality of the unit, water management regimes (i.e. flood-up and 

drawdown schedules), and available resources (i.e. manpower and funding). Examples of 

management activities include facilities maintenance (i.e. levees, water control structures, 

roads, fire breaks, fences, gates, boundary signs, etc.), vegetation management (i.e. 

herbicide application, prescribed fire, grazing, mowing and disking, irrigation, etc.), 

biological surveys, habitat restoration, research, public use monitoring and facilities 

maintenance, and law enforcement issues. 

Copies of the habitat management plans for 2006 are available for review at the 

Sacramento National Wildlife Refuge Complex, 752 County Road 99W, Willows, 

California 95988. (530) 934-2801. 

Copies are also available via the internet at the following address 

http://sacramentovalleyrefuges.fws.gov 

E-1
E-2
Appendix F. Integrated Pest Management 

Plan 

Table of Contents 

INTRODUCTION....................................................................................................................................... 1

REFUGE DESCRIPTION .........................................................................................................................2

HISTORICAL...............................................................................................................................................2

PHYSICAL...................................................................................................................................................2

REFUGE PURPOSES AND GOALS ............................................................................................................4

HABITAT MANAGEMENT PRACTICES .............................................................................................4

LISTED SPECIES ......................................................................................................................................5

CHAPTER 1. MOSQUITO CONTROL...................................................................................................6

INTRODUCTION.......................................................................................................................................6

MOSQUITO CONTROL ACTIVITIES...................................................................................................7

DISEASE HISTORY ..................................................................................................................................8

ENCEPHALITIS ..........................................................................................................................................8

WEST NILE VIRUS.....................................................................................................................................8

MALARIA.......................................................................................................................................................8

MOSQUITO BIOLOGY ............................................................................................................................9

FLOODWATER MOSQUITOES .........................................................................................................................9

Aedes melanimon..........................................................................................................................................9

STANDING WATER MOSQUITOES................................................................................................................10

Culex tarsalis...............................................................................................................................................10

Anopheles freeborni....................................................................................................................................10

MOSQUITO ABUNDANCE IN REFUGE HABITATS........................................................................10

MONITORING DISEASE ACTIVITY...................................................................................................11

MONITORING MOSQUITO POPULATIONS ....................................................................................14

IMMATURE STAGES.....................................................................................................................................14

ADULT STAGE .............................................................................................................................................14

POTENTIAL CONTROL METHODS AND MATERIALS.................................................................14

WETLAND MANAGEMENT BMPS (FROM KWASNY ET AL. 2004) ...............................................................14

Water Management.....................................................................................................................................15

Vegetation Management Practices..............................................................................................................18

Wetland Infrastructure Maintenance...........................................................................................................19

Wetland Restoration and Enhancement Features........................................................................................20

Biological Controls .....................................................................................................................................20

COORDINATION WITH MOSQUITO AND VECTOR CONTROL DISTRICTS...........................21

OTHER ACTIVE MOSQUITO CONTROL PRODUCTS ...................................................................29

BTI (BACILLUS THURINGIENSIS VAR. ISRAELENSIS)...................................................................................29

METHOPRENE..........................................................................................................................................29

CHEMICAL CONTROLS.................................................................................................................................29

Golden Bear Oil (GB-1111)........................................................................................................................29

Adulticides ..................................................................................................................................................30

INSECTICIDE RESISTANCE................................................................................................................30

MOSQUITO CONTROL TREATMENT EFFECTS ............................................................................30

MOSQUITO POPULATION......................................................................................................................30

F-i 
EFFECTS ON NON-TARGET ORGANISMS...........................................................................................31

Invertebrates in Aquatic Environments.......................................................................................................31

Invertebrates Outside Aquatic Environments .............................................................................................33

Sensitive Species and Habitats....................................................................................................................33

Consideration of Other Effects ...................................................................................................................36

RESPONSE THRESHOLDS ...................................................................................................................36

RESEARCH NEEDS ................................................................................................................................41

CHAPTER 2. INVASIVE SPECIES CONTROL AND OTHER VEGETATION MANAGEMENT

.................................................................................................................................................................... 42

INTRODUCTION.....................................................................................................................................42

SPECIES TO BE CONTROLLED ....................................................................................................................43

YELLOW STARTHISTLE (FROM BOSSARD ET AL. 2000)...............................................................................46

Mechanical methods ...................................................................................................................................47

Prescribed burning ......................................................................................................................................48

Biological ControL .....................................................................................................................................48

Grazing........................................................................................................................................................48

Plant competition ........................................................................................................................................48

CHEMICAL CONTROL............................................................................................................................49

ROUGH COCKLEBUR ...................................................................................................................................49

PHYSICAL CONTROL .............................................................................................................................50

PERENNIAL PEPPERWEED (FROM BOSSARD ET AL. 2000) ...........................................................................50

Physical Control..........................................................................................................................................51

Prescribed burning ......................................................................................................................................51

Inundation ...................................................................................................................................................51

Biological control........................................................................................................................................51

Chemical control.........................................................................................................................................51

RUSSIAN THISTLE (FROM UNIVERISITY OF CALIFORNIA 2007) ..................................................................53

FIELD BINDWEED (FROM UNIVERSITY OF CALIFORNIA 2007) ....................................................................54

BLACK LOCUST (FROM BOSSARD ET AL. 2000) ..........................................................................................55

Prescribed burning: .....................................................................................................................................56

Biological control........................................................................................................................................56

Chemical control.........................................................................................................................................56

PARROT’S FEATHER (FROM BOSSARD ET AL. 2000) ...................................................................................56

Physical control...........................................................................................................................................57

Biological control........................................................................................................................................57

Chemical control.........................................................................................................................................58

COMMON FIG (FROM BOSSARD ET AL. 2000)..............................................................................................58

Manual/mechanical .....................................................................................................................................59

Biological Control.......................................................................................................................................59

Chemical Control ........................................................................................................................................60

RED RIVER GUM (FROM BOSSARD ET AL.2000)..........................................................................................60

Physical control...........................................................................................................................................61

Prescribed burning ......................................................................................................................................61

Biological control........................................................................................................................................61

Chemical control.........................................................................................................................................61

WATER PRIMROSE (FROM UNPUBLISHED OBSERVATIONS AT THE COMPLEX) ............................................62

GIANT REED (FROM BOSSARD ET AL. 2000)................................................................................................62

F-ii 
Physical control...........................................................................................................................................63

Mechanical methods ...................................................................................................................................63

Prescribed burning ......................................................................................................................................63

Biological control........................................................................................................................................64

Grazing........................................................................................................................................................64

Chemical control.........................................................................................................................................64

SWAMP-TIMOTHY AND PRICKLEGRASS (FROM UNPUBLISHED OBSERVATIONS AT THE COMPLEX)............65

BERMUDA GRASS AND JOINTGRASS (FROM UNPUBLISHED OBSERVATIONS AT THE COMPLEX).................65

Mechanical control......................................................................................................................................65

Chemical control.........................................................................................................................................66

ANNUAL (ITALIAN) RYEGRASS...................................................................................................................66

Control Methods .........................................................................................................................................66

JOHNSONGRASS (FROM NEWMAN 1990).....................................................................................................67

Mechanical Control.....................................................................................................................................67

Chemical Control ........................................................................................................................................68

MEDUSAHEAD (FROM BOSSARD ET AL. 2000) ............................................................................................69

Physical control...........................................................................................................................................70

Grazing........................................................................................................................................................70

Chemical control.........................................................................................................................................70

WATER HYACINTH (FROM BOSSARD ET AL. 2000) ...................................................................................70

Physical Control..........................................................................................................................................71

Biological Control.......................................................................................................................................72

Grazing........................................................................................................................................................72

Chemical Control ........................................................................................................................................72

TREE-OF-HEAVEN (FROM BOSSARD ET AL. 2000).......................................................................................72

Physical Control..........................................................................................................................................73

Prescribed burning ......................................................................................................................................74

Biological Control.......................................................................................................................................74

Grazing........................................................................................................................................................74

Plant competition ........................................................................................................................................74

Chemical Control ........................................................................................................................................74

TAMARISK/SALTCEDAR (FROM UNIVERSITY OF CALIFORNIA 2007)..........................................................75

HIMALAYAN BLACKBERRY (FROM BOSSARD 2000)........................................................................76

Mechanical methods ...................................................................................................................................78

Manual methods..........................................................................................................................................78

Prescribed burning ......................................................................................................................................78

Biological Control.......................................................................................................................................79

Grazing........................................................................................................................................................79

Chemical Control ........................................................................................................................................79

POTENTIAL CONTROL METHODS AND MATERIALS.................................................................79

PRESCRIBED BURNING ................................................................................................................................79

DISKING.......................................................................................................................................................80

MOWING......................................................................................................................................................81

WATER MANAGEMENT ...............................................................................................................................81

PRESCRIBED LIVESTOCK GRAZING..............................................................................................................82

HERBICIDES.................................................................................................................................................83

2,4-D ...........................................................................................................................................................83

Aminopyrlid................................................................................................................................................84

Chlorsulfuron ..............................................................................................................................................84

Clopyralid ...................................................................................................................................................85

F-iii 
Glyphosate ..................................................................................................................................................85

Imazapyr .....................................................................................................................................................86

Triclopyr .....................................................................................................................................................86

Adjuvants ....................................................................................................................................................86

RESTORATION OF NATIVE SPECIES..............................................................................................................87

IPM MANAGEMENT STRATEGY ...............................................................................................................91

ASSESSMENT PROTOCOL.............................................................................................................................91

SACRAMENTO REFUGE COMPLEX HABITAT MANAGEMENT SYSTEM......................................................92

REFERENCES AND LITERATURE CITED ....................................................................................... 93

F-iv 
Figures 

Figure 1. Sacramento Refuge Complex map............................................................................. 3 

Figure 2. Seasonal wetland flooding and potential time periods for significant mosquito 

production.................................................................................................................................... 12 

Tables 

Table 1. Acreages and habitat types of Refuges within the Sacramento National Wildlife 

Refuge Complex............................................................................................................................ 4 

Table 2. Local Mosquito and Vector Control Districts............................................................. 6 

Table 3. Current disease surveillance methods that are employed on or in the vicinity of 

the Refuges at the Sacramento National Wildlife Refuge Complex..................................... 13 

Table 4. Water Management Practices to reduce mosquito production in managed 

wetlands. ...................................................................................................................................... 23 

Table 5.Vegetation management practices to reduce mosquito production in managed 

wetlands. ...................................................................................................................................... 27 

Table 6.Wetland infrastructure maintenance activities used to reduce mosquito production 

in managed wetlands. ................................................................................................................. 28 

Table 7. Wetland restoration and enhancement features to reduce mosquito production in 

managed wetlands. ..................................................................................................................... 29 

Table 8. Biological Controls to reduce mosquito production in managed wetlands............ 31 

Table 9.Suggested coordination activities between wetland managers and Mosquito and 

Vector Control Districts (MVCD)............................................................................................. 32 

Table 10.Federally listed and candidate species that can be found or suitable habitat 

occurs for at the Sacramento National Wildlife Refuge Complex. ....................................... 34 

Table 11. Mosquito-Borne Disease Health Threat and Response Matrix (adapted from 

USFWS 2005b). .......................................................................................................................... 38 

Table 12. Treatment thresholds for larvicide, pupacide and adulticide applications on 

refuges within the Complex....................................................................................................... 40 

Table 13. Selected invasive, non-native, or undesirable plant species of concern at 

Sacramento Refuge Complex1

................................................................................................... 44 

Table 14. Potential control methods and order of preference considered for use on 

selected invasive species at Sacramento National Wildlife Refuge Complex...................... 88 

F-v 
INTRODUCTION 

This Integrated Pest Management (IPM) Plan for controlling mosquito and invasive plants on the 

Sacramento National Wildlife Refuge Complex (Complex) is divided into two chapters: Chapter 1 

Mosquito Control, and Chapter 2 Invasive Species Control. 

This Plan is developed under the authority of: 

• Federal Noxious Weed Act of 1974, Public Law 93-629, as amended (7 U.S.C. 2801 et seq.) 

• Plant Protection Act (7 U.S.C. 7701 et seq.) 

• Federal Land Policy and Management Act of 1976 as amended, Public Law 94-579 (43 

U.S.C. 1701 et seq.) 

• Public Rangelands Improvement Act of 1978, Public Law 95-514 (43 U.S.C. 1901 et seq.) 

• Endangered Species Act, Public Law 93-205, as amended by Public Law 100-478 (16 U.S.C. 

1531 et seq.) 

• National Wildlife Refuge System Administration Act (16 U.S.C. 668dd) 

• National Wildlife Refuge System Improvement Act of 1997, Public Law 105-57 

• Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 (16 U.S.C. 4701 et 

seq.) 

• Executive Order 11514-Protection and Enhancement of Environmental Quality, as 

amended by Executive Orders 11541 and 11991 

• Executive Order 11987-Exotic Organisms 

• Executive Order 13112-Invasive Species 

• Department of the Interior (DOI) Manual 609 DM 1, Weed Control Program 

• Noxious Weed Regulations, 7 CFR Part 360 

• Pesticide Programs, 40 CFR Subchapter E 

• DOI Manual, Pesticide Use Policy, 517 DM 1 

• Administrative Manual, Pest Management Policy and Responsibilities, 30 AM 12 

This Plan also follows the requirements of the Refuge Manual, Pest Control Policy (7 RM 14), 

which states that it is the policy of the Service to engage in the control of wildlife and plants within 

the National Wildlife Refuge System to assure balanced wildlife and fish populations consistent 

with the optimum management of refuge habitat. 

The Service pest management policy goal (30 AM 12.1) is to eliminate the unnecessary use of 

pesticides through the use of IPM. IPM uses a combination of biological, physical, cultural, and 

chemical control methods (30 AM 12.5). This approach notes environmental hazards, efficacy, 

costs, and vulnerability of the pest. 

When plants or animals are considered a pest, they are subject to control on national wildlife 

refuges if: 1) the pest organism represents a threat to human health, well-being, or private 

property, the acceptable level of damage by the pest has been exceeded, or State or local 

governments have designated the pest as noxious; 2) the pest organism is detrimental to the 

primary refuge objectives; and 3) the planned control program will not conflict with the attainment 

of Refuge objectives or the purposes for which the Refuge is managed (7 RM 14.2). 

A pest is defined as any terrestrial or aquatic plant or animal which interferes, or threatens to 

interfere, at an unacceptable level, with the attainment of refuge objectives or which poses a 

threat to human health (7 RM 14.4). Pest management is defined as any practice or combination of 

F-1 
practices designed to manipulate pest or potential pest populations and to diminish pest injury or 

render them harmless. The objectives of pest management activities in the Refuge System (7 RM 

14.3) are: 

• To protect human health and well-being. 

• To prevent substantial damage to significant resources. 

• To protect newly introduced or re-established species. 

• To control exotic species and to allow normal populations of native species to exist. 

• To prevent damage to private property. 

• To provide individuals with quality wildlife-oriented recreational experiences. 

REFUGE DESCRIPTION 

HISTORICAL 

The Complex is composed of five National Wildlife Refuges (Refuges) and three Wildlife 

Management Areas (WMAs) in the northern Sacramento Valley (Figure 1). Historically, vast 

acreages of natural wetlands were created when the Sacramento River and its tributaries 

flooded during winter storms. This annual cycle provided habitat for millions of waterfowl and 

other wetland dependant wildlife. In the early and mid-1900s, the construction of levees along 

the rivers and agricultural development of the valley floor reduced wetland habitats by 

approximately 95 percent in the Central Valley (Gilmer et al. 1982, Central Valley Joint 

Venture [CVJV] 2006). Due to the loss of wetlands, crop depredation by waterfowl became a 

problem in the Sacramento Valley. Depredation issues and considerations for migratory bird 

conservation led to the establishment of a number of wildlife refuges, beginning with the 

Sacramento Refuge in 1937. Since then, Colusa (1945), Sutter (1945), and Delevan (1962) 

Refuges, Butte Sink WMA (1980), Willow Creek-Lurline WMA (1985), Sacramento River 

Refuge (1989) and North Central Valley WMA (1992) have also been established. Collectively, 

they comprise the Complex. 

For a detailed description of the Refuges, please refer to the Sacramento, Delevan, Colusa, and 

Sutter Refuges Draft Comprehensive Conservation Plan (CCP) (USFWS 2008) and the 

Sacramento River Refuge Final CCP (USFWS 2005a). 

PHYSICAL 

The Refuges range in size from 2,591 acres to over 11,000 acres. Habitats consist mostly of 

managed wetlands, with the exception of the Sacramento River Refuge, which consists 

primarily of riparian habitat (Table 1). 

Soils on Sacramento, Delevan, and Colusa Refuges are characterized by poorly drained, 

slightly to strongly alkaline clays. Sutter Refuge and Butte Sink WMA have poorly drained less 

alkaline clay soils. Soils on the Llano Seco Unit of the North Central Valley WMA are primarily 

loamy floodplain soils. Slope on all the Refuges ranges from 0-3 percent; elevation is 40-100 feet 

mean sea level; and average annual rainfall is 17-20 inches. Maximum daily temperatures can 

exceed 90 degrees Fahrenheit (°F) from May into October, and minimums can be in the 20s °F 

during winter months. 

F-2 
Figure 1. Sacramento Refuge Complex map. 

F-3 
Table 1. Acreages and habitat types of Refuges within the Sacramento National 

Wildlife Refuge Complex. 

Refuge Total1 

Managed Wetlands2 

Unmanaged 

Wetlands2 

Vernal 

Pool/Alkali 

Meadow2 

Irrigated 

Pasture Grassland2,5 

Riparian 

Forest2,6 Other2,7 

Seasonally 

Flooded 

Wetlands3 

Summer 

Wetlands4 

Sacramento 10,819 6,305 781 163 2,941 0 139 117 373 

Delevan 5,877 3,939 661 13 461 0 464 46 293 

Colusa 4,6868 2,957 390 119 619 0 438 15 148 

Sutter 2,5919 1,708 173 45 0 0 226 403 36 

Butte Sink 733 610 35 1 0 0 29 15 43 

Llano Seco 

Unit 1,732 667 93 2 6 184 611 116 53 

Sacramento 

River 10,059 0 0 88 0 0 119 7,373 2,479 

TOTAL 36,497 16,186 2,133 431 4,027 184 2,026 8,085 3,425 

1

 Official Refuge acres. 

2

 Acres calculated with GIS from 2006-07 annual habitat management plans. 3

 Includes irrigated and non-irrigated seasonally-flooded wetlands. 4 Includes semi-permanent and permanent wetlands. 

5 Includes annual and perennial grasslands. 6

 Includes mixed riparian forest, cottonwood willow, willow scrub, and valley oak riparian forest. 7

 Includes roads, facilities, and other miscellaneous areas. 8 Includes the 80-acre Rennick property. 

9 Includes 646 acres acquired under North Central Valley Wildlife Management Area. 

REFUGE PURPOSES AND GOALS 

The Service acquires Refuge System lands under a variety of legislative acts and administrative 

orders. The official purpose or purposes for a refuge are specified in or derived from the law, 

proclamation, executive order, agreement, public land order, donation document, or administrative 

memorandum establishing, authorizing, or expanding a refuge, refuge unit, or refuge subunit. The 

Service defines the purpose of a refuge when it is established or when new land is added to an 

existing refuge. These purposes, along with the Refuge System mission, are the driving forces in 

developing refuge vision statements, goals, objectives and strategies in the CCP. The purposes 

also form the standard for determining if proposed refuge uses are compatible. 

The Refuges purposes and goals are described in the Sacramento, Delevan, Colusa, and Sutter 

Refuges Draft CCP (USFWS 2008) and the Sacramento River Refuge Final CCP (USFWS 

2005a). 

HABITAT MANAGEMENT PRACTICES 

Currently, habitat management objectives at the Complex focus on maximizing benefits for 

wildlife, emphasizing feeding and resting areas for wintering waterfowl and other migratory 

F-4 
birds. Proper water and vegetation management is considered essential to maintaining high 

quality wetlands to meet the goals of the Complex. Most wetlands are “artificially” created and 

maintained using delivered water on leveed impoundments. They are flooded and drained with 

near complete control through inlet and outlet structures. The number of wetland units ranges 

from 40 to over 150 per Refuge. Flooding regimes are designed to approximate historical 

percentages of different wetland types as closely as possible, given water availability 

constraints. Furthermore, the timing of drawdowns, irrigations, and flood-ups largely dictates 

plant species composition (i.e. germination and growth of desirable food and cover plants). It 

also governs habitat availability (i.e. how much wetland is flooded at certain times of year for 

certain wildlife species). 

It is necessary to control certain plant and animal species that have undesirable effects on 

Refuge animals, plants, and habitats. The primary effect is competition with native plants for 

space, sunlight, nutrients, and water. The distribution and abundance of native plants that are 

important to wildlife as food, shelter, and nesting areas declines and wildlife habitat suffers. 

For a detailed description of habitat types and management practices, please refer to the 

Sacramento, Delevan, Colusa, and Sutter Refuges Draft CCP (USFWS 2008) and the 

Sacramento River Refuge Final CCP (USFWS 2005a). 

LISTED SPECIES 

A significant number of federal and/or state listed species occur on the Complex. In many 

cases, invasive species management is undertaken to maintain the populations and health of 

listed species (especially plants) in a variety of habitat types. Table 9 contains a list of federally 

threatened and endangered species on the Complex. For a description of listed species, please 

refer to the Sacramento, Delevan, Colusa, and Sutter Refuges Draft CCP (USFWS 2008) and 

the Sacramento River Refuge Final CCP (USFWS 2005a). 

Section 7 consultations with USFWS (2004) and NOAA-Fisheries (2004) concluded that the 

activities outlined in the Sacramento River Refuge Final CCP (USFWS 2005a) and in the 

accompanying hunting, fishing, fire management and integrated pest management plans will lead 

to long-term benefits to federally-listed species. Furthermore, they concluded the activities 

proposed in the CCP are consistent with the Intra-agency Formal Section 7 consultation (USFWS 

1999) regarding the operations and maintenance of the Complex. 

The Refuge has also requested Section 7 consultation with the USFWS and NOAA- Fisheries on 

the Sacramento, Delevan, Colusa, and Sutter Refuges Draft CCP (USFWS 2008). 

F-5 
CHAPTER 1. MOSQUITO CONTROL 

INTRODUCTION 

The Complex provides critically important habitats for a great diversity of wildlife, particularly 

migratory birds of the Pacific Flyway. Since the 1800s, over 95 percent of the historic wetlands in 

the Central Valley have been destroyed or modified (CVJV 2006). Despite these significant 

changes, approximately 60 percent of the total Pacific Flyway waterfowl population winters in the 

Central Valley and uses these Refuges (Gilmer et al. 1982). Today, wetlands are valued for their 

fish and wildlife habitat, recreational opportunities, and the benefits they provide in terms of flood 

control, water filtration, and ground water recharge. 

These wetland-dominated habitats can also produce or harbor significant quantities of mosquitoes 

during certain times of year. Some Refuges have been of particular concern to local Mosquito and 

Vector Control Districts (MVCDs or District) (Table 2) as areas that periodically require mosquito 

control to reduce human health risk from mosquito-transmitted diseases and significant public 

nuisance. Although the Service fully supports mosquito control under public health disease 

situations, control of mosquito populations outside of recent arbovirus detection has been allowed 

more reluctantly. The Service is obligated to both fulfilling its primary mission and refuge goals, 

while incorporating measures to ensure public safety. During the last 50 years, nationwide use of 

certain pesticides has resulted in negative effects to humans and natural resources. Consequently, 

regulations such as the Endangered Species Act, the 1988 revision of the Federal Insecticide, 

Fungicide, and Rodenticide Act, and increasingly restrictive pesticide use policies have been 

enacted in the long-term best interests of the public and the nation's resources. 

Table 2. Local Mosquito and Vector Control Districts 

Refuge Mosquito Control District 

Sacramento Refuge Glenn County MVCD 

Delevan Refuge Colusa MAD 

Colusa Refuge including Butte 

Sink fee title acres 

Colusa MAD 

Sutter Refuge Sutter-Yuba MVCD 

Sacramento River Refuge Butte County MVCD, Colusa MAD, Tehama MVCD 

MVCD=Mosquito and Vector Control Districts, MAD=Mosquito Abatement District 

MVCDs and wetland managers have a somewhat controversial history going back over 30 years in 

the Central Valley (Lusk 1979). MVCDs were perceived as relying solely on the use of chemical 

pesticides for control activities, while wetland managers were concerned about the potential 

effects of such control on wildlife and food chain resources such as invertebrates. However, MVCD 

use of IPM has helped to address this concern by employing a variety of control methods that 

include habitat management, biological control, and the use of more target-specific pesticide 

products. The increasing costs of pesticides and concerns over pesticide resistance have also 

spurred a more holistic approach to mosquito management. 

The Service is required to use an IPM approach for pest management activities on refuge lands 

(U. S. Department of Interior 2007). IPM employs a variety of mosquito control methods that 

include habitat management, biological control agents, and pesticide application. Wetland best 

management practices (BMPs) for mosquito control have been recently developed for the Central 

F-6 
Valley (Kwasny et al. 2004) and are a significant component of this plan. They can be used to lower 

the production of mosquitoes and reduce the need for chemical treatment, without significantly 

disrupting the ecological character, habitat function, or wildlife use of managed wetlands. 

The purposes of this IPM plan are to: 1) describe Refuge habitats and their role in the 

production or harborage of mosquitoes; 2) describe the use of approved mosquito control 

methods and materials in an IPM program that is consistent with the goals of the Complex, 

DOI and Service policy, and minimizes public health risk from Refuge-produced or harbored 

mosquitoes; and 3) provide long-term planning to meet the Service's goal of using IPM to 

minimize effects of mosquito control on trust resources to the greatest extent possible. 

MOSQUITO CONTROL ACTIVITIES 

The Complex coordinates annually with local MVCDs to allow the monitoring and, if necessary, 

control of mosquitoes to minimize public health risks from mosquito vectored diseases and 

significant nuisance. Wetland management BMPs for proactive mosquito control are regularly 

used by the Refuges, and are incorporated into annual habitat management plans. These include, 

but are not limited to, water management techniques, maintenance and improvement of water 

control structures, and strategic vegetation control. Refuge staff coordinates closely with the 

MVCDs on timing of irrigations, flood-up schedules, and communication of any problems with 

unplanned flooding. 

In addition, Pesticide Use Proposals (PUP) developed cooperatively with the MVCDs, are 

reviewed by Service IPM specialists, and if approved, are issued along with a Special Use Permit 

(SUP) that identifies conditions under which specific mosquito control activities can be conducted. 

Conditions specified in these documents include: products approved for use; application methods, 

rates, and timing; maximum number of applications allowed per season; measures to be taken to 

avoid sensitive areas; and annual reporting requirements for MVCDs. Currently, PUPs and SUPs 

are generated annually. Upon Service approval of this plan, approved PUPs can be valid for up to 

five years. 

During the last fifteen years at the Complex, most active mosquito control activities by MVCDs 

have been conducted during the summer irrigation and fall flood-up seasons. Mosquito control has 

most commonly been in response to production of floodwater mosquitoes after application of water 

onto wetland habitats that have been dry for some period of time; and secondarily, for standing 

water mosquitoes produced as a result of water maintained for periods of greater than two weeks. 

At times, Refuges also can harbor adult mosquitoes produced in nearby rice fields. Control efforts 

have focused primarily on Colusa and Sutter Refuges, and Butte Sink WMA, with some active 

control annually; and to a lesser degree on Sacramento and Delevan Refuges, and the Llano Seco 

Unit, with active control occurring only in some years. These differences in mosquito control 

efforts have been related to each Refuge’s proximity to an urban area, the level of arbovirus 

activity (i.e. West Nile Virus), whether or not the Refuge is within district boundaries, timing of 

wetland flooding/mosquito production, and differences in Districts’ control programs. 

Typically, control strategies at Colusa and Sutter Refuges, and Butte Sink WMA have focused on 

adulticides, using Ultra Low Volume (ULV) fogging. Larvicides have been used much less 

frequently, with MVCDs citing excessive cost, application problems, and reduced efficacy 

associated with their use on large expanses of seasonal wetlands. Despite these issues, there have 

been some recent changes in budgets for some MVCDs that have resulted in renewed interest to 

F-7 
use larvicides, particularly methoprene. Application methods for the various products include 

ground or aerial depending on the product, virus activity, and environmental conditions. 

Differences in control strategies among MVCDs (i.e. larviciding vs. adulticiding) have also been 

attributed to district size, budget, primary equipment on hand (aerial vs. ground), product efficacy, 

and restrictions of different control materials/methods. 

In the last ten years, products used by MVCDs for adult mosquito control have evolved from more 

toxic or persistent (including malathion and permethrin) to less toxic products that tend to break 

down in the environment more rapidly (i.e. pyrethrin). The Service has worked with local MVCDs 

to develop a “tool box” of mosquito control methods and materials available for use under 

appropriate conditions. These, along with wetland management BMPs implemented by the 

Refuge, are used as a combination of preventative and active mosquito control when treatment 

thresholds are met. There are continuing efforts to work with the MVCDs to minimize the amount 

and toxicity of mosquito control products used on the refuges. 

DISEASE HISTORY 

Western Equine Encephalitis (WEE), St. Louis Encephalitis (SLE), California Encephalitis (CE), 

West Nile Virus (WNV), and malaria can all be vectored to humans by mosquitoes. Currently, 

they are the main diseases that drive mosquito abatement programs based on human health risk 

in northern California. 

ENCEPHALITIS 

Encephalitis in humans resulting from exposure to WEE, SLE, or CE can result in mental or 

physical impairment or death. Culex tarsalis is the primary carrier or vector of encephalitis in 

northern California. Disease studies have also isolated WEE, SLE, and CE viruses from Aedes 

melanimon. A. melanimon has been shown to assist in the summer maintenance of WEE in the 

Sacramento Valley by means of a transmission cycle involving black-tailed jackrabbits (Hardy and 

Bruen 1974). 

WEST NILE VIRUS 

WNV was first reported in the United States in 1999. Since that time, cases of WNV have been 

reported in most states, with California first detecting the virus in 2003. In 2003, three locally 

acquired human WNV cases were detected in residents of Los Angeles, Imperial, and Riverside 

counties, and WNV activity was detected in dead birds, mosquitoes, sentinel chickens, and a horse 

in six southern California counties. As of fall 2007, WNV activity has been detected in most 

California counties, including all counties within the Complex. Laboratory testing has indicated 

that Culex tarsalis mosquitoes are likely to play a primary role in enzootic maintenance and 

transmission of WNV in California (Goddard et al. 2002). Ochlerotatus sp. and Aedes sp. 

mosquitoes were shown to be only moderately efficient vectors of WNV, and with a preference for 

mammalian hosts, they have little potential to act as secondary or bridge vectors from birds to 

mammals (Goddard et al. 2002). 

MALARIA 

Malaria was a major public health problem in California through the early 1900s (Gray and Fontaine 

1957). A combination of case detection and mosquito control reduced transmission to very low levels 

F-8 
by the 1920s. Three major outbreaks in the last 40 years have served as reminders that the 

introduction of the malaria parasites (Plasmodium falciparum and P. vivax), combined with 

presence of the Anopheles mosquito vectors, can result in transmission. 

MOSQUITO BIOLOGY 

Mosquitoes are dipteran insects with aquatic immature stages and an aerial adult stage. They 

have four aquatic larval stages (instars) plus an aquatic pupal stage. The adult emerges from the 

pupal stage onto the surface of the water, expands its wings, hardens its exoskeleton, and flies off. 

Depending on seasonal and environmental conditions and the particular mosquito species 

involved, it generally takes from three to 12 days for a mosquito to complete its life from 

developed egg to early adult stage. In general, as ambient temperature increases, the number of 

days required from hatching to emergence as an adult decreases. Although some species of 

mosquitoes (e.g., Culex tarsalis), are capable of long flights from the aquatic habitat, the mosquito 

problem created by a wetland will generally be proportional to it’s distance from concentrations of 

human and domestic animal populations. 

There are three primary species of mosquitoes (Aedes melanimon, Culex tarsalis, and Anopheles 

freeborni) that can be produced in managed wetlands and surrounding agricultural lands that have 

been the subjects of control efforts by MVCDs in the Central Valley. At times, Refuge habitats, such 

as riparian forest, may harbor mosquitoes produced on surrounding lands. These species can be 

categorized by life history traits into two distinct groups (floodwater mosquitoes and standing water 

mosquitoes). 

FLOODWATER MOSQUITOES 

AEDES MELANIMON 

The life cycle of the floodwater mosquito begins with flooding of ground that has undergone a dry 

period. The summer dry cycle in seasonal or semi-permanent wetlands fits the criteria for this 

species’ habitat needs. Once flooded, eggs that were laid during the previous dry cycle hatch, pupate, 

and emerge as adults. Research conducted in Merced County found that A. melanimon developed 

from first instar larvae to adult stage in eight to nine days in seasonal wetlands during the last half of 

September (Mortenson 1963). Gravid females then return to lay their eggs singly on drying soil, in 

leaf litter, in cracks in the soil, or at the bases of grasses and other plants in areas that have been 

flooded previously. Each female lays approximately 150 eggs per ovarian cycle. These eggs are very 

drought resistant, allowing them to survive during the summer. 

Floodwater mosquitoes are often the most abundant mosquito produced by managed seasonal 

wetlands, especially during summer irrigations and/or fall flooding. Relative to other species, adult 

females are aggressive and feed primarily on mammals. During the day, females will bite if disturbed 

or if a host presents itself, but generally biting and swarming activities peak at dawn or dusk. Other 

species of floodwater mosquitoes, including A. vexans and A. nigromaculus, may also occur in 

managed wetlands, but are much less common. Floodwater mosquitoes have been identified as a 

primary nuisance species and as playing secondary roles in transmission of CE and WEE. 

Floodwater species including A. melanimon and A. vexans have been shown to have only “moderate 

transmission rates,” for WNV, and with their preference for mammalian hosts, these species have 

little potential to act as secondary or bridge vectors for WNV from birds to mammals (Goddard et al. 

2002). 

F-9 
STANDING WATER MOSQUITOES 

CULEX TARSALIS 

Peak numbers of C. tarsalis occur in the Central Valley during the summer. Females lay their eggs 

on the water surface in bunches called rafts. Each raft contains around 100 to 150 eggs, hatching 

about 24 hours after being laid. The immature stages can be found in almost any source of water 

except tree holes. During the summer, development from egg to adult takes about seven to nine days. 

Peak populations occur in late June or early July, but can continue into late summer. Adults can 

emerge continuously throughout the summer and fall in areas that have been flooded for an extended 

period of time, usually for more than 2 to 3 weeks (i.e. rice fields, poorly drained pastures, semipermanent/permanent wetlands, seasonal wetlands flooded in August, sewer treatment plants, and 

dairy farms). 

Biting and swarming activities are typically at dawn or dusk. Adults spend daylight hours resting in 

secluded places such as animal burrows. C. tarsalis primarily bite birds, but will bite humans, 

livestock, and other mammals if the opportunity presents itself. In California, this species commonly 

feeds on songbirds in spring and early summer, and switches to mammalian feeding in late summer 

and fall. This change in feeding habits from birds to mammals, combined with large populations and 

the ability to travel long distances, makes C. tarsalis a potent vector of some of California’s 

arboviruses. C. tarsalis is considered the primary vector for WEE virus to humans and equines, and 

SLE virus to humans. C. tarsalis has been identified as a primary vector of WNV in the western 

United States (Goddard et al. 2002). 

ANOPHELES FREEBORNI 

A. freeborni also occurs in the Central Valley and is numerous during the summer, peaking in late 

July or August. Rice fields and semi-permanent and permanent wetlands are the primary production 

areas for this species, although the immature stages are also found in ditches, seepages, and sloughs. 

Females lay their eggs singly on the surface of the water where they hatch approximately 24 hours 

later. On the average, it takes about 9 to 12 days for A. freeborni to develop from egg to adult. Like C. 

tarsalis, this species can produce a continuous supply of newly emerged adults under the right 

habitat conditions. Adults rest during the day, and bite and swarm at dusk. In autumn, females enter 

a physiological state called diapause, during which reproduction is suspended and activity is 

diminished. They over-winter until January to March, when they come out of diapause and seek blood 

meals on warm days. After obtaining a blood meal, many females resume their over-wintering state 

until April or May when they begin laying eggs once more. The females will readily bite humans and 

livestock. This species can be a vector of malaria in the western United States. 

MOSQUITO ABUNDANCE IN REFUGE HABITATS 

Mosquito abundance reaches its peak on the Complex during flood-up of seasonally flooded 

wetlands (SFW) during late summer and early fall. Because hundreds of acres are flooded per 

week, there can be a constant influx of new mosquito cohorts, resulting in a sustained population of 

mosquitoes over the fall flood-up period. As each wetland floods, A. melanimon can be produced 

initially (on average within seven to ten days), potentially followed by C. tarsalis after 

approximately two weeks of inundation. There is a second smaller and much shorter-lived peak 

that is often observed during the spring/summer seasonal wetland irrigation season (Figure 2.). 

F-10 
This involves much less acreage and is not sustained since the irrigations are usually completed in 

seven to ten days. The irrigated wetlands then revert to a dry period until flooded in the fall. 

Semi-permanent and permanent wetlands can produce A. freeborni and C. tarsalis, but because of 

their limited acreage, stable water levels, and abundance of mosquito predators (fish, dragonflies, 

and other predatory invertebrates) they are typically not considered “problem” production areas 

that require additional control measures. However, they can still be managed to minimize 

mosquito populations by properly managing water and vegetation (Kwasny et al. 2004). If water 

levels are allowed to fluctuate, these wetlands can also produce floodwater mosquitoes that may 

become a concern. 

Refuge habitats can also function as staging or resting areas for adult mosquitoes produced both on 

and off Refuge lands. Sub-adult life stages of A. freeborni are typically not abundant; however, adults 

are found quite commonly during July and early August. This is when A. freeborni production in rice 

fields is at its peak. Riparian forests, or other heavily vegetated habitats, are attractive to adult 

mosquitoes because they provide moderate temperatures and available blood meals from birds and 

mammals. About 98 percent of the original riparian habitat has been destroyed in the Central Valley. 

As a result, riparian areas on Refuges can attract and concentrate adult mosquitoes produced from 

thousands of acres of surrounding rice fields and pastures. 

MONITORING DISEASE ACTIVITY 

Viral activity is monitored by local MVCDs by testing adult female mosquitoes or blood samples from 

live birds for presence of encephalitis virus. Center for Disease Control (CDC) light traps or artificial 

rest sites are used to collect live mosquitoes for virus testing (Table 3). CDC traps do not require 

electricity, which allows them to be used in remote areas to assess disease presence or relative 

abundance in a local area. Pools of 50 adult female mosquitoes of the desired species are collected and 

sent on dry ice to the Viral and Rickettsial Disease Laboratory (VRDL) for viral analysis. The VRDL 

tests the mosquitoes for the presence of arboviruses. 

To monitor the avian segment of the transmission cycle, sentinel chicken flocks are placed in areas 

throughout California and exposed to mosquitoes by MVCDs. Flocks exist at various locations 

around the Refuges. Once every two weeks, generally from May through October, blood samples 

are drawn from each chicken and centrifuged to collect the sera. The sera is then frozen and sent 

on dry ice to the VRDL where it is tested. If mosquitoes are actively passing encephalitis among 

birds, specific viral antibodies would theoretically show up in sera collected from sentinel chickens. 

Wild birds could also be sampled if they were available, but are otherwise considered too laborintensive for regular monitoring. 

Dead birds and some mammals (squirrels) are also monitored for WNV by local MVCD. Bird 

carcasses found by the public, Refuge, or District staff may be tested for WNV by local MVCDs, 

State laboratories, or the U. S. Geological Survey - National Wildlife Health Center. WNV cases in 

humans and horses are also monitored. Current data from all of these sources are available at the 

California West Nile Surveillance website (www.westnile.ca.gov). 

For malaria, MVCDs do not monitor the A. freeborni mosquito population for the presence of 

malaria parasites, but rely on information concerning human cases provided by local health 

departments. 

F-11 
Figure 2. Seasonal wetland flooding and potential time periods for significant 

mosquito production. 

J F M A M J J A S O N D 

Month 

Mosquito production 

potential 

Irrigations 

Fall Flood-up 

Acres of Flooded Managed Seasonal Wetland 

F-12 
 

 

Table 3. Current disease surveillance methods that are employed on or in the vicinity 

of the Refuges at the Sacramento National Wildlife Refuge Complex. 

Adult Mosquito Pools1 

Refuge or WMA 

Sentinel 

Chicken 

Flock CDC Traps2,3 

Artificial Rest 

Sites2 

Dead 

Birds4 

Sacramento X X X 

Delevan X 

Colusa X X X 

Sutter X X X X 

Butte Sink X X 

Llano Seco Unit X X X 

1

 Composite sample of adult mosquitoes (usually 50). 

2

 Often used to follow up specific disease source areas after a local chicken flock conversion. 

3

 Carbon dioxide-baited traps to collect adult mosquitoes. 

4

 Primarily for surveillance of West Nile Virus. 

F-13 
MONITORING MOSQUITO POPULATIONS 

Monitoring mosquitoes on the Complex is facilitated through a Special Use Permit (mosquito 

control is conducted under the same permit), allowing District personnel to sample wetlands and 

other areas on a weekly basis throughout the mosquito production season. Refuge maps and water 

management schedules made available to the MVCDs are used to help mosquito control 

technicians monitor current and potential mosquito habitat. Direct communication between 

Refuge staff and District personnel is used to identify changes in water management schedules. 

MVCDs are required to submit monitoring and treatment data annually. 

IMMATURE STAGES 

Larvae and/or pupae are typically sampled using a “dipper”, which is a 14-ounce white cup attached 

to a long wooden or metal handle. The dipper is used to determine the relative density of larvae by 

taking standard samples of water from a potential mosquito source. The contents are examined, 

recording mosquito numbers and species, resulting in a “number per dip” index. Sampling immature 

life stages of mosquitoes serves to identify significant production sites and can help determine the 

potential need for treatment. This is done based on the quantity and species of larvae found per dip, 

identification of the larval instar stage, number of days required for the larvae to pupate and emerge, 

and proximity to urban areas. Monitoring larval mosquito production throughout a wetland can help 

identify problem areas where certain BMPs can be employed to reduce future production. Larvicide 

and pupacide treatment thresholds are based on information using this monitoring technique. 

ADULT STAGE 

The relative abundance of adult mosquitoes is estimated using light traps, carbon dioxide-baited 

traps, or landing counts, depending on the individual MVCD’s protocol. Traps are hung from trees, 

buildings, or special stands, and usually remain in the same place throughout the season and from 

year to year. Light trap contents are collected weekly during the mosquito season. The total number 

of adult females, by species, is divided by the number of nights the trap was activated, and the index 

value is reported as adult females per trap night. New Jersey Light Traps (NJLT) are located on-site 

at Colusa and Sutter Refuges and northeast of Llano Seco Unit (between Llano Seco and the nearest 

town-Dayton). NJLTs are located in other areas near the Refuges, but are less effective in 

associating abundance to Refuge lands. 

Landing counts are used to sample adult mosquitoes in specific areas. With this method, an observer 

stands within the sample site, faces away from the wind and counts the number of mosquitoes that 

land on his/her pant legs over a period of one minute. The count is divided by two for a “leg count” 

index. This procedure is usually done early in the morning or at dusk, when temperatures are cool 

and mosquitoes are most active, and is repeated three or four times per site. Adulticide treatment 

thresholds are based on information using one or both of these monitoring techniques. 

POTENTIAL CONTROL METHODS AND MATERIALS 

WETLAND MANAGEMENT BMPS (FROM KWASNY ET AL. 2004) 

The BMPs in this document are habitat-based strategies that can be implemented when needed for 

mosquito control in managed wetlands. These strategies represent a range of practices that wetland 

managers can incorporate into existing habitat management plans, or in the design of new wetland 

F-14 
restoration or enhancement projects. Ideally, BMPs can be used to decrease the production of 

mosquitoes and reduce the need for chemical treatment without significantly disrupting the 

ecological character, habitat function, or wildlife use of managed wetlands. They can be used to 

exploit mosquito biology to minimize the production of larvae and ultimate emergence of the adult 

stage. More specifically, they are designed to take advantage of opportunities to discourage, 

minimize, delay, or compress mosquito production, and enhance natural mosquito predator 

populations. It should be recognized that BMPs function as a proactive first line of defense in 

deterring mosquito production and can be used in combination with other IPM tools such as, 

biological controls, larvicides, and adulticides when necessary. 

In many cases, BMPs overlap with commonly used habitat management practices to conserve water 

and manage wetland vegetation for wildlife (Batzer and Resh 1992a, Batzer and Resh 1992b, Resh 

and Schlossberg 1996). Not all BMPs will be appropriate for a given wetland location, or set of 

circumstances. Therefore, the Refuge staff works closely with local MVCDs to implement BMPs 

based on their potential effectiveness for regional or site specific conditions (such as wetlands that 

have a documented history of heavy mosquito production), and habitat management strategies. The 

implementation of BMPs is limited by cost and personnel constraints, potential impacts on wetland 

habitat, and wildlife response to these measures. 

BMPs have been divided into six categories. These categories are not listed in order of importance 

and may be used in combination. 

• Water Management Practices 

• Vegetation Management Practices 

• Wetland Infrastructure Maintenance 

• Wetland Restoration and Enhancement Features 

• Biological Controls 

• Coordination with MVCDs 

Following this BMP section is a series of tables (4-9) summarizing the BMPs in each category and 

outlining strategies, mosquito control objectives, advantages, and disadvantages. 

WATER MANAGEMENT 

Water management is one of the wetland manager’s best tools for reducing mosquito populations. 

Water management BMPs include timing and duration of flooding, the speed at which individual 

units are flooded or irrigated, and the stability of water levels (Table 4). Starting with the most 

persistently wet habitats, summer wetlands (permanent and semi-permanent) produce the least 

amount of mosquitoes, thus receive the least amount of concern from MVCDs. Stable water 

management is used regularly as a planned effort to discourage rank emergent plant cover from 

“taking over” wetlands designed for a combination of vegetative cover and open water. It also 

minimizes floodwater mosquito production. Abundant mosquito predators (fish, dragonflies, etc.) 

during mosquito production periods are the main attributes of these habitats that naturally 

discourage large-scale adult emergence. 

Historically, irrigations of seasonal wetlands at Colusa and Sutter Refuges, or Butte Sink WMA 

have periodically triggered mosquito control efforts, often adulticides to control newly emerged A. 

melanimon and in some cases Culex tarsalis. Several BMPs may be employed to modify 

irrigations and minimize mosquito production, while accomplishing habitat objectives for Refuge 

F-15 
resources. They include decisions on whether the irrigation is required, how soon after the initial 

drawdown it can be made, how rapidly the water can be applied, and how rapidly and completely 

the water can be drained. Following irrigations, a similar set of decisions can be made related to 

fall flood-up, including modifying flooding schedules, rapid flooding, or using water from summer 

wetlands that contain an inoculum of natural mosquito predators. 

Use of many of these BMPs requires water to be readily available, of sufficient quantity and 

quality, and that the conveyance infrastructure is adequate to permit rapid flooding or drainage. 

For some wetlands, circumstances outside the control of wetland managers (e.g. when agriculture 

drain water is used for flood-up, and must be taken at certain times) may limit their ability to 

implement water management BMPs. Sutter Refuge, Butte Sink WMA, and the northern portion 

of Colusa Refuge fall into this category. In managed wetlands where these limitations are not an 

issue, the following water management practices are considered. 

Timing of Flooding 

The timing of wetland flooding can greatly influence mosquito production (Fanara and Mulla 1974, 

Batzer and Resh 1992a). Delayed flooding may reduce mosquito production by shifting flooding 

schedules later in the year, when temperatures are cooler and mosquito production is less of a 

problem. Delayed flooding should be considered for wetlands with historic mosquito problems, as well 

as those in close proximity to urban areas. However, delayed flooding means that less wetland habitat 

is available for wildlife during times, such as August and September, when wetlands are particularly 

limited. Delayed flooding cannot be used exclusively on the Complex because Refuges have an 

obligation to provide habitat for early migrant waterfowl, sandhill cranes, and other waterbirds, and 

to reduce the potential for crop depredation by waterfowl. 

Given the limited feasibility of delayed flooding, phased or staggered flooding of wetlands is useful to 

provide a level of early-flooded habitat on some wetlands, while delaying flooding on others. Phased 

flooding involves flooding habitat throughout the fall and winter in proportion to wildlife need, and 

takes into consideration other wetland habitat that may be available in surrounding areas. 

For wetlands that are flooded early (August to early September) or in close proximity to urban areas, 

the use of vegetation and water management BMPs should be a high priority (Tables 4-9). 

 

BMPs: Delayed or phased fall flooding, Early fall flood-up planning (see Table 4 for additional 

explanation) 

Speed of Wetland Flooding 

As a general rule, the faster water can be applied during fall flooding and spring/summer irrigation, 

the fewer generations of mosquitoes will be hatched. Slow feather-edge flooding, although beneficial 

to foraging waterbirds, can produce multiple, staggered hatches of floodwater mosquitoes and, if 

treatment is necessary, often requires MVCDs to visit wetlands over a number of days for control 

activities (Garcia and Des Rochers 1983). Such an intensive treatment effort is expensive, and can 

result in more pesticide applications and additional disturbance to wildlife. 

BMPs: Rapid fall flooding, Rapid irrigation (see Table 4 for additional explanation) 

F-16 
 

Water Control 

Once wetlands have been flooded, it is important for managers to ensure that pond elevations do not 

fluctuate, except during planned drawdown or periods of low mosquito production (i.e. winter 

months). Fluctuating water levels tend to expose wetland edges to drying and provide suitable 

habitat for floodwater mosquitoes to lay eggs (Garcia and Des Rochers 1983). When water levels are 

subsequently raised, a new cohort of mosquitoes may be hatched. Water levels should be maintained 

through frequent monitoring, and adding water to offset any losses. A constant maintenance flow of 

water will also help maintain steady water levels, improve water quality, and reduce stagnation. 

If possible, wetlands can be flooded to deeper water depths during the fall and allowed to recede 

during the cooler winter months to provide shallow water depths for foraging waterbirds. Deeper 

water depths (24 inches) at initial flooding have been shown to significantly reduce mosquito densities 

at Grizzly Island Wildlife Area (Batzer and Resh 1992a,b). 

When flooding wetlands, water sources containing mosquito predators should be used to help colonize 

wetlands with predacious insects or mosquitofish that are passively transported by water from 

upstream locations (Collins and Resh 1989). Predator populations can be maintained in permanent 

waterways used to flood seasonal wetlands. In the Suisun Marsh, where water is readily available for 

flooding, seasonal wetlands are often initially flooded, and if mosquitoes become abundant, water 

levels are drawn down to concentrate mosquito larvae in ditches for biological control, larvicide 

treatment, or to drown larvae through turbulent water movement. Following this action, wetlands are 

immediately re-flooded. 

BMPs: Maintain stable water levels, Circulate water, Use deep initial flooding, Subsurface irrigate, 

Utilize water sources with mosquito predators for flooding, Flood and drain wetland (see Table 4 for 

additional explanation) 

Frequency and Duration of Irrigation 

Spring and summer irrigations are a common wetland management practices used to increase seed 

production and biomass of moist-soil plants (Naylor 2002), and reduce competition from undesirable 

plants in seasonal wetlands. The need to irrigate should be assessed closely by wetland managers. 

During years with above average spring precipitation, irrigations may not be necessary to maximize 

moist-soil plant production. When possible, managers should shorten the duration of irrigation to 4 to 

10 days to reduce the likelihood of hatching floodwater mosquitoes and eliminate the possibility of 

creating habitat for standing water mosquitoes. However, shorter irrigations may not always be 

feasible, especially when growing more water intensive plants such as watergrass and smartweed, or 

when conducting flooding to control undesirable plant species. In the case of weed control, plants 

should be monitored and water held only long enough to eliminate weeds. The necessary timing can 

be determined when weeds have turned black or have disintegrated. Finally, following wetland 

irrigations, water should be drawn down into waterways containing mosquito predators that can 

consume any mosquito larvae, which may have hatched. 

BMPs: Reduce number of irrigations, Use rapid irrigation, Drawdown and irrigate in early 

spring, Irrigate prior to field completely drying, Drain irrigation water into ditches or other 

water sources with mosquito predators, Use subsurface irrigation (see Table 4 for additional 

explanation) 

F-17 
VEGETATION MANAGEMENT PRACTICES 

Wetland managers commonly use vegetation control to alter plant species composition and 

abundance to influence wildlife use (Smith et al. 1995). As the vegetative community in a wetland 

changes through time, undesirable species inevitably encroach. Some species may be relatively 

benign, while others may be problematic, reducing habitat diversity or crowding out plants 

important as wildlife forage or cover. Vegetation is also an important habitat requirement for 

mosquitoes, and can improve mosquito survivorship by providing refuge from predators (Walton 

and Mulla 1989) and abundant food resources for larvae. Vegetation can also increase mosquito 

developmental rates by raising water temperatures (Collins and Resh 1989). To manage the 

vegetative community to benefit wildlife, a number of techniques are used, including mowing, 

burning, disking, spraying, and grazing. These habitat management practices can be used alone or 

in combination and can also be used to reduce mosquito production (Table 5). 

Any management action that alters the composition of wetland vegetation may create either benefits 

or detriments to wildlife. The decision to conduct such operations should be determined by the 

management objectives of an individual Refuge (e.g. in annual habitat management plans). Sitespecific characteristics, habitat management objectives, cost, and recreational use (e.g., hunter 

access) all have to be carefully considered in vegetation management plans. Typically, any vegetation 

control measure will result in the short-term loss of cover for wildlife. Such compromises have to be 

weighed in terms of the long-term benefits they provide for wildlife resources versus the ancillary 

benefits they provide for mosquito control. 

Mowing 

Mowing is commonly used to create open water habitat for shorebirds and waterfowl. Mowing 

provides opportunities for the biological control of mosquitoes, and enhances the effectiveness of 

pesticides by allowing greater saturation of mosquito habitats. Experimental mowing of 

approximately 50 percent of a wetland has been shown to reduce the density of mosquitoes and 

concentrate their distribution, while increasing densities of invertebrates that are consumed by 

waterfowl (Batzer and Resh 1992a). Similarly, Garcia and Des Rochers (1984) found that seasonal 

wetlands mowed with a 50 percent plant-cover ratio enhanced wind action that moved mosquito 

larvae to wetland edges where treatment efforts could then be concentrated. The benefits of mowing, 

unlike burning or disking, tend to be short term and require that the practice be implemented on an 

annual basis. Mowing may also leave residual matter that, when flooded, provides habitat for 

mosquitoes (Kwasny et al. 2004). 

Burning 

Controlled burning, where and when feasible, can effectively control vegetation. Burning, especially 

when immediately followed with disking, can offer multiple year control of mosquitoes, reduces 

vegetation used by mosquitoes for breeding activities, and also directly results in the kill of mosquito 

eggs due to high temperatures associated with fire (Resh and Schlossberg 1996, Whittle et al. 1993). 

Burning releases nutrients stored in plant materials and makes them available to benefit plant and 

invertebrate production during the following flooding cycle. However, due to difficulty with obtaining 

local burn permits on a consistent basis, the amount of acres that can be burned annually is limited. 

F-18 
Disking 

Disking is commonly used to reduce dense stands of emergent or undesirable vegetation, and provide 

favorable conditions for the establishment of moist-soil plants consumed by waterfowl. Disking, 

unlike mowing, tends to change the vegetation composition of a wetland and provides a more 

permanent means of control. Disking has also been shown to significantly reduce densities of 

mosquitoes over multiple years, increase the densities of macroinvertebrates important in the diets of 

waterfowl, and encourage the replacement of less desirable vegetation by moist-soil plants (Resh and 

Schlossberg 1996). Lawler et al. (2007) found that the use of herbicide and disking for jointgrass 

control also resulted in fewer mosquito larvae and pupae. Untreated plots had seven times more 

larvae and 20 times more pupae than did vegetation-removal plots. The benefit of disking can often be 

enhanced by first mowing or burning vegetation targeted for control. 

Haying and Grazing 

Agricultural practices such as haying and grazing may also be useful to control wetland vegetation. 

However, little information is available on their effectiveness as mosquito control measures. Haying, 

while functionally similar to mowing, may provide the same mosquito control benefits. Haying has a 

potential added benefit of removing cut plant material that may decay and negatively affect water 

quality, thereby increasing mosquito production (Kwasny et al. 2004). However, haying removes 

valuable seed resources consumed by wildlife and interrupts the cycle of nutrient release back into 

wetland environments. In addition, haying has limited applicability in most wetland environments 

because of the relative remoteness of wetlands from agricultural operations, difficulty of running 

haying equipment in unleveled wetland terrain, and low palatability of wetland vegetation as livestock 

forage. 

Grazing is frequently used to reduce plant biomass in wetlands, and provide short grass and open 

water habitats for shorebirds and waterfowl. However, grazing animals require sources of drinking 

water and often irrigated grasslands for forage. Water used to meet these needs may provide 

additional habitats for mosquitoes. Furthermore, grazing animals can create wallows or depressions 

in moist wetland terrain, which trap water and create additional microhabitats for mosquitoes 

(Kwasny et al. 2004). Additional research needs to be conducted to determine the usefulness of 

grazing as a mosquito reduction tool. 

WETLAND INFRASTRUCTURE MAINTENANCE 

Wetland infrastructure is the foundation for habitat management. A properly functioning water 

delivery and drainage system, well maintained levees, correctly operating water control structures, 

and efficient pumps are key to avoiding the unnecessary production of mosquitoes through simple 

neglect (Table 6). Time and money invested in these proactive maintenance activities will reduce 

mosquito production and help landowners improve wetland management efficiency, while avoiding 

the additional costs of controlling mosquitoes and unwanted vegetation. 

Levee and Water Control Structure Inspection and Repair 

Levees and water control structures should be inspected on an annual basis to identify problem areas 

including weak spots or rodent damage that may leak water and produce mosquitoes. Water control 

structures should be watertight and properly sealed to prevent seepage. 

F-19 
Ditch and Swale Cleaning 

Vegetation in water delivery ditches and swales can create habitat for mosquitoes or impede the flow 

of water that facilitates rapid flooding or drainage. Typical maintenance activities of water 

delivery/drainage ditches include the use of herbicides or periodic dredging to remove problem 

vegetation that inhibits water flow. Ditches and swales should be cut to grade to prevent the 

unintentional trapping of water. Likewise, silt that accumulates in front of inlet or outlet structures 

should be removed so it does not impede flow or trap water in swales. 

Pump Tests and Repair 

Pumps used for flooding should be periodically tested to make sure they are operating at optimum 

efficiency. This will ensure that pumps are providing maximum output, which will facilitate rapid 

flooding. 

WETLAND RESTORATION AND ENHANCEMENT FEATURES 

All well planned wetland restoration and enhancement projects begin with an initial survey and 

design phase. During this phase, landowners and restoration biologists have the opportunity to 

discuss design features with MVCDs and incorporate BMPs to reduce mosquito production (Table 7). 

Time spent at the design stage can save thousands of dollars in annual operation and maintenance 

costs and prevents problems resulting from poor water management and unintended mosquito 

production. Wetland design typically focuses on aspects of water control that promote vegetation 

beneficial to wildlife, conserve water, and allow for periodic vegetation control. 

Wetland design features to reduce mosquito production 

Wetland design features that reduce mosquito production include independent flooding and drainage 

capabilities, size considerations to facilitate rapid flooding, and the incorporation of features that 

promote habitats for mosquito predators and allow those predators access to mosquitoes. Water 

delivery ditches, water control structures and levees should be designed and built to specifications 

that prevent wind and water erosion, provide equipment access for maintenance activities, and reduce 

damage caused by burrowing animals. These design features will facilitate other mosquito BMPs 

such as water and vegetation management practices, infrastructure maintenance, and natural 

mosquito predation. 

BMPs: Independent water management, Adequately sized water control structures, Swale 

construction, Wetland size consideration, Ditch design, Levee design & compaction, Deep 

channels or basins constructed in seasonal wetlands, Permanent water reservoir that floods into 

seasonal wetlands (for additional explanation see Table 7) 

BIOLOGICAL CONTROLS 

Naturally occurring predators, such as fish, dragonflies, aquatic macroinvertebrates, and certain 

birds and bats, can contribute to the reduction of mosquitoes (Table 8). However, it often takes time 

before predator populations become established and have an effect on mosquito numbers. Natural 

predator populations can be supplemented, for example, through the stocking of mosquitofish 

(Gambusia affinis), but in most instances a habitat manager’s best strategy is to maintain natural 

predator populations on-site. Primary stockings of fish are usually conducted at a minimal initial rate 

F-20 
of 0.1 lb per acre. Stockings are augmented up to 1.0 lb per acre, based on larval dipping data. Past 

tests conducted by the Sutter-Yuba Mosquito Abatement District at the Gray Lodge Wildlife Area 

have demonstrated that 1 to 4 pounds of fish per acre were necessary for the successful control of 

Aedes sp. larvae, presumably on SFW (Lusk 1979, Hanna 1980). Follow-up test results also showed 

that sufficient numbers of fish must be stocked when the water is initially turned into each field. 

Some preparatory vegetation clearing and creation of open channels to facilitate fish movement and 

water flow were also helpful. For biological controls to be effective, wetland managers need to create 

an environment that is both conducive to maintaining predator populations and providing predators 

with access to mosquito prey. 

Encourage on-site predator populations 

Management practices have been developed that incorporate permanent water within seasonal 

wetlands to “inoculate” newly flooded habitats with an on-site predator source. This can be 

accomplished by maintaining permanent water in swales and deep borrow ditches, or by flooding 

wetlands with water from nearby permanent wetlands. Permanent water sources will need to be 

maintained when seasonal wetlands are dry, if wild populations of mosquitofish are to be sustained 

on-site. Such “dry season” predator reservoirs should be 18 inches or greater in depth to reduce 

predation of mosquitofish by herons and egrets (Collins and Resh 1989). Dry season reservoirs 

should be interconnected to seasonal wetlands through swales or ditches to allow mosquitofish to 

seek more permanent habitat as seasonal wetlands are drawn down and, conversely, to allow 

mosquitofish to disperse into seasonal wetlands as they are re-flooded in the fall. 

It is critical to the success of biological control to limit the use, when possible, of broad-spectrum 

insecticides that not only kill mosquitoes, but also eliminate their natural predators. Control 

programs that combine biological controls with chemical insecticides often result in suboptimal 

results because the predators take longer to recover from insecticide induced mortality than 

mosquito populations (Walton et al. 1990). 

Provide predator access to mosquitoes 

The extent of wetland vegetation may limit predator access to mosquitoes (Walton and Mulla 1989, 

Collins and Resh 1989). Wetlands with significantly dense vegetation provide an abundance of hiding 

places for mosquitoes and can limit aquatic predator dispersion. Vegetation management BMPs can 

be used to reduce dense stands of cattails, tules, or other emergent vegetation and provide predator 

access to mosquito prey. Isolated basins that do not interconnect to the main water body of a wetland 

will also limit an aquatic predator’s access to mosquito prey. To encourage mosquito predation, 

wetland swales can be constructed to connect isolated basins with deep-water areas containing 

aquatic mosquito predators. 

COORDINATION WITH MOSQUITO AND VECTOR CONTROL DISTRICTS 

The responsibilities of MVCDs and wetland managers have some inherent conflicts. MVCDs have 

a responsibility to reduce vectors that may transmit disease to humans or cause a significant 

nuisance. Wetland managers have a responsibility to maintain and enhance wetlands: a public 

trust resource that provides habitat for migratory birds, threatened and endangered species, and 

helps to reduce depredation from waterfowl on agricultural lands. Public resource agencies are 

increasingly being asked to provide wetland habitat to meet the recreational demands of hunters, 

anglers, bird watchers, photographers, and hikers. Wetland managers recognize that mosquito 

F-21 
production may be a by-product of wetland management and in some cases may contribute to 

problems requiring mosquito control. However, in order for both MVCDs and wetland habitat 

managers to accomplish their objectives, cooperation and coordination is essential (Table 9). 

Coordinate habitat management and flooding schedules 

By providing advanced information regarding habitat and water management schedules, wetland 

managers enable MVCDs to make suggestions regarding BMPs, schedule monitoring efforts, and, 

if necessary, control mosquitoes as efficiently as possible. In return, MVCDs can provide the 

Refuge with useful input and feedback on how to reduce mosquito production and potentially 

reduce abatement costs. 

Identify problem areas for mosquito production and target implementation of BMPs: Coordination 

is also required on the part of MVCDs and Refuges to identify the highest priority wetlands for 

the implementation of BMPs. For example, Garcia and Des Rochers (1983) found that A. 

melanimon larvae were largely restricted to specific areas in a few fields on Gray Lodge Wildlife 

Area. As a result, limited resources could be focused on these problem areas. 

Coordinate wetland habitat restoration and enhancement project design 

Prior to enhancement or restoration projects, MVCDs should be consulted to determine if design 

features to reduce mosquitoes can be incorporated. By involving MVCDs early in the process, 

problems associated with design features or poor engineering that may encourage mosquito 

production can be avoided. 

F-22 
Table 4. Water Management Practices to reduce mosquito production in managed wetlands. 

Best Management Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

Delayed or phased fall flooding 

Delay flooding of some wetland units until later in the fall. Delay flooding units with greatest historical mosquito production and/or those closest to urban areas. 

To delay initiation of floodwater mosquito production in seasonal wetlands by reducing the amount of mosquito habitat available during optimal breeding conditions (warm summer/early fall weather). Reduce the time available for standing water mosquito production in seasonal wetlands. 

Depending on flood date, can reduce the need or amount of additional treatment. Delayed flooding can provide “new” food resources for wildlife later in the season when wetlands are finally flooded. 

Reduces the amount of habitat for early fall migrants and other wetland-dependent species, and may increase potential for waterfowl depredation on agricultural crops (especially rice). Flooding is often dictated by water availability or contractual dates for delivery. Delayed flooding may still produce mosquitoes in warm years. Private hunting clubs can’t lease blinds that aren’t flooded. 

Early fall flood-up planning 

Apply BMPs to wetlands identified for early flooding. To the extent possible, areas targeted for early fall flooding should not be near urban centers and should not have a history of heavy mosquito production. 

To reduce the early season production of mosquitoes or to reduce their encroachment on urban areas. 

Allows for the provision of early flooded habitat while minimizing mosquito production and conflicts with urban areas. 

Some additional effort required to monitor and identify suitable areas. Requires the extensive use of BMPs to ensure mosquitoes are not produced. 

Rapid fall flooding Flood wetland unit as fast as 

possible. Coordinate flooding with neighbors or water district to maximize flood-up rate. 

To minimize number of mosquito cohorts hatching on a given area. 

Reduces the need for multiple treatments needed by synchronizing larval development and adult emergence. In turn, reduces wildlife disturbance by MVCDs. 

Requires coordination & ability to flood quickly. Reduces slow, feather-edge flooding that is heavily utilized by waterbirds. 

Rapid irrigation 4-10 day irrigation (from time 

water enters the pond to complete drawdown). 

Shorten irrigation period to reduce time available for mosquitoes (especially Culex 

tarsalis and Anopheles freeborni) to complete lifecycle. 

Provides some level of wetland irrigation while reducing the time available for mosquitoes to complete lifecycle. 

Requires ability to rapidly flood & drain wetland. If flooding is used for weed control, rapid irrigation may not be feasible. 

F-23 
Table 4 (cont.). Water Management Practices to reduce mosquito production in managed wetlands. 

Best Management Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

Maintain stable water level (summer and early fall flooding) 

Ensure constant flow of water into pond to reduce water fluctuation due to evaporation, transpiration, outflow, and seepage. 

To reduce conditions for additional floodwater mosquito production in summer and fall. 

Provides a stable wetland environment for breeding wildlife during spring and summer. Discourages undesired excessive vegetative growth which could also become additional mosquito breeding substrate. 

Requires regular monitoring and adjustment to water control structures. May be difficult if water availability is intermittent or unreliable. Reduces mudflat habitat that is attractive to shorebirds and waterfowl. 

Water circulation Provide a constant flow of 

water equal to discharge at drain structure. 

To keep water fresh and moving to deter stagnant conditions for mosquito production; reduces water level fluctuation and potential production of floodwater mosquitoes. 

Discourages warm water conditions associated with avian botulism outbreaks. 

Requires landowner to purchase additional “maintenance” water. May be difficult if water availability is intermittent or unreliable. 

Deep initial flooding (18-24”) 

Flood wetland as deep as possible at initial flood-up. 

To reduce shallow water habitat for mosquito breeding. May provide more open water by over-topping vegetation, thereby facilitating mosquito predation or wind action that drowns larvae. 

Potentially slows mosquito development by eliminating warm, shallow water habitat. 

Requires additional water and infrastructure adequate to flood deeply. Reduces shallow water foraging habitat for shorebirds and waterfowl. 

Utilize water sources with mosquito predators for flooding wetlands 

Flood wetlands with water sources containing mosquito fish or invertebrate predators. Water from permanent ponds can be used to passively introduce mosquito predators. 

To inoculate newly flooded wetlands with mosquito predators. 

May establish mosquito predators faster than natural colonization. 

Requires source of water with already established mosquito predators. Not applicable to wetlands flooded with well water. 

Drain irrigation water into ditches or other water bodies with abundant mosquito predators 

Drain irrigation water into locations with mosquito predators as opposed to adjacent seasonal wetland or dry fields. 

To reduce the amount of larvae through natural predation and minimize the number of adults that emerge. 

Already a common wetland management practice. 

Must have ditch or water body with established predator population available to accept drain water. 

F-24 
Table 4 (cont.). Water Management Practices to reduce mosquito production in managed wetlands. 

Best Management Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

Flood & drain wetland 

Flood wetland and hatch larvae in pond. Drain wetland to borrow or other ditch where larvae can be easily treated, drowned in moving water, or consumed by predators. Immediately reflood wetland. 

Hatches mosquito larvae and moves them to a smaller area for treatment before they can emerge as adults. 

Can eliminate or reduce the need for additional mosquito control efforts. 

Additional cost to purchase water to re-flood wetland. Timing is critical. Requires monitoring and is labor intensive. 

Reduce number of irrigations 

Evaluate necessity of irrigation, especially multiple irrigations, based on spring habitat conditions and plant growth. Eliminate irrigations when feasible. 

To eliminate unneeded additional irrigations which could provide potential habitat for mosquitoes. 

Reduces potential need for additional mosquito control. Saves water and manpower costs. Discourages excessive growth of undesirable vegetation (i.e. joint and Bermuda grass) 

May reduce seed production or plant biomass with less irrigation. 

Early spring drawdown and irrigation 

Drawdown wetland in late March or early April. Irrigate in late April or early May when weather is cooler and mosquitoes are less of a problem. 

To reduce need for irrigation in June, July, and August, when potential for mosquito production would be higher. 

Wetland irrigation can be accomplished without creating potential mosquito problems. May allow moist-soil plants to take advantage of natural rainfall during the spring. 

Reduces shallow wetland habitat for migratory shorebirds and waterfowl in April and May, during a major migration period. Newly germinated wetland plants may be impacted by cold weather conditions. May stimulate germination and growth of undesirable wetland plants. 

Don’t let field completely dry and crack between spring drawdown and irrigation 

Irrigate wetland before soil completely dries. 

To eliminate necessary drying period for floodwater mosquito to lay eggs. 

May reduce mosquitoes produced from irrigation 

Requires close monitoring of soil moisture to correctly time irrigation. 

F-25 
Table 4 (cont.). Water Management Practices to reduce mosquito production in managed wetlands. 

Best Management Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

Subsurface irrigation Maintain high ground water 

levels by keeping channels or deep swales permanently flooded. 

To reduce amount of irrigation water during mosquito breeding season. 

Reduce need for surface irrigation while maintaining soil moisture to promote moistsoil plant production. 

Requires deep swales or boat channels to be effective. Requires additional pipes in channels for equipment access. May not produce intended irrigation result if water table is naturally low. Requires that water be maintained longer than normal in swales. May promote unwanted vegetation growth in swales or promote irrigation of non-target plants in wetland. 

F-26 
Table 5.Vegetation management practices to reduce mosquito production in managed wetlands. 

Best Management Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

Mowing Mow undesirable or 

overgrown vegetation that serves as mosquito breeding substrate prior to flooding. 

To reduce standing vegetation that mosquitoes can use for egg laying and larval development. To create open water habitat that allows mosquito predators (fish, invertebrates, birds) better access to larvae and potentially more wave action to drown mosquito larvae. 

Improves wildlife habitat by providing open-water. 

Effects are largely temporary, so must be conducted annually. Overuse could be detrimental to some species of wildlife and nontarget invertebrates. Mowed vegetation may float providing mosquito habitat and decomposition may affect water quality. 

Burning Controlled burn of 

undesirable or overgrown vegetation that may provide mosquito breeding substrate. 

See mowing. Can also kill mosquito eggs. 

See mowing. Requires burn permit. Liability 

concerns. Most landowners are not adequately prepared to conduct a controlled burn. Special consideration should be taken around plastic pipes or water control structures. Overuse could be detrimental to some species of wildlife and non-target invertebrates. 

Disking Disk undesirable or 

overgrown vegetation that may provide mosquito breeding substrate. 

See mowing. See mowing. Can provide 

longer-term control of undesirable vegetation by itself or in conjunction with other management practices. 

Creates walking problems for hunters. Overuse could be detrimental to some species of wildlife and non-target invertebrates. 

Haying/grazing Mow and bale undesirable 

or overgrown vegetation that may provide mosquito breeding substrate. Spring, summer, or fall grazing. 

See mowing. Also removes vegetation after cutting. 

Dual benefits of improving habitat and reducing mosquito breeding substrate. Removal of mowed vegetation further decreases mosquito breeding substrate and may improve water quality. Grazing is relatively inexpensive and can also be used to meet wildlife habitat objectives. 

Overuse could be detrimental to some species of wildlife and nontarget invertebrates. Removes seed that wintering waterfowl forage on. Expensive. Often difficult to find someone to bale and haul plant material. Irrigation for livestock watering may exacerbate mosquito production. Livestock can also forage on desirable plants. 

F-27 
Table 6.Wetland infrastructure maintenance activities used to reduce mosquito production in managed wetlands. 

Best Management Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

Levee Inspection & Repair 

Walk or drive levees, flag problem spots, repair as needed. Consider design elements to improve integrity of levee 

To reduce mosquito habitat/production caused by seepage into adjacent fields or dry ponds. 

Allows for early identification of problem spots. Helps conserve water and reduces growth of unwanted vegetation. 

Requires annual monitoring and funding for repairs. 

Water Control Structure Inspection, Repair, & Cleaning 

Inspect structures and repair or replace as needed. Remove silt and vegetation build-up in front of structures. Adequately close, board or mud-up controls. 

To reduce mosquito habitat/production caused by seepage into adjacent ponds or drainage ditches. Remove silt blockages that may trap water and impede drainage. 

Enhances water management capabilities and limits unwanted vegetation or standing water. 

Requires annual monitoring and funding for cleaning or repair. 

Ditch Cleaning Periodically remove silt or 

vegetation from ditches to maintain efficient water delivery and drainage. 

To allow for rapid flooding/drainage & reduce vegetation substrate for breeding mosquitoes. 

Enhances water management capabilities and limits unwanted vegetation or standing water. 

Requires funding for ditch cleaning. Excessive vegetation removal on ditch banks can result in negative impacts to nesting birds and other wildlife. 

Pump Tests & Repair Test pump efficiency and make 

any necessary repairs to maximize output. 

Could identify output problems and if corrected, allow managers to flood more rapidly. 

May promote faster irrigation and flood-up if output can be improved. 

Requires pump test. May be costly to repair or replace pump/well. 

F-28 
Table 7. Wetland restoration and enhancement features to reduce mosquito production in managed wetlands. 

Best Management Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

Independent water management 

To the extent possible, design wetland projects to include independent inlets and outlets for each wetland unit. 

To reduce the need to move water through multiple wetland units when flooding or irrigating target areas. This can reduce the number of mosquitoes produced per flood event. 

Creates wetland units that are hydrologically distinct from one another allowing for diverse wetland management. 

May require additional water control structures and ditches to be constructed and maintained. Increases restoration costs and complexity of management. 

Adequately sized water control structures 

Increase size and number of water control structures. When installing, set to proper grade to allow for complete drawdown. 

To improve ability to implement rapid flooding/irrigation BMPs. 

See rapid flooding/irrigation BMPs. 

Increased size and number of water control structures will increase restoration costs and management complexity. 

Swale construction (sloped from intake to drain) 

Construct or enhance swales so they are sloped from inlet to outlet and allow the majority of the wetland to be drained. 

To improve ability to implement rapid flooding/irrigation BMPs. Creates a means to move water through wetlands without flooding entire wetland basin. Reduces mosquito habitat by allowing isolated sections of habitat to drain. Provides mosquito predators with access to all portions of wetland. 

See rapid flooding and irrigation BMPs. Provides habitat diversity and enhances capabilities to implement moist-soil management. Provides a more cost effective and wildlife friendly alternative to laser leveling to create drainage. 

See rapid flooding and irrigation BMPs. Reduces standing water in spring that is often used by foraging waterbirds. May result in additional expense to create swales. Shallow swales must be periodically re-cut if silt deposition or dense emergent vegetation is a problem. Could be a deep water hazard in hunting areas. 

Wetland size considerations 

Install cross-levees to facilitate more rapid irrigation and floodup. Build “underwater” levees that isolate irrigation water during the spring, but can be overtopped during fall and winter flooding. 

To improve ability to implement rapid flooding/irrigation BMPs. 

Assists with faster flooding and drainage. Cross levees (checks) can provide loafing habitat for waterfowl and shorebirds. 

Additional levees may result in decreased wildlife use and diversity. Expensive. Requires additional levee maintenance and water control structures. 

F-29 
Table 7 (cont.). Wetland restoration and enhancement features to reduce mosquito production in managed wetlands. 

Best Management Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

Ditch design (2:1 slopes & minimum 4 foot bottom)* *consider 3:1 slope or greater to discourage burrowing animal damage and potential seepage problems 

Construct or improve ditches to quality standard that prevents unwanted vegetation growth or unnecessary seepage. 

Reduces likelihood of vegetation growing along ditch banks. Excessive vegetation slows water flow, traps silt, and can be used as substrate for mosquito eggs. 

Improves water flow and decreases maintenance of vegetation that grows along canal banks. 

May require re-designing some delivery ditches to meet specific design criteria. Could affect habitat for wildlife species such as giant garter snakes. Steeper slopes may erode more quickly and created a hazard for hunters. 

Levee design & compaction (>3:1 slopes & >80% compaction)* *consider5:1 slope or greater in areas prone to over-land flooding and levee erosion. 

Construct or improve levees to quality standard that ensures stability and prevents unwanted seepage. 

To reduce mosquito habitat caused by seepage into adjacent fields or dry ponds. 

Properly constructed levees prevent seepage from erosion or rodent damage, and reduce need for annual maintenance. 

Additional expense to repair or build levees on existing properties. 

Deep channels or basins constructed in seasonal wetlands 

Excavate deep channels or basins to maintain permanent water areas (> 2.5 feet deep) within a portion of seasonal wetlands. Provides year-round habitat for mosquito predators which can inoculate seasonal wetlands when they are irrigated or flooded. 

To reduce mosquito larvae through predation. 

Provides on-site source of mosquitofish and other mosquito predators to seasonal wetlands. Increases overall habitat diversity. 

Expensive to excavate and maintain permanent water. Potential problems with emergent vegetation. May be a deep water hazard in hunting areas. 

Permanent water reservoir that floods into seasonal wetlands 

Maintain separate permanent water reservoir that conveys water to seasonal wetlands. Provides year-round habitat for mosquito predators which can inoculate seasonal wetlands when they are 

To reduce mosquito larvae through predation. 

Provides on-site source of mosquitofish and other mosquito predators to seasonal wetlands. Increases overall habitat diversity. 

Additional expense to construct reservoir that feeds water to seasonal wetlands and expensive to maintain permanent water. 

F-30 
Best Management 

Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

irrigated or flooded. 

Table 8. Biological Controls to reduce mosquito production in managed wetlands. 

Best Management Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

Encourage or stock Mosquitofish (Gambusia affinis) 

Stock managed wetlands with mosquitofish or encourage habitats for naturalized populations. Utilize water sources with mosquitofish to passively transport predators to newly flooded habitats. 

To supplement mosquito predator population. 

Provides a non-chemical control of mosquito larvae. Mosquito fish are often available free of charge to landowners from their local MVCD. 

May reduce non-target populations of invertebrates or other mosquito predators. Not appropriate for vernal pool habitats. May negatively impact sensitive species. 

Encourage invertebrate predators 

Maintain permanent or semipermanent water where mosquito predators can develop and be maintained. Discourage use of broad spectrum pesticides. 

To reduce mosquito populations through predation. 

Provides biological control of mosquito larvae and adults. 

None. 

Encourage swallow colonies and other insectivorous birds 

Do not discourage nesting swallows. 

To reduce mosquito populations through predation. 

Provides biological control of adult mosquitoes. 

Guano. The value of insectivorous birds has not been adequately quantified. 

Encourage Bats Encourage bat colonies (e.g. 

build bat boxes) 

To reduce mosquito populations through predation. 

Provides biological control of adult mosquitoes. 

Potential (or perceived potential) for transmission of rabies. The value of insectivorous bats has not been adequately quantified. 

F-31 
Table 9.Suggested coordination activities between wetland managers and Mosquito and Vector Control Districts 

(MVCD). 

Best Management Practice 

Strategies Mosquito Control Objective Advantages Disadvantages 

Habitat management and flooding schedule coordination 

Consult with MVCDs on agency-sponsored habitat management plans on private lands (i.e. Presley Program). Consult with MVCDs on the timing of wetland flooding on public lands – urge private landowners to do the same. 

Allows MVCDs the opportunity to provide input on habitat management and recommend BMPs to reduce mosquitoes. 

Reduces potential conflicts between MVCDs, landowners, and agencies/NGOs when managing or flooding wetlands. Provides information exchange. 

Requires a commitment of time from MVCDs, landowners, and agencies/NGOs to meet and coordinate activities. 

Identify problem areas for mosquito production and target for implementation of BMPs 

Identify problem locations for mosquito production with local MVCDs and work to implement mosquito BMPs. Identify potential cost-share opportunities to implement BMPs. 

Work to reduce mosquito production through BMPs on properties that are most problematic. 

Allows limited resources from MVCDs and agencies/NGOs to be targeted towards problem areas. Provides opportunities for monitoring the effectiveness of BMPs. 

None 

Wetland Habitat Restoration and enhancement project design & coordination 

Consult with local MVCDs on the design of restoration and enhancement projects. 

To determine where features to discourage mosquito production can be incorporated into wetland habitat restoration and enhancement projects where feasible. 

Reduces potential conflicts between MVCDs, landowners, and agencies/NGOs when restoring or enhancing wetlands. Provides a priori consultation for MVCDs on wetland projects. 

Requires some flexibility from MVCDs, landowners, and agencies/NGOs when designing projects. BMPs will likely increase the project cost. 

Coordinate Pest Control Activities 

Work with local MVCDs to understand pesticides used for mosquito treatment, and their costs and environmental impacts. 

To assure the use of mosquito control agents with the greatest efficacy and environmental safety. 

Reduces potential conflicts between MVCDs, landowners, and agencies/NGOs regarding pesticides used for mosquito treatment. 

May require additional coordination effort from MVCDs, landowners, and agencies/NGOs. 

Coordinate Monitoring Activities 

Facilitate monitoring mosquito populations of larval and adult stages before and after implementation of BMPs. 

Determine the effectiveness of BMPs to refine and prioritize their future use. 

Provides a means to evaluate and document effectiveness of BMPs. 

Requires time and resources to accomplish. 

F-32 
OTHER ACTIVE MOSQUITO CONTROL PRODUCTS 

BTI (BACILLUS THURINGIENSIS VAR. ISRAELENSIS) 

BTI is a bacterium (often considered a biological control) that has demonstrated selective larvicidal 

activity against mosquitoes, black flies, and some chironomid midges (Ali 1981). A protoxin is active 

upon being ingested. It must be applied during early stages of mosquito larval development (first 

instar to early fourth instar). BTI is not effective against mosquito pupae or late fourth instar larvae. 

BTI is not persistent, usually breaking down within 1 to 2 days (Mulla et al. 1982). Under the right 

environmental and larval density conditions, BTI has proven to be effective against Aedes and Culex 

larvae. Its efficacy is limited in anopheline larvae, probably due to the combined effects of their 

surface feeding behavior and the rapid settling of BTI crystals in the water column when applied 

(Standaert 1981). BTI’s effects can also be limited on Aedes in high densities. When larval density is 

high, there may not be enough toxins available for each larva (Becker et al. 1992). This can often be 

the case for Aedes mosquitoes found within the Sacramento Valley, due to their high densities in 

ephemeral habitats (i.e. SFW). Water quality can also have an impact on mortality. Water that is 

enriched with organic material significantly diminishes the effectiveness of BTI, probably due to the 

availability of other foods, and the binding of the BTI crystals to particulates (Ignoffo et al. 1981). B. 

sphaericus is another bacterium that has been used similar to BTI, but has better efficacy in 

wetlands with high organic content. 

METHOPRENE 

Methoprene is a man-made chemical that interferes with normal insect growth during critical 

developmental periods by mimicking the biological activity of insect juvenile hormones. The result is 

that larvae do not develop into pupae, and thus do not emerge as adults. It is applied as a liquid, 

granule, or pellet (depending on desired persistence) to sources, targeting larvae in the late instar 

stages, generally between late third and fourth stages. Methoprene is not effective against larvae that 

have already pupated. Methoprene has been found to be very effective against mosquito larvae, 

although effectiveness is generally better against later instar larvae than early instars (Schaefer and 

Wilder 1972). At doses required for mosquito control, most non-target organisms are not affected, but 

several aquatic dipterans showed some sensitivity (Miura and Takahashi 1973). Persistence of liquid 

methoprene usually does not last longer than 48 hours in the aquatic environment (Schaefer and 

Dupras 1973). Granular formulations can be applied 5 to 10 days prior to flooding, which could be a 

proactive treatment, targeted for units with a history of high mosquito production. 

CHEMICAL CONTROLS 

GOLDEN BEAR OIL (GB-1111) 

GB-1111 will effectively control all immature stages by acting as a suffocant. It is one of the few 

mosquito control products that will effectively control pupae. At the Complex, it is approved for 

control of mosquito pupae, if necessary. These situations are rare, with GB-1111 only being used 

infrequently during the last ten years. It is usually associated with pupal concentrations that were 

undetected during earlier dipper sampling for larvae. It is not intended for widespread use, but to 

treat discrete areas that provide narrow target applications such as windrows of pupae. Use in open 

water areas result in maximum efficacy. Dense vegetation hinders the ability of the oil to disperse 

across the water, requiring high-end application rates or multiple applications to be effective. 

F-29 
ADULTICIDES 

Adulticides are applied as an ultra-fine spray using vehicle-mounted (ground or aerial) ULV cold 

fogger spray units. ULV application rates are much lower than rates used for larviciding or 

agricultural purposes. Adulticiding is generally done at dusk when adult mosquito activity is at its 

highest. Adulticides are “drifted” across target areas, with optimal conditions being a light wind (3 

to 5 mph) and with an inversion. Three hundred-foot swath-widths are the standard for calculation 

of labeled application rates. However, MVCDs report efficacious mosquito control at times up to 

one-half mile under optimal conditions, and actual application routes/swaths tend to be much 

greater than 300 feet apart. 

INSECTICIDE RESISTANCE 

Insecticide resistance must be taken into consideration when planning an IPM mosquito control 

program. Currently, the mosquito species showing the most resistance to insecticides is C. tarsalis. 

Adult C. tarsalis are now highly resistant to malathion in most of California (Case and Kauffman 

1984, Thompson 1989). Malathion was last used on the Complex in 2003, and has since been removed 

from this IPM plan. C. tarsalis are very susceptible to Pyrethrin and synthetic pyrethroids, including 

sumithrin. Aedes and Anopheles adults occurring in northern California remain susceptible to all of 

the approved adulticides, but District’s advise rotating their use on these species to offset resistance 

(Mike Kimball, Sutter Yuba MCVD pers. comm.). 

MOSQUITO CONTROL TREATMENT EFFECTS 

MOSQUITO POPULATION 

Wetland management techniques, biological control agents, methoprene, larvicidal oils, and 

adulticides have all been shown to reduce various life stages of mosquitoes effectively under 

certain conditions. The nature of the wetland habitats at the Complex plays a significant role in 

the ability to apply control products efficaciously. The MVCDs identify the quantity of 

vegetation, water quality, and great concentrations of larvae as the most common constraints 

on the efficacy of the treatment. 

Ideally, control efforts on breeding habitat (e.g. water management, larval treatments) would 

prevent vector populations from reaching threshold levels that trigger more intensive control 

efforts (i.e. adulticiding). Mosquitofish appear to be most effective in permanent and semipermanent wetlands based on larvae dip sampling. However, they are not entirely effective in 

preventing emergence of adult floodwater mosquitoes in SFW, when larval concentrations are 

extremely high. 

The efficacy of BTI on Refuge wetlands has been a point of some debate. Although Garcia and 

Des Rochers (1984) found that use of BTI was up to 80 to 95 percent effective in reducing larval 

populations of A. melanimon in seasonal wetlands at nearby Gray Lodge Wildlife Area, only 

limited success has been achieved with BTI on A. melanimon on Colusa and Sutter Refuges. 

Dilution of active material (even at maximum application rates), and dispersal problems due to 

heavy emergent vegetation, and high organic content in the water are suspected causes (Mike 

Kimball, Sutter-Yuba MCVD, personal comm.). 

The predominant strategy used by MVCDs when faced with a disease epidemic is to reduce 

F-30 
numbers of infected adult female vectors through the application of adulticides (Reeves and 

Milby 1990). However, during non-epidemic periods when treatment is advised, there are 

inconsistencies in the literature regarding the effects that abatement treatments have on 

disease transmission. Reeves and Milby (1990) indicated that these effects are not well 

documented. 

EFFECTS ON NON-TARGET ORGANISMS 

Effects on non-target organisms can be loss of biomass, loss of diversity, interference with 

normal ecological relationships, bioaccumulation, or other unknown effects. Because one of the 

major objectives of the Complex is to provide high quality feeding areas for migratory birds 

and other wildlife, there is concern that mosquito control treatments may be interfering with 

that objective by reducing the existing food base. Another concern is that rare insects or 

insects that function as important pollinators for rare plants may be impacted by mosquito 

control treatments. Use of non-native biological controls such as mosquitofish may alter 

ecological relationships of native species. Significant bioaccumulation has not been associated 

with any of the approved chemical treatments referred to in this plan. In general, risk quotients 

(calculated by dividing acute and/or chronic exposure estimates by ecotoxicity values) for birds 

and mammals indicate negligible risk for application rates used for mosquito control. However, 

for fish and aquatic invertebrates, risk quotients for some products indicate significant risk 

(USFWS 2003). Depending on the product, these risks are mitigated by: 1) allowing active 

mosquito control (i.e. pesticides) only when thresholds are met; 2) using the least toxic 

methods/products (e.g. BMPs, larvicides) possible before more toxic products (e.g. adulticides) 

are considered; and 3) implementing measures to avoid sensitive areas/species identified in 

PUPs/SUPs. 

INVERTEBRATES IN AQUATIC ENVIRONMENTS 

Invertebrates are an important source of food for many wildlife species, particularly migratory birds. 

Waterbirds are a major focus of Refuge goals and objectives, and they consume a significant amount 

of aquatic invertebrates. Midges of the family Chironomidae and others, which are biologically, 

morphologically, and behaviorally similar to mosquitoes, appear to be susceptible to most mosquito 

control treatments. Chironomid midge larvae are important dietary components for waterfowl, 

shorebirds, and other waterbirds (Euliss and Harris 1985, Severson 1987). Midge larvae and/or adults 

may be subject to population reductions due to habitat modifications, or during mosquito abatement 

periods. 

Water management techniques associated with irrigations likely have little or no effect on aquatic 

invertebrates. Irrigated SFW habitats support relatively good biomass of chironomid and other 

invertebrates in the fall and winter (Severson 1987), plus a short-term bloom of invertebrate 

production during the actual irrigation (Lawler et al. 1997). 

Physical wetland management techniques could potentially result in some effects on aquatic 

invertebrate populations. Reducing rank wetland vegetation to improve moist-soil plant stands and 

seed biomass balances a temporary loss of vegetative substrate that could support significant 

invertebrate populations including mosquitoes, chironomids, and many others. This could be 

especially true in cases where jointgrass or Bermuda grass have been treated. However, one year 

following treatment, these units often become very productive in terms of desirable vegetation and 

bird use. Because these techniques are used on a small proportion of the habitat base at any one time, 

F-31 
the overall effects are not likely to be significant. 

BTI has traditionally been a “preferred” mosquito control material because of its status as a 

biological control. However, it has been shown to impact some non-target invertebrate species, 

including chironomid midge larvae (Charbonneau et al. 1994). Effects on chironomid midges were 

significant under laboratory conditions, but may be mitigated during use in the field because of 

reduced efficacy (Garcia et al. 1980, Charbonneau et al. 1994). Efficacy problems have been cited by 

MVCDs as a major reason that widespread BTI use is not cost-effective for mosquito control in many 

cases at the Complex. Current levels of use are low and overall effects on non-targets are not likely to 

be significant. 

GB-1111 can cause significant mortality in surface-breathing invertebrates that are susceptible to 

suffocation. Some diving beetle larvae and adults, as well as corixids and notonectids, are markedly 

affected (Mulla and Darwazeh 1981). Miles et al. (2002) found that both adult and immature corixids 

declined 73 percent and 78.5 percent, respectively, in treated areas, although populations rebounded 

within one week of treatment. Corixids are common in Refuge wetlands and are important prey items 

for waterfowl (Miller 1987) and other wetland birds. Young ducklings may be at risk from GB-1111 

applications due to the oil matting feathers and potentially impeding their ability to thermoregulate, 

especially during cooler temperatures (Miles et al. 2002). GB-1111 applications would be avoided in 

areas with significant numbers of young duck broods when nighttime temperatures are below about 

15o

 C (~59o F) (Miles et al. 2002). The use of GB-1111 may also damage vegetation or produce an 

unsightly appearance. Typical use of GB-1111 has been infrequent (0-2 applications/year) and 

localized (specific edges of certain wetlands) for control of mosquito pupae. No increases in frequency 

of use are planned or expected, so overall effects on non-targets are not likely to be significant. 

Risk quotients for all of the adulticides (using rates for mosquito control) in this plan indicate 

significant risk to aquatic invertebrates. The risk quotients for both pyrethrin and sumithrin also 

indicate significant risk for fish. Surprisingly, in a study conducted at Sutter and Colusa Refuges, the 

use of pyrethrin, malathion, or permethrin as adulticides (applied with ULV ground fogger) did not 

result in reductions in abundance or biomass in a wide variety of taxonomic groups of aquatic 

invertebrates (Lawler et al. 1997). Aerial life stages of chironomids were affected however (see next 

section). Surface water samples taken immediately after applications directly adjacent to the 

application route represented the highest probability for detection and the highest concentrations. 

Water samples did not contain detectable amounts of pyrethrin or permethrin, but malathion was 

present at six parts per billion (ppb). In a similar more recent study at Colusa Refuge, pyrethrin and 

piperonyl butoxide deposition in wetlands following adulticide applications were as high as 34.5 and 

14.9 ppb, respectively (Lawler et al. 2008, in press). These malathion and pyrethrin concentrations 

are within acute toxicity levels for some invertebrate species. 

Because there is a negative relationship between the amount deposited in water and the distance 

from application, there is more concern for non-target aquatic mortality in areas closest to the 

application routes. Based on pesticide deposition testing from ground ULV adulticide applications at 

Colusa Refuge, the amount of malathion deposited into adjacent wetlands was estimated to be 

approximately eight percent of what was applied over open water areas within a 300-foot swath 

(Steinke 1995, unpubl. data). The total amount expected to be deposited in the water over a 1037­

meter distance was 32 percent. Predicted malathion concentrations in the water immediately after 

treatment were 0.8 ppb in open water areas and 0.3 ppb in areas of emergent vegetation, an order of 

magnitude less than detected directly next to the treatment routes in the previous study (Lawler et 

al. 1997). 

F-32 
INVERTEBRATES OUTSIDE AQUATIC ENVIRONMENTS 

Invertebrates outside the aquatic environment include non-aquatic species or life stages of 

aquatic species that have left aquatic environments. These invertebrates function as food items 

for migratory birds, but also serve as pollinators for a variety of plant species. There are some 

that serve other functions in the biological community, including maintenance of predator-prey 

relationships, scavenging, and contributing to the overall biological diversity. 

These species may be susceptible to adulticide applications. In particular, species which are 

active around dusk or later, concurrent with typical adult mosquito activity, are likely incurring 

some degree of mortality. 

A limited sampling effort for non-target flying insects during adulticide applications at Colusa 

Refuge indicated some mortality based on a combination of knockdown boxes, significant 

sentinel mosquito mortality, and light trap data (Lawler et al. 1997). The extent of the mortality 

could not be determined, but species of chironomids comprised the majority. Light trap data 

indicated immediate drops in adult chironomids; however, populations rebounded back to preadulticide treatment levels within 24 hours. 

SENSITIVE SPECIES AND HABITATS 

Table 10 lists federal and state listed species and federal species of concern and their habitats that 

exist at the Complex. The study conducted at Colusa and Sutter Refuges (Lawler et al. 1997) did 

not detect any significant mortality to aquatic insects. Because toxicity levels for higher species 

(reptiles, birds, and mammals) are at least a magnitude greater than for aquatic insects, it is likely 

that the risk of toxicity impacts to higher aquatic organisms (i.e. those listed in Table 10 in wetland 

or riverine habitats) are not as great. Timing of use by other species, relative to applications of 

mosquito control products, is also a factor in determining risk. 

Species that feed primarily on aerial insects or rely on them for pollination probably have the 

greatest probability of being impacted by the effects of adulticide treatments. Although bats are 

not listed in Table 10, they would be a good example of a species group that could potentially be 

impacted significantly from adulticide treatments. Sacramento Valley bat species are mostly 

insectivorous and likely to be feeding around the same time treatments are being made. Insects 

F-33 
Table 10.Federally listed and candidate species that can be found or suitable habitat 

occurs for at the Sacramento National Wildlife Refuge Complex. 

Species Scientific Name Habitat Status1 

Refuge 

Occurrence2 

Giant Garter Snake Thamnophis gigas W, U FT, ST All 

Western Yellow-billed Cuckoo 

Coccyzus americana 

occidentalis R CS 

SR, NC, SU, 

BS 

Winter-run Chinook Salmon 

Oncorhynchus 

tshawytscha RV 

FE, 

SE 

SR, NC, 

SU,BS 

Chinook Salmon-Fall and Late 

Fall Run 

Oncorhynchus 

tshawytscha RV CS 

SR, NC, 

SU,BS 

Steelhead, Central Valley 

ESU Oncorhynchus mykiss RV FT 

SR, 

NC,SU,BS 

Conservancy Fairy Shrimp Branchinecta conservatio VP FE SA, D, C 

Vernal Pool Fairy Shrimp Branchinecta lynchi VP FT SA, D, C, NC 

Vernal Pool Tadpole Shrimp Lepidurus packardi VP FE SA, D, C, NC 

Valley Elderberry Longhorn 

Beetle 

Desmocerus californicus 

diamorhpus R FT SR, NC 

Palmate-bracted Bird's Beak Cordylanthus palmatus AM FE SA, D, C 

Hairy Orcutt Grass Orcuttia pilosa VP,AM FE SA, D, C 

Green's Tuctoria Tuctoria greenei VP,AM FE SA, D, C 

Hoover's Spurge Chamaesyce hooveri VP,AM FT SA, D, C 

1

 FT-federal threatened, FE-federal endangered, CS-Federal Candidate Species 

2

 SA-Sacramento NWR, D-Delevan NWR, C-Colusa NWR, SU-Sutter NWR, BS-Butte Sink 

WMA, SR-Sacramento River NWR, NC-North Central Valley WMA-Llano Seco Unit; has been 

observed at Refuge or suitable habitat is present. 

F-34 
active during dusk or later (i.e. adulticide application periods) are likely to be affected to some 

degree, depending on species and habitat. Although aerial insect populations rebounded within 24 

hours of applications during the Colusa/Sutter Refuge study (Lawler et al. 1997), effects on 

insectivorous species (e.g. songbirds) were not studied. Of the insectivorous birds listed in Table 

10, western yellow-billed cuckoo (YBC) may be most impacted by adulticide treatments by 

reducing the aerial invertebrate food base. Applications made during the irrigation period (JuneJuly) would coincide with the nesting season of YBC, possibly impacting food resources available 

to feed nestlings. Recent surveys have indicated YBC breed at Sutter and Sacramento River 

Refuges (Halterman et al. 2001). Sutter and Sacramento River Refuges represent areas where 

riparian areas are treated with adulticide and not treated, respectively. Direct comparisons of bird 

densities between the two areas are not available. YBC are present during fall migration and could 

be impacted by reduced food resources during fall adulticiding. Rapid rebounding of aerial insect 

abundance following adulticide applications reported by Lawler et al. (1997) may indicate that the 

short-term reduction in insects would not affect YBC or other insectivorous animals. 

Other insectivorous birds, including burrowing owl and Swainson’s hawk, are likely unaffected by 

mosquito control treatments. Chemical treatments do not focus on the upland habitats where 

these species and other raptors tend to feed. Some wetland BMPs that remove vegetation in 

wetlands during their dry phase provide short-term benefits by attracting Swainson’s hawks and 

other raptors in great numbers to feed on rodents and large invertebrates (e.g. grasshoppers 

during and after a burn). 

Giant garter snakes (GGS), federal and state-listed as threatened, historically ranged from the 

Sacramento/San Joaquin Delta to the south end of the Tulare Lake Basin. The present 

distribution is from Chico to central Fresno County. Based on recent research and monitoring 

efforts, Colusa Refuge has a large and healthy population of GGS, relative to many other areas in 

the Central Valley (Wylie et al. 2006). The GGS requires freshwater wetlands, such as marshes 

and low gradient streams. Permanent wetlands are of particular importance, as they provide 

habitat over the summer and early fall when seasonal wetlands are dry. Giant garter snakes have 

adapted to drainage and irrigation systems, especially those associated with rice cultivation. 

Direct applications of mosquito pesticides are restricted and do not occur in the flooded ditches or 

permanent wetlands that GGS prefer. The effects of adulticides on GGS are unknown. Conditions 

in SUPs identify permanent wetlands as sensitive and are to be avoided with adulticide 

treatments. 

Valley Elderberry Longhorn Beetles (VELB) may be present at the Sacramento River Refuge on 

any areas containing elderberry plants (Sambucus sp.). Conditions in SUPs identify these habitats 

as sensitive and are to be avoided with adulticide treatments. 

Animal species occupying vernal pools in their aquatic phase (i.e. fairy and tadpole shrimp) are 

likely unaffected by mosquito control treatments, due mostly to timing of their annual cycle. 

Vernal pools receive no larvicide treatments (including mosquitofish) and adulticide applications 

are conducted after they have gone into their dry cycle. Conditions in SUPs identify these habitats 

as sensitive and are to be avoided with adulticide treatments based on the 300-foot application 

swath and/or prevailing wind conditions. 

Plant species growing in dry vernal pools or alkali meadow habitats during the mosquito season 

may be affected if insects that serve as pollinators are reduced by adulticide treatments. Because 

these habitats are very rare on the valley floor, they may also contain other rare invertebrates 

that have yet to be identified and may be at risk. Conditions in SUPs identify these habitats as 

F-35 
sensitive and are to be avoided with adulticide treatments based on the 300-foot application swath 

and/or prevailing wind conditions. 

The anadromous fish (i.e. salmon and steelhead) listed in Table 10 potentially could occur in the 

Butte Creek system, including the east and west Sutter Bypass canals, or the Sacramento River. 

Adult fall-run Chinook salmon are present in the lower Butte Creek system during fall mosquito 

control activities. The other species/runs do not coincide as significantly, and in some cases (i.e. 

winter-run Chinook), most fish would be absent during mosquito control periods. Avoidance 

measures include no direct applications made to riverine environments, and adulticide applications 

not made within 100 feet of wetlands, lakes, or streams containing listed fish species (this would 

include Butte Creek, the east and west Sutter Bypass canals, and the Sacramento River), unless 

winds or inversions favor pesticide drift away from the water. Currently, mosquito control is not 

an issue on units directly adjacent to the Sacramento River. 

Because mosquitofish are a non-native species, there is some concern that their presence has 

changed the biological community and may have some detrimental consequences to native species. In 

the Central Valley, including the Complex, mosquitofish exist as a naturalized species, along with 

many other non-native fish species. They undoubtedly have contributed to changes in the biological 

community, but the extent or significance of such changes is unknown. They do serve as prey for 

other fish, reptiles (including giant garter snakes), and fish-eating birds. There are numerous other 

non-native fish species that exist throughout the Valley. In fact, the majority of fisheries resources on 

the Complex are non-native. 

CONSIDERATION OF OTHER EFFECTS 

Although local studies of the effects of adulticides at the Complex documented little or no effect on 

aquatic invertebrate populations, deposition of those pesticides in wetlands were measured to be at 

levels shown to be harmful to similar invertebrates in laboratory studies. While actual field 

application conditions appear to have moderated these effects (at least in these studies), there are 

still concerns about sub-lethal effects to invertebrates and other animals that would not have been 

detected. These effects are inherently difficult to document and study, but should not be dismissed. 

Continuing to work to reduce the amount and toxicity of pesticides will, by default, minimize the risk 

of these effects. 

RESPONSE THRESHOLDS 

Thresholds for mosquito control are based on a combination of mosquito-borne public health risk 

levels and the presence of mosquito populations on Refuge lands. Table 11 outlines threat 

categories and corresponding mosquito monitoring or control responses allowed on Refuges. Table 

12 defines the specific action thresholds (identified in Table 11) by Refuge for using adulticides, 

larvicides, and pupacide based on Refuge-specific populations of adult, larval, and pupal mosquito 

populations as determined by standard monitoring by the Districts. These thresholds were 

developed in consultation with the Districts based on relating mosquito population indices and 

distance to urban areas (i.e. nearest town) with perceived outbreak risk or nuisance complaints by 

local residents. Generally, the closer a refuge is to an urban area, the lower the treatment 

threshold. Based on historical treatment patterns and risk of level of human health threat, certain 

Refuges would not be treated unless mosquito-borne virus is detected in the local area. The terms 

public “health threat” and “health emergency” used in the tables are as follows: 

F-36 
Mosquito-associated health threat - an adverse impact to the health of human populations from 

mosquitoes. A health threat determination will be made by the appropriate Federal, State, or local 

public health authority that has the expertise and the official capacity to identify human health 

threats. Documentation of a specific health threat from refuge-based mosquitoes by a Federal, 

State, or local public health agency must be based on local and current mosquito population and/or 

mosquito-borne disease monitoring data. 

Health emergency - indicates an imminent risk of serious human disease or death. A health 

emergency represents the highest level of mosquito-associated health threats. Health 

emergencies will be determined by Federal, State, or local public health authorities and 

documented with local and current mosquito population and disease monitoring data. 

For the purposes of this plan, the Refuge will consider the local county Public Health Officers the 

appropriate authority to make these declarations. 

F-37 
Table 11. Mosquito-Borne Disease Health Threat and Response Matrix (adapted 

from USFWS 2005b). 

Current Conditions 

Threat 

Level Refuge Response 

Health Threat 

Category1 

Refuge Mosquito 

Populations2 

No documented existing or 

historical health threat/ 

emergency 

No action threshold 1 

Remove/manage artificial mosquito 

breeding sites such as tires, tanks, 

or similar debris/containers. Allow 

compatible monitoring by MVCDs. 

Documented historical 

health threat/ emergency 

Below action threshold 2 

Response as in threat level 1, plus: 

allow compatible non-pesticide 

management options (BMPs) by 

MVCDs to reduce mosquito 

production. 

Above action threshold 3 

Response as in threat level 2, plus: 

allow compatible site-specific 

larviciding of infested areas by 

MVCDs as determined by 

monitoring. 

Documented existing 

health threat 

Below action threshold 4 

Response as in threat level 2, plus: 

allow increased monitoring and 

disease surveillance by MVCDs. 

Above action threshold 5 

Response as in threat levels 3 and 4, 

plus: allow compatible site-specific 

larviciding, pupaciding, or 

adulticiding of infested areas by 

MVCDs as determined by 

monitoring data. 

Officially determined 

existing health emergency 

Below action threshold 6 Maximize monitoring and disease 

surveillance by MVCDs. 

Above action threshold 7 

Response as in threat level 6, plus: 

allow site-specific larviciding, 

pupaciding, and adulticiding of 

infested areas by MVCDs as 

determined by monitoring. 

1 Mosquito-associated health threat - an adverse impact to the health of human populations from 

mosquitoes. A health threat determination will be made by the appropriate Federal, State, or local public 

health authority that has the expertise and the official capacity to identify human health threats. 

Documentation of a specific health threat from refuge-based mosquitoes by a Federal, State, or local 

public health agency must be based on local and current mosquito population and/or mosquito-borne 

disease monitoring data. 

Health emergency - indicates an imminent risk of serious human disease or death. A health emergency 

F-38 
represents the highest level of mosquito-associated health threats. Health emergencies will be 

determined by Federal, State, or local public health authorities and documented with local and current 

mosquito population and disease monitoring data. 

For the purposes of this plan, the Refuge will consider the local county Public Health Officers the 

appropriate authority to make these declarations. 

2

 Action (treatment) thresholds represent mosquito population levels that may require intervention 

measures and are identified in Table 12. 

F-39 
Table 12. Treatment thresholds for larvicide, pupacide and adulticide applications on Refuges within the Complex. 

Treatment Thresholds 

Larvicide Pupacide1 Adulticide 

Refuge 

Distance From Nearest 

Urban Area Dipper2 Dipper 

Aedes sp. 

Landing Count3 

NJLT Index for 

C. tarsalis4 

Sacramento 6 miles south of Willows Nt5 nt nt 606 Delevan 4 miles east of Maxwell nt nt nt 406 Colusa 1 mile west of Colusa 2 nt 5 20 

Sutter 3 miles south of Sutter 2 nt 10 40 

Butte Sink 3.5 miles northeast of Colusa 2 nt 10 no trap present 

Llano Seco Unit 1.5 miles southwest of Dayton 2 nt 5 20 

1Refers specifically to GB-111; used under rare circumstances where pupae have accumulated in abundance in discrete areas (i.e. windrows) 

would be conducted in consultation with Refuge staff to avoid areas with significant numbers of young duck broods (Miles et al. 2002). 2 Average number per dip. 

3 Average number landing per pant leg per minute. 4 Per trap night, based on weekly index of adult females. 5 No threshold established. 6 Only during an existing human health threat or emergency. 

F-40 
RESEARCH NEEDS 

There are still concerns about the applications of adulticides because of their toxicity and potential 

negative impacts to aquatic species. Because adulticides are not insect-selective (although the 

application rate may be), reduction of non-target aerial or terrestrial insects, especially those that 

are rare or serve as pollinators for rare plant species, is still a concern. Inventories of these 

invertebrate species should be undertaken, and those at risk based on their susceptibility to 

mosquito control treatments should be identified. The studies at Colusa and Sutter Refuges 

(Lawler et al. 1997, Lawler et al. 2008) provided data that indicated no major impacts to aquatic 

macroinvertebrates from the use of three adulticides. Despite those somewhat encouraging 

results, concentrations of mosquito adulticides documented to be harmful have been measured in 

wetlands following applications in some cases. This remains a significant concern. Aerial insects 

are still subject to local reductions whenever adulticides are applied. How these reductions affect 

the overall ecological functions (predator-prey relationships, etc.) of wetlands and other habitats is 

still largely unknown. Sub-lethal effects of adulticides on invertebrates and other animals have 

not been well-studied, and represent an unknown level of impact. As new methods or products 

become available to control mosquitoes, those that can provide adequate control with less toxicity 

and negative impacts than the existing methods should be evaluated for use on the Complex. 

F-41 
CHAPTER 2. INVASIVE SPECIES CONTROL AND OTHER 

VEGETATION MANAGEMENT 

INTRODUCTION 

The Complex contains critically important habitats and core use areas for a great diversity of 

wildlife, particularly migratory birds of the Pacific Flyway and a number of indigenous, rare, and 

endangered plants and animals. Over 95 percent of the historic wetlands, riparian forests, and 

grasslands in the Central Valley have been destroyed or modified since the 1800s (Gilmer et al. 

1982, CVJV 2006). Despite these significant changes, approximately 60 percent of the total Pacific 

Flyway waterfowl population winters here. Millions of waterfowl and other migratory birds use 

the Complex annually (USFWS 1989-2007). It serves as a significant breeding, migration, and 

wintering area for Neotropical migrants (Small et al. 2000). The Refuges support some of the last 

remaining habitats for a number of rare plants and invertebrate species (Center for Conservation 

Biology 1994, Silveira 2000, USFWS 1993-2007). 

Invasive species are a significant threat to native fauna and flora on refuges and other resource 

areas throughout the country (USFWS 2002). Unfortunately, exotic and invasive plant species are 

very common throughout the Central Valley, and recently published floras have indicated that 23­

41 percent of plant species are non-native, depending on the county or basin (Oswald and Ahart 

1994, Oswald and Silveira 1995). They occur throughout the Complex’s habitat types and 

infrastructure (i.e. canals, levees, roads, etc.). The area’s mild climate creates a year-round 

growing season that results in the germination and expansion of a variety of undesirable species 

throughout the year. Controlling or eliminating non-native species are objectives found in many 

local and regional habitat management plans, endangered species recovery plans, and various 

weed management areas. Some native plant species can also become problematic, or even invasive 

due to local conditions or successional changes. In such cases, they may also be controlled, if 

necessary, to maintain desirable abundances and distributions to meet wildlife and habitat 

objectives of the Complex. As a result, vegetation management is relatively common on the 

Refuges, and is a primary component of the Refuges’ annual habitat management plans, where 

control and enhancement objectives are identified and treatments are prescribed to achieve them 

(USFWS 1988-2007). 

Specific reasons for vegetation management include maintaining biodiversity, maintaining 

desirable proportions of emergent vegetation in wetlands, enhancing desirable species, preparing 

for habitat restoration projects, reducing mosquito breeding habitat, and providing maintenance 

and safety around facilities including protecting communities and assets at risk to wildfire. Nonnative and invasive species are often a significant impediment to habitat restoration and 

maintenance, and without their control, many native species cannot be re-established. A variety of 

vegetation management techniques (e.g. mow, disk, burn, graze, spray, etc.) are used, depending 

on the habitat type, plant species, and resource objectives. Some are used alone, while others may 

be used in combination with one or more other techniques. In general, mechanical methods are 

preferred over herbicides, but in some cases, the opposite is true (i.e. to avoid ground disturbance 

an herbicide may be the most effective method). The need to use any of these techniques annually 

depends on species present, condition of the habitat, effects of climate on plant growth, available 

funding and resources, and in some cases, the extent that legal mandates allow (e.g. burning 

restrictions due to local air quality legislation). 

F-42 
The Service is required to use an integrated pest management approach for pest management 

activities on refuge lands (U. S. Department of Interior 2007). IPM employs a variety of control 

methods to control invasive species and other weeds that include various forms of physical habitat 

management, biological control agents, and herbicide application. The purposes of this IPM plan 

are to: 1) describe refuge habitats and their role in the conservation of trust animal and plant 

species; and 2) describe the use of vegetation control methods and materials in an IPM program 

that is consistent with the purposes and goals of the Complex, and DOI and Service policy. 

SPECIES TO BE CONTROLLED 

Table 13 summarizes the invasive, exotic, and other undesirable plant species that are of primary 

concern to control or eliminate at the Complex. The plant species targeted for treatment were 

chosen due to their actual or potential threat to ecosystem processes, federally listed species 

and/or their status as noxious weeds in the State of California. The full extent (current distribution 

and abundance) of these species are unknown, but in some cases has been estimated and mapped. 

The size of an infestation, its pervasiveness, and management difficulty will determine whether 

the goal is eradication or containment. For instance, relatively small, separated populations of 

perennial pepperweed will be targeted for eradication. The current goal for the extensive 

pepperweed infestations is containment, with a long-term goal of reduction. 

Species that are not on the target species list (see Table 13) will still be considered for treatment if 

they are found to be threatening rare and/or desirable species, or are newly established on the 

Refuge. The list will be reviewed and updated periodically as more information is gained. 

The following profiles of targeted species include a discussion of possible treatment methods and 

priority sites for treatment. Most of these profiles were taken directly, or slightly adapted for this 

document from the UC IPM Online Statewide Integrated Pest Management Program (University 

of California 2007), the Cal-IPC online version of Invasive Plants of California’s Wildlands 

(Bossard et al. 2000), or The Nature Conservancy (TNC) Element Stewardship Abstracts from the 

TNC Global Invasive Species Team website (TNC 2007). For additional information on the 

descriptions, phenology, and other ecological characteristics of these species and other weeds, see 

DiTomaso and Healy (2003, 2007). Relevant information and observations from the Complex were 

also included. 

F-43 
 

Table 13. Selected invasive, non-native, or undesirable plant species of concern at 

Sacramento Refuge Complex1. 

Species 1 Common Name Habitat 

ASTERACEAE [Compositae] SUNFLOWER FAMILY

 Centaurea solstitialis YELLOW STAR-THISTLE grassland, fields, levees, 

roadsides, ditch banks 

Xanthium strumarium ROUGH COCKLEBUR wetlands, riparian habitats, 

vernal pools 

BRASSICACEAE [Cruciferae] MUSTARD FAMILY

 Lepidium latifolium BROAD-LEAVED (PERENNIAL) 

PEPPERWEED 

wetland edges, riparian 

habitats, fields, levees, 

ditch banks 

CHENOPODIACEAE GOOSEFOOT FAMILY

 Salsola soda FLESHY-LEAVED RUSSIANTHISTLE 

alkali meadows, non-native 

alkali grassland 

CONVOLVULACEAE MORNING-GLORY FAMILY

 Convolvulus arvensis BINDWEED vernal pools 

HALORAGACEAE WATER-MILFOIL FAMILY

 Myriophyllum aquaticum PARROT’S-FEATHER wetlands, ditches 

JUGLANDACEAE WALNUT FAMILY

 Juglans californica var. hindsii 

2 

NORTHERN CALIFORNIA 

BLACK WALNUT 

riparian forest 

MORACEAE MULBERRY FAMILY

 Ficus carica FIG riparian forest 

MYRTACEAE MYRTLE FAMILY

 Eucalyptus camaldulensis RIVER RED GUM uplands, wetland edges 

ONAGRACEAE EVENING-PRIMROSE FAMILY

 Ludwigia peploides ssp. 

Peploides 

YELLOW WATERWEED wetlands, waterways 

Ludwigia peploides ssp. 

montevidensis 

MONTEVIDEO WATERWEED wetlands, waterways 

F-44 
 

 

 

Table 13. (cont.). Selected invasive, non-native, or undesirable plant species of concern at 

Sacramento Refuge Complex1

. 

Species 1 Common Name Habitat 2 

POACEAE [Gramineae] GRASS FAMILY

 Arundo donax GIANT REED riparian habitats, ditch 

banks 

Crypsis schoenoides SWAMP-TIMOTHY vernal pools 

Crypsis vaginiflora AFRICAN PRICKLEGRASS vernal pools 

Cynodon dactyton BERMUDA-GRASS wetlands 

Elytrigia pontica ssp. pontica TALL WHEATGRASS alkali meadows 

Phalaris aquatica HARDING-GRASS, PERLA-GRASS alkali meadows 

Lolium multiflorum ANNUAL RYEGRASS various habitats 

Sorghum halepense JOHNSONGRASS wetland edges, fields, 

ditches, roadsides 

Taeniatherum caput-medusae MEDUSA-HEAD uplands 

Paspalum distichum JOINTGRASS/KNOTGRASS managed wetlands 

PONTEDERIACEAE PICKERELWEED FAMILY

 Eichhornia crassipes WATER HYACINTH wetlands, waterways 

SCROPHULARIACEAE FIGWORT FAMILY

 Kickxia elatine SHARP-LEAVED FLUELLIN various disturbed areas 

SIMAROUBACEAE QUASSIA FAMILY

 Ailanthus altissima TREE-OF-HEAVEN riparian forest 

TAMARICACEAE TAMARISK FAMILY

 Tamarix parviflora SMALL-FLOWERED TAMARISK riparian habitats 

Tamarix ramosissima SALT-CEDAR riparian habitats 

ROSACEAE ROSE FAMILY

 Rubus discolor HIMALAYAN BLACKBERRY riparian habitats 

1 This table contains the species with the highest priority of concern to control or eradicate; other 

species are also controlled as deemed necessary to meet wildlife and habitat objectives. 

2

 Non-native plants are indicated by an italic typeface. Severe problem plants indicated by 

underline. 3

 Feral hybrid with commercial English walnut (J. regia). 

F-45 
YELLOW STARTHISTLE (FROM BOSSARD ET AL. 2000) 

In California, yellow starthistle (Centaurea solstitialis) grows as a deep taprooted winter annual, 

or rarely as a short-lived perennial. It produces one to many solitary, spiny, yellow flower-heads 

during late spring, summer, and fall. Seeds begin to germinate soon after fall rains, and young 

plants grow as prostrate to ascending taprooted rosettes until bolting occurs in late spring or early 

summer. Yellow starthistle is most widely distributed in the Sacramento and northern San 

Joaquin valleys, Inner North Coast Ranges, northern Sierra Nevada foothills, Cascade and 

Klamath ranges, and the central-western regions of the state (Hickman 1993). There are many 

small to large relict populations in the southwestern region of California. It is currently spreading 

in mountain regions of the state below 7,500 feet (2,250 m) and in the central-western region. It is 

uncommon in deserts and at moist coastal sites. It is primarily a problem in moderately warm, 

exposed areas on fertile, drier soils, including disturbed sites, grasslands, rangeland, hay fields, 

pastures, roadsides, and recreational areas (DiTomaso et al. 1999a). 

Yellow starthistle is native to southern Europe and western Eurasia and was first collected in 

Oakland, California, in 1869. It was most likely introduced after 1848 as a contaminant of alfalfa 

seed. By 1917, it had become a serious weed in the Sacramento Valley and was spreading rapidly 

along roads, trails, streams, ditches, overflow lands, and railroad rights-of-way (Newman 1917). 

Human activities are the primary mechanisms for the long-distance movement of yellow 

starthistle seed. Seed is transported in large amounts by road maintenance equipment, as well as 

on the undercarriage of vehicles. The movement of contaminated hay and uncertified seed is also 

an important long-distance transportation mechanism. Once established, seed is transported in 

lesser amounts and over short to medium distances by animals and humans. The short, stiff, 

pappus bristles are covered with microscopic, stiff, appressed, hair-like barbs that readily adhere 

to clothing and to hair and fur (Gerlach unpubl. data). The pappus is not an effective long-distance 

wind-dispersal mechanism, as wind moves seeds only short distances, with maximum wind 

dispersal being sixteen feet (<5 m) over bare ground with wind gusts of twenty-five miles per hour 

(40 km/hr) (Roché 1992). 

Dense infestations of yellow starthistle displace native plants and animals, threatening natural 

ecosystems and nature reserves. Yellow starthistle also significantly depletes soil moisture 

reserves in annual grasslands in California (Gerlach unpubl. data) and in perennial grasslands in 

Oregon (Borman et al. 1992). Long-term ingestion by horses causes a neurological disorder known 

as chewing disease, a lethal lesion of the nigropallidal region of the brain. This disease is expressed 

as a twitching of the lips, tongue flicking, and involuntary chewing. Permanent brain damage is 

possible, and affected horses may starve to death (Kingsbury 1964). Yellow starthistle interferes 

with grazing and lowers yield and forage quality of rangelands, thus increasing the cost of 

managing livestock (Roché and Roché 1988). It can also reduce land value and limit access to 

recreational areas. 

Plants reproduce only by seed and generally flower from May to September. When adequate 

moisture is available, yellow starthistle can survive as a short-lived perennial and flower 

throughout fall, winter, and spring. However, the flowers produced during winter are often killed 

by frost (Gerlach unpubl. data). Almost all plants are self-incompatible and require pollen from a 

genetically compatible plant to produce seed (Maddox et al. 1996). 

European honeybees are an important pollinator, and in some populations are responsible for 57 

F-46 
percent of seed set (Barthell unpubl. data). Seeds produced per head (30-80) and flowerhead 

production per plant (1-1,000) is variable, depending on soil moisture levels and intensity of 

competition (DiTomaso, unpubl. data). Large plants can produce nearly 75,000 seeds. Seed 

production in heavily infested areas varies between fifty to 200 million seeds per acre. Studies of 

seed survival in soil have found significant survival to ten years (Callihan et al. 1993). Seeds 

typically germinate in late fall or early winter, when soil moisture is present (Maddox 1981) and 

overwinter as basal rosettes. 

Germination responses in yellow starthistle are greatly reduced in dark environments and by 

exposure to light enriched in the far-red portion of the spectrum (Joley 1995). The two types of 

achenes also differ in response to light (Joley 1995). During early seedling establishment, root 

growth is vigorous and can extend deeper than one meter (3.3 ft) (Roché et al. 1994, DiTomaso 

unpubl. data), providing plants with access to deep soil moisture reserves during dry summer 

months. Reduced light levels cause the rosettes to produce fewer but larger leaves and to assume 

a more upright growth form (Roché et al. 1994). Reduced light levels also significantly reduce root 

growth and flower production (Roché et al. 1994). Consequently, survival and reproduction are 

significantly reduced in shaded areas, and the plant is probably less competitive in dense stands of 

established perennials. Bolting occurs from late spring to early summer, and spiny flowerheads 

generally are produced from early summer to late summer or fall. The spines on the flowerheads 

may protect them from herbivory by large animals, but they do not prevent significant herbivory 

by grasshoppers or seed predation by birds (Gerlach unpubl. data). 

It is important to prevent large-scale infestations by controlling new invasions. Spot eradication is 

the least expensive and most effective method of preventing establishment of yellow starthistle. In 

established stands, any successful control strategy will require dramatic reduction or, preferably, 

elimination of new seed production, multiple years of management, and follow-up treatment or 

restoration to prevent rapid reestablishment. 

Effective control using any of the available techniques depends on proper timing. Combinations of 

techniques may prove more effective than any single technique. For example, prescribed burning 

followed by spot application of post-emergence herbicides to surviving plants can prevent the 

rapid reinfestation of the treated area. Similarly, combining mowing and grazing, revegetation and 

mowing (Thomsen et al. 1996a, 1996b), or herbicides and biological control may provide better 

control than any of these strategies used alone. Effective combinations may depend on location or 

on the objectives and restrictions imposed on land managers. 

MECHANICAL METHODS 

Tillage can control this thistle; however, this will expose the soil for rapid reinfestation if 

subsequent rainfall occurs. Under these conditions, repeated cultivation is necessary (DiTomaso et 

al. 1998). During dry summer months, tillage practices designed to detach roots from shoots prior 

to seed production are effective. For this reason, the weed is rarely a problem in agricultural 

crops. Weedeaters or mowing can also be used effectively. However, mowing too early, during the 

bolting or spiny stage, will allow increased light penetration and more vigorous plant growth and 

high seed production. Mowing is best when conducted at a stage where 2 to 5 percent of the seed 

heads are flowering (Benefield et al. 1999). Mowing after this period will not prevent seed 

production, as many flowerheads will already have produced viable seed. In addition, mowing is 

successful only when the lowest branches of plants are above the height of the mower blades. 

Under this condition, recovery is minimized. Results should be repeatedly monitored, as a second 

F-47 
or perhaps a third mowing may be necessary to ensure reduced recovery and seed production 

(Thomsen et al. 1996a, 1996b). 

PRESCRIBED BURNING 

Under certain conditions, burning can provide effective control and enhance the survival of native 

forbs and perennial grasses (Robards, unpubl. data, DiTomaso et al. 1999b). This can be achieved 

most effectively by burning after native species have dispersed their seeds but before yellow 

starthistle produces viable seed (June-July). Dried vegetation of senesced plants will serve as fuel 

for the burn. At Sugarloaf Ridge State Park in Sonoma County, three consecutive burns reduced 

the seedbank by 99.5 percent and provided 98 percent control of this weed, while increasing native 

plant diversity and perennial grasses (DiTomaso et al. 1999b). No additional control method was 

used in the fourth year. In that year, unfortunately, the seedbank of yellow starthistle increased 

by thirty-fold compared to the previous year (DiTomaso unpubl. data). 

BIOLOGICAL CONTROL 

Six U.S. Department of Agriculture (USDA) approved insect species that feed on yellow 

starthistle have become established in California (Pitcairn 1997a, 1997b). These include three 

weevils, Bangasternus orientalis, Eustenopus villosus, and Larinus curtus, and three flies, 

Urophora sirunaseva, Chaetorellia australis, and C. succinea (Woods et al. 1995). All of these 

insects attack yellow starthistle flowerheads, and the larvae utilize the developing seeds as a food 

source. The most effective of these species are E. villosus and C. succinea (Balciunas and Villegas 

1999). With the possible exception of a few sites, the insects do not appear to be significantly 

reducing starthistle populations, but success may require considerably more time for insect 

numbers to increase to sufficient levels. 

Current evidence indicated a 50 to 75 percent reduction in seed production in areas with 

significant bioagent populations (Pitcairn and DiTomaso unpubl. data). A root-attacking flea beetle 

(Ceratapion brasicorne) is also being studied (Pitcairn, pers. comm.). Researchers are seeking 

other starthistle-specific foliar- and stem-feeding insects in Asia Minor. Research is also currently 

being conducted on three native or naturalized fungal pathogens, Ascochyta sp., Colletotrichum 

sp., and Sclerotinia sclerotiorum for the control of yellow starthistle seedlings (Woods and 

Popescu 1997). 

GRAZING 

Intensive grazing by sheep, goats, or cattle before the spiny stage but after bolting can reduce 

biomass and seed production in yellow starthistle (Thomsen et al. 1996a, 1996b). To be effective, 

large numbers of animals must be used for short durations. Grazing is best between May and 

June, but depends on location. This can be a good forage species. 

PLANT COMPETITION 

Revegetation with annual legumes capable of producing viable seed provides some level of control 

in pastures (Thomsen et al. 1996a, 1996b). In some areas, subterranean clover (Trifolium 

subterraneum) proved to be the best of sixty-six legumes tested. In other sites, rose clover (T. 

hirtum) and/or perennial grasses may be the preferred species. Control was enhanced when 

revegetation was combined with repeated mowing (Whitson et al. 1987). At the Complex, a number 

F-48 
of areas infested with yellow starthistle have been successfully replaced with native perennial 

grasses, including purple needlegrass, blue wildrye, and meadow barley (M. Wolder, pers. comm.). 

Regular maintenance control on these areas includes sheep grazing, mowing, or spot herbicide 

treatments. 

CHEMICAL CONTROL 

Although several non-selective pre-emergence herbicides will control yellow starthistle, few of 

these can be used in rangeland or natural ecosystems. The exception is chlorsulfuron, which 

provides good control in winter when combined with a broadleaf selective post-emergence 

compound. However, chlorsulfuron is not registered for use in rangelands or pastures. 

The primary options for control in non-crop areas are post-emergence herbicides: 2,4-D, triclopyr, 

dicamba, clopyralid, and glyphosate (DiTomaso et al. 1998). All but glyphosate are selective and 

preferably applied in late winter or early spring to control seedlings without harming grasses. 

Once plants have reached the bolting stage, the most effective control can be achieved with 

glyphosate (1 percent solution). The best time to treat with glyphosate is after annual grasses or 

forbs have senesced, but prior to yellow starthistle seed production (May-June). The most 

effective compound for yellow starthistle control is clopyralid (as Transline), a broadleaf selective 

herbicide (DiTomaso et al. 1998). Clopyralid provides excellent control, both pre-emergence and 

post-emergence, at rates between 1.5-4 acid equivalent or 4-10 oz formulated product per acre. 

Although excellent control was achieved with applications from December through April, earlier 

applications led to significant increases in quantity of other forage species, particularly grasses. 

ROUGH COCKLEBUR – Adapted from the TNC Element Stewardship Abstract for 

Xanthium strumarium 

Cocklebur (Xanthium strumarium) is considered one of the world's worst weeds (Holm et al. 

1977). Cocklebur is often associated with open, disturbed areas, particularly flood-prone areas with 

good soil moisture (Martin and Carnahan 1982), but it is found in a wide variety of habitats. 

Cockleburs are broadleaf annuals that grow in seasonal wetlands and floodplains in many areas of 

California, and are common in the Central Valley (Wolder, pers. comm.). Cocklebur seeds are 

easily spread, due to their ability to float or 'hitchhike' on humans and animals. The plants can 

quickly become dominant in an area because of their prolific seed production and high germination 

and survival rates. It reproduces from seeds that are viable for several years. Cocklebur grows on 

a wide range of soils (sands to heavy clays) and available moisture. On rich soils with abundant 

moisture and little competition from other plants, it grows tall and luxuriant, forming pure stands. 

In dry, poor soils, plants may grow to only a few centimeters high, persist through drought, and 

set seed. The ability to grow under a variety of conditions results in a continuous seed supply if 

plants are not controlled (Holm et al. 1977). Open grown plants produce 500 to 5,400 burs per 

plant. The number of fruits produced is dependent upon the amount of vegetative growth at the 

time of floral initiation. On crowded plants, production is reduced to 71 to 586 burs per plant 

(Weaver and Lechowicz 1983). Burs are buoyant and will float for up to 30 days (Kaul 1961), thus 

being easily dispersed to shorelines, downstream areas, and areas subject to flooding. The burs 

also become entangled in animal hair or human clothing. The burs are a serious problem in sheep 

production areas where they become entangled in the wool, reducing its value (Wapshere 1974). X. 

strumarium burs contain a highly toxic substance, carboxyatractyloside, capable of killing hogs, 

cattle, goats, horses, sheep, and poultry. 

F-49 
Germination of cocklebur seeds has been extensively researched (Crocker 1906, Davis 1930, Katoh 

and Esashi 1975, Zimmerman and Weis 1983). More than 80% of cocklebur seeds are viable in 

most populations (Weaver and Lechowicz 1983). Plants produce seeds of two types (termed 

somatic polymorphism). Each bur contains two seeds, with the smaller one often pushed upwards 

toward the beaked end of the fruit. The lower seed has a shorter dormant period and germinates 

first. Dormancy in Xanthium involves the presence of a different water-soluble germination 

inhibitor in each seed type, to which the testa are impermeable. The presence of oxygen causes 

degradation of these two inhibitors and subsequent rupture of the seed coat, but apparently at 

very different rates in the two types. Thus, at least two batches of seeds are present in each 

generation to assure germination in the event the immediate environment happens to be 

unsuitable (Redosevich and Holt 1984). 

For the purposes of this IPM Plan, cocklebur is considered invasive in managed wetlands, as it has 

little value for forage or cover and tends to out compete vegetation that is more desirable for 

waterfowl and other waterbirds. 

PHYSICAL CONTROL 

Cocklebur control requires that treatments be made prior to seed being set on actively growing 

plants. Young plants can be controlled effectively by short-term flooding, often referred to as 

“scalding.” Water should be turned in at a point when plants can be completely covered for a 

period of 7-14 days. The actual length of time it takes to kill the plants can vary based on air/water 

temperature, the size of the plants, and how deeply they are flooded. The warmer the 

temperature, the smaller the plants, and the deeper they are flooded, the quicker they will 

succumb. Cocklebur plants should be monitored during the scalding process, and when they turn 

completely black and slimy they are dead and water can be removed. This treatment will often 

result in the added benefit of irrigating a number of desirable aquatic species such as watergrass, 

sprangletop and smartweeds. However, if plants are not fully inundated, killing them will require 

prolonged flooding. Often, this can mean enhancement of other undesirable species, such as 

Bermuda grass and jointgrass, and potentially cause significant production of mosquitoes (which 

may initiate mosquito control in some areas). 

The other method of controlling cocklebur is mowing plants prior to their formation of burs. 

Plants should be allowed to put maximum energy into vertical growth and flowers, then mowed as 

close to the ground as possible. In cases where significant soil moisture is still present, plants may 

regrow and require an additional mowing to kill them. A third option, especially with larger plants 

is to mow, then follow with a short inundation. Mowed plants are particularly susceptible to 

scalding. Refer to Mensik and Reid (1995) for additional information. 

PERENNIAL PEPPERWEED (FROM BOSSARD ET AL. 2000) 

Perennial pepperweed (Lepidium latifolium) is a multi-stemmed herb that grows three to eight 

feet tall with a heavy, sometimes woody, crown and a spreading underground root system. 

Pepperweed invades brackish to saline or alkaline wetlands throughout California, from the coast 

to the interior, and north and eastward into the Great Basin and Columbia Basin. According to 

observations by wildlife area managers and others, within the last fifteen years pepperweed 

populations in California have expanded, and the plant has significantly increased its overall 

range. Pepperweed can be distributed by seeds, or by pieces of the underground stems. The small 

seeds have no special adaptations for long-distance dispersal. They are capable of being 

F-50 
transported by wind, water, and possibly waterfowl. Pepperweed is an aggressive invader of 

coastal and interior wetlands and adjacent uplands throughout California. It forms dense 

monospecific stands that exclude other plants, including natives (Corliss 1993, Trumbo 1994). 

Pepperweed reproduces from seed, as well as vegetatively from intact root systems or from pieces 

of rootstock. Flowering time varies from May to July in different parts of California. Peak bloom 

lasts for several weeks. Seeds mature by June or July. Each mature plant has the capacity to 

produce thousands of seeds each year. 

PHYSICAL CONTROL 

Manual/mechanical methods: Mechanical methods are unlikely to control pepperweed because 

new plants quickly regenerate from pieces of rootstock left in the soil (Young et al. 1995). 

Segments much shorter than one inch (2.5 cm) are capable of resprouting. Disking of pepperweed 

at Grizzly Island Wildlife Area resulted in a significant increase in distribution (Feliz, pers. 

comm.). Young et al. (in press) attempted to control pepperweed in native hay meadows near 

Honey Lake, Lassen County, in tillage experiments conducted from 1991 to 1992, using monthly 

disking throughout the growing season. They concluded that this treatment resulted in no 

permanent reduction in pepperweed cover. This conclusion was based on the finding that the year 

following disking, pepperweed reestablished approximately 100 percent cover. 

PRESCRIBED BURNING 

Experiments at Malheur National Wildlife Refuge in southern Oregon indicate that fire alone is 

unlikely to be effective in controlling pepperweed, in part because typical fuel loads in infestations 

of this plant are inadequate to sustain burns. 

INUNDATION 

Pepperweed may be intolerant of prolonged inundation. At West Navy Marsh in Contra Costa 

County, pepperweed distribution and abundance were significantly reduced after a diked marsh 

was returned to tidal action, increasing inundation time (May 1995). Young et al (1995) report that 

pepperweed does not appear to survive lengthy periods of flooding during the growing season. 

BIOLOGICAL CONTROL 

Insects and fungi: Development of a biological control program seems unlikely because of risks to 

many important crop plants that are members of the mustard family (Brassicaceae) (Young et al. 

1995, Birdsall et al. 1997). Additionally, several native Lepidium species from the western United 

States either are listed as endangered or are being considered for listing (Young et al. 1995). 

Fifteen species of Lepidium are native to California, including four that are considered rare and 

endangered by the California Native Plant Society (Skinner and Pavlik 1994). Acknowledging 

these difficulties, Birdsall et al. (1997) pointed out the limitations of herbicidal control and 

suggested that L. latifolium-specific biocontrol agents, either insects or fungi, be sought in the 

many European countries with other native Lepidium species. 

CHEMICAL CONTROL 

Attempts have been made to control pepperweed with chemical herbicides in California, Oregon, 

Wyoming, Idaho, Nevada, and Utah. The most effective herbicides appear to be chlorsulfuron (as 

F-51 
Telar), metsulfuron methyl (as Escort), and imazapyr (as Arsenal) based on field trials of one to 

four years (Cox 1997). Neither Escort nor Arsenal is registered for use in California at this time. 

Trumbo (1994) reports that tests of chlorsulfuron, triclopyr, and glyphosate at Grizzly Island 

Wildlife Area in Suisun Marsh, California, showed that each of these compounds can provide 

significant control of pepperweed. Chlorsulfuron (as Telar) was most effective, with one 

application resulting in a reduction in cover of more than 95 percent after two years. Telar was 

applied at the recommended rate of 0.75-1 oz/acre, mixed in 30 gallons water with 0.5 percent nonionic surfactant. It is selective against broadleaved plants. This was advantageous at Grizzly 

Island Wildlife Area because desirable grasses were not affected. After the initial test, large-scale 

use of Telar at Grizzly Island Wildlife Area has confirmed its effectiveness. However, retreatment 

may be necessary because of the regenerative ability of pepperweed. Telar exhibits some residual 

soil activity, and its use is not permitted near water. 

Triclopyr as Garlon3A and Garlon4 provided moderate to good control after one year in tests at 

Grizzly Island Wildlife Area. Garlon3A was applied as a 2 percent solution with 0.5 percent nonionic surfactant added. Garlon4 was applied as a 1.5 percent solution with 0.5 percent non-ionic 

surfactant added. Currently, neither formulation of Garlon is registered for use over water in 

California. Triclopyr is broadleaf-specific, so it generally does not affect grasses. Garlon4 does not 

show residual soil activity. As with chlorsufuron, retreatment may be needed to maximize control. 

Glyphosate as Rodeo and Roundup provided fair to moderate control after one year in tests at 

Grizzly Island Wildlife Area. Roundup was effective as a 2 percent solution. Rodeo was also used 

as a 2 percent solution with the addition of 0.5 percent non-ionic surfactant. Rodeo can be used 

over water, but Roundup cannot. Roundup and Rodeo are broad-spectrum herbicides that control 

most plants, including grasses. At Grizzly Island Wildlife Area, resprouting of pepperweed the 

year following treatment indicated that several follow-up treatments likely are needed for full 

control. 

In Lassen County, California, Young et al. (in press) tested the effectiveness of 2,4-D, glyphosate, 

and chlorsulfuron against pepperweed. They found that, while 2,4-D and glyphosate greatly 

reduced top growth and eliminated seed production in the year of application; they provided no 

permanent control, since cover returned to 100 percent by the second year after application of 

these compounds. One application of chlorsulfuron provided up to three years of nearly complete 

control of pepperweed. 

In Nevada, Young et al. (1997) found that chlorsulfuron is effective in controlling pepperweed. The 

highest level of control was obtained from applications during the bud stage. However, in the 

native hay meadows where the studies were conducted, excellent control was possible with early 

spring or late fall applications. 

At Malheur National Wildlife Refuge in Oregon, chlorsulfuron and metsulfuron methyl were 

tested alone and in combination with either fire or disking. The herbicides were more effective 

when used alone, with chlorsulfuron reducing pepperweed densities by 100 percent in all three 

sites tested, and metsulfuron methyl resulting in density reductions of 90 to 100 percent. 

In Idaho herbicides used to control pepperweed include metsulfuron methyl, 2,4-D, dicamba (as 

Vanquish), imazapyr, chlorsurfuron, and picloram (Cox 1997). Metsulfuron methyl is the most 

commonly used and is described as “quite” effective. Other compounds noted as “successful” in 

controlling this species include imazapyr and chlorsulfuron (Cox 1997). 

F-52 
In Wyoming, metsulfuron methyl and chlorsulfuron proved most effective in controlling 

pepperweed. Either compound, used at the recommended rate of 0.75-1.0 oz/acre, resulted in 

stand reductions of 90 percent or more that persisted for four to five years. 

RUSSIAN THISTLE (FROM UNIVERISITY OF CALIFORNIA 2007) 

Russian thistle, also known as tumbleweed, is in the goosefoot family (Chenopodiaceae). Its 

scientific name is Salsola tragus, but it also has been known as S. iberica, S. kali, and S. australis. 

It is a summer annual that is primarily a weed in sites where the soil has been disturbed, such as 

along highways. At the Complex, fleshy-leaved Russian thistle (Salsola soda) is a similar species 

and also of concern (Silveira, pers. comm.). However, little species-specific information is available 

at this time, so control efforts will follow this profile in the interim, until more information 

becomes available. 

Russian thistle has numerous slender ascending stems that become quite woody at maturity. 

Stems vary from eight to 36 inches in length and usually have reddish to purplish stripes. 

Seedlings have very finely dissected leaves that almost look like pine needles. Leaves of young 

plants are fleshy, dark green, narrow, and about 1 inch in length. Young plants are suitable for 

livestock forage and are sometimes grazed. 

The Russian thistle seed is a naked, coiled embryo that begins to uncoil when it is exposed to the 

proper temperature (52° to 90°F) and moisture conditions. As it uncoils, the taproot extends into 

the soil within about 12 hours, making the germination period quite rapid and giving Russian 

thistle a decided advantage under limited moisture conditions. A minimum amount of moisture, 

lasting only a few hours, will allow germination and root growth to deeper, subsurface moisture. 

Russian thistle normally will not germinate successfully in firm soil: the soil in the site must be 

loose. Likely sites for germination include vacant lots, abandoned gardens and agricultural fields, 

roadsides, fence lines—any open site with loosened soil. Germination normally occurs in late 

winter or early spring when the seed can take advantage of winter moisture. Seed viability is 

rapidly lost in soil. Over 90 percent of the seed either germinate or decay in the soil during the 

first year. 

Russian thistle is extremely drought tolerant. The taproot can extend several feet into the soil to 

reach subsurface moisture. Early leaves are linear and fleshy, much like pine needles, but as the 

plant matures, later leaves are short, spiny, and much more capable of conserving moisture. 

Russian thistle normally matures in late summer. An abscission layer forms in the stem near the 

soil surface that allows the shoot to break off from the taproot in fall and early winter. The seed is 

spread when mature plants are blown along by the wind. A large Russian thistle plant may 

produce more than 200,000 seeds. In spring, months after their dissemination, it is possible to 

trace the paths of tumbleweeds across plowed fields by the green trails of germinating Russian 

thistle seedlings. 

Russian thistle can tolerate alkaline soil conditions. It is very competitive when moisture is a 

limiting factor to the growth of other vegetation, when soils are disturbed, or when competing 

vegetation is suppressed by overgrazing or poor crop establishment. If moisture is not limiting, 

Russian thistle is less competitive with other species. Seedlings of Russian thistle are suppressed 

when other plants become established first and shade out the sunlight. 

F-53 
Control of Russian thistle is difficult. There have been numerous attempts through the years to 

import biological control agents, but none has been successful. Normally the best place to look for 

a biological control agent is the native habitat of the species. Unfortunately, Russian thistle’s 

native habitat is thought to be at the site of major military installations in Russia. Until recently, it 

was impossible to collect potential biological control organisms in these areas. 

Cultural control practices such as mowing or destroying young plants can prevent seed 

production. Avoid disking or loosening the soil in abandoned areas because loose soil is necessary 

for Russian thistle germination. Burning is sometimes used to destroy accumulated Russian 

thistle plants. While this may eliminate the accumulated organic debris and some seed, much of 

the seed will already have been disseminated. Planting competitive, more desirable species can be 

an effective method of preventing Russian thistle establishment in most non-crop environments. 

Russian thistle competes poorly in situations with firm, regularly irrigated soil, and it is rarely a 

problem in managed gardens, turfgrass, or landscapes. 

In addition, there are many herbicides that will control Russian thistle in agricultural crops and 

non-crop areas. Aim treatments at controlling the immature plants to prevent them from reaching 

the seed production stage. The selection of an appropriate herbicide depends on the site or the 

crop. 

Pre-emergent herbicides are applied to the soil before the weed seed germinates and are usually 

incorporated into the soil with irrigation or rainfall. The most effective pre-emergent herbicides 

are Aatrex (atrazine), Velpar (hexazinone), Devrinol (napropamide), Telar (chlorsulfuron), Oust 

(sulfometuron), Princep (simazine) and Hyvar (bromacil). Other pre-emergent herbicides that are 

registered but only moderately effective in controlling Russian thistle are Surflan (oryzalin), 

Treflan (trifluralin), Prowl (pendimethalin), Endurance (prodiamine), Lasso (alachlor), Predict 

(norflurazon), and Kerb (pronamide). 

Herbicide-resistant biotypes of Russian thistle have evolved in only a couple of years following 

treatment with Telar (chlorsulfuron) or Oust (sulfometuron). Avoid repeated use of a single 

herbicide or of herbicides that have the same mode of action to prevent the evolution of herbicideresistant populations. 

Post-emergent herbicides are applied to plants, but timing is critical. For best results, these 

herbicides must be applied while the weed is in its early growth stages, preferably the early 

seedling stage, before it becomes hardened and starts producing its spiny branches. Do not use 

post-emergent herbicides to try to control the mature seed (either on the plant or on the ground) 

as they are not effective for this purpose. In addition, the later spiny stage of Russian thistle is not 

readily controlled by any post-emergent herbicide. If rain or irrigation occurs after a postemergent application, additional seedlings may emerge and require future treatments. Postemergent herbicides that are effective when properly applied include Banvel or Vanquish 

(dicamba), Roundup (glyphosate), 2,4-D and Gramoxone (paraquat). 

FIELD BINDWEED (FROM UNIVERSITY OF CALIFORNIA 2007) 

Field bindweed (Convolvulus arvensis) is a hardy perennial found throughout California below 

5,000 feet elevation. It spreads from an extensive rootstock as well as from seed. Most parts of the 

bindweed roots and rhizomes can produce adventitious buds, which can create new roots and 

F-54 
shoots. Roots capable of budding are found to depths of 14 feet. This extensive underground 

network allows for over-wintering without foliage, and it can persist for many years in the soil. 

Drought tolerance is a characteristic of field bindweed. In California, it seems to prefer heavy clay 

soils rather than sandy soils. When water is withheld, bindweed competes better than most other 

plants. 

Control of field bindweed is not easy, and it cannot be accomplished with a single treatment or in a 

single season. It has a vigorous root and rhizome system that makes it almost impossible to control 

with cultivation. Once established it is almost impossible to control with herbicides. 

Effective control requires prevention of seed production, reduction of stored carbohydrates by 

deep tillage of the root system, competition for light from other plants, and constant vigilance in 

removing top growth. It is important to control new infestations when they are small, because spot 

control is least expensive and the most effective. Seedlings of field bindweed are easy to control 

with cultivation, but only for about 3 to 4 weeks from germination. After that, perennial buds are 

formed, and control is much more difficult. 

Cultivation or hoeing has been partially effective in reducing established stands of field bindweed. 

Cultivate about every 2 to 3 weeks, as soon as the bindweed reaches 6 inches in length, and repeat 

whenever necessary. In conjunction with cultivation, withholding water to dry the site may help to 

reduce the perennial population in a summer season. 

Herbicides have been relatively effective for suppression of bindweed, but have not been very 

effective for eradication. If herbicides are used, supplement them with appropriate preventive and 

cultural controls. 

In areas outside the landscape or orchard, cultivation and herbicide treatment can be used. If 

herbicides are to be used, treat the bindweed plants before they are drought stressed. Use a 

translocated herbicide, such as glyphosate or a combination of glyphosate and dicamba in areas 

where its use is allowed, at the flowering stage of growth. The addition of dicamba gives the 

treatment some soil residual activity that helps with control of new seedlings. Re-treatments will 

be necessary to control both established plants and seedlings. If possible, grow a competitive 

planting of other plants to reduce field bindweed growth. 

BLACK LOCUST (FROM BOSSARD ET AL. 2000) 

Black locust (Robinia pseudoacacia) is widespread, particularly in northern California, below 

about 6,300 feet (1,910 m) elevation (Hickman 1993). This tree can grow on a wide range of sites, 

but grows best on rich, moist, limestone-derived soils. It does not do well on heavy or poorly 

drained soils, although it appears to be tolerant of some flooding (Huston and Smith 1987, Huntley 

1990). In the northeast United States, it is found on floodplain sites with a 40 to 100 percent 

probability of flooding in any given year. Through root sprouts and seedling establishment, black 

locust creates large stands that displace native vegetation. Its seeds, leaves, and bark are toxic to 

humans and livestock (Hickman 1993). Black locust reproduces both by seed and by root sprouts. 

It flowers in May-June. Fruits ripen in fall and open on the tree, dispersing seeds throughout fall 

and winter (Olson 1974). Seeds remain viable for ten years or more and require scarification for 

germination (Olson 1974, Strode 1977). Seedlings are intolerant of shade and herbaceous 

competition, but once established, they are capable of growing over 3.3 feet (1 m) per year on 

better sites (Huntley 1990). Saplings begin producing seed at about six years. Black locust 

F-55 
produces root and stump sprouts. Sprout production is stimulated by top damage. Root suckers 

usually are more important to reproduction than are seedlings. Root suckers first appear when 

stems are four to five years old. Sprout production is greatest in full sun (Huntley 1990). Sprouting 

is an important mechanism for colonizing areas that have herbaceous plant cover but no woody 

canopy. Grasses form a sod that prevents establishment of black locust seedlings, but root sprouts 

are able to colonize these areas (Hardt and Forman 1989). 

Physical control: Mechanical methods: Cutting or girdling a black locust stem will result in prolific 

root suckering. Mechanical removal therefore will be ineffective in controlling black locust unless 

all stems are cut several times per year. Repeated cutting of sprouts can kill the tree. Cutting 

probably will need to be repeated for several years. Mowing may not be effective in controlling 

seedlings and sprouts. More effective control can be obtained by immediately brushing the freshly 

cut surface of the stem with herbicide. 

PRESCRIBED BURNING: 

Burning has not been effective in controlling black locust. Fire may kill main stems, but this will 

result in prolific sprouting. Fire also may stimulate seed germination and create favorable 

conditions for seedling establishment. 

BIOLOGICAL CONTROL 

Black locust suffers considerable damage from insects, particularly the black locust borer, 

Megacylline robinine. However, no USDA biological control program for black locust has been 

attempted, and no USDA approved biocontrol agents exist for this species. Black locust suffers 

some browse herbivory, particularly the young growth of sprouts, which may aid eradication 

efforts (Huntley 1990, Luken 1992). 

CHEMICAL CONTROL 

Black locust has been effectively controlled with herbicides (Gouin 1979, Liegel et al. 1984, 

Scheerer and Jackson 1989). Herbicide applications should be most effective in spring, just after 

leaves are fully expanded. Smaller sprouts may be controlled by spraying all foliage with 4 percent 

glyphosate (Chemical & Pharmaceutical Press 1997). Young stems may be killed by generously 

applying 15-20 percent triclopyr (as GarlonÂ®) to the bark from the stem base to twenty inches 

above the ground (Gouin 1979, Chemical & Pharmaceutical Press 1997). The thicker bark of larger 

stems interferes with uptake of herbicide, and therefore, to kill larger plants, the stem needs to be 

frilled (have an encircling ring of bark removed) and the herbicide applied to the freshly exposed 

surface. 

Applying herbicide to freshly cut stumps is probably the most effective means of controlling black 

locust. Wiping the stump with 100 percent glyphosate (as Roundup Ultra®) within fifteen minutes 

of cutting should reduce or even eliminate subsequent root suckering (Chemical & Pharmaceutical 

Press 1997). 

PARROT’S FEATHER (FROM BOSSARD ET AL. 2000) 

Parrot’s feather (Myriophyllum aquaticum) is a stout aquatic perennial that forms dense mats of 

intertwined brownish stems (rhizomes) in water. These stems grow to six and a half feet in length 

F-56 
and resemble bright green bottlebrushes emerging from the water. Both parrot’s feather and 

spike watermilfoil can be found in freshwater lakes, ponds, and canals with slow-moving waters in 

northern and central California (Anderson 1990). Parrot’s feather is capable of sexual 

reproduction in its native range, but the spread of parrot’s feather in the United States results 

solely from vegetative reproduction. The stems of parrot’s feather are brittle and fragment easily. 

These fragments settle in sediments and produce new plants (Orchard 1981, Kane et al. 1991). 

Fragments can be spread by boats, trailers, and by dumping aquarium plants in waterways. 

Parrot’s feather may compete with native aquatic plants, eliminating them or reducing their 

numbers in infested sites. It forms dense mats that can entirely cover the surface of the water in 

shallow lakes and other waterways. These mats clog waterways, making them unusable for 

navigation or recreation and causing flooding out of the channel. It can block irrigation pumps and 

water intakes, and it provides optimal habitat for mosquitoes (Orr and Resh 1989, Systma and 

Anderson 1989; Parsons 1992). In California, this species is becoming an increasing problem in 

irrigation and drainage canals. A 1985 survey of irrigation, mosquito abatement, flood control, and 

reclamation agencies in California indicated that parrot’s feather infested nearly 600 miles of 

waterways and over 500 surface acres (Washington Water Quality Program 1998). Growth is most 

rapid from March until September. In spring, shoots begin to grow rapidly from over-wintering 

rhizomes as water temperature increases. Rhizomes function as a support structure for 

adventitious roots and provide buoyancy for emergent growth in summer. 

Parrot’s feather is difficult to remove from an aquatic system, so it is best to prevent it from 

establishing in the first place. The public must be made aware of the problems caused by parrot’s 

feather and how it can be spread by dumping unwanted plants from water gardens or aquaria, or 

by boats, trailers, and fishing equipment that are not cleaned before being moved to a new 

waterway. If parrot’s feather becomes established, only chemical and mechanical control methods 

are available. 

PHYSICAL CONTROL 

Parrot’s feather can be removed by mechanical harvesters. In Washington, workers use a dragline 

to remove parrot’s feather plants. A truck-mounted crane with a special attachment plucks weeds 

out of the ditch. The dragline operation is conducted annually from August to December, with 

control generally lasting for one growing season (Washington Water Quality Program 1998). Care 

must be taken to ensure removal of all plant parts during harvest, since even tiny stem or rhizome 

fragments can root and establish new plants. Because of this, mechanical harvesting often results 

in the spread of parrot’s feather rather than its elimination or suppression. 

BIOLOGICAL CONTROL 

Parrot’s feather has a high tannin content, so most grazers, including grass carp 

(Ctenopharyngodon idella), find it unpalatable. Grass carp also prefer soft plants, such as Elodea 

canadensis, and the tough, woody parrot’s feather stems are avoided. USDA approved biological 

control agents are not currently available. Potential agents do exist, but they have yet to be tested 

for host specificity. A complex of insects feed on parrot’s feather in its native habitat. Lysathia 

flavipes, a flea beetle found on parrot’s feather in Argentina, causes moderate damage under field 

conditions. Also found in Argentina is a weevil, Listronotus marginicollis, that apparently feeds 

only on parrot’s feather in its native range. Other insects have been found on parrot’s feather in 

Florida. Lysathia ludoviciana, a flea beetle native to the southern United States and the 

Caribbean, uses parrot’s feather as a host plant for larvae under laboratory conditions. However, 

F-57 
the flea beetle is not often found on parrot’s feather in the field. Two members of the Tortricidae 

family, Argyrotaenia ivana and Choristoneura parallela, have also been found on parrot’s feather 

in Florida, but their effect on the plant is unknown. In addition, larvae of the caterpillar 

Parapoynx allionealis mine parrot’s feather leaves, but the impact of these larvae is unknown. 

Fungal control options exist as well. An isolate of Pythium carolinianum collected in California 

has shown some promise as a potential biocontrol agent. Parrot’s feather stems experimentally 

inoculated with this fungus produced significantly less growth than control plants (Washington 

Water Quality Program 1998). 

CHEMICAL CONTROL 

The underwater and above-water foliage of parrot’s feather make herbicides difficult to deliver 

effectively. Emergent stems and leaves have a thick, waxy cuticle that inhibits herbicide uptake, 

and a wetting agent is required to penetrate it. Often the weight of the spray will cause emergent 

vegetation to collapse into the water, where the herbicide is washed off before it can be 

translocated throughout the plant. The most recent version of an herbicide label will give 

recommended rates and information about whether the compound is registered for use in specific 

situations. Herbicide use is more highly regulated in aquatic systems than in terrestrial systems. 

Westerdahl and Getsinger (1988) report excellent control of parrot’s feather with 2,4-D, diquat, 

diquat and complexed copper, endothall dipotassium salt, fluridone, and endothall and complexed 

copper. Diquat is used on emergent parrot’s feather, as well as in the water to kill rhizomes. 

Copper complexes are used only on submersed plants. Diquat is not legal for use in aquatic 

systems in California. Fair control was obtained with acrolein and glyphosate. Acrolein is used 

only in non-fisheries water, and glyphosate, formulated as Rodeo, is used only on emergent 

parrot’s feather. The Monsanto Company suggested that applying a 1.75 percent solution of Rodeo 

with surfactant to the plants in summer or fall when water levels are low would give about 95 

percent control. Control of parrot’s feather may be achieved with low-volatility ester of 2,4-D at 

4.4-8.9 kg/ha, sprayed onto emergent foliage. The granular formulation of 2,4-D was needed to 

control parrot’s feather for periods greater than twelve months. It is more effective when applied 

to young, actively growing plants (Washington Water Quality Program 1998). 

In practice, weed control efforts report little success with herbicides to control parrot’s feather. 

Glyphosate causes emergent vegetation to turn black, but within two weeks, the plants have 

recovered. An experimental fall application of triclopyr also proved ineffective (Washington Water 

Quality Program 1998). 

COMMON FIG (FROM BOSSARD ET AL. 2000) 

Mature trees often have multiple trunks and may grow to thirty feet tall. The heavy trunk and 

branches are covered with a smooth, light gray, flaky bark. The sap is thick, sticky, and slightly 

milky. The leaves are rough to the touch, bright green, with three to five lobes, the classic fig-leaf 

shape. Edible figs (Ficus carica) invade and dominate riparian forests, streamside habitats, 

levees, and canal banks in and around California’s Central Valley, surrounding foothills, the south 

coast, and the Channel Islands (Hickman 1993). They are also widely cultivated for fruit and 

ornament in areas below 2,500 feet (800 m) elevation. 

Edible fig is most likely to escape where soils stay moist throughout the summer. It is not clear 

F-58 
how edible fig spreads into natural areas. It grows quickly and can spread vegetatively by root 

sprouts, soon forming dense thickets that exclude most other plants. Limbs that have been cut or 

broken and fallen to the ground can take root, and it is thought that branches broken off during 

storms or floods may wash up and root at downstream sites. Many birds eat the fruits and may 

spread the seeds. Hujik (pers. comm.) reports that deer also feed on the fruits. Seeds germinate 

only if they are removed from the fleshy synconium during passage through an animal’s gut or by 

mechanical means such as heavy rainfall (Lisci and Pacini 1994). 

It has invaded many nature preserves and parks in California. Plants form dense thickets covering 

roughly twenty-five acres along a seven-mile-long section of Dye Creek at the Dye Creek Preserve 

northeast of Chico and have begun to invade the riparian forest at Woodson Bridge State Park 

along the Sacramento River to the west. Several rapidly expanding fig thickets were found in the 

most pristine valley oak riparian forest on the Cosumnes River Preserve south of Sacramento. 

These thickets were repeatedly cut and the stumps treated with herbicide, but they were difficult 

to eliminate. 

If not controlled, edible fig trees could crowd out native trees and understory shrubs 

characteristic of California’s riparian forests. Riparian forests are already rare in California, 

especially in the Central Valley, where over 95 percent have been converted to cropland, pasture, 

or developed areas in the past 150 years. No published or unpublished reports are available with 

quantitative information on the impacts of edible figs invading natural vegetation in California or 

elsewhere. 

Edible fig grows quickly in soils with enough moisture and with exposure to high light levels. It is 

winter-deciduous, and the timing of leaf-out and leaf drop varies with the cultivar and with climatic 

conditions. 

Edible fig reproduces by seed and by vegetative growth. Most of the world’s Ficus species depend 

on a species-specific agaonid wasp (family Agaonidae, Hymenoptera) for pollination. Ficus carica 

depends on the wasp Blastophaga psenes. The wasps are in turn dependent on F. carica because 

they breed only inside its fruits (Kjellberg et al. 1987). 

An efficient control method for edible fig has not yet been developed. The trees resprout 

vigorously after cutting and are difficult to control without herbicides. 

MANUAL/MECHANICAL 

Edible figs are shallow-rooted in heavy, wet soils typical of riparian forests and can be pulled up 

fairly easily when young. They often root-sprout, however, so what looks like one small sapling 

may be one of many sprouts from a large network of roots. A small or medium-sized weed wrench 

may help remove some of the mid-sized specimens. Repeated cutting of resprouts may eventually 

exhaust the root reserves of a tree or small thicket if the interval between cuttings is short 

enough, but this has not yet been demonstrated. 

BIOLOGICAL CONTROL 

No biological control species are approved by the USDA for this species. However, figs are subject 

to damage from nematodes, tree borers, and rust. 

F-59 
CHEMICAL CONTROL 

At the Cosumnes River Preserve, all trunks and sucker shoots in a thicket were cut six to eighteen 

inches above the ground and the cut stumps treated with a 100 percent solution of an amine 

formulation of triclopyr (sold under the names Garlon3A and Brush-B-Gone). This was successful, 

although some thickets had to be retreated at least once because there was some resprouting. The 

retreatments were carried out at yearly intervals, but shorter intervals (two to six months) might 

have improved their impact by giving the plants less time to replenish root reserves. Managers at 

the Cosumnes River Preserve recently have been using a hack-and-squirt method, applying 100 

percent triclopyr amine formulation to the wounds, but it is too early to tell if this will be as 

effective as the cut-stump treatments. This method was also tried at the Dye Creek Preserve, but 

was not effective there. 

Herbicide may be applied in an eight- to twelve-inch-wide band around the uncut trunks of trees 

with trunk diameters up to two or three inches and perhaps greater. This is known as basal bark 

application, and it has been shown to be highly effective for a variety of trees and shrubs. Other 

herbicides, including glyphosate (marketed under a variety of names, including Rodeo and 

Roundup) and imazapyr (as Chopper and Arsenal) may be at least as effective as triclopyr against 

edible fig, but studies of this have yet to be conducted. 

RED RIVER GUM (FROM BOSSARD ET AL.2000) 

This profile is specific to blue gum (Eucalyptus globulus), which is a close relative, but may, in 

fact, also refer to Red River gum (E. camaldulensis) as well based on description and range given 

in Bossard et al. (2000). For the purposes of this IPM Plan, the control and management of Red 

River gum will follow this profile. Red River gum is abundant in local areas throughout the 

Sacramento Valley, and groves or treelines occur in areas such as roadsides, parking areas, and 

around buildings in several areas on the Complex. Within gum tree groves, biological diversity is 

lost due to displacement of native plant communities and corresponding wildlife habitat. 

Abundance and diversity of understory vegetation is dependent on stand density. Understory 

establishment is inhibited by the production of allelopathic chemicals and by the physical barrier 

formed by high volumes of forest debris consisting of bark strips, limbs, and branches. The fuel 

complex formed by this debris is extremely flammable, and under severe weather conditions could 

produce drifting burning material with the potential to ignite numerous spot fires. Because stringy 

bark is carried away while burning, eucalyptus forests are considered the worst in the world for 

spreading spot fires. The Oakland hills firestorm was both intense and difficult to control because 

of the many stands of eucalyptus. Individual trees growing near structures or in public use areas 

are hazardous because of the potential for branch failure. Stature and growth form are distinctive 

and unlike native tree species, which compromises the visual quality of natural landscapes. 

Blue gum reproduces by seed and by resprouting. In California, flowering occurs from November 

to April. Seeds are small and abundant. Capsules open immediately on ripening, and seed is 

dispersed by wind within one to two months. Dispersal distance from one 131-foot (40 m) tall tree, 

with winds of six miles per hour (10 km/h), was sixty-six feet (20 m). Newly released seeds 

germinate within a few weeks under suitable conditions. Blue gum sprouts readily from the main 

trunk, from stumps of all sizes and ages, from the lignotuber, and from roots. Large masses of 

foliage are produced by sprouting stumps after tree felling. Numerous clusters of shoots later thin 

to one stem per cluster. A number of small-diameter stems can continue to thrive on each stump, 

resulting in bush-like growth. Production of lignotubers, which may live for many years in soil, 

F-60 
may account for sprouting that sometimes occurs away from the main stump of cut trees (Skolmen 

1983). 

PHYSICAL CONTROL 

Manual/mechanical methods: Removing trees is a difficult task and can be expensive if individual 

trees are felled. It is also unlikely that this cost can be offset because of the low value of the wood 

as fuel. An effective method to control stump resprouting is absolutely necessary. Stump grinding 

can eliminate sprouting, as well as remove all evidence of trees. Where there are few stumps and 

the terrain is gentle, this may be a preferred method. It is expensive to treat many stumps this 

way, even if a powerful and efficient self-propelled grinder is used. Care must be taken to grind all 

underground portions of stumps to a depth of approximately two feet. Provision must be made to 

fill resulting craters with soil. 

Manual removal of eucalyptus sprouts from stumps results in eventual control as food resources 

are exhausted. This method is expensive and impractical if a large number of stumps are to be 

treated. Manual removal should be limited to situations where close attention can be given to a few 

stumps. 

PRESCRIBED BURNING 

This method can reduce fuels in blue gum stands, but the species is fire tolerant. Only seedlings 

can be killed by fire. Fuel replenishment is rapid. 

BIOLOGICAL CONTROL 

None known to be effective, although the red gum lerp psyllid has infested at least 27 species of 

eucalyptus in California, including local Red River gum at the Complex. These infestations have 

resulted in some defoliation and possibly some weakening of some branches, but no mortality has 

been documented. 

CHEMICAL CONTROL 

The most effective control of sprouting is achieved through application of triclopyr or glyphosate 

directly to the outer portion of the stump’s cut surface at the time of tree felling. Triclopyr (as 

Garlon 4 and Garlon 3A) should be applied at the rate of 80 percent in an oil carrier. Imazapyr (as 

Arsenal or Stalker) can be used as an alternate to Garlon. Glyphosate (as Roundup or Rodeo) 

should be applied at 100 percent. Stumps should be cut as low to the ground as practical and 

brushed clean of sawdust to maximize absorption of the herbicide. For best results, herbicides 

should be applied to the freshly cut surface as soon after cutting as possible. Maximum success is 

achieved if cutting occurs in fall (Carrithers, pers. comm.). Complete control of sprouting on every 

stump will not always be achieved. Any resprouts, when three to five feet tall, should be treated 

with a foliar application of 2 percent of triclopyr or glyphosate. 

Triclopyr (as Garlon 4) offered the best results of the herbicides currently available in California 

for a 1996 eucalyptus removal project at Angel Island State Park in Marin County. A high 

concentration was used (80 percent Garlon 4, 20 percent oil carrier; an alternative is 100 percent 

Garlon 3A). Glyphosate (as Roundup) was used in 1990 on a similar eucalyptus removal project on 

Angel Island, but with less consistent results. When sprouting occurred following the 1990 

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eucalyptus removal project on Angel Island, excellent follow-up control was achieved by applying 

triclopyr as Garlon 4 (80 percent Garlon 4, 20 percent oil carrier) to overlapping frill cuts. These 

cuts were made on portions of the vertical surfaces of stumps with live cambium. 

Application of these herbicides to the foliage or stems of sprouts are less effective. Several years 

of foliar applications of triclopyr at Annadel State Park, Sonoma County, following a major 

eucalyptus removal project produced only incremental results. The visual impact of tall, herbicidekilled sprouts must also be considered. 

At TNC’s Jepson Prairie preserve near Rio Vista, Solano County, over 1,200 eucalyptus stumps 

were killed by repeated foliar herbicide treatments over one summer period (Serpa, pers. comm.). 

The stumps were not treated at the time of felling, and sprouts were allowed to grow to a height of 

about ten feet. The sprouts were then cut and the resulting resprouts were treated with 

glyphosate as Roundup (5 percent solution). By the third herbicide application, all of the stumps 

were dead. It is possible that the dry climate of this site contributed to the success of this method. 

WATER PRIMROSE (FROM UNPUBLISHED OBSERVATIONS AT THE 

COMPLEX) 

Water primrose (Ludwigia sp.) is a floating or emergent perennial that occurs in wetlands, 

irrigation canals, and drainage ditches. There are at least two subspecies that occur and have 

expanded in many areas of California. In the last 5 years, there have been significant infestations 

in parts of the state, including the Central Valley and the Complex. It can form tangled mats of 

stems that can reduce water flow in irrigation canals and drains, causing water management 

problems in managed wetlands, replacement of native species, and potential mosquito abatement 

issues. 

Literature regarding control methods is sparse, but experience at the Complex has indicated that 

combinations of mechanical removal, dewatering, disking, and herbicide applications can control 

water primrose to some degree. Applications of aquatic-labled glyphosate at 1.5-2% with ~1% 

Agri-dex adjuvant has resulted in containment in irrigation canals and drainage ditches. In some 

cases, removing most above-canal bottom stems by raking or excavating and/or dewatering prior 

to spraying resprouting stems has enhanced control. Although, this provides short-term control, it 

requires annual retreatment in some areas. More rigorous studies of these treatments are being 

undertaken starting in 2007 (Grewell pers. comm.). Water primrose has more recently started 

expanding into managed seasonally flooded wetlands at the Complex. Control has been achieved 

through disking during the dry phase of the wetlands during the summer. Following disking, the 

plants, including stems and rhizomes are allowed to desiccate for several weeks to 2 months. 

Although, this provides short-term control, it requires annual retreatment in some areas. 

GIANT REED (FROM BOSSARD ET AL. 2000) 

Giant reed (Arundo donax) is a robust perennial grass nine to thirty feet tall, growing in manystemmed, cane-like clumps, spreading from horizontal rootstocks below the soil, and often forming 

large colonies many meters across. Giant reed occurs in central and southern California and in 

Baja California, usually below 1,000 feet (350 m) elevation. It has invaded central California river 

valleys in San Luis Obispo and Monterey counties, the San Francisco Bay Area, and in the 

Sacramento and San Joaquin River valleys, and is also increasing in the North Coast region 

(Dudley and Collins 1995). Giant reed displaces native plants and associated wildlife species 

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because of the massive stands it forms (Bell 1994, Gaffney and Cushman 1998). Competition with 

native species has been shown to result from monopolization of soil moisture and by shading 

(Dudley unpubl. data). It clearly becomes a dominant component of the flora, and was estimated to 

comprise 68 percent of the riparian vegetation in the Santa Ana River (Douthit 1994). As giant 

reed replaces riparian vegetation in semi-arid zones, it reduces habitat and food supply, 

particularly insect populations, for several special status species such as least Bell's vireo, 

southwestern willow flycatcher, and yellow-billed cuckoo (Frandsen and Jackson 1994, Dudley and 

Collins 1995). Giant reed is also suspected of altering hydrological regimes and reducing 

groundwater availability by transpiring large amounts of water from semi-arid aquifers. It alters 

channel morphology by retaining sediments and constricting flows, and in some cases may reduce 

stream navigability (Lake, pers. comm., TNC 1996). 

Plants in North America do not appear to produce viable seed, and seedlings are not seen in the 

field. Population expansion here occurs through vegetative reproduction, either from underground 

rhizome extension of a colony or from plant fragments carried downstream, primarily during 

floods, to become rooted and form new clones. 

PHYSICAL CONTROL 

Manual methods: Minor infestations can be eradicated by manual methods, especially where 

sensitive native plants and wildlife may be damaged by other methods. Hand pulling is effective 

with new plants less than six feet (2 m) in height, but care must be taken that all rhizome material 

is removed. This may be most effective in loose soils and after rains have made the substrate 

workable. Plants can be dug up using hand tools (pick-ax, mattock, and shovel), especially in 

combination with cutting of stems near the base with pruning shears, machete, or chainsaw. Stems 

and roots should be removed or burned on site to avoid re-rooting, or a chipper can be used to 

reduce material, although clogging by the fibrous material makes chipping difficult (R. Dale, pers. 

comm.). For larger infestations on accessible terrain, heavier tools (rotary brush-cutter, chainsaw, 

or tractor-mounted mower) may facilitate biomass reduction, followed by rhizome removal or 

chemical treatment. Such methods may be of limited use on complex or sensitive terrain or on 

slopes over 30 percent, and may interfere with reestablishment of native plants and animals. 

MECHANICAL METHODS 

Mechanical eradication is extremely difficult, even with a backhoe; as rhizomes buried under three 

to ten feet (1-3 m) of alluvium readily resprout (R. Dale, pers. comm., Else et al. 1996). Removal of 

all such material is infeasible, especially where extensive soil disturbance would be disruptive. 

PRESCRIBED BURNING 

In most circumstances burning of live or chemically treated material should not be attempted, as it 

cannot kill the underground rhizomes and probably favors giant reed regeneration over native 

riparian species (Gaffney and Cushman 1998). Burning in place is problematic because of the risks 

of uncontained fire, the possibility of damage to beneficial species, and the difficulties of promoting 

fire through patchily distributed stands. There may be some cases where burning of attached 

material can be done, but only if other means of reducing biomass cannot be carried out. Cut 

material is often burned on site, subject to local fire regulations, because of the difficulty and 

expense involved in collecting and removing or chipping all material. 

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BIOLOGICAL CONTROL 

No biological control agents against Arundo donax have been approved by the USDA, although 

some invertebrates are known to feed on the grass in Eurasia/Africa (Tracy and DeLoach 1999). 

The green bug (Schizaphiz graminum) has been observed to feed on giant reed in winter (Zuniga 

et al. 1983). In France, Phothedes dulcis caterpillars may feed on it. The insect Zyginidia guyumi 

uses giant reed as an important food source in Pakistan (Ahmed et al. 1977). A moth borer 

(Diatraea saccharalis) has been reported to attack it in Barbados. A USDA evaluation of the 

potential benefits of biological control against giant reed ranked it as a promising candidate and 

suggested several insects and pathogens as possible control agents (Tracy and DeLoach 1999). 

GRAZING 

Vertebrate grazers such as cattle and sheep may be useful in controlling giant reed, and Angora 

goats have been partially successful in reducing this plant and other brush in southern California 

(Daar 1983). Grazers are unlikely to reduce population size sufficiently to eliminate the risks 

posed. Likewise, management of native plants to increase competition with giant reed probably 

provides insufficient control, and in fact seems to offer little resistance against the invading reeds. 

CHEMICAL CONTROL 

In many, if not all, situations it may be necessary to use chemical methods to achieve eradication, 

especially in combination with mechanical removal. The most common herbicidal treatment 

against giant reed is glyphosate, primarily in the form of Rodeo, which is approved for use in 

wetlands (Round-Up can be used away from water). Because glyphosate is a broad-spectrum 

herbicide, care should be taken to avoid application or drift onto desirable vegetation. The 

standard treatment is a foliar spray application of 1.5 percent by volume glyphosate with a 0.5 

percent non-ionic surfactant (Monsanto 1992). Most effective application is post-flowering and predormancy, usually in late August to early November when plants are translocating nutrients into 

roots and rhizomes (TNC 1996). Foliar uptake and kill may be achieved by spray application 

during active growth periods, primarily late spring through early fall (Monsanto 1992). Small 

patches can be treated from the ground using backpack or towed sprayers, and major infestations 

have been aerially sprayed using helicopters. 

Direct treatment to cut culms can reduce herbicide costs and avoid drift onto desirable plants, 

with fair results year-round and best kill in fall, although it appears to be more successful in 

shaded sites (Else et al. 1996, Vartanian, pers. comm.). Concentrated glyphosate solution (50 

percent to 75 percent Rodeo, or 27 percent to 40 percent glyphosate) is applied to stems, cut within 

two to four inches (5-10 cm) of the substrate, by painting with a cloth-covered wand or a sponge or 

spraying with a hand mister. It may be helpful to add a dye or food coloring to the solution to 

identify treated material. Solution must be applied immediately following cutting because 

translocation ceases within minutes of cutting: a five-minute maximum interval is suggested (TNC 

1996). 

New growth is sensitive to herbicides, so a common alternative is to cut or mow a patch and allow 

regeneration, returning three weeks to three months later when plants are three to six feet (1-2 m) 

tall to treat new growth by foliar spraying of glyphosate. Promoting regrowth causes nutrients to 

be drawn from the roots, potentially reducing the movement of glyphosate to the roots (TNC 

1996). With all methods, follow-up assessment and treatment should be conducted, and some 

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professional applicators suggest six return spot treatments over six months (Van Diepen, pers. 

comm.). Other chemical control methods have been tested, including paraquat and triclopyr 

compounds (Arnold and Warren 1966, Horng and Leu 1979, Franklin 1996), but are not 

recommended near water. 

Imazapyr has also been reported to be effective on giant reed. Habitat herbicide is an aquaticlabeled imazapyr product that can be used near water (M. Wolder, personal comm.) 

SWAMP-TIMOTHY AND PRICKLEGRASS (FROM UNPUBLISHED 

OBSERVATIONS AT THE COMPLEX) 

These species are both common non-native annuals in seasonal wetlands. Swamp-timothy (Crypsis 

schoenoides) is a high-quality forage species for waterfowl and considered a desirable species in 

managed wetlands. However, swamp-timothy and pricklegrass (Crypsis vaginiflora) are 

considered invasive in vernal pools (J. Silveira, pers. comm.). The ability to control them in vernal 

pools is currently limited because any control measures other than grazing or burning could likely 

be more detrimental to the pools than the control they would provide. Physical manipulation of the 

soil, such as disking would greatly alter the hydrology and make the site receptive for potentially 

worse invasive species. Both species are likely susceptible to chemical control, but the effect of 

herbicides, such as glyphosate, on the integrity of the pools is unknown, and would need a 

thorough evaluation before using them given the number of listed and/or rare endemic species 

that occur there. Maintaining the natural hydrology is a standard strategy for maintaining the 

native biological communities in vernal pools. Hand-pulling young swamp-timothy and 

pricklegrass may have some merit, but would be very labor intensive. At this time, there are no 

plans to specifically control these species at the Complex. 

BERMUDA GRASS AND JOINTGRASS (FROM UNPUBLISHED 

OBSERVATIONS AT THE COMPLEX) 

Bermuda grass (Cynodon dactylon) and jointgrass (Paspalum distichum) are very similar in their 

growth forms, habitats that they can dominate, and methods used to control them. They also 

commonly occur together and are controlled similarly. Therefore, they are considered together in 

this profile. 

Bermuda grass and jointgrass are low-growing, wiry perennials that have two types of shoots: 

those aboveground (stolons) and those belowground (rhizomes). The stolons and rhizomes are 

capable of rooting in the soil, thus creating new plants as they grow out from the original plant or 

when they are cut and left on moist soil. In areas where the soil has not been disturbed, rhizomes 

are shallow (1 to 6 inches). However, where the soil has been spaded or tilled deeper than 6 inches, 

or in sandy soil, under sidewalks, and against solid structures such as building foundations or 

walls, the rhizomes may be deeper than 6 inches. Both species commonly occur in managed 

wetlands, and are more often a problem in those that are irrigated during the summer. They can 

form dense sod mats that replace desirable moist-soil plant species and can create homogenous 

stands. When these mats are allowed to persist, they can become so thick and wiry that they are 

difficult to impossible to control mechanically. 

MECHANICAL CONTROL 

Neither species are easy to control, but can be managed in seasonal wetlands with a persistent 

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program of mechanical methods and water management. Ideally, they are burned after being 

allowed to dry in the summer, followed by disking, and then withholding water until later in the 

fall to desiccate the remaining stolons and rhizomes. In certain areas, it is rare for these species to 

dry out enough to burn them: these areas typically also have the thickest mats and are the most 

extreme problem sites. In such cases, spraying first (see chemical control below) to “crisp” aboveground vegetation, will facilitate burning and disking. Disking alone can be effective in many 

cases, however multiple passes with a heavy stubble disk are often necessary to cut into the sod 

mats and effectively turn over rhizomes so they can desiccate in the summer heat. Ideally, these 

rhizomes are left to “bake” in the sun for at least several weeks to achieve best results. 

CHEMICAL CONTROL 

Bermuda grass and jointgrass can be controlled with post-emergent herbicides applied to actively 

growing foliage and stems during spring and summer. Glyphosate (Roundup and other brand 

names) is a nonselective herbicide that kills plants by translocating down into the root system, in 

addition to killing top-growth. Both species require different application rates for control, with 

Bermuda grass requiring a greater rate. If the species are mixed together, use the higher 

(Bermuda grass) rate. For glyphosate to be most effective it must be applied to vigorously 

growing plants (not drought stressed) that have lots of leaf surface (do not mow the weed for 2 to 3 

weeks before treating). At least 7 days after applying glyphosate plants can be disked for 

additional control. Disking will bring the remainder of any still living underground parts of the 

plant (stolons and rhizomes) to the surface of the soil so they can dry. Spraying alone can be 

effective in some areas, but without the follow-up disking, deeper rhizomes and roots may survive 

the first application and regrow. 

ANNUAL (ITALIAN) RYEGRASS 

Annual ryegrass (Lolium multiflorum) is a common annual grass in roadsides, fields, and 

pastures. Plants produce abundant seed, which is their only form of reproduction. In non-irrigated 

situations in California, most seeds germinate in the fall after the first significant rainfall. The 

seed bank is apparently short-lived, although seed has been reported to survive for many years 

under certain conditions (DiTomaso and Healy 2007). At the Complex, annual ryegrass is invasive 

in native grasslands, alkali meadows, and roadsides/levees. It can form dense monocultures that 

out compete native plant species for sunlight and soil moisture. In many cases, this includes rare, 

listed, and or endemic species in alkali meadows. 

CONTROL METHODS 

Annual ryegrass and other non-native Mediterranean annual grasses can be controlled a number 

of different ways. Prescribed burning can be effective (also see medusahead profile), especially 

when conducted in a dry fall after seedlings have recently germinated. If this opportunity in 

timing and conditions can be taken advantage of, burning can eliminate a good portion of seed 

produced that year plus young seedlings that would mature the following spring/summer. In many 

cases, there will be an increase in broadleaf forbs the next spring. 

Grazing can be an effective tool for maintaining control of annual ryegrass and other palatable 

non-native annual grasses. These palatable grasses are readily consumed by domestic livestock, 

and especially selected for by cattle. Recent operational and experimental grazing treatments 

applied to Refuge grasslands and alkali meadows have shown improvements in native species 

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diversity. Typically, timing of grazing should be in the spring when grass is tall enough to provide 

reasonable forage for cooperating permittees, and continues into early summer until target 

stubble height is achieved (typically 1-3”). Refer to grazing management plans in overall Refuge 

Annual Habitat Management Plans for more specific details. 

JOHNSONGRASS (FROM NEWMAN 1990) 

Johnsongrass (Sorghum halepense) is considered to be one of the ten worst weeds in the 

world (Holm et al. 1977). Fifty-three countries, ranging in latitude from 55°N to 45°S 

report Johnsongrass as a major problem; the problem is most serious in the region from 

the Mediterranean to the Middle East and India, Australia, central South America and the 

Gulf Coast of the United States (Holm et al. 1977). 

Johnsongrass is an invasive and tenacious weed, which thrives in disturbed soils. The 

prolific seed production, extensive rhizome system, sprouting ability of fragmented 

rhizomes and ability to grow in a wide range of environments make Johnsongrass difficult 

to control. The best time to implement control techniques is during the first two weeks of 

growth when new rhizome development has not yet begun and when the carbohydrate 

supply is at its lowest concentration. During the fall the rhizome carbohydrate levels are 

again low, due to the formation of over- wintering rhizomes, making this an appropriate 

time for herbicide application. A combination of mowing, tilling, and herbicide applications 

may provide adequate control of Johnsongrass and may produce better effects than just 

one technique alone. Once successful control has been reached, a rapid re-vegetation 

project should be implemented for the establishment of native plants. If transplants are to 

be used, plants should be grown during the eradication period (Newman 1989). Subsequent 

spot control of remaining Johnsongrass, that avoids jeopardizing the native plants, may be 

necessary during the subsequent years to fully eradicate this weed. 

Several techniques may be helpful in controlling Johnsongrass: torching and burning, 

mowing and grazing, tilling and plowing, and herbicide applications. These methods 

primarily focus on starving the plants by reducing growth, thus limiting photosynthesis, 

which results in a reduction of stored carbohydrates (Oyer et al. 1959, McWhorter 

1961a&b, Horowitz 1972b, McWhorter 1974). 

A single application of the herbicide glyphosate results in an 85 percent reduction in 

Johnsongrass (Heathman pers. comm.). The encouraging effects of chemicals on the 

control of Johnsongrass are addressed below. 

MECHANICAL CONTROL 

Mowing Johnsongrass for several seasons weakens the plants and reduces rhizome growth 

(McWhorter 1981, Hamilton B. pers. comm.). Removing aerial grass shoots close to the ground is a 

technique used to exhaust the stored carbohydrates of perennial weeds (Horowitz 1972a). 

Horowitz (1972a) reports that clipping three-week-old seedlings will kill them, whereas 

McWhorter (1961b) claims that seedlings must be clipped within 14 days after emergence for 

death of the plants to occur. As compared to the single clipping of seedlings, plants arising from 

rhizomes require two clippings within the first two weeks of growth to insure death of the plant 

(McWhorter 1961b). Because the lowest rhizome carbohydrate concentration occurs in the spring, 

during initial above-ground growth, and in the fall, during over-wintering rhizome formation, 

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clipping at this time will have the maximum controlling effect by preventing the formation of 

photosynthates and thus precluding a stored energy supply (Horowitz 1972b). 

Repeated clipping is required to control plants, which emerged more than 20 days prior to 

the initial treatment. Slight amounts of rhizome growth occur even under continuous 

clipping (McWhorter 1961b). Bi-weekly clipping of potted plants severely reduces growth 

during that growing season; however, one quarter of clipped plants display renewed 

growth the following year (Horowitz 1972a). A single clipping of the aerial growth of plants 

28 days after germination or sprouting reduces the amount of total carbohydrates in the 

rhizomes by 25 percent; however, a rapid replenishment of carbohydrates is seen within 30 

days after clipping (McWhorter 1974). McWhorter (1981) reports maximum growth 

reduction when plants are allowed to reach 12 to 15 inches in height before cutting them at 

ground level, whereas Lorenzi and Jefferey (1987) feel that eight inches is the maximum 

size that Johnsongrass should be allowed to reach in order to starve the plants. 

Hand hoeing is practical only where the concentration of Johnsongrass is low. Shallow 

cultivation using sharp hoes, shovels, knives or hand pulling will remove the plants and the 

rhizomes from the upper portion of the soil without dividing or pulling up deep rhizomes 

(Heathman et al. 1986, Lorenzi and Jefferey 1987). Hoeing early in the season when plants 

are under three weeks old will be much more effective than hoeing older plants, which 

have larger rhizome systems and greater concentrations of stored carbohydrates 

(McWhorter 1961b). Six to eight fallow plowings throughout the summer is the most 

effective tilling routine for large-scale problems. Plows break up the rhizomes and bring 

them to the surface of the soil where they desiccate (McWhorter 1981). A 99 percent 

reduction in rhizome production resulted from six thorough tillings at two-week intervals 

(Warwick and Black 1983). However, plowing could spread the rhizomes and increase the 

problem if contaminated machinery is used in uninfested areas (Cox pers. comm.). 

CHEMICAL CONTROL 

Extensive literature is available on herbicides available for Johnsongrass control. The use of soilactive herbicides is not recommended due to the residual activity seen eight years after application 

(Hunter et al 1978). Herbicides alone will not successfully eradicate Johnsongrass (Cox pers. 

comm.). Yearly applications will be required for an effective control plan. 

Many herbicides are recommended for use on Johnsongrass. Only two of them are foliar 

sprays that are mildly toxic and rapidly decay in the soil: glyphosate (commercial name -- 

Roundup) and dalapon (commercial name -- Dowpon). Both of these chemicals are 

translocated to the underground tissue and act on all of the growing sites (Ross 1986). 

Glyphosate is recommended for controlling Johnsongrass in natural, non-agricultural sites 

(Brookbank pers. comm., K. Hamilton pers. comm., Heathman pers. comm., Lorenzi and 

Jefferey 1987). K. Hamilton (pers. comm.) recommends using spot applications of 

glyphosate with a knapsack sprayer to control small areas of Johnsongrass. Multiple 

applications for several years will be required. An 85 percent reduction in Johnsongrass is 

commonly seen during the first year of application using glyphosate. Seeds and nonactive 

rhizomes account for the 15 percent regrowth of Johnsongrass during herbicide activity 

(Heathman pers. comm.). 

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Best results in controlling Johnsongrass with glyphosate have been seen when the plants 

are actively growing, greater than 18 inches tall and have reached the bloom-to-head stage 

of growth (Silberman pers. comm., McWhorter 1981). The inflorescences should be 

removed to prevent the dispersal of mature seeds. In southern Arizona, maximum control 

of Johnsongrass occurs with fall applications of glyphosate (Brookbank pers. comm.). The 

low amount of rhizome carbohydrates in the fall may account for the effectiveness of the 

herbicide during this season of maximum rhizome growth. The land should not be tilled for 

at least a week after applying the herbicide in order to insure optimal efficiency from the 

single application (McWhorter 1981). 

Johnsongrass grown under high salt and low water conditions result in reduced plant 

growth (Sinha et al. 1986). High salt concentrations have little effect on the overall biomass 

accumulation when water availability is not reduced. There is, however, a decrease in the 

ratio of growth between shoots and roots with increased salinity (Sinha et al. 1986). 

MEDUSAHEAD (FROM BOSSARD ET AL. 2000) 

Medusahead (Taeniatherum caput-medusae) is a slender annual grass. The one- to three-inch 

awns are straight and compressed when green, but upon drying, the awns twist and spread 

erratically in a manner reminiscent of the snake-covered head of the mythic Medusa. It has been 

reported from almost every county in northern California and in many areas of central California, 

extending as far south as Riverside County. It also infests rangeland, grassland, and sagebrush 

communities in Oregon, Washington, Idaho, Nevada, and Utah. 

Medusahead invades grasslands, oak savannah, oak woodland, and chaparral communities. It 

grows in a wide range of climatic conditions. Clay or clay-loam soils with at least ten inches of 

rainfall annually are most susceptible to invasion (Dahl and Tisdale 1975). However, medusahead 

has been found on coarse-textured soils as well (Young 1992). The grass reproduces by seed, which 

is dispersed locally by wind and water. The long-awned seeds cling to the coats of grazing animals, 

such as sheep or cattle, and in this way are transported to more distant sites. Seeds can also 

disperse by attaching to machinery, vehicles, and clothing. Medusahead out competes native 

grasses and forbs, and, once established, can reach densities of 1,000 to 2,000 plants per square 

meter. After seed set, the silica-rich plants persist as a dense litter layer that prevents 

germination and survival of native species, ties up nutrients, and contributes to fire danger in 

summer. Because of its high silica content, medusahead is unpalatable to livestock and native 

wildlife except early in the growing season. 

Medusahead is predominantly self-pollinating and reproduces by seed. In California, medusahead 

seeds usually germinate in October or November. The shoot system remains small, while the root 

system develops throughout the cold winter months. Early germination and rapid root growth 

consumes available water and nutrients, out competing slower-growing native species. 

Medusahead continues to grow, extract soil moisture, and produce seeds after most other annual 

grasses have turned brown. 

Flowering usually occurs in May. An average of eight to fifteen seeds is produced per spike in late 

spring or early summer. Seeds usually disperse by mid-summer. Seed dormancy varies from a few 

weeks to over six months, depending on location. Germination normally occurs with the first rains 

in fall, and the germination rate is high. The seeds are well adapted to germinating and growing in 

the dense litter layer. Under these conditions, seeds can germinate even if they are not touching 

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the soil. If they dry out, the primary root dies, but if they are moistened again, a new adventitious 

root develops (Young et al. 1971). 

PHYSICAL CONTROL 

Mowing alone, or in combination with grazing, was found to be effective in reducing infestations. 

Plowing or disking is also effective means for controlling medusahead (Hilken and Miller 1980). 

Several studies have shown that burning stands of medusahead prior to seed dispersal is an 

effective control measure (Furbush 1953, Hilken and Miller 1980, McKell et al. 1962, Murphy and 

Lusk 1961, Pollak and Kan 1996). Burns should be scheduled for late spring, after seed set but 

before seed heads have shattered (known as the “soft dough” stage of seed development). Seeds 

still on the plants are destroyed by the burn, while dispersed seeds lying on or buried below the 

soil surface are protected from the intense heat of the burn. With few seed reserves in the soil, 

medusahead abundance can be dramatically reduced if the seed input for even one year is 

eliminated. 

This method takes advantage of the fact that medusahead matures later than most of the 

surrounding vegetation so most other species have already dispersed their seeds and are dry 

enough to carry a burn. At the Jepson Prairie Preserve in Solano County effective control burns 

were conducted in late May and early June. Proper timing may vary depending on local conditions 

and weather. Some studies have found medusahead to increase after burning, but most of these 

studies conducted burns in August, presumably after seed dispersal. 

GRAZING 

Heavy grazing by sheep in early spring (when medusahead is still palatable) can assist in 

controlling medusahead, but animals should be removed before seed heads form to limit seed 

dispersal. Early spring grazing is especially effective in areas where dried medusahead litter has 

been previously burned or grazed. Fertilizing with nitrogen improves the palatability of 

medusahead (Lusk et al. 1961). Properly timed grazing may reduce, but not eliminate, 

medusahead infestations. 

CHEMICAL CONTROL 

Small-scale infestations can be controlled by chemical herbicides. Atrazine applied in fall at 2 

lbs/acre, was effective in controlling medusahead (Hilken and Miller 1980). 

WATER HYACINTH (FROM BOSSARD ET AL. 2000) 

Water hyacinth (Eichhornia crassipes) is a floating aquatic plant with bright green, waxy leaves 

and attractive, violet flowers that have yellow stripes on the banner petals. These plants tend to 

form mats on the water surface. Sometimes water hyacinth can be found growing in muddy soils 

near the edge of an aquatic system. The leaves are arranged in a rosette. The leaf stem usually is 

somewhat to completely swollen and filled with spongy tissue and thus acts as a float. In plants 

anchored in mud, the leaf stem tends not to be swollen. The blade of the leaf is oval to round and 

usually much smaller than the leaf stem. 

Water hyacinth can be found in both natural and man-made freshwater systems (ponds, sloughs, 

rivers). It will not tolerate brackish or saline water with salinity levels above 1.8 percent 

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(Penfound and Earle 1948). In California, water hyacinth typically is found below 660 feet (200 m) 

elevation in the Central Valley, San Francisco Bay Area, and South Coast. The Sacramento-San 

Joaquin Delta and several of the rivers drained by this delta are heavily infested (Thomas and 

Anderson 1984). 

Native to the Amazon River basin of tropical South America, water hyacinth has now spread to all 

tropical and subtropical countries and is universally regarded as one of the most serious of the 

world’s weeds (Parsons 1992). It was introduced into the United States in 1884 as an ornamental 

plant for water gardens. The plant quickly spread throughout the country, becoming a major weed 

in southern states from Florida to California. By 1897, it had clogged many waterways and was 

interfering with shipping (Parsons 1992). It was found in California in 1904 (Thomas and Anderson 

1984). 

Water hyacinth spreads through fragmentation of established plants and may resprout from 

rhizomes or germinate from seeds (Penfound and Earle 1948). Dispersal also occurs by waterborne seeds and by seeds that stick to the feet of birds. Migratory birds may be important in longdistance dispersal (Parsons 1992). Water hyacinth can quickly dominate a waterway or aquatic 

system because of rapid leaf production, fragmentation of daughter plants, and copious seed 

production and germination. It degrades habitat for waterfowl by reducing areas of open water 

used for resting, and when decomposing it makes water unfit for drinking. It displaces native 

aquatic plants used for food or shelter by other wildlife species. Water hyacinth causes problems 

for humans by obstructing navigable waterways, impeding drainage, fouling hydroelectric 

generators and water pumps, and blocking irrigation channels. 

The protected water within mats of water hyacinth makes ideal breeding sites for mosquitoes and 

other vectors, which, in tropical countries, increases the danger of malaria, schistosomiasis, and 

other diseases (Parsons 1992). Water hyacinth increases water losses from lakes and rivers 

because of the plant’s high transpiration rate, calculated to be almost eight times the evaporation 

rate of open water surfaces (Parsons 1992). It changes water quality beneath the mats by lowering 

pH, dissolved oxygen, and light levels, and increasing carbon dioxide tension and turbidity 

(Penfound and Earle 1948; Center and Spencer 1981). This affects the health of fish, while 

decaying plants make water unfit for drinking by humans, livestock, and wildlife. 

Water hyacinth can reproduce either sexually or vegetatively. Flowering (i.e., sexual reproduction) 

occurs in mid-summer and early fall. The flower stalks bend back into the water once they are 

pollinated (it is thought to be self-pollinated) and release the seeds. Seeds sink to the bottom and 

can remain viable in sediments for several years. Water hyacinth seeds require warm, shallow 

water and high light intensity for germination. Vegetative reproduction occurs from late spring 

through fall. Parts of the stem may break off at the water surface to form independent plants 

called daughter plants (Penfound and Earle 1948). These daughter plants are capable of producing 

additional reproductive stem segments within weeks. Water hyacinth grows rapidly. Growth of 

more than one ton of dry matter per day per hectare is not uncommon. One plant may be able to 

produce enough growth to cover 600 square meters in one year. 

PHYSICAL CONTROL 

For small ponds or lakes infested with water hyacinth, harvesting and removal of plant material 

from the water can be attempted. Care must be taken to remove all plant material, including small 

fragments. Harvesting and removal of plant material is labor-intensive and expensive. A less 

F-71 
expensive method of containing water hyacinth is the use of floating barriers that can contain the 

weed in a small area. Dredges, which drag plants onto river banks, are effective if the material is 

allowed to dry and is then burned. These are costly efforts, and they have been replaced in most 

areas by chemical control (Parsons 1992). 

BIOLOGICAL CONTROL 

Biological control has been successful in many, but not all, areas. Three insects and a fungus have 

been extensively studied and subsequently released by the USDA to control water hyacinth. The 

insects include two weevils, Neochetina eichhorniae, and N. bruchi (Coleoptera: Curculionidae), 

and a moth, Sameodes albiguttalis (Lepidoptera: Pyralidae). The fungus is Cercospora rodmanii 

(Fungi Imperfecti: Moniliales), which was first found in Florida in 1976 (Conway 1976). 

In the southern United States, the weevils have been most effective in reducing water hyacinth 

populations (Center et al. 1989). In Florida, the weevils combined with the fungus have also 

produced good results. In California, all three species of insects have been released. However, only 

Neochetina eichhorniae has established, and its impact on density of water hyacinth is slight. The 

fungus is currently unavailable for use in California. 

GRAZING 

Most animals, except rabbits, do not readily eat the plant, possibly because its leaves are 95 

percent water and have high tannin content. 

CHEMICAL CONTROL 

Water hyacinth can be controlled using glyphosate as a foliar spray (formulated as Rodeo) and 

copper complexes used only as a foliar spray. Herbicide use is more highly regulated in aquatic 

systems than in terrestrial systems. A current label for the herbicide must be obtained to 

determine suitability for a given system and amount of active ingredient to be applied. Both 

suitability and the amount of active ingredient may change from one year, habitat type, and/or 

jurisdiction to another. Consult your county agricultural agent or a certified herbicide applicator. 

TREE-OF-HEAVEN (FROM BOSSARD ET AL. 2000) 

Ailanthus (Ailanthus altissima) is a deciduous tree thirty to sixty-five feet high, with gray bark, 

and generally with root sprouts. Its branches have a large pith and prominent heart-shaped leaf 

scars. Ailanthus has large compound leaves with several circular glands on the underside of most 

leaflets. Ailanthus is widely but discontinuously distributed in California. It is most abundant 

along the coast and in the Sierra foothills, primarily in wastelands and disturbed, semi-natural 

habitats. However, it also occurs in riparian areas and other naturally disturbed habitats 

throughout California's mid-lower elevations, below 6,600 feet (2000 m). A native of eastern China, 

ailanthus has been introduced throughout the northern hemisphere. 

Ailanthus reproduces by seed and vegetatively by root sprouts. By producing abundant root 

sprouts, ailanthus creates thickets of considerable area, displacing native vegetation (Kowarik 

1983, 1995). Although it may suffer from root competition by other trees already established, 

usually it competes successfully with other plants (Cozzo 1972, Hu 1979). In California, its most 

significant displacement of native vegetation is in riparian zones. It also produces allelopathic 

F-72 
chemicals that may contribute to displacement of native vegetation (Lawrence 1991). A high 

degree of shade tolerance gives ailanthus a competitive edge over other plant species (Grime 

1965). A tree generally become reproductive at ten to twenty years, but younger shoots also may 

produce fruits. Trees are deciduous, leaving clumps of stark, bare stems over the winter. Most 

trees produce only male or only female flowers (dioecy). Flowering follows leaf expansion in late 

spring. Female trees may produce several hundred inflorescences per year, and at maturity an 

inflorescence contains hundreds of seeds (Hunter 1995). A single tree can produce up to a million 

seeds per year. Seeds ripen in large, crowded clusters from September to October of the same 

year and may persist on the tree through the following winter (Little 1974, Hu 1979). Most 

ailanthus seeds are viable, even those that have over-wintered on the tree (Little 1974, Hunter 

1995). Germination ranges from 14 to 75 percent. Because its seeds do not remain dormant for 

more than a year, ailanthus does not have a persistent soil seed bank. Despite prolific seed 

production, seedling establishment of ailanthus is infrequent in California. Most new shoots are 

root sprouts. Root sprouts are produced up to fifty feet (15 m) away from the nearest shoot. Their 

initial growth is rapid, commonly over a meter per year (Miller 1990, Hunter unpubl. data). In 

favorable settings, rapid growth continues, but for shaded sprouts growth drops to several 

centimeters per year (Hunter unpubl. data). 

PHYSICAL CONTROL 

If mechanical and/or chemical control is attempted, sites should be monitored several times per 

growing season. All new root sprouts should be removed, and monitoring should be continued for 

one year after the last sprout is removed. 

Hand pulling 

Young seedlings are best pulled after a rain when the soil is loose. This allows removal of the root 

system, which may resprout if left in the ground. After the tap root has developed, root removal is 

more difficult. Plants should be pulled as soon as they are large enough to grasp but before they 

produce seeds. 

Hand digging 

Removal of rootstocks by hand digging is a slow but sure way of destroying weeds that resprout 

from roots. The work must be thorough to be effective as every piece of root that breaks off and 

remains in the soil may produce a new plant. This technique is suitable only for small infestations 

and around trees and shrubs where other methods are not practical. 

Cutting 

Manually operated tools such as brush cutters, power saws, axes, machetes, loppers, and clippers 

can be used to cut ailanthus. This is an important step before many other methods are tried, as it 

removes the above-ground portion of the plant. For thickly growing, multi-stemmed shrubs and 

trees, access to the base of the plant may be not only difficult but dangerous where footing is 

uncertain. 

Girdling 

This involves manually cutting away bark and cambial tissues around the trunks of undesirable 

F-73 
trees. A relatively inexpensive method, girdling is done with an ordinary ax in spring when trees 

are actively growing. Hardwoods are known to resprout below the girdle unless the cut is treated 

with herbicides. Although it may be undesirable to leave standing dead trees in some areas, this 

technique has been shown to reduce stump sprouting in live oaks, and may be a useful technique 

for controlling ailanthus. 

Cutting an ailanthus stem induces prolific root suckering and the production of stump sprouts. 

After a stem is cut, its stump sprouts may grow over ten feet (3 m) per year and its root sprouts 

three to seven feet (1-2 m) per year (Pannill 1995). As a consequence, mechanical removal will be 

ineffective unless all stems are cut at least several times per year (Pannill 1995). 

PRESCRIBED BURNING 

This is probably not an effective technique for controlling ailanthus. Fire may kill main stems, but 

this will result in prolific sprouting. 

BIOLOGICAL CONTROL 

Biological control of ailanthus has not been investigated. The species is not significantly affected 

by insects or disease (Miller 1990). French (1972) reports that the zonate leafspot fungus 

(Cristulariella pyramidalis) causes defoliation of ailanthus in Florida. In India the insect Atteva 

fabricella is considered an ailanthus defoliator (Misra 1978), and seedlings in Italy, weakened by 

cold, were weakly parasitized by the fungus Placosphaeria sp. (Magnani 1975). 

GRAZING 

Ailanthus may suffer extensive browse herbivory from deer and cattle, particularly the young 

growth of sprouts, which may aid eradication (Pannill 1995, Hunter 1995). 

PLANT COMPETITION 

In most cases ailanthus prevents the establishment of other native plants and must be initially 

removed. Following removal of mature plants, root crowns must be treated to prevent 

resprouting. Seedlings of native plant species usually cannot establish fast enough to compete with 

sprout growth from untreated stumps. Ailanthus is shade tolerant, so presumably will sprout 

under other plants. 

CHEMICAL CONTROL 

Herbicide applications should be most effective in spring, just after leaves are fully expanded. 

Smaller sprouts probably can be controlled by spraying foliage with 4 percent glyphosate (as 

Roundup). Young stems usually can be killed by generously applying 15-20 percent triclopyr (sold 

as Garlon) to all of the bark from the stem base to twenty inches above the ground. The thicker 

bark of larger plants interferes with uptake of herbicide, and therefore, to kill larger individuals, 

the stem needs to be frilled (have an encircling ring of bark removed) before herbicide is applied. 

In order to damage the root system, concentrated herbicide (such as 15 to 20 percent triclopyr or 

15 to 40 percent glyphosate) needs to be applied with brush or wick to the freshly exposed surface 

immediately after cutting (Pannill 1995). Applying herbicide to freshly cut stumps is probably the 

most effective technique for controlling ailanthus. Wiping the stump with full strength, 41 percent 

F-74 
glyphosate within several minutes of cutting should reduce or even eliminate subsequent root 

suckering. 

TAMARISK/SALTCEDAR (FROM UNIVERSITY OF CALIFORNIA 2007) 

Saltcedar (Tamarix ramosissima) is a deep-rooted shrub or small tree (5 to 20 feet tall) in the 

tamarisk family (Tamaricaceae). A single mature saltcedar may produce hundreds of thousands of 

tiny seeds, which are readily dispersed by wind and water. Seed dispersal may occur throughout 

the spring and summer months. Seedling growth is very rapid. The species can resprout 

vigorously from buried, submerged, or damaged stems and mature plants spread vegetatively as 

well (Sudbrock 1993). Once established, even dramatic changes in soil moisture will not eliminate 

saltcedar, as long as abundant ground water is available (Brotherson and Field 1987, Frasier and 

Johnsen 1991). 

Aggressive and long-lived, saltcedar has colonized more than one million acres of floodplains, 

riparian areas, and wetlands throughout the arid west. Saltcedar out competes and crowds out 

native vegetation and alters patterns of sediment deposition (Carpenter 1999, Sudbrock 1993, 

Tallent-Halsell and Walker 2002). Saltcedar uses more water than comparable native plant 

communities use and alters local hydrology by lowering the water table (Hoddenbach 1987 cited in 

Carpenter 1999). The stems and leaves of mature plants secrete salt, increasing soil salinity and 

further excluding many native plant species (Sudbrock 1993). Infestations also have detrimental 

impacts on wildlife. Saltcedar is not favored habitat for most bird species. Saltcedar seeds have 

almost no protein and are too small to be eaten by most granivores, and the scale-like leaves offer 

little suitable forage for browsing animals (Anderson et al. 1977). Stands of saltcedar are 

associated with lower diversity of aquatic invertebrates (Bailey et al. 2001). 

The following is from the TNC Element Stewardship Abstract for Tamarix species (Carpenter 

1999): 

Tamarisk can be controlled by five principal methods: 1) applying herbicide to foliage of 

intact plants; 2) removing above ground stems by burning or mechanical means followed 

by foliar application of herbicide; 3) cutting stems close to the ground followed by 

application of herbicide to the cut stems; 4) spraying basal bark with herbicide; and 5) 

digging or pulling plants. In addition, The USDA has tested and proposed the release of 

two species of insects for tamarisk bio-control. 

Selecting an appropriate control method involves considering the size of the area where 

tamarisk is to be controlled, restrictions on the use of particular herbicides or herbicides in 

general, the presence or absence of desirable vegetation where tamarisk is growing, the 

presence or absence of open water, adjacent land uses that might restrict prescribed 

burning, and the availability and cost of labor. 

For larger areas (> 2 hectares) that are essentially monotypic stands of tamarisk, the best 

methods would likely be foliar application of imazapyr (Arsenal) [Also now available in an 

aquatic-approved formulation called Habitat] herbicide to the intact plants or burning or 

cutting plants followed by foliar application of imazapyr or triclopyr (e.g. Garlon4 or 

PathfinderII) to the resprouted stems. Foliar application of imazapyr or imazapyr in 

combination with glyphosate (e.g. Rodeo) can be effective at killing large, established 

plants. Over 95 percent control has been achieved in field trials during the late summer or 

F-75 
early fall. The herbicide can be applied from the ground using hand-held or truck-mounted 

equipment or from the air using fixed-wing aircraft [or helicopter (B. Lee, pers. comm.)]. 

Foliar application of herbicide works especially well in monotypic stands of tamarisk, 

although experienced persons using ground equipment can spray around native trees and 

shrubs such as cottonwood and willow. As an alternative to herbicides, prescribed fire or a 

bulldozer can be used to open up large stands of tamarisk. Once opened, the resprouts can 

be sprayed when they are 1 to 2 m tall using imazapyr, or imazapyr plus glyphosate, or 

triclopyr. 

Tamarisk eradication in areas that contain significant numbers of interspersed, desirable 

shrubs and trees is problematic. Depending upon site conditions, it may not be possible to 

rapidly kill tamarisk plants without also killing desirable shrubs and trees. In such 

situations, it may be necessary to cut and treat tamarisk stumps with herbicide, as outlined 

in the next paragraph. While this method is relatively slow and labor-intensive, it will spare 

desirable woody plants. Alternatively, it may be more cost-effective to kill all woody plants 

at a site and replant desirable species afterward. 

For modest-sized areas (< 2 hectares), cutting the stem and applying herbicide (known as 

the cut-stump method) is most often employed. The cut-stump method is used in stands 

where woody native plants are present and where their continued existence is desired. 

Individual tamarisk plants are cut as close to the ground as possible with chainsaws, 

loppers or axes, and herbicide is applied immediately thereafter to the perimeters of the 

cut stems. The herbicides triclopyr (e.g. Garlon4 or PathfinderII) and imazapyr (Arsenal) 

can be very effective when used in this fashion. This treatment appears to be most 

effective in the fall when plants are translocating materials to their roots. The efficacy of 

treatments is enhanced by cutting the stems within 5 cm of the soil surface, applying 

herbicide within one minute of cutting, applying herbicide all around the perimeter of the 

cut stems, and retreating any resprouts 4 to 12 months following initial treatment. 

No matter how effective initial treatment of tamarisk might be, it is important to re-treat 

tamarisk that is not killed by initial treatment. It is also essential to continue to monitor 

and control tamarisk indefinitely because tamarisk is likely to re-invade treated areas. 

However, follow-up control is likely to require much less labor and materials than the 

initial control efforts. 

HIMALAYAN BLACKBERRY (FROM BOSSARD 2000) 

Himalayan blackberry (Rubus discolor) grows as a dense thicket of long, bending branches 

(canes), appearing as tall, ten-foot mounds or banks, particularly along watercourses. Canes have 

hooked prickles. Flowers are white, yielding black berries that usually ripen later than native 

blackberries. 

Himalayan blackberry occurs in California along the coast in the Coast Ranges, Central Valley, 

and the Sierra Nevada (Dudley and Collins 1995). It forms impenetrable thickets in wastelands, 

pastures, and forest plantations. It grows along roadsides, creek gullies, river flats, fence lines 

(Parsons and Amor 1968), and right-of-way corridors. It is common in riparian areas, where it 

establishes and persists despite periodic inundation by fresh or brackish water. Periodic flooding 

can produce long-lived early seral communities conducive to the growth and spread of 

blackberries. Himalayan blackberry is one of few woody plants that pioneer certain intertidal 

F-76 
zones of the lower Sacramento River (Katibah et al. 1984). 

Blackberries grow well on a variety of barren, infertile soil types (Brinkman 1974). These shrubs 

tolerate a wide range of soil pH and texture, but do require adequate soil moisture. Himalayan 

blackberry prefers disturbed and wet sites even in relatively wet climates. It prefers areas with an 

average annual rainfall greater than 76 cm on both acidic and alkaline soils (Amor 1972). It 

appears to be tolerant of periodic flooding by brackish or fresh water (Willoughby and Davilla 

1984). It grows at elevations of over 6,000 feet in Arizona and to 5,000 feet in Utah (Kearney et al. 

1960, Welsh et al. 1987). 

Himalayan blackberry is native to western Europe (Hickman 1993). There is no botanical evidence 

to show that it is native to the Himalayan region. It may have found its way there as a cultivar. 

Himalayan blackberry probably was introduced to North America in 1885 as a cultivated crop 

(Bailey 1945). By 1945, it had become naturalized along the West Coast. By this time, it also 

occurred in nursery and experimental grounds along the East Coast and in Ohio (Bailey 1945). It 

seeds heavily, and seeds are readily dispersed by mammals and birds. Seeds can be spread 

considerable distances by streams and rivers (Parsons 1992). It also spreads vegetatively by 

rooting of cane tips. 

Himalayan blackberry colonizes areas initially disturbed and then neglected by humans and can 

dominate range and pasture lands if not controlled. Himalayan blackberry is a strong competitor, 

and it rapidly displaces native plant species. Blackberries are highly competitive plants. Thickets 

produce such a dense canopy that the lack of light severely limits the growth of other plants. 

Because plants are prickly, livestock, particularly sheep and cattle, avoid grazing near them, 

effectively decreasing the usable pasture area. Young sheep and goats that get tangled up in the 

canes have been known to die of thirst and hunger. In wet areas, blackberries may hinder 

medium-sized to large mammals from gaining access to water. The impenetrable nature of 

blackberry thickets reduces access for maintenance of fence lines and for forestry practices, as 

well as recreational pursuits. Dense thickets around farm buildings and fence lines are a 

considerable fire hazard. 

Flowering begins in May and continues through July. Fruit is produced from July to September. 

Most blackberries produce good seed crops nearly every year. Immature fruit of Himalayan 

blackberry is red and hard, but at maturity, fruit becomes shiny black, soft, and succulent. 

Himalayan blackberry thickets can produce 7,000 to 13,000 seeds per square meter (Amor 1974). 

When grown in dense shade, however, most species of blackberry do not form seeds (Brinkman 

1974). Seeds of blackberries are readily dispersed by gravity and by many species of birds and 

mammals. The large, succulent fruits are highly favored and, after they mature, rarely remain on 

the plant for long (Brinkman 1974). A hard seed coat protects the embryo even when seeds are 

ingested. Passing through animal digestive tracts appears to scarify seeds and may enhance 

germination. Prompt invasion of cut-over lands by Himalayan blackberry suggests that dispersed 

seeds can remain viable in the soil for several years (Brinkman 1974). Seeds germinate mainly in 

spring. 

Blackberry seeds have a hard, impermeable coat and a dormant embryo (Brinkman 1974). 

Consequently, germination is often slow. Most blackberries require, at a minimum, warm 

stratification at 68 to 86 degrees F (20 to 30 degrees C) for ninety days, followed by cold 

stratification at 36 to 41 degrees F (2 to 5 degrees C) for an additional ninety days (Brinkman 

1974). These conditions are frequently encountered naturally as seeds mature in summer and 

F-77 
remain in the soil throughout the cold winter months. 

In Australia, Himalayan blackberry seedlings receiving less than 44 percent of full sunlight did not 

survive (Amor 1974). The slow growth of seedlings and their intolerance of shading suggest that 

few seedlings would be expected to survive in dense pastures or forest plantations. Blackberry 

thickets are also poor sites for seedling development. Amor (1972) counted less than 0.4 seedlings 

per square meter near thickets. Establishment of Himalayan blackberry seedlings depend on the 

availability of open habitats such as land neglected after cultivation, degraded pastures, and 

eroded soils along streams (Amor 1974). Although seedlings show the potential for rapid growth 

under laboratory conditions, they grow much more slowly in the field and are easily surpassed by 

the more rapid growth of daughter plants. 

MECHANICAL METHODS 

Mechanical removal may be the most effective way of removing mature plants. Subsequent 

treatment with herbicides should be conducted. 

Most mechanical control techniques, such as cutting or using a weed wrench, are suitable for 

Himalayan blackberry. Care should be taken to prevent vegetative reproduction from cuttings. 

Burning slash piles is an effective method of disposal. 

An advantage of cane removal over use of foliar herbicides is that cane removal does not stimulate 

sucker formation on lateral roots. Amor (1974) provides evidence that herbicides such as picloram 

are not much more effective than cane removal. However, removal of canes alone is insufficient to 

control Himalayan blackberry, as root crowns will resprout and produce more canes. 

MANUAL METHODS 

Removing rootstocks by hand digging is a slow but effective way of destroying Himalayan 

blackberry, which resprouts from roots. The work must be thorough to be effective because every 

piece of root that breaks off and remains in the soil may produce a new plant. This technique is 

suitable only for small infestations and around trees and shrubs where other methods are not 

practical. 

Himalayan blackberry plants may be trimmed back by tractor-mounted mowers on even ground 

or by scythes on rough or stony ground. Perennial weeds such as Himalayan blackberry usually 

require several cuttings before underground plant parts exhaust their reserve food supply. If only 

a single cutting can be made, the best time is when plants begin to flower. At this stage, the 

reserve food supply in the roots has been nearly exhausted, and new seeds have not yet been 

produced. After cutting or chopping with mechanical equipment, Himalayan blackberry may 

resprout from root crowns in greater density if not treated with herbicides. 

PRESCRIBED BURNING 

Burning is also an effective way of removing mature plants. Prescribed burning is suitable for 

removing large thickets, but requires follow-up to control resprouts. 

F-78 
BIOLOGICAL CONTROL 

The USDA will not support introduction of herbivorous insects to control Himalayan blackberry 

because of the risk posed to commercially important Rubus species. 

GRAZING 

Sheep, cattle, and horses can be effective in reducing the spread of Himalayan blackberry (Amor 

1974). In New Zealand infestations have been controlled by the grazing of large numbers of goats. 

This method has been effective in preventing canes from covering large areas (Featherstone 

1957). Crouchley (1980) mentions that blackberry is readily eaten by goats throughout the year, 

even when there is an abundant supply of other plants. In many areas of California, the use of 

angora and Spanish goats is showing promise in controlling Himalayan blackberry (Daar 1983). 

CHEMICAL CONTROL 

Picloram suppresses cane regrowth of Himalayan blackberry but stimulates the development of 

adventitious shoots. Picloram is currently not registered for use in California wildlands. Foliage 

spraying is more effective in summer than in winter. 

Many other herbicides have been used in efforts to control Himalayan blackberry with varying 

degrees of effectiveness. Fosamine can be effective (Shaw and Bruzzese 1979), and blackberry 

control has also been accomplished with amitrole-thiocyanate (Amor 1972), and triclopyr ester (as 

GarlonÂ®) (McCavish 1980). Not all of these are currently registered for use in California. 

POTENTIAL CONTROL METHODS AND MATERIALS 

Treatment methodologies will be based upon the best information available from pest 

management literature, professional expertise, and local experience. The most appropriate 

treatment for an infestation typically depends on the scale of the infestation and on the biology 

and ecology of the target species. Other considerations include effects of the treatments on 

desirable species. Desirable species are avoided whenever possible. In some cases, non-target 

species will be affected if determined that short-term negative impacts will be worth long-term 

habitat improvements from controlling invasive or undesirable species. Listed species receive 

special consideration, and will be completely avoided unless it can be shown that treatments will 

not result in any significant impacts. Invasive plant management techniques are expected to 

change and become more refined as more experience is gained. Presently, the following 

techniques are considered for use at the Complex. For additional information on control 

techniques refer to The Nature Conservancy Weed Control Methods Handbook: Tools and 

Techniques for Use in Natural Areas (Tu et al. 2001). 

PRESCRIBED BURNING 

Prescribed burning is used in both wetland and upland habitats to remove rank vegetation, control 

non-native invasive species, as well as to enhance and maintain habitat values. Burning in wetland 

areas is generally used to reduce perennial vegetation that has expanded to a point that decreased 

wildlife use and overall productivity has resulted. Examples include wetlands where long-term 

expansion of hard-stemmed bulrush and cattail growth have exceeded the optimum range of 

emergent vegetation and open water, or where Bermuda grass or jointgrass has replaced the 

F-79 
majority of annual moist-soil food plants, thus reducing the use by many wildlife species (Mensik 

1990). Prescribed burns can be applied to managed wetlands during various times of the year, but 

most occur from late spring through the fall. Depending on conditions and habitat objectives, both 

dry and overwater burning can be successful. Fire lines are disked around the burn area and 

buffers are disked around any trees to be saved. The firing pattern allows for an avenue or 

direction of escape for wildlife. In some cases, burning is conducted over water to increase 

controllability. Follow-up disking is often used to ensure that roots of target species (i.e. hardstemmed bulrush, cattail, jointgrass, etc.) are killed and to enhance germination of desirable 

species (Mensik 1990; Mensik and Reid 1995). The result is a desirable mix of vegetation species, 

stature, and distribution, a recycling of nutrients, and a successional stage that is more productive. 

The frequency of burning wetland units depends on habitat type, vegetation species composition, 

soil type, and tendency for growth. In some cases, this may be as often as once every five years 

and in others it may be one in 20 to 30 years. 

Prescribed burns in grasslands, alkali meadows, and vernal pools are used to reduce invasive 

species and to stimulate native plant species (Pollak and Kan 1998; Wight 2000). Resource benefits 

include maintaining biodiversity, especially native plant communities and the wildlife they 

support; providing browse for waterfowl; and general maintenance of habitat for short grass 

wildlife species. Burns may occur at any time of year, depending on specific objectives and 

condition of the habitat. Fall or winter burns are usually used when sensitive plants are present 

because they are dormant at that time. For optimal control of annual grasses, it is most effective 

to burn in the late spring/early summer when seeds remain on the plants and can easily be 

consumed by the fire. 

Annually, 500 to 2,000 acres of upland and wetland habitats are burned on the five Refuges. 

Prescribed burns are consistent with the Fire Management Policy (621 FW 1-3 of the Service 

Manual). Prescribed burns are consistent with approved habitat and fire management plans for 

the Complex. Individual prescribed burn plans are written, reviewed, and approved for each unit 

as outlined in the Interagency Prescribed Fire Guide. They include a variety of information 

detailing how the burn will be conducted, considerations for safety, and measures to minimize 

impacts to sensitive species. 

DISKING 

Disking is an important management tool that has a variety of uses. It is most commonly used in 

managed wetlands to reduce vegetation that has exceeded beneficial quantities or distributions 

required for wildlife use objectives. Used by itself, or in combination with burning or spraying, 

disking helps control bulrushes, cattails, Bermuda grass, jointgrass, primrose, and other perennial 

plant species (Mensik 1990; Mensik and Reid 1995). In addition to controlling undesirable plants, 

disking also creates a seedbed conducive to both increased germination and seed production of 

desirable moist-soil plants in seasonal wetlands (Naylor 2002). Caution must be exercised in some 

wetlands, where disking can enhance or spread invasive species such as cocklebur and 

pepperweed. Disking is often used in thick vegetation to create openings that facilitate improved 

wildlife use, better visibility for disease monitoring and carcass removal, and increased wildlife 

viewing opportunities. Waterfowl loafing areas can be greatly enhanced by removing vegetation 

on islands and levees. As the use of prescribed burning has declined due to local air quality 

restrictions, disking has become a more frequent vegetation control option. 

Disking is typically conducted during late spring, summer or early fall months when wetlands are 

F-80 
dry. Target species/areas may be disked one or more times to ensure that roots are dead, reducing 

the need for more frequent treatments. Vegetation succession is set back in disked areas, and 

typically desirable moist-soil plants and open water areas replace the species that are removed. 

Multiple disk passes are sometimes necessary to break up large clods for optimal germination. 

Circumstances dictate how much of an area will be disked. In most cases, a mosaic pattern is 

created, leaving equal proportions of emergent cover plants and open areas with annual moist-soil 

plants. The amount left undisked may be altered if special needs for certain species are identified 

(Mensik and Reid 1995). Examples include leaving more emergent vegetation in units that have 

historical use by colonial nesting birds such as tricolored blackbirds or white-faced ibis, or less 

vegetation in units that support large numbers of open water species such as pintails or 

shorebirds. In cases of widespread problem vegetation, sometimes the most cost-effective 

treatment is for the majority of a unit to be disked realizing that the benefits will last a minimum 

of 3-5 years (Mensik and Reid 1995). 

Disking is rarely used in upland areas, as ground disturbance typically results in invasions or 

expansions of non-native species. However, it is sometimes used to prepare native habitat 

restoration sites, including riparian forest and perennial grasslands. 

MOWING 

Mowing is used to control a variety of invasive species, enhance wetlands, reduce fire risk, and to 

accomplish general weed maintenance around facilities. It is conducted with a tractor pulling a 

large mowing implement, but may also be accomplished with smaller equipment such as push 

mowers or string trimmers. 

In wetlands, mowing is a primary tool for controlling cocklebur that can be invasive and overtake 

seasonal wetlands and crowd out more desirable species (Mensik and Reid 1995). By mowing prior 

to plants setting seed, or in combination with short-term irrigations afterwards, cocklebur can be 

kept under control. This treatment results in a greater diversity of desirable species, while 

reducing the need to use herbicides. Mowing is also used for keeping islands and selected sections 

of levees clear of vegetation to provide optimal loafing and resting sites for waterfowl, shorebirds, 

and other wildlife. Whenever possible, mowing is used instead of disking in order to minimize 

ground disturbance, erosion, and invasive species expansion. 

Some invasive vegetation in upland habitats is also managed with mowing, although burning or 

grazing are preferred in most cases. Yellow starthistle and non-native grasses such as annual 

ryegrass can be significantly reduced by mowing, but timing is critical and multiple applications 

may be necessary (Thomsen et al. 1997). 

A number of roads, levees, and areas around buildings and other facilities are mowed during the 

spring and summer to minimize risk of wildfires by allowing safer access for habitat management 

tasks (i.e. checking water control structures), conducting biological surveys, and general 

maintenance. 

WATER MANAGEMENT 

Water management is the most important tool for vegetation enhancement and control in 

managed wetlands. The timing, depth, and duration of flooding can be manipulated to enhance 

F-81 
desirable moist-soil plants and also to reduce certain undesirable species. Short-term irrigations 

(7-10 days) conducted in the spring and summer can greatly increase the amount of moist-soil 

plant seed production (Naylor 2002) and vegetative stature in managed seasonal wetlands. One 

irrigation is usually all that is necessary to bring seedling plants to maturity in the Sacramento 

Valley. 

Cocklebur, an undesirable and sometimes common species in seasonal wetlands, is particularly 

susceptible to control by flooding. As with many desirable species such as watergrass or 

smartweeds, cocklebur seedlings germinate on seasonal wetland pond bottoms as they dry in 

spring. By reflooding the wetlands when cocklebur plants are at the seedling stage, entire cohorts 

of cocklebur can be eliminated while at the same time encouraging the growth of desirable species 

that are better adapted to aquatic habitats (i.e. watergrass, smartweeds). The amount of time the 

water is held depends on when the cocklebur is blackened and disintegrating, indicating death. 

This can take one to three weeks, depending on the weather and how deep the seedlings are 

flooded. Considering annual climatic variation and wetland drawdown date, this technique can be 

used as early as March or late as June. It is extremely efficient and cost-effective when compared 

to other methods. However, prolonged irrigations (e.g. longer than necessary to kill the 

cocklebur), can cause species such as Bermuda grass, jointgrass, or cattails to expand, resulting in 

decreased overall productivity for wildlife, plus the need to control those species. An additional 

result can be potentially unacceptable levels of mosquito production, which may be a human health 

issue in some areas. 

PRESCRIBED LIVESTOCK GRAZING 

Historically, grazing by native wildlife species has shaped the botanical and zoological resources of 

the California landscape (Edwards 1992, 1996). Currently, well managed livestock grazing is an 

important method of vegetation management (Barry 2003; Griggs 2000) on the Refuges. Benefits 

associated with the grazing program include: the reduction of plant material; reduction in nonnative invasive weeds (Thomsen et al. 1993); increases in native plants, including special status 

plant species due to reduced competition for sunlight, and with non-native annual grasses for 

water and nutrients (Coppoletta and Moritsch 2001; Davis and Sherman 1992; Menke 1992; Muir 

and Moseley 1994); increased primary production and resultant increases in plant biomass 

(McNaughton 1985); increases in native vernal pool and grassland wildflowers (Marty 2004, 2005), 

with consequent increases in macro-invertebrate populations, including native pollinators of native 

plants, and prey items for Refuge wildlife such as migratory land birds like the horned lark and 

savanna sparrow; and increases in the inundation period with habitat benefits to vernal pool 

crustaceans (Pyke and Marty 2005). Grazing provides optimal shorebird and sandhill crane 

foraging habitat by reducing grass height and contributing organic matter for the prey base 

(Colwell and Dodd 1995; Knopf and Rupert 1995) and also provides short, nutritious grasses for 

grazing migratory waterfowl (Buchsbaum et al. 1986) and local deer. Aquatic invertebrates, 

insects, and special status species associated with vernal pool and vernal pool/alkali meadow 

complexes benefit from grazed herbaceous habitats (Bratton 1990; Bratton and Fryer 1990; 

Panzer 1988; Germano et al. 2001), especially cattle grazing (Marty 2004, 2005). Grazed areas 

support increased numbers of primary burrowing mammals such as California ground squirrels 

and secondary burrowing animals such as burrowing owls and various snakes. 

Long-term benefits from the grazing program include continued annual native plant production, 

non-native invasive plant species control, and maintenance of annual or seasonal use of Refuge 

habitat by migratory birds and resident deer herds. Periodic grazing can also lessen the threat of 

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wildfire near rural structures and agricultural industrial facilities. Overall, the short-term impacts 

of seasonal grazing on local ground-nesting birds and some small mammals would be mitigated by 

the long-term improvements to Refuge plant species composition and structure, native plants and 

overall wildlife habitat quality that would benefit migratory birds, resident deer herds and nesting 

habitat condition. 

Grazing is facilitated through a Cooperative Land Management Agreement (CLMA) or Refuge 

SUP with a local cooperator. Depending on species to control and wildlife objectives, cattle, sheep, 

or goats may be used. Benefits of the CLMA program are the cooperator’s shared responsibilities 

in maintaining corals, fences, gates, water systems, and vegetation management/invasive weed 

control. 

HERBICIDES 

Due to differences in species susceptibility and the variety of habitats within the Complex, a 

number of potentially available herbicides are necessary in order to choose the one that is most 

effective for a particular species in a particular environment. Examples of considerations in 

making these choices are: 1) some herbicides are very effective on some species, but completely 

ineffective on others (this is often related to the growth form of the plant, such as a grass, shrub, 

or tree; or a perennial rhizomatous species versus a small annual species); 2) using a broadspectrum (kills many species of grasses, other monocots, and broad-leaved plants) versus a 

broadleaf-specific herbicide; and 3) using a herbicide or herbicide formulation approved for use in 

aquatic areas versus those approved for use just on terrestrial sites. 

There is a process for using herbicides on the Refuge that includes development and approval of 

PUPs. PUPs are developed by Refuge staff, and then reviewed by appropriate Service staff. 

Depending on the product/chemical proposed, PUPs can be approved at the Refuge Manager 

level, or some products require review and approval by Service IPM specialists at the regional or 

national level. PUPs must also be consistent with other Service and DOI policies, including 

National Environmental Policy Act (NEPA) and Endangered Species Act (ESA). Table 10 

indicates the federally listed species and their habitats on the Complex. Conditions specified in 

PUPs include application methods, rates, and timing; maximum number of applications allowed 

per season; and measures to be taken to avoid sensitive areas. With an approved IPM plan, PUPs 

can be valid for up to five years. 

Currently, seven herbicides have been approved for use at the Complex. Summarized below is 

specific information regarding each chemical, including product names, how they work, and 

potential risks to the environment. Appendix 2 summarizes properties, behaviors, persistence, and 

toxicities of commonly used herbicides. For a more in-depth discussion of the properties of these 

products, see The Nature Conservancy Weed Control Methods Handbook: Tools and Techniques 

for Use in Natural Areas – Chapter 7 (Tu et al. 2001) and the Herbicide Handbook Eighth Edition 

(Vencill 2002). 

2,4-D 

Common name: 2,4-D 

Chemical name: 2,4-Dichlorophenoxyacetic acid 

Common product names: Weedar 64, Weedone 

F-83 
2,4-D is the most widely used herbicide worldwide and has been used for over 50 years. 2,4-D is a 

plant hormone (auxin) mimic that kills the plant by causing rapid cell division and abnormal 

growth. It is a systemic herbicide and can be absorbed through the roots, although it is most often 

applied to foliage. Depending on the formulation, 2,4-D is recommended for control of terrestrial 

and aquatic broadleaf weeds with little or no activity against grasses. Salt formulations are 

registered for use against aquatic weeds, but ester formulations are toxic to fish and aquatic 

invertebrates. The World Health Organization (1984) concluded that 2,4-D does not accumulate or 

persist in the environment. 

AMINOPYRLID 

Common name: Aminopyrlid 

Chemical name: 2-pyradine carboxylic acid, 4-amino-3,6-dichloro-2-pyradinecarboxylic acid 

Common product names: Milestone 

Aminopyrlid is an auxin growth regulator used to control susceptible broadleaf weeds, including 

Russian knapweed and yellow starthistle, at very low labeled use rates compared to other 

herbicides with the same mode of action. It translocates throughout the entire plant and 

accumulates in the meristematic tissues, including the roots, disrupting plant growth metabolic 

pathways and affecting the growth process of the plant. Broad-leaved species are controlled with 

little or no injury to cool- and warm-season grasses. It has great potential for use at the Complex 

due to its low toxicity to animals (practically non-toxic to birds, fish, honeybees, earthworms, and 

aquatic invertebrates), non-volatile formulation, and low use rates. MilestoneTM is registered under 

the U.S. Environmental Protection Agency (EPA) Reduced Risk Pesticide Initiative. This 

program is reserved for compounds that demonstrate lower risk to humans and the environment 

than other available alternatives. It has also demonstrated a low risk of resistance development 

compared to herbicides with other modes of action. 

CHLORSULFURON 

Common name: Chlorsulfuron 

Chemical name: 2-chloro-N-[(4-methoxy-6-methly-1,3,5-triazin-2-yl) aminocarbonyl] 

benzenesulfonamide 

Common product names: Telar 

Chlorsulfuron is used as a pre- and post-emergent herbicide to control a variety of weeds on cereal 

grains, pasture and rangeland, industrial sites, and turf grass. It controls many broadleaf weeds 

including Russian thistle, and mustards. It is the only herbicide that effectively controls perennial 

pepperweed (Young et al. 1998), which is a common invasive species of concern at the Complex. 

Chlorsulfuron is rapidly absorbed through both leaves and roots. It inhibits a key enzyme in the 

biosynthesis of certain amino acids. Plant death occurs from events that take place in response to 

the enzyme inhibition, but the actual sequence of processes is unclear. 

Chlorsulfuron is likely to be persistent and highly mobile in the environment. It is not for use in 

aquatic sites. It is practically nontoxic to freshwater fish, birds, mammals, and honeybees on an 

acute exposure basis (Environmental Protection Agency 2005). The EPA determined ecological 

risks to be low except for non-target plants; and therefore, the agency requires that it be applied 

in a manner that minimizes spray drift. 

F-84 
CLOPYRALID 

Common name: Clopyralid 

Chemical name: 3,6-dichloro-2-pyridinecarboxylic acid, monoethanolamine salt 

Common product names: Transline 

Clopyralid is an auxin-mimic type herbicide. It is used to control broadleaf weeds, but is more 

selective than some other herbicides using the same mode of action. Clopyralid has little effect on 

grasses and other monocots, but also does little harm to mustards and several other groups of 

broadleaf plants. It is effective on members of the sunflower (Asteraceae), legume (Fabaceae), 

nightshade (Solanaceae), knotweed (Polygonaceae), and violet (Violaceae) families. Clopyralid has 

been used on yellow starthistle with excellent control at low rates when used on seedlings prior to 

bud stage. 

Clopyralid is considered non-toxic to fish, birds, mammals, and other animals; however, it is 

relatively persistent in soil, water, and vegetation making it potentially highly mobile and a 

contamination threat to water. Although of low toxicity to mammals, direct contact with the eye 

can cause severe eye damage including permanent impairment. 

GLYPHOSATE 

Common name: Glyphosphate 

Chemical name: N-(phosphonomethyl)glycine 

Common product names: Rodeo, Aquamaster, Aquaneat, Roundup, Buccaneer, Alecto 

Glyphosphate is a broad-spectrum, nonselective, systemic herbicide that kills or suppresses many 

grasses, herbaceous plants, brush, vines, shrubs, and trees. Applied to foliage, it is absorbed by 

leaves and rapidly moves through the plant. It can also be applied to green stems and cut-stems 

(cut-stumps), but cannot penetrate woody bark. It tends to accumulate in plant regions with 

actively dividing cells and acts by preventing the plant from producing several essential amino 

acids. This reduces the production of protein in the plant, and inhibits plant growth. Roundup and 

equivalent formulations are approved for terrestrial sites only. Rodeo and equivalent formulations 

are approved for aquatic use. Glyphosate by itself is essentially non-toxic to submersed plants. It 

is the adjuvants (surfactants) often sold with glyphosate that may be toxic to aquatic plants and 

animals and these formulations are not registered for aquatic use. Aquatic-approved glyphosate is 

used to control water primrose (Ludwigia sp.), non-native watermilfoils (Myriophyllum sp.), and 

other weeds in or near water. Application timing is critical for effectiveness on most broadleaf 

plant species. 

Because glyphosate is a nonselective herbicide, extra care must be taken to prevent it from being 

applied to desirable, native plants. Glyphosate by itself is of low toxicity to mammals and 

earthworms; and is practically nontoxic to birds, fish, aquatic invertebrates, and honeybees. The 

chemical is essentially immobile in soil and is readily degraded by soil microbes (Environmental 

Protection Agency 1993). When used as an aquatic herbicide in non-flowing water (e.g. ponds, 

lakes), only 1⁄3 to 1⁄2 of the water body should be treated at any one time to prevent fish kills caused 

by dissolved oxygen depletion. 

F-85 
IMAZAPYR 

Common name: Imazapyr 

Chemical name: (±)-2-[4,5-dihydro-4-methyl-4-(1-methlyethly)-5-oxo-1H-imidazol-2-yl]-3­

pyridinecarboxylic acid 

Common product names: Habitat, Stalker 

Imazapyr is a broad-spectrum herbicide that controls annual and perennial grasses, broadleaf 

weeds, and woody species. It kills plants by inhibiting the production of certain amino acids, which 

are necessary for protein synthesis and cell growth. It is relatively slow acting, does not readily 

break down in the plant; and therefore, is particularly good at killing large woody species such as 

saltcedar. It is also effective on giant reed. Some formulations (e.g., Habitat) are approved for 

aquatic use. Habitat is a low-volume herbicide; it is effective at low rates of the active ingredient, 

thereby reducing the chemical load on the environment. 

Because imazapyr is a broad-spectrum herbicide that is relatively persistent in soil, care must be 

taken during application to prevent accidental contact with non-target species. A few studies have 

reported that imazapyr may be actively exuded from the roots of legumes (such as mesquite), 

likely as a defense mechanism by those plants and this exudate may therefore adversely affect the 

surrounding desirable vegetation. Imazapyr is of relatively low toxicity to mammals, birds, fish, 

and invertebrates, but some formulations (inert ingredients in Chopper and Stalker) can cause 

severe, permanent eye damage in humans. 

TRICLOPYR 

Common name: Triclopyr 

Chemical name: 3,5,6-trichloro-2-pyridinyloxyacetic acid, butoxyethel ester 

Common product names: Garlon 4, Garlon 3A 

Triclopyr is a selective systemic herbicide used to control woody plants and broadleaf weeds. It 

has little or no effect on grasses, but is particularly effective on woody species like saltcedar with 

cut-stump or basal bark treatments. Triclopyr controls weeds by mimicking a plant hormone and 

causing uncontrolled growth that leads to plant death. It may be mixed with picloram, clopyralid, 

or with 2,4-D to extend its utility range. 

There are two formulations of triclopyr – a salt and an ester. Both formulations are relatively nontoxic to terrestrial vertebrates and invertebrates, but the ester formulation is extremely toxic to 

fish and aquatic invertebrates. The ester is also highly volatile and must be applied at cool 

temperatures and on days with little wind. The salt formulation (e.g., Garlon 3A) cannot readily 

penetrate plant cuticles so is best used in a cut-stump treatment or with a surfactant. This 

formulation can also cause severe eye damage. 

ADJUVANTS 

An adjuvant is any compound that is added to a herbicide formulation or tank mix to facilitate the 

mixing, application, or effectiveness of that herbicide. Spray adjuvants often improve spray 

retention and absorption by reducing the surface tension of the spray solution, allowing the spray 

droplet to spread more evenly over the leaf surface. Herbicide absorption may be further 

enhanced by interacting with the waxy cuticle on the leaf surface. They are sometimes included in 

F-86 
the formulations of herbicides (e.g. Roundup), or they may be purchased separately and added 

into a tank mix prior to use (Tu et al. 2001). 

Adjuvants are chemically and biologically active, not chemically inert, compounds. Some adjuvants 

have the potential to be mobile and pollute water. The Material Safety Data Sheet (MSDS) for an 

adjuvant and the herbicide label (if the adjuvant is included in the formulation) should be checked 

for conditions in which the adjuvant should not be used. At the Complex, Agri-dex is a non-ionic 

adjuvant that is commonly used with glyphosate for some terrestrial and aquatic applications. 

RESTORATION OF NATIVE SPECIES 

Where appropriate, native vegetation is restored using a variety of grasses, forbs, shrubs, or tree 

species depending on habitat and wildlife objectives (USFWS 2005a, 2008). A combination of the 

above vegetation management techniques may be used for weed control in preparation for reestablishing (cultivating) native species. Planting seeds, plugs, and cuttings are the most common 

methods for establishing native vegetation that will, often with some management, out compete 

non-native species over the long-term. The use of local genetic stocks for any plantings helps to 

increase the chance of success. Restoration sites typically use farm-style irrigation systems for the 

first several years. 

Table 14 summarizes current preferred treatments for initial control and maintenance control of 

selected invasive and undesirable species at the Complex. 

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Table 14. Potential control methods and order of preference considered for use on selected invasive species at 

Sacramento National Wildlife Refuge Complex. 

Control Method/General Order of Preference1 

Species 

Initial Control Maintenance Control 

1 2 3 1 2 3 

Annuals Yellow starthistle herbicide - 2,4-D or clopyralid burning mowing native species restoration grazing mowing/haying Prickly lettuce herbicide - 2,4-D or other broadleaf - - native species restoration grazing -Cocklebur scalding mowing 

herbicide - 2,4-D 

or other 

broadleaf 

scalding mowing -

Perennial pepperweed 

herbicide -

chlorosulfuron - -

grazing - cattle, 

sheep, or goats 

herbicide -

chlorosulfuron -

Russian thistle herbicide - glyphosate - - Hand-pulling herbicide - glyphosate -

Bindweed herbicide - 2,4-D disking - native species restoration herbicide - 2,4-D -Black locust 

herbicide -

glyphosate or 

triclopyr 

- -

native species 

restoration 

herbicide -

glyphosate or 

triclopyr 

-

Parrot's feather raking and removal herbicide - glyphosate or 2,4-D 

-

raking and 

removal 

herbicide -

glyphosate or 2,4­

D 

-

Black walnut hybrid 

herbicide -

triclopyr - -

native species 

restoration 

herbicide -

triclopyr -

F-88 
Control Method/General Order of Preference1 

Species 

Initial Control Maintenance Control 

1 2 3 1 2 3 

Common fig herbicide - triclopyr - - herbicide - triclopyr - -

Red River gum herbicide - triclopyr herbicide - glyphosate - native species restoration herbicide - triclopyr herbicide - glyphosate 

Water primrose ­aquatic areas 

herbicide -

glyphosate 

raking, 

excavating 

-

herbicide -

glyphosate 

raking, 

excavating 

-

Water primrose ­dry areas disking herbicide - glyphosate - disking herbicide - glyphosate -Giant reed mechanical-for small infestations herbicide - glyphosate or imazapyr - mechanical-for young infestations herbicide - glyphosate or imazapyr -Swamp-timothy/ African pricklegrass (in vernal pools) 

hand pulling prior 

to seed-set 

- -

maintain natural 

hydrology of 

vernal pools 

hand pulling 

prior to seed-set 

-

Tall wheatgrass herbicide - glyphosate - - native species restoration herbicide - glyphosate -

Perlagrass herbicide - glyphosate - - native species restoration herbicide - glyphosate -Non-native annual grass - general, inc. Lolium, Bromus, and Hordeum sp. 

burning or 

grazing mowing 

herbicide -

glyphosate (prerestoration 

planting) 

native species 

restoration 

burning or 

grazing mowing 

F-89 
Control Method/General Order of Preference1 

Species 

Initial Control Maintenance Control 

1 2 3 1 2 3 

Bermuda grass burning followed by disking herbicide - glyphosate disking alone - may require multiple passes disking/water management herbicide - glyphosate -

Jointgrass burning followed by disking herbicide - glyphosate disking alone - may require multiple passes disking/water management herbicide - glyphosate -Johnsongrass herbicide - glyphosate - - native species restoration herbicide - glyphosate -Medusahead burning - - grazing burning herbicide - glyphosate Water hyacinth raking and removal herbicide - aquatic glyphosate - raking and removal herbicide - aquatic glyphosate -

Sharp-leaved fluellin 

herbicide - 2,4-D 

or other broadleaf 

herbicide -

glyphosate 

-

native species 

restoration grazing -

Tree-of-heaven herbicide - triclopyr - - native species restoration herbicide - triclopyr -Tamarisk/salt cedar 

herbicide -

triclopyr 

- - bio-control beetle - -

1 Additional specific information on formulations, application rates and methods, etc. can be found in the text of this document. 

F-90 
INTEGRATED PEST MANAGEMENT STRATEGY 

The components of a successful IPM program include: 

• Identification of pests and natural enemies. 

• A monitoring and record keeping system for regular sampling of pest and natural enemy 

populations. Monitoring is an ongoing activity throughout any IPM program. 

• Setting injury levels, or determining the size of the pest population correlated with an 

injury sufficient to warrant treatment. Setting action levels, the pest population size, along 

with other variables such as weather, from which it can be predicted that injury levels will 

be reached within a certain time if no treatments are undertaken. 

• An integration of treatment methods that are effective against the pest, least disruptive to 

natural controls, and least hazardous to human health and the environment. 

• An evaluation system to determine the outcome of treatment actions. 

The ongoing monitoring of treatments and results of an IPM program is critical to the adaptive 

management approach. Information provided by the monitoring component shall be used to 

evaluate the effectiveness of treatment methods in light of site conservation goals. Managers shall 

use this information to adjust priorities, modify treatments, and improve planning and budgeting. 

ASSESSMENT PROTOCOL 

A prioritization strategy is necessary to effectively utilize the limited funds available to eradicate 

or control the many non-native species found throughout the 36,000-acre Complex. The following 

criteria, based on An Invasive Species Assessment Protocol (Morse et al. 2004), a collaborative 

effort of NatureServe and TNC, will be considered when assessing invasive species impacts and 

prioritizing target species and treatment sites: 

• Ecological impact: impacts on native plant and animal populations, ecosystem processes, 

ecological community structure and composition; and the significance of those species and 

communities that are affected (i.e., rare, endemic, keystone, or threatened and endangered 

species; unique ecosystems). 

• Current distribution and abundance: size of infestation, proximity to valuable resources, 

and diversity of habitats or ecological systems invaded. 

• Trend in distribution and abundance: the potential for spread, especially to new, 

uninfested areas; the rate of spread; reproductive characteristics. 

• Management difficulty: susceptibility to treatment/difficulty to control, accessibility of 

sites, potential for control methods to impact non-target species. 

A high impact rank does not always translate into a high priority for treatment. Other 

considerations such as Refuge operations or earmarked funding can change priorities. For 

instance, a species that is difficult to manage will have a greater chance of causing significant 

damage, giving it a high impact rank. However, it may be that the difficulty is such that 

attempting to eradicate it is not the best use of limited funds. On the other hand, a species that 

may rank low in these areas could be a high priority for treatment if it is a new or small infestation 

and can be readily eradicated. 

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SACRAMENTO REFUGE COMPLEX HABITAT MANAGEMENT SYSTEM 

The above IPM Strategy components and Assessment Protocol are considered and included in the 

annual habitat management process at the Complex. Overall Refuge management is determined, 

guided, and tracked by this same process (USFWS 2002). Among other information, vegetation 

control in general, and the control of invasive species in particular, are included in detail in annual 

habitat management plans (AHMP) that are generated for each Refuge. Identification of target 

species, their location, specified control methods, and monitoring of treatments is included in the 

plans. The planning cycle starts in the late winter/early spring. Refuges are toured by staff, during 

which time each management unit is visited and evaluated. Staff includes the refuge manager, 

biologist, work leader, irrigator, outdoor recreation planner, fire management officer, and law 

enforcement officer. Each unit is evaluated based upon what was planned for the year vs. what 

actually was accomplished in terms of management activities (e.g. water regimes, vegetation 

control, public use improvements, etc.), repairs (e.g. levee construction or replacement of water 

control structures), and the resulting habitat condition, wildlife use, or other resource data. Data 

and observations collected by all refuge programs are presented and discussed. Nearly all of this 

data is collected by unit, so it can be compared and evaluated in relation to past years and/or other 

units. Examples include vegetation species composition, wildlife survey data, disease mortality, 

wetland drawdown and flood-up dates, vegetation control measures conducted (i.e. prescribed fire, 

grazing, mowing and disking, irrigation, herbicide application, etc.), quality of public use 

opportunities (i.e. wildlife observation on tour routes, hunting success, etc.), and law enforcement 

issues. Information gathered and decisions made on the tours are then used to generate the next 

year’s AHMP for each Refuge. The decisions made during this process also involve a number of 

other considerations including, but not limited to, Refuge purposes, Service management 

directives (i.e. Improvement Act), historic habitat conditions, other regional habitat plans (i.e. 

Central Valley Joint Venture Implementation Plan), Flyway management plans, endemic species 

conservation, endangered species recovery plans, and specific resource needs. 

The end result is a modestly sized document that is distributed to all staff members to provide 

direction, and furnish a reference, as well as a place to keep notes on their respective programs 

and responsibilities. The AHMP identifies physical attributes of the unit, habitat objectives, 

specifies management activities to make any necessary repairs or improvements; emphasizes 

positive results from previous years; and notes special management considerations (i.e. presence 

of special status species or other significant wildlife use). The AHMP also includes a prioritization 

of management activities and projects based on the overall condition of the unit, which would 

include the degree to which invasive species were present or threatening other priority species. 

Data is maintained in a computer database, which serves to generate the AHMPs and can also be 

queried to evaluate a variety of biological data that is collected on the Refuges. In summary, the 

AHMP facilitates the adaptive management process for controlling invasive species, as well as 

other resource objectives. It allows for modification within or between years based upon changing 

conditions, serves as a place to input current data from all refuge programs to be considered 

together, and helps to ensure that informed management decisions are made. 

F-92 
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Appendix G. Resource Inventory and 

Monitoring Plan for the Sacramento 

National Wildlife Refuge Complex 

Table of Contents 

Introduction.................................................................................................................................................... 1

Regular Wildlife Surveys (RWS) ................................................................................................................ 1

Flyway-coordinated Waterfowl Surveys.................................................................................................... 3

Threatened and Endangered (T&E) Species Surveys ............................................................................ 3

Shorebirds ...................................................................................................................................................... 4

Colonial Nesting Birds ................................................................................................................................. 5

Breeding Bird Survey (BBS) Routes ......................................................................................................... 5

Non-game Bird Surveys ............................................................................................................................... 5

Incidental Wildlife Observations................................................................................................................. 5

Annual Habitat Management Plans ........................................................................................................... 5

Periodic Vegetation Surveys........................................................................................................................ 6

Geographic Information System (GIS) ...................................................................................................... 6

Refuge Narratives......................................................................................................................................... 7

Data Storage and Maintenance ................................................................................................................... 7

Bibliography................................................................................................................................................. 12

Figures 

Figure 1. Sacramento Refuge Complex map............................................................................. 2 

Figure 2. Example of Standardized Wildlife Survey Route .................................................. 12 

Figure 3. Example Waterfowl Survey Data Sheet ................................................................. 13 

Figure 4. Example Wildlife Survey .......................................................................................... 16 

Tables 

Table 1. Surveys and other monitoring efforts currently conducted by Sacramento Refuge 

Complex staff1

. .............................................................................................................................. 8 

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Introduction 

Sacramento National Wildlife Refuge Complex (Complex) includes five national wildlife 

refuges (Refuges) and three wildlife management areas (WMAs) in the northern 

Sacramento Valley. The Complex includes Sacramento, Delevan, Colusa, Sutter, and 

Sacramento River Refuges and Butte Sink, Willow Creek-Lurline, and North Central 

Valley WMAs (Figure 1). Wildlife and habitat resources at the Complex are inventoried or 

monitored through a variety of regular and special surveys and annual habitat 

management plans (AHMP). While some surveys are used to monitor resources on a 

Refuge or unit basis, others contribute to coordinated efforts to monitor populations on a 

Central Valley, State, Pacific Flyway, or National level. The objectives vary greatly, and, 

along with staff and available funding, determine the methodology, frequency, timing, and 

precision of the surveys. These may be coordinated with a number of agencies or other 

organizations, including but not limited to, other U.S. Fish and Wildlife Service (Service) 

offices, California Department of Fish and Game (CDFG), U.S. Geological Survey 

(USGS), Point Reyes Bird Observatory (PRBO), and universities. Some surveys or 

monitoring investigations are not regularly scheduled, but serve as important baseline 

data for management until new information becomes available. The objective of this 

document is to outline the current inventory and monitoring plan including the efforts 

that the Complex conducts, facilitates, or otherwise participates in. Table 1 summarizes 

the current surveys, schedules, geographic coverage, coordination, and reporting location 

of inventory and monitoring (I&M) surveys that the Complex participates in. 

Regular Wildlife Surveys 

Regular Wildlife Surveys (RWS) serve as an index to document wildlife population trends 

on the Complex (USFWS 1989-2007) and monitor wildlife use in relation to a variety of 

habitat management activities. Survey data for waterfowl or other relatively common 

species can be converted to density (i.e. ducks or geese per acre) and used to evaluate 

response to habitat management treatments (e.g. vegetation manipulation, water regime, 

water level management) or other factors that might affect bird use (e.g., disturbance 

levels from public use areas.). 

RWS are conducted 1-2 times per month, depending on time of year. During SeptemberApril, when migratory bird populations are relatively great, surveys are conducted twice 

monthly. During May-August, when most wetlands are dry and migratory bird 

populations are relatively low, surveys are conducted once per month. On average, each 

Refuge takes about a day to complete. Surveys are conducted by experienced refuge 

biologists from a vehicle along standardized routes for each Refuge (Figure 1). When 

geese are present (i.e. September-April), surveys are started in mid- to late morning, 

after most geese have returned to roost on Refuges following morning foraging in 

agricultural fields. They are conducted from a pick-up or other full-size vehicle unless 

road conditions are wet, when an all-terrain vehicle (ATV) would then be used. The routes 

are designed to give viewing access to all management units within the Refuges. Numbers 

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Figure 1. Sacramento Refuge Complex map 

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of waterfowl, shorebirds, waterbirds, raptors, and a selection of other species are 

estimated and recorded for each unit (Figure 2 and 3). Depending on the magnitude of 

birds, totals for each unit are made by estimating numbers of individuals of each species 

or groups of like species (e.g. ducks, geese, or shorebirds) to the nearest 10,000, 5,000, 

1000, 500, 100, 50, 10, or 1 bird. If estimates are made for groups of like species (e.g. total 

ducks), percentages of individual species are also estimated and applied to calculate 

numbers for each species. For each survey period, an attempt is made to complete a RWS 

for all individual Refuges within a week or less, ideally with consistent weather conditions. 

Waterfowl summary reports are generated for each Refuge and the Complex. 

RWS data is maintained in hard copy in Refuge files and electronically as a component of 

the Complex Biological Database (see below). 

Flyway-coordinated Waterfowl Surveys 

These mostly annual surveys are conducted in coordination throughout the Pacific Flyway 

(Table 1). Depending on the individual survey, the Complex participates through 

conducting, coordinating, and/or summarizing results for various geographic segments. A 

combination of aerial and ground surveys are conducted. Currently, these surveys include 

the Special White-fronted Goose, Special Dark Goose, Special White Goose (including 

Snow/Ross’s Species Composition every third year), Special Tule White-fronted Goose 

(both direct and indirect surveys), and Mid-winter Waterfowl Inventory. Aleutian Canada 

goose populations are also monitored annually on the Complex, but most specifically in 

the Colusa/Butte Sink area. In addition to population surveys, productivity surveys (ratios 

of juvenile and adults) are also conducted for Arctic-nesting geese, including lesser snow, 

Ross’s, Pacific greater white-fronted, and tule greater white-fronted geese. 

All surveys are summarized and submitted to the Service’s Pacific Flyway 

Representative, for inclusion in the Pacific Flyway Data Book (Trost 2006), annual 

productivity reports (USFWS 2006), or other Flyway reports. Operational waterfowl 

banding efforts, both pre- and post-season, are conducted or facilitated annually, with all 

banding data kept in hard copy in Refuge files and reported to the USGS Bird Banding 

Lab. 

Threatened and Endangered Species Surveys 

Threatened and endangered (T&E) species are monitored through various surveys, 

depending on the species (Table 1). Population surveys for T&E vernal pool and alkali 

meadow plants are conducted by estimating the number of individuals at each vernal pool 

(or Refuge Tract or Pool for palmate-bracted bird’s beak). Surveys occur in vernal pools, 

alkali meadows, and the tapered, shallow margins of some managed wetlands at 

Sacramento, Delevan, and Colusa National Wildlife Refuges (Refuges) (no suitable 

habitat exists on Sutter Refuge). Rare plant surveys are conducted up to four times 

annually to account for all T&E vernal pool and alkali meadow species (Silveira 1992-

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2006a, b). Presence-absence surveys for vernal pool invertebrates are also conducted 

periodically (Silveira 2005). These data are maintained in Refuge files and are provided 

(annually) to the Sacramento Fish and Wildlife Office, Ecological Services, Endangered 

Species Division (T&E Permits, Sacramento Valley Branch, and Section 7) and the CDFG 

Habitat Conservation Planning Branch and, when new populations are discovered, 

California Natural Diversity Database in Sacramento. 

Swainson’s hawks, and greater sandhill cranes are monitored through RWSs (USFWS 

1989-2007), but refuge staff also participate in periodic special coordinated surveys by 

CDFG and others (CDFG and UC Davis 2006). Yellow-billed cuckoos have only been 

monitored on Sacramento River and Sutter Refuges, which are the only Refuges with 

suitable habitat, through infrequent periodically coordinated surveys during the breeding 

season using tape-playback methodology (Isola 2000, Halterman et al. 2001). 

Most of the monitoring information for giant garter snakes (GGS) was collected through 

USGS efforts between 1996 and 2005 (Wylie et al. 2006). A combination of mark-recapture 

and radio telemetry techniques was used to determine population estimates, habitat use, 

and response by GGS to wetland restoration at the Complex. These efforts have provided 

baseline information with associated management recommendations that are incorporated 

into annual habitat management plans. Incidental observations (see below) are recorded 

and site-specific surveys are conducted prior to projects that are planned to occur on or 

near GGS habitats. 

Anadromous fish are not monitored on the Refuges on a regular basis. Salmon and 

steelhead use on Sutter Refuge is limited mostly to outmigrating juvenile salmon from 

Butte Creek or the Sacramento River during flood conditions within the Sutter Bypass. 

Adult fish migrate up the Sutter Bypass canals (considered part of lower Butte Creek), 

which are directly adjacent to the Refuge. There has been a very limited amount of 

sampling for juvenile salmonids in Sutter Refuge wetlands within the Bypass. Otherwise, 

anadromous fish monitoring is conducted elsewhere for the Sacramento River and Butte 

Creek systems. 

Shorebirds 

Shorebirds are surveyed with RWSs (see above), but also with special surveys 

periodically. Spring shorebird use on Sacramento Refuge was intensively surveyed for 

two years in 1997 and 1998. The data indicated significant differences in Refuge use 

during wet and dry springs, identified management units with the greatest shorebird use, 

and provided detailed habitat use by species information (Wolder et al. 1999). Coordinated 

surveys for shorebirds in the Central Valley were also conducted during 1992-1995, 

including the Refuges (Shuford et al. 1998). 

G-4 
Colonial Nesting Birds 

Colonial nesting birds are monitored annually, via RWSs (see above) and additional 

special surveys. An attempt is made to assess size, reproductive success, and any 

problems for each colony. Species include, but are not limited to, great blue heron, great 

egret, snowy egret, cattle egret, black-crowned night-heron, white-faced ibis, and 

tricolored blackbird. Colony size (i.e. number of adults associated with a colony) are 

estimated with direct ocular estimates of birds on nests or by using early morning fly-off 

counts (ibis). This data is mostly maintained in the Complex’s Biological Database and 

Refuge files, with some published summary reports or publications. 

Breeding Bird Survey (BBS) Routes 

BBS Routes provide data for a long-term survey coordinated by USGS throughout the 

country. Refuge staff currently conducts the Orland BBS route annually. The Glenn BBS 

route was also conducted by refuge staff until 1999. These data are submitted annually to 

USGS, who maintains the data and generates trend reports and data analyses periodically 

(Sauer et al. 2005). 

Non-game Bird Surveys 

Non-game bird surveys were collected for eight years on standardized routes on the four 

Refuges during 1986-1993 and serve as a baseline (Gilmer et al. 1998). These surveys 

could be repeated at some point in the future to evaluate trends on the Refuges. 

Incidental Wildlife Observations 

These are observations recorded by refuge staff opportunistically to document rare or 

unusual species, unusual concentrations of wildlife or plants, or species occurring at 

atypical times of year or locations. Observations are included from both on and the 

general vicinity of Refuges. Where, when, and for which species these data are collected 

are subjective and the amount of annual effort is not standardized in any way. Data for 

these observations are recorded in binders and entered into the Incidental Wildlife 

Observations table with the Complex’s Biological Database. 

Annual Habitat Management Plans 

AHMPs are produced for each Refuge (Appendix E of the CCP, USFWS 2008), with the 

purpose of prioritizing, implementing, tracking, and adapting habitat management 

activities to meet resource objectives. The plans contain basic parameters of individual 

management units, including their total acreage, the acreage of each habitat type, and 

primary habitat objective. The information is summarized in a series of tables, schedules, 

prioritized work plans, and Refuge maps. AHMPs identify planned management 

activities, including water management (i.e. drawdown, irrigation, and flood-up dates), 

G-5 
prescribed habitat treatments, special management considerations, and specific projects 

for a “biological year,” which is generally spring to spring. In late winter, staff members 

from the various Refuge programs, including managers, biologists, work leaders, 

irrigators, recreation planners, and fire management personnel visit each unit on each 

Refuge to review the previous year’s management plan and initiate the development of 

the upcoming year’s plan. In addition to being planning and implementation documents, 

AHMPs also function as monitoring surveys, having embedded datasheets for the 

collection of information on actual (compared to planned) water and vegetation 

management, specific project completion, and anecdotal data for any notable comments 

(e.g. reasons for differences in actual vs. planned management activities) or problems. 

Data is provided by the respective staff members (e.g., irrigators provide water 

management data, biologists provide wildlife and vegetation response data from surveys, 

work leaders track project work accomplishments, recreation planner provides public use 

data, etc.). All of the information is evaluated by the group (e.g. what was/was not 

effective, which projects were or were not completed) and used to develop the upcoming 

year’s plan. Plans are ideally completed sometime in the spring although interim wetland 

drawdown schedules/implementation is sometimes necessary while plans are being 

completed. All of the above refuge staff receives a copy of the plan for their area(s) of 

responsibility. The AHMPs are maintained as hard copies in Refuge files and 

electronically as a component of the Complex’s Biological Database (see below). 

Periodic Vegetation Surveys 

Periodic vegetation surveys are conducted to evaluate habitat management treatments in 

managed wetland units at the Refuges. Due to time constraints of collecting vegetation 

data for the great number of management units, these surveys often involve very basic 

visual estimates of percentages of cover by species. These surveys involve driving around 

individual units and walking out to specific areas in the unit to gain a clear view of the 

species and/or to verify the plant species identity. 

The Region 1 Fire Effects Monitoring Program has facilitated more rigorous evaluations 

of prescribed burning at specific Refuge locations. Investigations of the effects of 

prescribed burning in alkali meadow vegetation at Sacramento and Colusa Refuges have 

also been conducted (Wight 2000). 

Geographic Information System (GIS) 

The Complex also maintains a GIS system that consists of a series of shapefiles that 

reflect past and current habitat types and infrastructure systems. The original shapefiles 

were created from acetate overlays on aerial photos (1:7920) in 1997, with subsequent 

updates created on top of USGS Digital Ortho Quarter Quadrangles (1998) and custom 

ortho-rectified aerial coverages flown in April 2004 (AirPhotoUSA). The purposes of these 

data sets are to provide georeferenced base map layers outlining Refuge and unit 

boundaries, hydrography, roads, hunt areas, public use facilities, and habitat categories. 

G-6 
They provide an effective tool to evaluate use and distribution patterns of wildlife and 

plant species within the Complex and general vicinity. Examples of GIS products include 

analyses of resource response to habitat management and public use activities, accurate 

locations for species observations, calculation of habitat types and features available for 

different species, and maps for AHMPs, habitat restoration/enhancement projects, 

biological reports, public use areas, and a variety of publications. 

Refuge Narratives 

Prior to 1996, much of the inventory and monitoring information was summarized in 

annual narrative reports generated for each Refuge (USFWS 1937-1995). Narrative 

reports are maintained at the headquarters office at Sacramento Refuge. 

Data Storage and Maintenance 

The biological staff at the Complex is responsible for maintaining I&M data. Most current 

data is maintained in both hard copy and electronic versions. Hard copy files include 

sections J (Resource Management), K (Wildlife), and L (Habitat Management) of the 

general filing system, which are located in the supervisory wildlife biologist’s office. 

Additional scientific literature, including research investigations, reference books, 

scientific journals, graduate theses, agency reports, and a variety of other publications are 

located on shelves in the public use room, and can be searched using the Sacramento 

Refuge Library database (Microsoft Access file). Biological staff members also maintain a 

significant amount of reports, literature, and references in their individual offices in both 

hard copy and electronic formats. 

Electronic data is maintained in the Complex’s Biological Database (currently a Microsoft 

Access file), GIS, and a number of other Microsoft Excel and Word files at the 

headquarters office at Sacramento Refuge. Electronic data files are backed up on at least 

a monthly basis on a large portable hard disk that resides with the supervisory wildlife 

biologist. 

G-7 
 

 

Table 1. Surveys and other monitoring efforts currently conducted by Sacramento 

Refuge Complex staff1. 

Survey/ 

Monitoring Time of Year/ Geographic Agency 

Effort Species Frequency Area Purpose Coordination2 Product 

REGULAR 

WILDLIFE 

SURVEYS 

Regular Wildlife 

Surveys 

Waterfowl, 

shorebirds, 

waterbirds, 

raptors, 

selected other 

birds and 

mammals 

Twice monthly 

SeptemberApril; once 

monthly MayAugust 

All Refuge 

units 

Document 

and evaluate 

Refuge 

habitat use 

and 

management 

Refuge Staff summary 

reports 

Instream Wildlife 

Surveys 

Waterfowl, 

shorebirds, 

waterbirds, 

raptors, 

selected other 

birds and 

mammals 

Quarterly Sacramento 

River NWR 

Document 

and evaluate 

Refuge 

habitat use 

and 

management 

Refuge Staff summary 

reports 

PACIFIC 

FLYWAYCOORDINATED 

SURVEYS 

Tule greater 

white-fronted 

goose direct 

Tule greater 

white-fronted 

goose 

September/annu 

al 

Sacramento 

NWR 

Complex 

monitor PF3 

population 

USFWS, 

CDFG 

summary 

report 

Tule greater 

white-fronted 

goose indirect 

Tule greater 

white-fronted 

goose 

Fall-Winter/four 

survey periods 

annually 

Sacramento 

NWR 

Complex 

monitor PF 

population 

USFWS, 

CDFG 

summary 

report 

Special Whitefront 

all greater 

white-fronted 

geese 

October/annual Sacramento 

Valley 

monitor PF 

population 

distribution 

USFWS, 

CDFG 

summary 

report 

Aleutian Canada 

Goose 

Aleutian 

Canada goose 

FallSpring/annual 

Sacramento 

NWR 

Complex & 

vicinity 

monitor PF 

population 

distribution 

USFWS summary 

report 

Special Dark 

Goose 

all whitefronted geese, 

all Canada 

geese 

November/annu 

al 

Sacramento 

Valley 

monitor PF 

population 

distribution 

USFWS, 

CDFG 

summary 

report 

Special White 

Goose 

lesser snow 

goose, Ross' 

goose 

December/annua 

l 

Sacramento 

Valley 

monitor PF 

population 

distribution 

USFWS, 

CDFG 

summary 

report 

determine 

White Goose 

Species 

Composition 

lesser snow 

goose, Ross' 

goose 

December/once 

every 3 years 

Sacramento 

Valley 

proportions of 

snow and 

Ross' geese in 

"white goose" 

USFWS, 

CDFG 

summary 

report 

population 

G-8 
 

Survey/ 

Monitoring Time of Year/ Geographic Agency 

Effort Species Frequency Area Purpose Coordination2 Product 

monitor 

Mid-winter 

Waterfowl Index all waterfowl January/annual Sacramento Valley 

wintering 

waterfowl 

populations 

and 

USFWS, 

CDFG 

summary 

report 

distribution 

Arctic Goose 

Productivity 

tule whitefronted goose, 

pacific whitefronted goose, 

lesser snow 

goose, Ross' 

goose 

Fall/annual 

Sacramento 

NWR 

Complex and 

vicinity 

monitor 

annual 

productivity 

USFWS Flyway Report 

Waterfowl 

Banding 

mallard, other 

waterfowl 

banded 

incidentally 

summer/annual 

Sacramento 

NWR 

Complex 

monitor PF 

survival and 

harvest rates 

USFWS Flyway Report 

THREATENED 

AND 

ENDANGERED 

SPECIES 

SURVEYS 

Vernal pool and 

alkali meadow 

plants 

palmatebracted bird's 

beak, hairy 

orcutt grass, 

Greene's 

tuctoria, 

Hoover's 

spring through 

early fall/up to 

four times 

annually 

Sacramento, 

Delevan, and 

Colusa 

NWRs 

monitoring 

annual 

production 

and 

population 

trends 

Refuge Staff summary table 

spurge 

Vernal pool 

invertebrates 

Conservancy 

fairy shrimp, 

vernal pool 

fairy shrimp, 

vernal pool 

tadpole shrimp 

late winter-early 

spring/periodical 

ly-not every year 

Sacramento, 

Delevan, and 

Colusa 

NWRs 

determine 

presence/abse 

nce in 

particular 

pools 

Refuge Staff summary table 

Regular wildlife 

surveys 

Swainson's 

hawk, Greater 

sandhill crane 

Twice monthly 

SeptemberApril; once 

monthly MayAugust 

All Refuge 

units 

Document 

and evaluate 

use of Refuge 

habitats and 

their 

management 

Refuge Staff summary 

reports 

Yellow-billed 

cuckoo monitoring 

Yellow-billed 

cuckoo and 

associated 

species 

no regular 

survey schedule 

Sutter NWR 

& 

Sacramento 

River NWR 

Document 

occurrence 

and habitat 

use 

USFWS, 

USGS 

summary and 

status reportssee Isola 2000 

and Halterman 

et al. 2001 

Giant garter 

snake monitoring 

Giant garter 

snake 

no regular 

survey schedule 

Sacramento 

NWR 

Complex 

Document 

and evaluate 

use of Refuge 

habitats and 

their 

management 

USFWS, 

USGS 

summary 

report - see 

Wylie et al. 

2006 

G-9 
 

Survey/ 

Monitoring Time of Year/ Geographic Agency 

Effort Species Frequency Area Purpose Coordination2 Product 

Document 

Bank Swallow 

monitoring Bank swallows June Sacramento River NWR 

and evaluate 

use of Refuge 

Refuge Staff 

CDFG 

summary 

reports 

habitats 

OTHER 

SURVEYS 

Special surveys 

for colonial birds 

white-faced 

ibis, 

herons/egrets, 

cormorants 

MayAugust/variable 

based on 

occurrence 

Sacramento 

NWR 

Complex 

monitor 

reproductive 

effort and 

success on 

Refuges 

USFWS summary 

report 

Special surveys 

for shorebirds 

shorebirds, 

white-faced ibis variable 

Sacramento 

NWR 

Complex 

monitor 

habitat use on 

Refuges or 

Central 

Valley 

Refuge Staff, 

PRBO 

see Shuford et 

al. 1998, 

Wolder et al. 

1999 

monitor state 

Special Tricolored Blackbird tri-colored 

blackbird 

AprilAugust/variable 

based on 

occurrence 

Sacramento 

NWR 

Complex 

population/ 

distribution, 

reproductive 

effort and 

USFWS, 

CDFG, PRBO 

state summary 

report 

success 

document 

Non-game birds non-game bird 

species 

no regular 

survey schedule 

Sacramento 

NWR 

Complex 

relative 

abundance, 

habitat use, 

and 

population 

trends 

USGS 

PRBO 

summary 

report - see 

Gilmer et al. 

1998, Small et 

al 2000. 

Breeding Bird specified monitor 

Survey-Orland all birds June/annual route in national bird USGS USGS report 

Route Glenn County trends 

Resighting 

Marked Birds 

various 

waterfowl, 

shorebirds, or 

other 

waterbirds 

variable 

Sacramento 

NWR 

Complex and 

vicinity 

indirect pop. 

estimates, 

survival 

rates, habitat 

use, 

migration 

patterns, etc. 

USFWS, 

USGS, CDFG, 

CWS, PRBO, 

various 

universities 

various 

Additional 

surveys/research 

discussed in the 

Appendix O of various various Sacramento 

River NWR various various various 

CCP (USFWS 

2005) 

G-10 
 

Survey/ 

Monitoring 

Effort Species 

Time of Year/ 

Frequency 

Geographic 

Area Purpose 

Agency 

Coordination2 Product 

HABITAT 

MANAGEMENT 

SURVEYS AND 

MONITORING 

Periodic 

Vegetation 

various 

wetland and 

upland plants 

variable 

Sacramento 

NWR 

Complex 

evaluation of 

vegetation 

response to 

management 

activities and 

target plant 

species 

composition 

and wildlife 

use objectives 

Refuge Staff 

annual habitat 

management 

plans 

Water 

management 

flood-up, 

irrigation, and 

drawdown 

dates; water 

level 

management4 

yearround/periodic 

Sacramento 

NWR 

Complex 

monitor and 

refine 

strategies to 

meet 

vegetation 

composition 

and wildlife 

objectives in 

managed 

wetlands 

Refuge Staff 

annual habitat 

management 

plans 

Vegetation 

management 

mowing, 

disking, 

burning, 

spraying, or 

other 

vegetation 

management 

treatments4 

yearround/periodic 

Sacramento 

NWR 

Complex 

monitor and 

refine 

strategies to 

meet 

vegetation 

composition 

and wildlife 

objectives in 

managed 

wetlands 

Refuge Staff 

annual habitat 

management 

plans 

1

 Includes surveys that Refuge conducts, coordinates, facilitates, or otherwise participates in. 2

 USFWS=U.S. Fish and Wildlife Service, CDFG=California Department of Fish and Game, USGS=U.S. Geological Survey, 

CWA=Canadian Wildlife Service, PRBO=Point Reyes Bird Observatory. 

3 PF=Pacific Flyway. 

G-11 
Figure 2. Example of Standardized Wildlife Survey Route 

G-12 
Figure 3. Example Waterfowl Survey Data Sheet 

G-13 
Figure 3. Example Waterfowl Survey Data Sheet (continued) 

G-14 
Figure 3. Example Waterfowl Survey Data Sheet (continued) 

G-15 
Figure 4. Example Wildlife Survey 

G-16 
Figure 4. Example Wildlife Survey (continued) 

G-17 
Figure 4. Example Wildlife Survey (continued) 

G-18 
Bibliography 

California Department of Fish and Game and University of California, Davis. 2006. 

California Swainson’s Hawk Inventory: 2005-2006, 2005 Progress Report. 

Sacramento, CA. 

Gilmer, D. S., K. A. Gonzalez, M. A. Wolder, and N. R. Graves. 1998. Nongame and upland 

gamebird surveys on Sacramento Valley National Wildlife Refuges, 1986-1993. 

Western Birds 29:83-102. 

Halterman, M.D., D.S. Gilmer, S.A. Laymon, G.A. Falxa. 2001. Status of the Yellow-billed 

Cuckoo in California: 1999-2000. Report to the USGS-BRD Dixon Field Station, 

6924 Tremont Rd, Dixon, CA 95620. 

Isola, J. E. 2000. Population assessment and distribution of the yellow-billed cuckoo on the 

Sacramento National Wildlife Refuge Complex and some surrounding areas, 

California. Progress Rep.-Nov. 2000. Sacramento National Wildlife Refuge files, 

21pp. 

Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, 

Results and Analysis 1966 - 2005. Version 6.2.2006. USGS Patuxent Wildlife 

Research Center, Laurel, MD. http://www.mbr-pwrc.usgs.gov/bbs/bbs.html 

Shuford, D. W., G. W. Page, and J. E. Kjelmyr. 1998. Patterns and dynamics of shorebird 

use of California’s Central Valley. Condor 100:227-244. 

Silveira, J. G. 1992-2006a. Survey results for Cordylanthus palmatus at Sacramento 

National Wildlife Refuge Complex, 1992-2006. Sacramento National Wildlife 

Refuge files, Willows, CA. 

Silveira, J. G. 1992-2006b. Survey results for rare vernal pool plants at Sacramento 

National Wildlife Refuge, 1992-2006. Sacramento National Wildlife Refuge files, 

Willows, CA. 

Silveira, J. G. 2005. Survey results for vernal pool invertebrates at Sacramento National 

Wildlife Refuge Complex, during 1993-2005 (not all years). Sacramento National 

Wildlife Refuge files, Willows, CA. 

Small, S.L., N. Nur, A. Black, G.R. Geupel, D. Humple, and G. Ballard. 2000. Riparian 

Bird Populations of the Sacramento River System: Results from the 1993-1999 

Field Seasons. PRBO Report to The Nature Conservancy and the U.S. Fish and 

Wildlife Service. PRBO. Stinson Beach, CA. 76 pp. 

G-19 
Trost, R. E. 2006. Preliminary Draft 2006 Pacific Flyway Data Book – Waterfowl 

Harvests and Status, Hunter Participation and Success in the Pacific Flyway and 

United States, July 13, 2006. USFWS Rep. Div. of Mig. Bird Manage., Portland, 

OR. 62 pp. 

U. S. Fish and Wildlife Service. 1937-1995. Sacramento National Wildlife Refuge Complex 

Annual Narratives, 59 volumes, 1937-1995. Sacramento National Wildlife Refuge, 

Willows, CA. 

U. S. Fish and Wildlife Service. 2005. Final Comprehensive Conservation Plan and 

Environmental Assessment for Sacramento River National Wildlife Refuge, 

California Nevada Office. Sacramento, CA. 

U. S. Fish and Wildlife Service. 2006. Productivity surveys of geese, swans, and brant 

wintering in North America 2005. U. S. Dept. of Int., U. S. Fish and Wildl. Serv., 

Div. of Mig. Bird Manage., Arlington, VA. 58 pp. 

U. S. Fish and Wildlife Service. 2008. Draft Comprehensive Conservation Plan and 

Environmental Assessment for Sacramento, Delevan, Colusa, and Sutter National 

Wildlife Refuges, Region 8. Sacramento, CA. 

U. S. Fish and Wildlife Service. 1988-2007. Annual Refuge Habitat Management Plans for 

Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges, Sacramento 

National Wildlife Refuge files, Willows, CA. 

U. S. Fish and Wildlife Service. 1989-2007. Regular wildlife surveys, 1989-2007. 

Sacramento National Wildlife Refuge files, Willows, CA. 

Wight, N.K. 2000. Effects of prescribed burning on rare alkali plants at the Sacramento 

National Wildlife Refuge Complex. Master's Thesis, California State University, 

Chico. 

Wolder, M. A., J. E. Isola, and C. L. Feldheim 1999. Shorebird population and habitat use 

variations between a dry and wet spring on Sacramento National Wildlife Refuge, 

California. Draft Rep., May 1999, Sacramento Nat. Wildl. Refuge files. 

Wylie, G.D., M.L. Casazza, L.L. Martin, and M. Carpenter. 2006. In draft., Identification 

of key GGS habitats and use areas on the Sacramento National Wildlife Refuge 

Complex. Prepared for U. S. Fish & Wildlife Service and U. S. Bureau of 

Reclamation by U. S. Geological Survey, Western Ecological Research Center, 

Dixon Field Station, Dixon, CA. 31 pp. 

G-20 
Appendix H. Waterfowl Disease 

Contingency Plan 

Table of Contents 

INTRODUCTION ..........................................................................................................................1

Diseases ........................................................................................................................................3

Past History of Disease ..............................................................................................................4

WILDLIFE POPULATIONS AND HABITAT USE..............................................................6

Pacific Flyway Waterfowl Populations ....................................................................................6

Populations at the Local Level ..................................................................................................8

Bird Movement Patterns..........................................................................................................10

Weather Patterns ......................................................................................................................10

Habitat Use ................................................................................................................................10

DISEASE PREVENTION, SURVEILLANCE, & MANAGEMENT...............................12

Water Circulation......................................................................................................................12

Maintenance of Lanes in Heavily Vegetated Wetlands.......................................................12

Wetland Drainage .....................................................................................................................12

Proactive Disease Monitoring in Wetlands ...........................................................................13

Carcass Removal .......................................................................................................................13

Diagnostic Specimens ...............................................................................................................14

Logistics......................................................................................................................................17

Working Areas.......................................................................................................................17

Personnel ................................................................................................................................17

Communications ....................................................................................................................18

Equipment..............................................................................................................................18

Supply Sources ......................................................................................................................19

Lodging...................................................................................................................................19

Food.........................................................................................................................................20

SUPPLEMENTAL INFORMATION......................................................................................20

LITERATURE CITED...............................................................................................................21

Figures 

Figure 1. Sacramento National Wildlife Refuge Complex Map.............................................. 2 

Figure 2. California Mid-winter Indices (USFWS 1965-2007)................................................ 7 

Figure 3. Disease surveillance data card (front side). ............................................................ 15 

H-i 
Tables 

Table 1. Acreage and habitats of Sacramento National Wildlife Refuge Complex............... 3 

Table 2. Sacramento National Wildlife Refuge Complex disease carcass totals between 

1980-2007. ...................................................................................................................................... 5 

Table 3. Most common species affected by avian cholera and avian botulism (Type C) at 

the Sacramento National Wildlife Refuge Complex................................................................. 6 

Table 4. Regular waterfowl survey summary at Sacramento National Wildlife Complex, 

early December, 2006................................................................................................................... 9 

Table 5. Vehicles and other large equipment available for use in disease operations at the 

Sacramento National Wildlife Refuge Complex. .................................................................... 18 

Table 6. Personal protective and other equipment for disease control operations located in 

cache at Sacramento National Wildlife Refuge, January 2008. ............................................ 19 

Table 7. Local lodging. ............................................................................................................... 20 

Appendices 

Appendix 1. Highly Pathogenic Avian Influenza Response Plan ........................................ 24 

Appendix 2. Principal Local and Regional Contacts (March 2008)....................................... 26 

Appendix 3. Media Contact List (March 2008)........................................................................ 28 

H-ii 
 

INTRODUCTION 

Diseases in migratory and non-migratory avian species can be significant causes of mortality. 

Because of bird movement, disease can spread rapidly between areas and populations. Early 

detection and diagnosis of disease mortality is essential to initiating appropriate disease control to 

minimize bird loss during an outbreak. Because avian species do not recognize political 

boundaries, close communication between State and Federal agencies such as the California 

Department of Fish and Game (CDFG) and U.S. Fish and Wildlife Service (Service) is important 

in accomplishing the objectives of disease detection, diagnosis and control. Because of greatly 

reduced habitat acreage in the Central Valley, the Sacramento National Wildlife Refuge Complex 

(Complex) is an area of wildlife concentration. With peak wintering migratory bird populations of 

over three million, it has the potential for high transmission rates of some avian diseases. 

The purpose of this plan is to outline surveillance and control operations that detect and address a 

number of wildlife diseases on the Complex. The Complex includes Sacramento, Delevan, Colusa, 

Sutter, and Sacramento River National Wildlife Refuges (Refuge or NWR) and Butte Sink, 

Willow Creek-Lurline, and North Central Valley Wildlife Management Areas (WMA) located in 

Tehama, Butte, Glenn, Colusa, and Sutter counties (Figure 1). Ultimate goals are to reduce 

wildlife disease losses and address any associated human health risks. 

The Refuges consist mostly of managed wetlands, with much smaller areas of unmanaged 

wetlands, vernal pools, alkali meadows, grasslands, riparian forest, and other habitats (Table 1). 

Most Refuge wetlands are “artificially created and maintained”. That is to say, they are created 

using a series of levees and water control structures to maintain impoundments that are flooded 

and maintained with water delivered or diverted under various water rights. The delivered water 

on Sacramento, Delevan, and Colusa Refuges is provided by the Bureau of Reclamation (BOR) 

from the Sacramento River via the Glenn-Colusa Irrigation District (GCID) under the authority of 

the Central Valley Project Improvement Act (CVPIA). The majority of wetlands are seasonally 

flooded, with 10-15 percent managed as summer wetlands (Figures 6-9 of the Comprehensive 

Conservation Plan (CCP)(USFWS 2008)). A comprehensive list of plant and animal species can be 

found in Appendix K of the CCP. Descriptions of the habitats and their associated plant/wildlife 

species can be found in Chapter 3 of the CCP. 

H-1 
Figure 1. Sacramento National Wildlife Refuge Complex Map. 

H-2 
Table 1. Acreage and habitats of Sacramento National Wildlife Refuge Complex. 

Refuge Total1 

Managed Wetlands2 

Unmanaged 

Wetlands2 

Vernal 

Pool/Alkali 

Meadow2 

Irrigated 

Pasture Grasslands2,5 

Riparian 

Forest2,6 Other2,7 

Seasonally 

Flooded 

Wetlands3 

Summer 

Wetlands4 

Sacramento 10,819 6,305 781 163 2,941 0 139 117 373 

Delevan 5,8778 3,939 661 13 461 0 464 46 293 

Colusa 4,6869 2,957 390 119 619 0 438 15 148 

Sutter 2,591 1,708 173 45 0 0 226 403 36 

Butte Sink 733 610 35 1 0 0 29 15 43 

Llano Seco 

Unit 1,732 667 93 2 6 184 611 116 53 

TOTAL 26,438 16,186 2,133 343 4,027 184 1,907 712 946 1

 Official Refuge acres. 

2

 Acres calculated with GIS from 2006-07 annual habitat management plans. 

3

 Includes irrigated and non-irrigated seasonally-flooded wetlands. 4 Includes semi-permanent and permanent wetlands. 5 Includes annual and perennial grasslands 6

 Includes mixed riparian forest, cottonwood, willow, willow scrub, and valley oak riparian forest. 7

 Includes roads, facilities, and other miscellaneous areas. 

8 Includes the 80-acre Rennick property. 

9 Includes 646 acres acquired under North Central Valley Wildlife Management Area. 

Diseases 

Avian botulism (Type C) and avian cholera are currently the two most common wildlife diseases 

that affect migratory birds on the Refuges. Botulism is generally a warm weather disease that 

usually occurs between July and October. Botulism spores from the bacteria Clostridium 

botulinum occur naturally in wetlands and can reproduce under the right environmental 

conditions including low oxygen levels and warm temperatures (Sandler et al. 1993, Rocke and 

Samuel 1999). These bacteria produce a powerful neurotoxin that affects the central nervous 

system of waterfowl and other waterbirds, resulting in paralysis and eventually death. During 

warm months, the disease can be spread rapidly through a carcass-maggot cycle involving 

maggots that have fed on carcasses, which concentrates botulism toxin in their bodies, and then 

are consumed readily by other birds to their demise (USGS 1999). Outbreaks during winter or 

spring months are possible, but are much less common and less severe in terms of mortality. 

Avian cholera is typically a cold weather disease that occurs between the months of November and 

March. With cholera, the bacteria Pasturella multocida infects and directly attacks birds’ internal 

organs and respiratory system. Recent studies indicate that cholera does not persist long in the 

environment, therefore, it is an unlikely reservoir for the bacteria (Samuel et al. 2004). Outbreaks 

are more likely started via carrier birds and transmitted primarily from bird-to-bird (Mensik and 

Samuel 1995, Samuel et al. 1999). While a wide variety of other wildlife diseases have been 

documented, or could potentially occur on the Refuges, botulism and avian cholera account for the 

majority of disease management operations. 

For the last decade in the Sacramento Valley, reported annual mortality from botulism and avian 

cholera has decreased. This decrease may be related to wetland habitat restoration efforts, as well 

H-3 
as increases in other waterfowl habitat (flooding of rice for straw decomposition) that have 

significantly changed waterfowl distribution in the Central Valley (Eddings and Eadie 2003, 

Fleskes et al. 2005). 

Other diseases of significance and concern that have not yet been detected or have not been 

documented to affect many animals at the Refuges include West Nile Virus (WNV), Duck Viral 

Enteritis (DVE) and Avian Influenza (AI). WNV is a mosquito-borne disease commonly found in 

Africa, Asia, and the Middle East. It spread rapidly across North America beginning in 1999 and 

was first reported in California in 2002. It has been detected in 48 species of mosquitoes, over 250 

species of birds, and at least 18 species of mammals, including humans. 

DVE, or duck plague, affects only ducks, geese and swans and is caused by a herpes virus. 

Transmission can occur through direct contact with infected birds and by ingestion of 

contaminated food or water. Although DVE outbreaks have occurred in captive and feral 

waterfowl throughout North America, the only known duck plague outbreaks in wild waterfowl 

took place in Lake Andes, South Dakota in 1973 and the Finger Lakes in New York in 1993 

(USGS 1999). 

Avian Influenza (AI), or bird flu, is a disease caused by a virus that infects birds, including pets, 

domestic poultry, and wild birds. Since 2005, there have been specific concerns about one 

particular strain, the highly pathogenic Asian H5N1 (HPAI H5N1), based on outbreaks in Asia, 

Europe, Africa and the Philippines. There is concern that avian influenza could potentially reach 

North America from either Asia or Europe, possibly via inter-Flyway movements of migratory 

birds. Because of the potential for this disease to affect people, surveillance of migratory birds and 

their habitats throughout North America, has increased significantly since 2005 (Interagency 

Asian H5N1 Early Detection Working Group 2006, Pacific Flyway Council 2006, CDFG et al. 

2006). Refuge staff have facilitated on-going HPAI H5N1 surveillance in live wild birds (primarily 

pintails), hunter-harvested birds, environmental sampling (fecal samples from loafing sites), and 

mortality events. To date, collectively over 250,000 samples have been collected and tested in 

North America, with no detections of HPAI H5N1. A HPAI H5N1 response plan flowchart is 

included in Appendix 1. 

Additional information on wildlife diseases can be found in the Field Manual of Wildlife Diseases – 

General Field Procedures and Diseases of Birds (USGS 1999). 

Past History of Disease 

To some degree, botulism and avian cholera occur nearly every year on the Complex (Table 2). 

Typically, botulism losses are most numerous from August through October and avian cholera 

losses are more prevalent beginning in November and continuing through February. Table 3 

shows the most common species affected by avian cholera and botulism on the Complex. 

H-4 
Table 2. Sacramento National Wildlife Refuge Complex disease carcass totals between 1980-2007. 

Year 

Avian Botulism Avian Cholera 

# Botulism Carcasses Collected 

Outbreak Start 

Outbreak End 

# Cholera Carcasses Collected 

Outbreak Start 

Outbreak End 

Sacramento NWR 

Delevan NWR 

Colusa NWR 

Sutter NWR 

Butte Sink NWR 

Sacramento River NWR 

Sac NWR Complex Totals 

Sacramento NWR 

Delevan NWR 

Colusa NWR 

Sutter NWR 

Butte Sink NWR 

Sacramento River NWR 

Sac NWR Complex Totals 

1980-81 1800 5900 0 0 0 - 7700 8/12/80 1/31/81 800 350 20 40 800 - 2010 11/3/80 2/25/81* 1981-82 185 43 0 0 0 - 228 8/10/81 11/15/81 832 975 182 550 47 - 2586 11/9/81 2/18/82 1982-83 46 369 0 409 0 - 824 7/29/82 12/30/83 450 437 220 198 143 - 1448 12/1/82 1/31/83 1983-84 14791 210 355 5549 45 - 20950 8/10/83 3/31/84 683 736 221 661 0 - 2301 12/1/83 3/31/84 1984-85 2806 19 31 31 0 - 2887 6/22/84 10/30/84 2238 262 86 627 960 - 4173 11/14/84 3/13/85 1985-86 590 7 19 9 0 - 625 7/16/85 10/31/85 2164 887 112 215 137 - 3515 11/14/85 1/21/86 1986-87 870 1184 6 0 0 - 2060 8/15/86 11/13/86 1262 222 138 87 1216 - 2925 11/1/86 3/2/87 1987-88 5633 46 0 4311 0 - 9990 8/8/87 4/13/88 1212 171 4 488 1454 - 3329 11/8/87 2/8/88 1988-89 83 0 71 0 0 - 154 7/26/88 11/3/88 1113 1291 359 359 315 - 3437 11/8/88 3/11/89 1989-90 1156 6 3 9 0 0 1174 7/7/89 11/9/89 1876 602 391 346 1618 0 4833 11/7/89 2/27/90 1990-91 13 768 0 5 1385 0 2171 8/10/90 11/20/90 1994 2146 1289 1917 1430 0 8776 11/8/90 2/19/91 1991-92 7 2 8 0 161 0 178 9/12/91 11/7/91 699 349 451 294 760 0 2553 10/24/91 2/6/92 1992-93 1 6 0 410 0 0 417 8/26/92 10/21/92 131 240 543 186 133 0 1233 11/16/92 2/10/93 1993-94 5 2 0 2280 3 0 2290 9/5/93 11/23/93 259 837 411 472 2412 0 4391 11/3/93 3/30/94 1994-95 6 21 256 41 16 0 340 8/24/94 11/7/94 121 448 78 179 3481 0 4307 9/23/94 3/7/95 1995-96 6 4 0 38 16 0 64 9/7/95 10/24/95 337 959 957 591 1867 14 4725 11/6/95 2/14/96 1996-97 1012 2439 317 1007 6 0 4781 8/19/96 3/12/97 25 263 163 801 11 45 1308 11/14/96 3/18/97 1997-98 43 52 0 0 4 0 99 7/31/97 11/13/97 262 101 259 637 360 417 2036 11/25/97 1/22/98 1998-99 105 998 0 13 6 0 1122 8/6/98 10/27/98 2510 1751 1814 1126 4140 277 11618 11/17/98 2/23/99 1999-00 491 10 4 107 0 0 612 8/17/99 11/5/99 616 502 987 476 1879 940 5400 11/23/99 2/10/00 2000-01 34 10 0 110 15 0 169 8/7/00 10/13/00 5 54 419 208 190 0 876 11/14/00 2/6/01 2001-02 390 30 3 154 5 0 582 7/28/01 10/23/01 0 0 0 165 0 0 165 1/30/02 2/21/02 2002-03 1 0 0 274 0 0 275 7/6/02 10/12/02 0 22 76 3 36 0 137 12/3/02 1/16/03 2003-04 114 156 0 274 0 0 544 7/8/03 10/27/03 1 0 7 13 227 0 248 12/9/03 2/13/04 2004-05 21 1582 0 0 0 0 1603 7/28/04 10/18/04 0 0 0 0 0 0 0 2005-06 48 324 90 0 0 0 462 7/12/05 10/25/05 0 0 0 0 0 0 0 2006-07 737 16 0 1 0 0 754 7/19/06 10/19/06 97 0 0 472 3239 0 3808 1/4/07 2/12/07 1 Regular font indicates data from Refuge narrative or regional annual reports; bold font indicates from Refuge’s biological database. 

H-5 
 

Table 3. Most common species affected by avian cholera and avian botulism (Type C) at 

the Sacramento National Wildlife Refuge Complex. 

Avian Cholera Avian Botulism (Type C) 

#1 #2 #3 #1 #2 #3 

Goose Snow Ross's Whitefronted 

Whitefronted - -

Duck Wigeon Pintail Ruddy Mallard Pintail Shoveler 

Other birds Grebe sp.1 Gull sp.2 Snowy 

egrets 

Whitefaced Ibis White 

pelican 

Pied-billed 

grebe 

Coots Coots - - Coots - -

1

 Mostly pied-billed, with some eared. 

2

 Mostly herring, with some ring-billed. 

WILDLIFE POPULATIONS AND HABITAT USE 

Pacific Flyway Waterfowl Populations 

Historically, the Central Valley of California has been a major wintering area for Pacific Flyway 

waterfowl. Populations have fluctuated over the last century, with some species experiencing 

significant declines, others showing dramatic recoveries, and still others have shifted their 

distribution away from California. During the 1970s, California mid-winter waterfowl surveys, as 

indexed by the Mid-winter Indices, routinely estimated between 4 and 6 million ducks and 500,000 

to 600,000 geese. Pintails comprised the majority of the ducks, outnumbering all other duck 

species combined. 

Following the 1970s, extended droughts in the Canadian prairie breeding areas caused significant 

declines in breeding duck populations and duckling production. Changing agricultural practices in 

important Canadian prairie breeding areas was also likely responsible for decreased numbers of 

pintail following the 1970s droughts (CDFG et al. 2003). These declines were also reflected in 

wintering numbers in California’s Central Valley. Comparatively, as indexed by the Mid-winter 

Indices (Figure 2), in the last 25 years wintering ducks in California (of which most are in the 

Central Valley) have fluctuated between 2 and 4 million ducks, including about 1 to 1.5 million 

pintails (USFWS 1955-2007). 

H-6 
(1000's)

6,000

5,000

4,000

3,000

2,000

1,000

0

65 70 75 80 85 90 95 00 05

Year

Pintails 

All Other Ducks 

 

 

Figure 2. California Mid-winter Indices (USFWS 1965-2007). 

California Mid-winter Indicies for Pintail vs. 

"All Other Ducks" in California, 1965-2007 

7,000

However, when the droughts in the prairies ended in the 1990s, while most other duck species 

showed significant increases, pintail showed only modest increases. There is evidence that 

changes in agricultural practices in the Canadian prairies initiated in the 1970s have negatively 

impacted the early nesting habitats of pintails, and are thought to be the primary reason for their 

lagging recovery (Miller et al. 2003). 

In general, goose populations have undergone some significant changes and shifts in the last 

thirty years. Pacific white-fronted goose and cackling cackling goose (cackler) populations reached 

their lowest levels in the 1980s, due mainly to over harvest on both wintering and arctic breeding 

areas. Following the implementation of more restrictive harvest regulations, both these 

populations have rebounded dramatically. Recent estimates of Pacific white-fronts, on both their 

wintering and breeding grounds, indicate a population of over 500,000. Cackler populations have 

also increased and estimates now total 150,000-200,000 birds, but very few winter in California. 

Historically, about 90 percent wintered in the Central Valley and 10 percent in Oregon’s 

Willamette Valley. Today, this distribution has essentially reversed, largely due to turf agriculture 

in Oregon attracting the bulk of wintering cacklers (Trost et al. 2007). 

Aleutian cackling geese (Aleutian goose) represent another successful recovery story. On the 

brink of extinction with a population of approximately 800 birds in 1975, Aleutian goose numbers 

have rebounded to over 100,000 today (Trost et al. 2007). This has largely been the result of 

removing non-native predators and repopulating geese on their key breeding areas in the Aleutian 

Islands (Pacific Flyway Study Committee 1999, USFWS 1982). Once on the endangered species 

list, they were delisted in 2001. 

“White goose” populations of lesser snow (snow) and Ross’s geese in California have remained 

relatively stable to slowly increasing in recent years (Trost et al. 2007). Although the Pacific 

Flyway’s wintering populations have not (yet) shown the dramatic increases seen in other goose 

H-7 
species, there appears to be potential for future increases based on those occurring in most other 

North American white goose populations (USFWS 2001). 

Populations at the Local Level 

Despite both declines in waterfowl numbers and habitat, millions of waterfowl still concentrate in 

the Central Valley of California during the fall and winter. Duck and goose use during this period 

account for over 95 percent of all annual waterfowl use-days on the Refuges. Ducks breeding in 

areas to the north (mostly from Alaska and Western Canada) start migrating into the Sacramento 

Valley in August (initially pintails and green-winged teal), and by early October, hundreds of 

thousands of both ducks and geese are present. Many birds arrive via the Klamath Basin, one of 

the most important migration staging areas in the Pacific Flyway (Gilmer et al. 2004). 

Presently, peak wintering waterfowl numbers in California occur during late November through 

January, when 3 to 4 million ducks and over a million geese have been present in recent years 

(USFWS 1955-2007). For perspective, together, the four Refuges have an average peak of over 1 

million ducks and 300,000 geese. In some years, the four Refuges can exceed 1.5 million ducks and 

300,000 geese (USFWS 1989-2007). The most common wintering duck species include northern 

pintail, mallard, American wigeon, green-winged teal, gadwall, northern shoveler, and ring-necked 

duck (Table 4). The most common goose species include lesser snow, Ross’s, and Pacific and tule 

greater white-fronted geese. At certain times of the fall and winter, the majority of the Flyway’s 

portion of the population of Pacific greater white-fronted geese will be present on the four 

Refuges (USFWS 1985-2006, Trost et al. 2007). Sacramento, Delevan, and Colusa Refuges 

comprise the core wintering area for tule greater white-fronted geese (Hobbs 1995). 

H-8 
 

Table 4. Regular waterfowl survey summary at Sacramento National Wildlife 

Complex, early December, 2006. 

Refuge Sacramento Delevan Colusa Sutter 

Butte 

Sink 

Llano 

Seco TOTALS 

Coot 36,310 23,080 6,589 6,920 7,400 3,160 83,459 

White-fronted 

goose 29,836 32,410 15,980 29,800 910 0 108,936 

Snow/Ross’s 

goose 147,460 78,600 39,940 68,830 68,000 0 402,830 

Western 

Canada goose 30 160 0 0 0 185 375 

Cackling 

Canada goose 8 0 222 0 0 0 230 

Total Geese 177,334 111,170 56,142 98,630 68,910 185 512,371 

Mallard 42,576 28,928 5,955 11,265 16,500 7,855 113,079 

Pintail 426,060 169,780 32,478 41,540 387,375 80,335 1,137,568 

Gadwall 38,919 30,354 8,574 3,615 16,675 1,985 100,122 

Wigeon 50,595 59,810 24,426 8,725 197,650 45,770 386,976 

Green-winged 

teal 64,700 94,450 14,480 4,784 64,825 980 244,219 

Cinnamon teal 616 255 30 0 0 0 901 

N. shoveler 34,899 37,555 17,446 6,151 17,575 3,195 116,821 

Wood duck 2 0 64 352 0 0 418 

Total 

Dabbling 

Ducks 658,367 421,132 103,453 76,432 700,600 140,120 2,100,104 

Ring-necked 

duck 13,880 6,020 1,874 276 2,000 570 24,620 

Ruddy duck 7,360 4,950 39 280 2,000 70 14,699 

Bufflehead 273 390 184 191 20 155 1,213 

Canvasback 30 0 0 0 0 0 30 

other divers 0 0 0 2 0 0 2 

Total Diving 

Ducks 21,543 11,360 2,097 749 4,020 795 40,564 

Total All 

Ducks 679,910 432,492 105,550 77,181 704,620 140,915 2,140,668 

H-9 
 

Bird Movement Patterns 

During the non-breeding period, there is a great deal of waterfowl movement from one basin to 

another within the Sacramento Valley, and even throughout the Central Valley (Fleskes et al 

2005). The actual patterns vary from species to species and from month to month throughout the 

fall and winter. Hunting and weather influence these movement patterns. 

Prior to the hunting season (August to mid-October), newly flooded and flooding habitat helps to 

hold birds on the Refuges, which helps to prevent depredation on private croplands. As private 

croplands are harvested and the food base on the Refuges (such as watergrass and smartweed) is 

consumed, birds begin to move off the Refuges to pick up leftover “waste” grain in rice fields. 

With the onset of the hunting season (mid-October - mid-January), most birds begin a pattern of 

resting and feeding on-Refuge sanctuaries during the day and feeding off-Refuge at night. Birds 

will start to disperse again following the hunting season. 

Birds tend to disperse from the Refuges during periods of extensive precipitation, particularly if 

widespread flooding occurs. Fog also will alter distribution patterns of waterfowl throughout the 

Central Valley. When fog is present, generally birds will attempt to move into any areas where 

visibility remains, which can result in major local population decreases or increases on Refuges 

within a relatively short time span. 

Weather Patterns 

The region is characterized by mild wet winters and dry hot summers. Rainfall averages about 18 

to 20 inches annually and occurs from November through April. Rain is unusual from June 

through September. A hard freeze is unusual and wetlands rarely ice up. Summer temperatures 

will frequently exceed 100 degrees and can reach up to 110-115 degrees. Droughts and extremely 

wet winters also occur, but it is unusual for these periods to extend beyond one or two consecutive 

years. In winter, valley fog is not unusual, sometimes persisting for several days at a time. 

Habitat Use 

Waterfowl use of the Refuges’ habitat varies by species and includes many other factors such as 

water depth, ratio of open water to emergent vegetation, food availability, access to loafing sites, 

level of human disturbance, and tradition. Over 95 percent of the waterfowl that occur on the 

Refuges are dabbling ducks and geese, which all prefer relatively shallow water. Only 1 to 5 

percent are diving duck species, which prefer deeper water. Species including pintail, wigeon, 

green-winged teal, and shovelers, prefer more open water, whereas mallards and gadwall will use 

wetlands with denser cover (Heitmeyer and Raveling 1988). 

Seasonally flooded wetlands (including watergrass and smartweed units) contain abundant seeds 

and other vegetative food items (leaves, stems, tubers, etc.) produced from moist soil and other 

aquatic plants, and invertebrates (insects, spiders, crustaceans, etc.). They are diverse in the 

amount and distribution of emergent vegetation (bulrushes, cattails), and also contain bare 

islands, levees, and open shorelines that provide excellent waterfowl loafing sites. Not 

surprisingly, the majority of wintering waterfowl select this habitat type above all other managed 

wetlands (Table 1). Waterfowl survey data collected on the Complex indicates that seasonally 

H-10 
flooded wetlands can support up to three times the densities of semi-permanent wetlands and ten 

times that of permanent wetlands (M. Wolder, unpublished data). Seasonal wetlands also support 

the greatest overall abundance and diversity of other migratory birds (shorebirds, wading birds, 

raptors, etc.). In managed wetland units with extensive emergent vegetation, it is typical that a 

series of lanes and openings are made prior to their scheduled fall flood-up. These openings are 

made by either disking or mowing, depending on the vegetation species, time of year, and 

available equipment. In addition to providing added habitat diversity and attractiveness for 

waterfowl in general, they allow for better visually monitoring and access to help detect sick or 

dead birds. 

Semi-permanent and permanent (year-round) wetlands, while much less acreage, play an 

important role for breeding waterfowl, colonial nesting species (egrets, herons, ibis, tricolored 

blackbirds, etc.), giant garter snakes, western pond turtles, resident wildlife in general, and a 

number of other wetland dependent species during the summer months. They are also very 

important to molting waterfowl, single units sometimes supporting several thousand molting adult 

ducks. The wildlife that occurs on these units in the late spring and summer are very dependent 

on them since most other seasonal wetlands are dry. As a result, when disease outbreaks occur in 

these wetlands (usually botulism), there is little wildlife movement and certain species, sex, and 

age cohorts (such as molting adult female mallards) are vulnerable. 

Managed wetland water supplies are mostly delivered (75 percent) and to a lesser degree diverted 

(25 percent) surface water by way of gravity flow through a network of delivery/drain ditches and 

series of water control structures. GCID delivers good quality CVPIA water from the Sacramento 

River to Sacramento, Delevan and Colusa Refuges under contract with the BOR. Additional 

supplies are diverted on both Sacramento and Colusa Refuges through various Refuge water 

rights. Sutter Refuge, the majority of which is located within the Sutter Bypass, has yet to receive 

any CVPIA water, and relies on diversions from a California Department of Water Resources 

weir in the east bypass channel for wetlands within the Bypass, and Sutter Extension Water 

District deliveries to wetlands outside the Bypass. Because the majority of the Sutter Refuge is 

located in a flood bypass channel, winter runoff and river overflows sometimes flood Sutter more 

than 10 feet deep for days or weeks at a time. According to studies in the 1980s, there is some 

degradation of water quality related to agricultural drainage in the region for diverted water 

supplies on all except Delevan Refuge (which has only delivered water). Additionally, elevated 

concentrations of some chemical constituents were detected in water, sediment and biological 

samples. These elevated concentrations were only slightly greater than Service guidelines for 

possible effects on wildlife (Dileanis et al. 1992). 

Vernal pools are naturally flooded wetlands that are also heavily used once they fill during the 

winter and spring, especially by mallards, wigeon, green-winged teal, shovelers, and a variety of 

shorebirds (Bogiatto and Karnegis 2006, Silveira 1998). In addition, geese and wigeon will readily 

forage in adjacent alkali meadows and short grass uplands as soon as green browse is available in 

the fall (Silveira 1998, USFWS 1989-2007). Typically, disease outbreaks have not been an issue in 

these areas. 

H-11 
DISEASE PREVENTION, SURVEILLANCE, & MANAGEMENT 

Knowing the history and patterns of disease outbreaks on the Complex helps focus efforts to 

minimize their risk and/or detect them at an early stage to minimize wildlife losses. Data from 

regular wildlife surveys (Chapter 3 of the CCP, USFWS 2008) indicate current populations and 

use by waterfowl and other species at the Refuge and management unit level. In addition, disease 

surveillance and carcass pick-up data is collected at the same level and summarized annually. Data 

from past years can be summarized to indicate outbreak histories for specific management units 

(i.e. outbreak detection and cessation dates, total losses, and effort spent monitoring/managing 

outbreaks), and thus, can be used to help predict future outbreaks and direct surveillance 

operations. 

The following proactive prevention and management options are recommended to minimize 

outbreak risk or waterfowl mortality once an outbreak occurs: 

Water Circulation 

Increase water circulation in managed wetlands, especially those with disease outbreak histories. 

Water circulation may be increased during late spring through early fall to prevent stagnation and 

moderate high water temperatures that may be conducive to botulism outbreaks. The Refuges 

shall budget for this water in annual and monthly water delivery scheduling and requests. 

Maintenance of Lanes in Heavily Vegetated Wetlands 

Create lanes, areas where vegetation has been cleared, in at least 10 percent of heavily vegetated 

managed wetland units. Create lanes throughout the perimeter and interior areas that are evenly 

spaced, evenly distributed, and connected to each other. This is a standard management practice 

identified in Annual Habitat Management Plans. In some cases, construction of channels and 

potholes during habitat enhancement projects will “naturally” maintain these openings at a result 

of differences in water depth, and will not require annual disking or mowing. 

Wetland Drainage 

This option is for use only in extreme cases or when conditions are such that the impact to local 

wildlife populations is minimal and the disease loss potential is relatively great. An example of 

such a condition would be a permanent wetland that is receiving very little wildlife use and has 

had repeated botulism outbreaks in July. The risk of stranding a small number of animals (that 

may eventually succumb to botulism anyway) must be weighed by refuge staff against the impact 

of an ongoing outbreak spreading into newly flooded seasonal wetlands in the fall and potentially 

killing many more migrant birds (i.e. thousands of pintails and green-winged teal typically show 

up in early August). When considering long-term management of specific management units with 

frequent summer botulism outbreaks, maintaining them as semi-permanent wetland regime may 

be more beneficial than a permanent (year round) regime. Again, this option is not common, but 

has some use in specific situations. 

H-12 
Proactive Disease Monitoring in Wetlands 

Wildlife disease monitoring shall be conducted throughout the year. Wetland units and other 

areas shall be inspected both regularly (specific surveys) and opportunistically (while conducting 

other field activities) for dead or sick animals. During months of greater outbreak probability, 

certain wetland types or even specific units with notable disease histories shall be surveyed by 

airboat to facilitate early detection (usually summer/early fall for botulism and by December for 

cholera). For example, summer botulism outbreaks commonly start in semi-permanent and 

permanent wetlands; as a result, monitoring efforts are focused there during the months of July 

and August. Cholera outbreaks typically do not occur prior to November and often follow or are 

associated with extended periods of cold weather. Presence and locations of increased numbers of 

scavengers such as turkey vultures, raptors, and herring gulls may also be used as indications of 

potential disease outbreaks, and are investigated as part of routine surveillance. Earlier detection 

of outbreaks give management response activities, such as carcass removal and habitat 

manipulations (which increase water circulation), a greater chance for success to slow an 

outbreak’s rate of spread and minimize overall losses. Areas of waterfowl and coot population 

concentrations are vulnerable to outbreaks, and are monitored on a more frequent basis. During 

outbreaks, dead birds shall be located and removed using airboats, as necessary, to systematically 

cover all areas within a unit. Standard safety precautions shall be followed when picking up 

carcasses or conducting other disease surveillance (USGS 1999, USFWS 2006). Areas with 

historic outbreaks and those with relatively high bird concentrations (such as major day or night 

roost sites) shall be monitored closely. Species susceptibility shall also be considered. For 

example, white geese (both lesser snow and Ross’s) and coots are more susceptible to avian 

cholera compared to other species. There is evidence that wood ducks are more susceptible to 

HPAI H5N1 relative to other duck species (Brown et al. 2006); therefore, areas with wood ducks 

concentrations shall be monitored regularly. 

Disease monitoring visits are documented by management unit, recording date, disease type, 

number and condition of dead and sick animals observed and/or picked up (or not), and hours of 

effort used. Data is collected on special weatherproof data cards (Figure 3) and entered into the 

Complex’s biological database. Surveillance continues until carcasses are no longer present. 

In the event of an outbreak, the supervisory wildlife biologist and refuge manager are notified 

immediately. He/she initiates carcass removal operations and shipment of diagnostic specimens as 

appropriate. Based on the type and severity of the disease outbreak, appropriate contacts outside 

the Refuge-level are made (Appendix 2). 

Carcass Removal 

Once an outbreak has been detected and the causative agent confirmed, prompt pick-up and 

disposal of carcasses is essential in helping to control the potential spread of infectious disease by 

pathogens or toxins that may be present in or on carcasses. Botulism can spread rapidly through 

the well-documented maggot-cycle, and cholera from bird-to-bird contact; this is especially true in 

areas of high bird concentrations. Depending on severity, outbreak sites (management units) and 

adjacent areas are typically visited at least weekly until mortality ceases. 

For small outbreaks confined to discrete easily viewed areas, carcasses are often removed by 

wading out and retrieving them. For areas of heavy vegetation, an airboat is usually the most 

efficient method to search for and pick up carcasses. 

H-13 
 

Diagnostic Specimens 

When outbreaks are first detected, a sample of diagnostic specimens will be saved and shipped to 

the U.S. Geological Survey National Wildlife Health Center, in Madison, Wisconsin, where the 

carcasses are necropsied and tested to confirm the cause of death (USGS 1999). When 

appropriate, results are shared with other Service divisions (e.g. Regional Office, Law 

Enforcement, National Forensics Laboratory in Ashland, Oregon) and CDFG (e.g. Wildlife 

Investigations Laboratory at Rancho Cordova, game wardens). Confirming the disease at hand 

helps determine how the outbreak will be managed. There are reliable standard signs in the field 

that can indicate probable cause of mortality for several diseases (USGS 1999). 

The most common diseases have been botulism and cholera, which continue to be managed 

annually with standard procedures (mentioned above). However, should an outbreak of HPAI 

H5N1 or like disease occur (to date there has not been an outbreak in North America), human 

health considerations would be much more intensive, and the situation would be handled very 

differently (Appendix 1). It is likely that the Incident Command System (ICS) would be used and 

personnel from a variety of agencies would be involved. 

Carcass removal also offers opportunities to save (freeze) specimens for appropriate scientific or 

educational activities. Sometimes specimens of relatively rare species can be salvaged. Outbreaks 

during winter period can provide very high quality specimens in full breeding plumage. Local 

universities, the National Forensics Laboratory, or other sources may have beneficial uses for 

these otherwise destroyed carcasses. The remainder of the carcasses that are not used for 

diagnostic or educational specimens are incinerated. 

H-14 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 3. Disease surveillance data card (front side). 

 DISEASE PICK-UP DATA 

Refuge_______________ Unit____________ Cell___________ Date______________ 

Crew_______________________________ Start Time__________ Stop___________ 

Method of pick-up (check one): Boat___ ATV___ Incidental___ Other_________ 

CONDITION: 

Diseases % Old % Maggot % Fresh % Flopper 

Diseases 

>> 

Pintail 

Shoveler 

Mallard 

Wigeon 

G-W Teal 

Gadwall 

Ruddy 

Ring-necked 

Unident. 

Coot 

Whitefront 

Snow 

Ross’s 

Cackler 

Others: 

H-15 
_____________________________________________________________________________________ 

_____________________________________________________________________________________ 

_____________________________________________________________________________________ 

_____________________________________________________________________________________ 

_____________________________________________________________________________________ 

_____________________________________________________________________________________ 

Figure 3 (cont.). Disease surveillance data card (backside). 

COMMENTS: (Include unusual events or conditions that influenced pick-up, i.e. weather, thick 

vegetation, or breakdowns. Also should include any unusual characteristics of the outbreak. Please 

note current bird use of the unit by healthy and sick birds.) Include band #’s, band colors, band 

tyes (i.e. leg, neck, tarsal), species, and sexes of any banded birds. 

INSTRUCTIONS: 

1. Be sure and fill out all of the site/time information, even if no birds are picked up. Use the 

below abbreviations for refuge and disease. Fill out one card for each separately managed 

unit/cell. 

2. Use a tally system to record birds picked up. 

3. After completing pick-up, fill in stop time, disease(s), and condition for each disease 

separately. Write and circle the total for each species for each disease beside the tally within the 

appropriate box. 

4. For disease(s) indicate your best judgment on which diseases are most likely to be affecting the 

birds. If you are not reasonably sure, leave this entry blank and consult with a biologist before 

destroying the carcasses. 

5. Count lead-poisoned birds and crippled/hunter-killed birds as separate diseases. Lead poisoned 

birds will often be very thin, have swollen heads, and no injuries. Crippled/hunter-killed birds 

should be identified by obvious trauma (i.e. broken wings, blood-shot areas under wings, breast, or 

other areas). Do not assume dead birds have died from disease. 

6. For condition, estimate the percentage (to the nearest 5%) of birds picked up in each category. 

If possible, tally birds in the condition boxes as well as species boxes for a better estimate. Use the 

following criteria for determining condition: OLD- decomposed past maggot infestation 

(summer/fall) or water-logged/algae-covered (winter/spring); MAGGOT- maggot infested; 

FRESH- no obvious maggots, includes scavenged fresh birds; FLOPPER - live but sick or 

wounded birds. 

7. Save several fresh carcasses of each species picked up for lab analysis. Notify a biologist to bag, 

tag, and freeze each bird individually. The tag information should include date, location (refuge, 

unit, cell), species, suspected cause of death, and whether the bird was euthanized. 

ABBREVIATIONS: 

Sacramento-SAC, Delevan-DEL, Colusa-CLS, Sutter-SUT, Butte Sink-BTS, Llano Seco-LS; 

Botulism-BO, Cholera-CH, Lead Poisoning-PB, Cripple/Hunter-killed-CR, Others-write out. 

H-16 
Logistics 

Supplies and lodgings are located in several towns within a short distance of the Refuges (Figure 

1). Willows is most convenient for Sacramento and Delevan Refuges and Colusa is most 

convenient for the Colusa and Butte Sink Refuges. Yuba City may be most convenient for Sutter 

Refuge. Sacramento River Refuge units are distributed along 77 miles of the Sacramento River 

from Red Bluff to Colusa. Depending on the unit, the following cities may be the closest: Chico, 

Corning, and Hamilton City. 

Working Areas 

The principal command post for a disease outbreak on the Sacramento Complex is at Sacramento 

Refuge Headquarters located seven miles south of Willows. Most necessary facilities are at the 

Refuge Headquarters as well as the Sacramento disease laboratory. (The disease lab is currently 

in a standby status so the Refuge Headquarters would serve as command post pending activation 

of the disease lab). A large shop and garage area with running water and a telephone line is 

available at the Delevan, Colusa, Sutter, and Sacramento River Refuges. No facilities are present 

at Butte Sink WMA. A water tender is located at Sacramento Refuge that could be used as a 

portable supply of water. 

Current procedures for botulism and avian cholera are decontamination on site to the extent 

possible and transport of carcasses (in plastic bags) to the incinerators at Sacramento or Colusa 

Refuge for disposal. For an outbreak of a more virulent disease, decontamination on site will be 

enhanced as much as feasible. To the extent possible, exposed equipment, such as clothing will be 

put in plastic bags and transported to Sacramento Refuge (washing machine is available in the 

disease lab). Carcasses will be disposed of in one of the incinerators or in on-site pits, if necessary. 

Personnel 

A number of refuge staff maintain qualifications (e.g. boat operation certification, respirator fit 

testing, etc) and personal protective equipment (PPE)(e.g. floatation vest, ear and eye protection, 

disposable nitrile gloves, waders, etc.) in order to safely participate in avian disease surveillance 

and outbreak cleanup/control efforts. Currently, there are about 10 staff members that are 

qualified to operate airboats and another 10 that have been certified for using respirators. 

In addition to refuge staff, the CDFG has personnel stationed at Gray Lodge, Upper Butte Basin 

and Oroville Wildlife Areas, and in other communities in this region. CDFG will lend support to 

the Service when needed and the Service will reciprocate. CDFG is the primary agency 

responsible for addressing disease events on private lands. However, depending on the situation, 

Refuge staff may assist with addressing mortality events on private lands near the Complex. 

At times, volunteers are used to help with disease monitoring efforts. They are required to use the 

same PPE as Service employees. 

Appendix 2 contains a list of the principle and regional contacts for State and Federal agency 

personnel. 

H-17 
Communications 

A media contact list is attached in Appendix 3. 

The refuge staff can communicate via a network of cell phones, and are also connected by a radio 

network with a base station on the Sutter Buttes. In addition, most refuge vehicles are equipped 

with mobile units, and there are a number of hand-held radios available, all of which are on the 

same frequency for transmitting (171.6750) and receiving (172.6750) 

Equipment 

The Refuges have equipment to address significant disease outbreaks. Table 5 indicates the 

number of vehicles and heavy equipment, as well as disease-specific equipment that are located at 

individual Refuge shop/office areas. 

Table 5. Vehicles and other large equipment available for use in disease operations 

at the Sacramento National Wildlife Refuge Complex. 

Refuge 

Equipment Sacramento Delevan Colusa Sutter Llano Seco 

Unit 

4-wheel drive 

pick-ups 12 1 2 2 1 

2-wheel drive 

pick-ups 1 0 0 0 1 

Airboats 2 0 1 1 0 

All-terrain 

vehicles 8 1 1 1 1 

Heavy 

Equipment1 present present present present present 

Propane 

Incinerators 1 0 1 0 0 

Pressure 

washers 1 1 1 1 1 

Freezers for 

diagnostic 

specimens 

2 0 1 0 0 

1

 Heavy equipment includes bulldozers, backhoes/excavators and tractors. 

Disease problems on other Refuges, both within the Complex and throughout California, may 

require moving airboats to other locations. In all, about 20 State and Federal airboats are 

available at various locations (many at Refuges and Wildlife Areas) in California. Other all-terrain 

vehicles as well as airboats, incinerators, and bird disposal equipment are located on other Federal 

and State areas in California. 

There are no aircraft on the Complex, but a Service Flyway Biologist and airplane are stationed at 

nearby Placerville and could be available for additional surveillance needs. In addition, CDFG also 

H-18 
has pilots and aircraft available in case of emergency or large outbreaks requiring additional 

surveillance. Should it become necessary, there are also Office of Aircraft Safety approved pilots 

and airplanes available to be contracted in the local area. 

There is a cache of equipment and PPE located in the disease lab at Sacramento Refuge (Table 6). 

This cache was established as part of statewide AI preparedness on Federal Refuges in 2006. It is 

stocked with basic disease operations supplies (e.g. nitrile gloves, goggles, hand sanitizer, large 

plastic bags, hearing protection, etc.), but also contains special equipment to be used in the event 

of an outbreak of HPAI H5N1 (e.g. disposable respirators, tyvech coveralls, portable tank 

sprayers and bleach for decontamination operations). Smaller quantities are available at the 

individual shops/offices at Delevan, Colusa, and Sutter Refuges, and the Llano Seco Unit for 

immediate and short-term use. 

Table 6. Personal protective and other equipment for disease control operations 

located in cache at Sacramento National Wildlife Refuge, January 2008. 

Equipment Quantity 

Nitrile gloves (5 ml) 55 boxes (3,400 pair) 

Goggles 10 

N-99 disposable respirators 85 boxes (850 total) 

Tyvech coveralls 8 boxes (200 total) 

Disposable ear plugs 1 box (100 pair) 

Hand Sanitizer 5 boxes (60 12-oz. containers) 

Large plastic bags 12 boxes (1500 bags) 

2-gal. portable tank sprayers 5 

Bleach 5 boxes (30 1-gallon jugs) 

Supply Sources 

Limited supplies are available at Messick Ace Hardware in Colusa and Willows Hardware in 

Willows. Other large retail stores (Lowe’s, Orchard Supply Hardware, etc.) exist in nearby larger 

cities including Yuba City and Chico. 

Lodging 

The Complex has the ability to house some temporary personnel in the bunkhouse located on 

Sacramento Refuge. Housing is available at motels in Willows, Colusa, and Williams. The 

following motels are available in these communities (Table 7). 

H-19 
 

Table 7. Local lodging. 

Town Hotel Name Phone Number 

Willows Baymont Inn & Suites 530-934-9700 

Best Western Golden Pheasant Inn 530-934-4603 

Days Inn 530-934-4444 

Economy Inn 530-934-4224 

Motel 6 530-934-7026 

Super 8 530-934-2871 

Colusa Colusa Motel 530-458-4906 

Riverside Motel/Hotel 530-458-5880 

Williams Granzella’s Inn 530-473-3310 

Comfort Inn 530-473-2381 

Holiday Inn Express 530-473-5120 

Motel 6 530-473-5337 

Food 

There is a kitchen in the bunkhouse on Sacramento Refuge. There are a number of restaurants in 

Willows and Colusa and other nearby towns. Restaurants in Willows that are open 24 hours 

include Nancy’s Airport Café, Dennys, and the Arco Mini-Mart. 

SUPPLEMENTAL INFORMATION 

In addition to the disease laboratory at Sacramento Refuge, CDFG maintains a Wildlife 

Investigations Lab in Rancho Cordova, just outside the city of Sacramento, (916) 355-0124. 

The Refuges hold a Federal collecting permit that enables refuge employees to take and possess 

migratory birds. When collection involves federally-listed species protected by the Endangered 

Species Act (ESA), refuge employees are required by the ESA to hold a valid permit for the 

particular species involved before salvaging or capturing sick or diseased animals. Contact the 

Sacramento Fish and Wildlife Office (916-414-6600) regarding requirements and permit 

applications. Except for a small capacity live animal room in the disease lab, there are no facilities 

for holding live animals. 

H-20 
 

 

 

LITERATURE CITED 

Bogiatto, R. J. and J.D. Karnegis. 2006. The use of eastern Sacramento Valley vernal pools by 

ducks. California Fish and Game 92(3):125–141. 

Brown, J. D., D. E. Stallknecht, J. R. Beck, D. L. Suarez, and D. E. Swayne. 2006. Susceptibility of 

North American Ducks and Gulls to H5N1 Highly Pathogenic Avian Influenza Viruses. 

Emerging Infectious Diseases, www.cdc.gov/eid, 12 (11):1663-1670. 

California Department of Fish and Game, California Waterfowl Association, Ducks Unlimited, 

Inc., U. S. Fish and Wildlife Service, U. S. Geological Survey, and Canadian Wildlife 

Service. 2003. The northern pintail in North America: The problem and prescription for 

recovery. Part 1 - Proceedings of the Northern Pintail Workshop, 23-25 March, 2001, 

Sacramento, CA. 2003. 

California Department of Fish and Game, U. S. Department of Agriculture-APHIS/Wildlife 

Services, U. S. Fish and Wildlife Service, U. S. Geological Survey, Point Reyes Bird 

Observatory, and California Waterfowl Association, in conjunction with Pacific Flyway 

Council, Pacific Flyway Study Committee, and Pacific Flyway Non-game Technical 

Committee. 2006. Draft 7/5/06, Surveillance for early detection of highly pathogenic avian 

influenza (HPAI H5N1) in wild birds. 2006-07 California Sampling Plan, CDFG Report. 15 

pp. 

Dileanis, P. D., S. K. Sorenson, S. E. Schwarzbach, and T. C. Maurer. 1992. Reconnaissance 

investigation of water quality, bottom sediment, and biota associated with irrigation 

drainage in the Sacramento National Wildlife Refuge Complex, California, 1988-89. U. S. 

Geological Survey Water-Resources Investigation Report 92-4036, 79pp. 

Eddings, R. and J. Eadie. 2003. Avian Disease in the Central Valley of California: A Survey of 

Trends from 1980-2001. Rep. to Central Valley Joint Venture, 32 pp. 

Fleskes, J. P., L. L. Yee, M. L. Casazza, M. R. Miller, J. Y Takekawa, and D. L. Orthmeyer. 2005. 

Waterfowl distribution, movements, and habitat use relative to recent habitat changes in 

the Central Valley of California: A cooperative project to investigate impacts of the 

Central Valley Joint Venture and changing agricultural practices on the ecology of 

wintering waterfowl. Final Report. U. S. Geological Survey-Western Ecological Research 

Center, Dixon Field Station, Dixon, California. 

Gilmer, D. S., J. L. Yee, D. M. Mauser, and J. L. Hainline. 2004. Waterfowl Migration on Klamath 

Basin National Wildlife Refuges 1953-2001: U. S. Geological Survey, Biological Resources 

Discipline, Biological Science Report USGS/BRD/BSR-2003-0004. 66 pp 

Heitmeyer, M. E., and D. G. Raveling. 1988. Winter resource use by three species of dabbling 

ducks in California. Final report to Delta Waterfowl and Wetlands Research Center, 

Portage La Prairie, Manitoba, Canada. 

H-21 
Hobbs, J. H. 1995. Fall and winter distribution and habitat use of the tule greater white-fronted 

goose (Anser albifrons gambelli) in the Sacramento Valley, California. M. S. Thesis, Cal. 

State Univ., Sacramento. 84 pp. 

Interagency Asian H5N1 Early Detection Working Group. 2006. An early detection system for 

Asian H5N1 highly pathogenic avian influenza in wild migratory birds: U. S. Interagency 

Strategic Plan. Unpubl. Rept. Report to the Dept. of Homeland Security, Policy 

Coordinating Committee for Pandemic Influenza Preparedness. 

Mensik, J. G. and M. D. Samuel. 1995. Studying snow geese and avian cholera. California 

Waterfowl (October/November): 16. 

Miller, M. R., D. C. Duncan, K. Guyn, P. Flint, and J. Austin. 2003. Proceedings of the Northern 

Pintail Workshop, 23-25 March, 2001, Sacramento, CA. Part 1 in The northern pintail in 

North America: The problem and prescription for recovery. 38 pp. 

Pacific Flyway Study Committee. 1999. Pacific Flyway Management Plan for the Aleutian Canada 

goose. Prepared by the Subcommittee on the Aleutian Canada goose for U. S. Fish and 

Wildl. Service and the Pacific Flyway Council. 27 pp. 

Pacific Flyway Council. 2006. Surveillance for early detection of highly pathogenic avian influenza 

H5N1 in wild migratory birds: a strategy for the Pacific Flyway. Pacific Flyway Study 

Committee. [c/o USFWS], Portland, OR. Unpubl. rept. 13pp + appendices. 

Rocke , T. E. and M. D. Samuel. 1999. Water and sediment characteristics associated with avian 

botulism outbreaks in wetlands. J. Wildl. Manage. 63(4):1249-1260. 

Samuel, M. D, D. J. Shadduck, D. R. Goldberg, V. Baranyuk, L. Sileo, and J. I. Price. 1999. 

Antibodies against pasteurella multocida in snow geese in the western arctic. Journal of 

Wildlife Diseases 35: 440–449. 

Samuel, M. D., D. J. Shadduck, and D. R. Goldberg. 2004. Are wetlands the reservoir for avian 

cholera? Journal of Wildlife Diseases 40: 377–382. 

Sandler, R. J., T. E. Rocke, M. D. Samuel, and T. M. Yuill. 1993. Seasonal prevalence of 

Clostridium botulinum Type C in sediments of a northern California wetland. J. Wildl. 

Diseases 29(4):533-539. 

Silveira, J. G. 1998. Avian uses of vernal pools and implications for conservation practice. Pages 

92-106 in: C. W. Witham, E. T. Bauder, D. Belk, W. R. Ferren Jr., and R. Ornduff (Eds.). 

Ecology, Conservation, and Management of Vernal Pool Ecosystems – Proceedings from a 

1996 conference. California Native Plant Society, Sacramento, CA. 

Trost, R. E., J. S. Gleason, and T. A. Sanders. 2007. Draft 2007 Pacific Flyway Data Book – 

Waterfowl Harvests and Status, Hunter Participation and Success in the Pacific Flyway 

and United States, July 19, 2007. USFWS Rep. Div. of Mig. Bird Manage., Portland, OR. 

97 pp. 

H-22 
U. S. Fish and Wildlife Service. 1955-2007. California Mid-winter Waterfowl Survey reports, 1955­

2007. Sacramento National Wildlife Refuge files, Willows, CA. 

U. S. Fish and Wildlife Service. 1982. Aleutian Canada goose recovery plan. Prepared by the 

Aleutian Canada Goose Recovery Team, 27 pp plus appendices. 

U. S. Fish and Wildlife Service. 1985-2006. Special Fall goose survey summaries for California, 

1985-2006. Sacramento National Wildlife Refuge files, Willows, CA. 

U. S. Fish and Wildlife Service. 1989-2007. Regular wildlife surveys, 1989-2007. Sacramento 

National Wildlife Refuge files, Willows, CA. 

U. S. Fish and Wildlife Service. 2001. Draft Environmental Impact Statement: Light goose 

management. U. S. Fish and Wildlife Service, Division of Migratory Bird Manage., 

Arlington, VA. 125 pp. plus appendices. 

U. S. Fish and Wildlife Service. 2006. Employee safety and health for highly pathogenic avian 

influenza surveillance and response activities. August 11, 2006 memo from acting USFWS 

Director. 8 pp. 

U. S. Fish and Wildlife Service. 2008. Sacramento, Delevan, Colusa, and Sutter National Wildlife 

Refuges Draft Comprehensive Conservation Plan. Region 8. Sacramento, CA. 

U. S. Geological Survey. 1999. Field Manual of Wildlife Diseases – General Field Procedures and 

Diseases of Birds. M. Friend and J. C. Franson, Tech. Eds. Biological. Resources Division 

- Info. and Technology Rep. 1999-001. 

H-23 
Appendix 1. Highly Pathogenic Avian Influenza Response Plan 

U.S. Fish & Wildlife Service, Region 8 

Highly Pathogenic Avian Influenza Reponse Plan 

Flow Chart 

H-24 
Refuge HPAI Contact List (March 2008) 

Contact Name Phone Cell Phone E-mail 

R8 HPAI Coordinator Richard Hadley 916-414-6483 916-769-3918 Richard_hadley@fws.gov 

Alternate Dan Walsworth 916-414-6472 916-717-0365 Dan_walsworth@fws.gov 

R8 HPAI Media Coordinator Jane Hendron 760-431-9440 x205 760-271-6487 Jane_hendron@fws.gov Alternate Alex Pitts 916-414-6619 916-804-4967 Alexandra_pitts@fws.gov 

Other Local FWS Offices Sac F&W Office Red Bluff F&W Office Coleman NFH Stone Lakes NWR 

Susan Moore Jim Smith Scott Hamelberg Tom Harvey 

319-414-6700 530-527-3043 530-365-8622 916-775-4426 

Susan_moore@fws.gov 

Jim_smith@fws.gov Scott_hamelberg@fws.gov Tom_harvey@fws.gov 

Local State Fish & Game Offices (CNO will contact State Office): Willows Gray Lodge WA Upper Butte Basin WA Oroville WA Local Warden Lieutenants 

Paul Hofmann Mike Womack Pete Blake Andy Atkinson Sam Castillo Kent Harrison 

530-934-9309 530-846-7500 530-982-2169 530-538-2236 530-895-4240 530-899-1806 

530-624-8656 530-624-8279 530-624-8277 

phofmann@dfg.ca.gov 

mwomack@dfg.ca.gov dblake@dfg.ca.gov aatkinson@dfg.ca.gov 

Local APHIS Offices North District Sacramento District 

Jim Shuler Jack Pariott 

530-336-5623 916-434-0663 

USGS Wildlife Life Health Lab Krysten Schuler 608-270-2447 kschuler@usgs.gov 

State Diagnostic Lab Pam Swift 916-358-1462 916-590-8916 (pager) pswift@dfg.ca.gov 

Local Refuge User Groups CA Waterfowl Association Altacal Audubon Chapter 

Bill Gaines Phil Johnson 

916-648-1406 503-893-3222 

916-275-1018 bill_gaines@calwaterfowl.org 

pjohnsonhardwood@sunset.net 

USGS- Dixon Field Station Joe Fleskes 707-678-0682 x628 Joe_fleskes@usgs.gov County Public Health Officers Butte County Colusa County Glenn County Sutter County Tehama County 

Mark Lundberg Phil Reinheimer Grinnell Norten Mike Kinnison Sydnei Wilby 

530-538-7581 530-458-0250 530-934-6588 530-822-7215 530-527-6824 

mlundberg@buttecounty.net 

rreinheimer@colusadhhs.org gnorton@glenncountyhealth.net mkinnison@cc.sutter.ca.us wilbys@tcha.net 

H-25 
Appendix 2. Principal Local and Regional Contacts (March 2008) 

US Fish and Wildlife Service 

USFWS Region 8 

Marge Kolar, Assistant Regional Director, Refuges 

2800 Cottage Way, Suite W-2606 

Sacramento, CA 95825 

916-414-6476 

USFWS Region 8 

Dan Walsworth, Refuge Supervisor 

2800 Cottage Way, Suite W-2606 

Sacramento, CA 95825 

916-414-6472 

USFWS Region 8 

Nancy Hoffman, Assistant Refuge Supervisor 

2800 Cottage Way, Suite W-2606 

Sacramento, CA 95825 

916-414-6473 

USFWS Region 8 

Richard Hadley, HPAI Media Coordinator 

2800 Cottage Way, Suite W-2606 

Sacramento, CA 95825 

916-414-6483 

USFWS Region 8 

Alex Pitts, External Affairs 

2800 Cottage Way, Suite W-2606 

Sacramento, CA 95825 

916-414-6619 

State of California 

California Department of Fish and Game 

Waterfowl Program 

Dan Yparraguirre 

1812 9th Street 

Sacramento, CA 

(916) 445-3685 

California Department of Fish and Game 

Wildlife Investigations Lab 

Dr. Pam Swift 

Rancho Cordova, CA 

(916) 358-1462 

H-26 
California Department of Fish and Game 

Gray Lodge Wildlife Area 

Mike Womack or Andy Atkinson 

530-846-7500 

California Department of Fish and Game 

Glenn and Colusa County Unit Manager 

Paul Hofmann 

530-934-9309 

California Department of Food and Agriculture 

1220 N Street 

Sacramento, CA 95814-5607 

(916) 654-0462 (office) 

(916) 654-0466 (recorded info) 

866-922-2473 (Bird Illness Hotline) 

California Department of Public Health 

744 P Street 

Sacramento, CA 95814 

(916) 558-1784 

877-968-2473 (West Nile Virus Hotline) 

Federal Agencies 

Federal Information Center 

800-333-4636 

U.S.D.A. Animal and Plant Health Inspection Service 

10365 Old Placerville Road, Suite 210 

Sacramento, CA 95827-2518 

(916) 854-3950 

U.S. Environmental Protection Agency, Region 9 

75 Hawthorne Street 

San Francisco, CA 94105 

(415) 556-6695 

U.S. Department of Health and Human Services, Region 9 

90 Seventh Street 

Federal Building, Suite 5-100 

San Francisco, CA 94103 

(415) 437-8500 

H-27 
Appendix 3. Media Contact List (March 2008) 

Organization Name Address City State 

Zip Code 

Phone Number 

Contact Name/Title Fax Number Email 

USFWS 

2800 Cottage Way, Suite W2606 Sacramento CA 95825 916-414-6464 Alexandra Pitts, External Affairs 916-414-6486 alexandra_pitts@fws.g ov 

USFWS 

2800 Cottage Way, Suite W2606 Sacramento CA 95825 916-414-6566 Al Donner, ES External Affairs 916-414-6712 al_donner@fws.gov 

Newspapers AppealDemocrat PO Box 431 Marysville CA 95901 530-749-4715 Todd Hansen, Sports 503-741-0140 thansen@appeal­ democrat.com AppealDemocrat PO Box 431 Marysville CA 95901 530-749-4722 

Leticia Gutierrez, Community Edit. 503-741-0140 

lgutierrez@appealdemocrat.com 

Chico Enterprise Record PO Box 9 Chico CA 95927 530-891-1234 

Heather Hacking, reporter 530-342-3617 hhacking@chicoer.com 

Chico Enterprise Record PO Box 9 Chico CA 95927 530-891-1234 

Steve Carson, sports 530-342-3617 scarson@sunset.net 

Chico News & Review 3536 2nd Street Chico CA 95928 530-894-2300 Tom Gascoyne 530-894-0143 tomg@newsreview.com 

Colusa Sun Herald 530-458-2121 James Nair 530-458-5711 

sunherald@frontiernet. net 

Corning Observer PO Box 558 Corning CA 96021 530-824-5473 Diane 530-824-4804 

corningobserver@dmtech.net 

Davis Enterprise 315 G Street Davis CA 95616 530-756-0800 

Debbie Davis (Ed.) 

530-756-6707 (newsrm) 

newsroom@davisenter 

prise.net 

H-28 
Organization 

Name Address City State 

Zip 

Code 

Phone 

Number 

Contact 

Name/Title Fax Number Email 

Fishing & Hunting News 206-624-3845 

Joel Shangle, California Editor 206-695-8512 

awalgamott@fishingan dhuntingnews.com 

Oakland Tribune 510-208-6450 

Steve Herendeen (sports) 

510-208-6477 (newsrm) 

sherendeen@angnewsp apers.com 

Oakland Tribune 510-208-6450 

Mario Dianda (Editor) 

510-208-6477 (newsrm) 

mdianda@angnewspap ers.com 

Red Bluff Daily News PO Box 220 Red Bluff CA 96080 530-527-2151 Newsroom 530-527-3719 

Newsdesk@redbluffdai lynews.com 

Redding Record Searchlight 

1101 Twin View Blvd. Redding CA 96003 530-225-8230 

Tom Gabrukiewicz 530-225-8212 

tgabrukiewicz@redding 

.com 

S.F. Chronicle 

901 Mission Street 

San Francisco CA 94013 415-777-7201 

Paul McHugh, Outdoors 415-543-3754 

pmchugh@sfchronicle.c om 

Sacramento Bee PO Box 15779 Sacramento CA 95852 916-321-1000 

William Enfield (Editor) Chris Bowman (Enviro) 916-326-5503 

benfield@sacbee.com cbowman@sacbee.com 

Tri-County Newspapers PO Box 731 Willows CA 95988 530-934-6800 Susan, Reporter 530-934-6815 editor@tcnpress.com 

Tri-County Newspapers PO Box 731 Willows CA 95988 530-934-6800 Mike Griffin 530-934-6815 Valley Mirror PO Box 290 Artois CA 95913 530-934-9511 Tim Crews 530-934-9208 

valleymirror@pulsarco. 

com 

Western Outdoor News 

1054 Elmwood Avenue Stockton CA 95204 209-468-4809 Pete Ottesen 209-468-9232 pottesen@sjcoe.net 

Magalia CA 530-343-2981 Ed Migale 530-343-2981 emigale@comcast.net 

Western Outdoor News PO Box 1536 Placerville CA 95667 530-642-0870 Bill Karr 530-642-0873 

EDITORS@wonews.co m 

H-29 
Organization 

Name Address City State 

Zip 

Code 

Phone 

Number 

Contact 

Name/Title Fax Number Email 

Western Outdoor News, N. CA 

3197 East Airport Loop Drive Costa Mesa CA 92626 

714-546-4370 ext 33 Pat McDonald 714-662-3486 

EDITORS@wonews.co 

m 

Woodland Daily Democrat 711 Main Street Woodland CA 95695 530-662-5421 Jim Smith 530-662-1288 

ddnews@dailydemocrat 

.com 

Radio Broadcasters KALF-FM ­95.7 

1459 Humboldt Road, Suite D Chico CA 

95928­9100 530-899-3600 

Scott Michaels, Program Mgr 916-343-0243 scottkalf@yahoo.com 

KBLF-AM ­1490 

Box 1490, Suite 54, 645 Antelope Blvd. Red Bluff CA 96080 530-527-1490 

Donna Hunter, News Director 530-527-3525 

KCHO 

California State University Chico Chico CA 

95929­0500 530-898-5896 

Todd Thorton, News Director 530-898-4348 

joleksiewicz@csuchico. edu 

KEWB-FM - 94.7 

1588 Charles Drive Redding CA 96003 530-244-9700 

Rick Healey. Program Mgr 530-244-9707 

KFBK-FM ­1530 

11352 Gold Country Blvd. Gold River CA 95670 916-852-6310 Bob Simms 916-921-5555 bsimms43@aol.com 

KFMF-FM -93.9 

1459 Humboldt Rd., Ste. D Chico CA 95928 916-899-3600 

Marty Griffin, Program Director 916-343-0243 

KHSL-FM - 103.5 

2654 Cramer Lane Chico CA 

95928­8838 530-345-0021 

Michael Wessels, Program Director 530-893-2121 

KIQS-AM - 1560 

118 West Sycamore, Box 118 Willows CA 95988 

530-934-4654 530-934-1212 

Damian Hunter Newsline 530-934-4656 

KKCY-FM ­103.1 Box 7568 Chico CA 95927 530-342-2200 

Jan Baker, Station Manager 530-342-2260 

H-30 
Organization 

Name Address City State 

Zip Code 

Phone Number 

Contact Name/Title Fax Number Email 

KLRS-FM ­92.7 Box 7568 Chico CA 95927 530-342-2200 

Ron Woodward, Program Mgr 530-342-2260 

KMJE-FM - 101.5 Box 7568 Chico CA 95927 530-342-2200 530-342-2260 KMXI-FM ­95.1 

2654 Cramer Lane Chico CA 

95928­8838 530-345-0021 

Larry Scott, Prgram Mgr 530-893-2121 

KNCQ-FM ­97.3 

1588 Charles Drive Redding CA 96003 530-244-9700 

Bob Thomas, News Director 530-244-9707 

KPAY-AM ­1290 

2654 Cramer Lane Chico CA 

95928­8838 530-345-0021 Veronica Carter 530-893-2121 

vcarter@deercreekbroa 

dcasting.com 

Television Broadcasters KHSL Ch 12 3460 Silver Bell Chico CA 

95973­0388 530-342-0141 Newsroom 530-342-2405 news@khsltv.com 

KNVN Ch 24 180 E. 4th Street Chico CA 95928 530-893-2424 Newsroom 530-342-2405 news@khsltv.com KOVR Ch 13 

2713 KOVR Drive 

West Sacramento CA 95605 916-374-1301 Newsroom 916-374-1304 news@kovr13.com 

KRCA Ch 3 

3 Television Circle Sacramento CA 4 

95814­079 916­ 446-3333 Frank Wolff 916-441-4050 fwolff@hearst.com 

KRCR Ch 7 

Box 992217, 755 Auditorium Dr. Redding CA 96001 530-343-7706 Donna Stiles 530-345-2165 dstiles@krcrtv.com 

KRCR Ch 7 

Box 992217, 755 Auditorium Dr. Redding CA 96001 530-243-7777 Diane Chestnut 530-243-0217 info@krcrtv.com 

UPN-FOX 30 300 Main Street Chico CA 

95928­5438 530-893-1234 Christy Wallace 530-899-5475 spotlight@fox30.com 

H-31 
H-32 
Appendix I. Water Management Plan 

Annual Water Management Plans are prepared for Sacramento, Delevan, and Colusa 

Refuges. The development of these plans is a requirement of the Central Valley Project 

Improvement Act (CVPIA), which requires the Bureau of Reclamation to purchase and 

deliver water to these Refuges. The plan outlines water management goals and objectives 

and inventories existing facilities, water quality monitoring, water inventory, and best 

management practices. 

Copies of the water management plans are available for review at the Sacramento 

National Wildlife Refuge Complex, 752 County Road 99W, Willows, California 95988. 

(530) 934-2801. 

Copies are also available via the internet at the following address 

http://sacramentovalleyrefuges.fws.gov 

I-1 
I-2 
Appendix J. Fire Management Plan 

The Department of the Interior (DOI) fire management policy requires that all refuges 

with vegetation that can sustain fire must have a Fire Management Plan that details fire 

management guidelines for operational procedures and values to be protected/enhanced. 

The Fire Management Plan (FMP) for the Sacramento National Wildlife Refuge Complex 

(Complex) provides guidance on preparedness, prescribed fire, wildland fire, and 

prevention. Values to be considered in the FMP include protection of Refuge resources 

and neighboring private properties, effects of burning on refuge habitats/biota, and 

firefighter safety. Refuge resources include properties, structures, cultural resources, 

trust species including Endangered, Threatened, and species of special concern, and their 

associated habitats. The FMP will be reviewed periodically to ensure that the fire 

program is conducted in accordance and evolves with the U.S. Fish and Wildlife Service 

(USFWS) mission and the Refuge’s goals and objectives. 

The FMP is written to provide guidelines for appropriate suppression and prescribed fire 

programs at Sacramento Refuge Complex. Prescribed fires may be used to reduce hazard 

fuels, restore the natural processes and vitality of ecosystems, improve wildlife habitat, 

remove or reduce non-native species, and/or conduct research. 

This plan will help achieve resource management objectives by enabling the Refuge to 

utilize prescribed fire, as one of several tools, to control non-native vegetation and reduce 

fire hazards in grassland and riparian habitats. It will be used in conjunction with other 

management tools that are currently applied on Refuge properties (i.e., grazing, mowing 

and herbicide applications) to meet resource objectives. 

It is the intent of the USFWS to conduct wildland fire suppression and prescribed fire 

operations within the Sacramento Refuge Complex. 

Copies of the plan are available for review at the Sacramento National Wildlife Refuge 

Complex, 752 County Road 99W, Willows, California 95988. (530) 934-2801. 

Copies are also available via the internet at the following address 

http://sacramentovalleyrefuges.fws.gov 

J-1 
J-2 
Appendix K. Wildlife and Plant List for 

Sacramento, Delevan, Colusa, and Sutter 

National Wildlife Refuges 

 

 

Table 1. Birds that occur on Sacramento, Delevan, Colusa, or Sutter Refuges. 

(* -non-native species; 1 B-breeding, NB-nonbreeding, A-accidental, M-migrant, SRsummer resident, WR-wintering resident, YR-year-round resident; 2 w-wetland, frforested/riparian, g-grassland) 

BREEDING/ 

MIGRATORY HABITAT 

ORDER/COMMON NAME SCIENTIFIC NAME STATUS1 TYPES2 

Gaviiformes (loons) 

 Red-throated loon Gavia stellata NB/A w 

 Common loon Gavia immer NB/A w 

Podicipediformes (grebes) 

Pied-billed grebe Podilymbus podiceps B/YR w 

Horned grebe Podiceps auritus NB/A w 

Red-necked grebe Podiceps grisegena NB/A w 

Eared grebe Podiceps nigricollis B/WR w 

Western grebe Aechmophorus occidentalis B/YR w 

Clark's grebe Aechmophorus clarkii B/YR w 

Pelicaniformes (pelicans and cormorants) 

American white pelican Pelecanus erythrorhynchos NB/YR w 

Double-crested cormorant Phalacrocorax auritus B/YR w 

Ciconiiformes (ibis, herons, and egrets) 

American bittern Botaurus lentiginosus B/YR w 

Least bittern Ixobrychus exilis B/YR w 

Great blue heron Ardea herodias B/YR w 

Great egret Casmerodius albus B/YR w 

Snowy egret Egretta thula B/YR w 

Little blue heron Egretta caerulea B/A w 

Cattle egret Bubulcus ibis B/YR w 

Green heron Butorides striatus B/YR w 

Black-crowned night heron Nycticorax nycticorax B/YR w 

 White-faced ibis Plegadis chihi B/YR w 

Turkey vulture Cathartes aura B/YR g 

Anseriformes (ducks, geese, and swans) 

 Black-bellied whistling-duck Dendrocygna autumnalis NB/A w 

 Fluvous whistling-duck Dendrocygna bicolor NB/A w 

Greater white-fronted goose Anser albifrons NB/WR w,g 

Emperor goose Chen canagica NB/A w 

Snow goose Chen caerulescens NB/WR w 

Ross's goose Chen rossii NB/WR w 

Brant Branta bernicla NB/A w 

Aleutian cackling goose Branta hutchinsii leucopareia NB/WR w,g 

K-1
Cackling cackling goose Branta hutchinsii minima NB/WR w,g 

Lesser Canada goose Branta canadensis parvipes NB/WR w,g 

Taverner's Canada goose Branta canadensis taverneri NB/WR w,g 

Western Canada goose Branta canadensis moffitti B/YR w,g 

 Trumpeter swan Cygnus buccinator NB/A w 

 Tundra swan Cygnus columbianus NB/WR w 

Wood duck Aix sponsa B/YR w 

Gadwall Anas strepera B/YR w 

American wigeon Anas americana NB/WR w,g 

Eurasian wigeon Anas penelope NB/WR w 

American black duck Anas rubripes NB/A w 

Mallard Anas platyrhyncos B/YR w 

Blue-winged teal Anas discors B/YR w 

Cinnamon teal Anas cyanoptera B/YR w 

Northern shoveler Anas clypeata B/WR w 

Northern pintail Anas acuta B/WR w 

Baikal teal* Anas formosa* NB/A w 

Green-winged teal Anas crecca NB/WR w 

Canvasback Aythya valisineria B/WR w 

Redhead Aythya americana B/YR w 

Ring-necked duck Aythya collaris B/WR w 

Greater Scaup Aythya marila NB/A w 

Lesser scaup Aythya affinis NB/WR w 

Harlequinn duck Histrionicus histrionicus NB/A w 

Surf scoter Melanitta persoicillata NB/A w 

White-winged scoter Melanitta fusca NB/A w 

Long-tailed duck Clangula hyernalis NB/A w 

Bufflehead Bucephala albeola NB/WR w 

Common goldeneye Bucephala clangula NB/WR w 

Barrow's goldeneye Bucephala islandica NB/A w 

Hooded merganser Lophodytes cucullatus NB/WR w 

Common merganser Mergus merganser B/WR w 

Red-breasted merganser Mergus serrator NB/A w 

Ruddy duck Oxyura jamaicensis B/YR w 

Mandarin duck* Aix galericulata* NB/A w 

Falconiformes (vultures, hawks, eagles, and falcons) 

Osprey Pandion haliaetus B/YR r 

White-tailed kite Elanus leucurus B/YR g,w 

Bald eagle Haliaeetus leucocephalus NB/WR w,fr 

Northern harrier Circus cyaneus B/YR w,g 

K-2
Sharp-shinned hawk Accipiter striatus NB/WR fr,w 

Cooper's hawk Accipiter cooperii NB/WR fr,w 

Red-shouldered hawk Buteo lineatus B/YR fr 

Swainson's hawk Buteo swainsoni B/SR g,fr 

Red-tailed hawk Buteo jamaicensis B/YR g,fr 

Ferruginous hawk Buteo regalis NB/M g 

Rough-legged hawk Buteo lagopus NB/WR g 

Golden eagle Aquila chrysaetos NB/WR g,fr 

American kestrel Falco sparverius B/YR g,fr 

Merlin Falco columbarius NB/WR w,g 

Prairie falcon Falco mexicanus NB/WR g 

Peregrine falcon Falco peregrinus NB/WR w,fr 

Galliformes (turkey, quail, and pheasants) 

Ring-necked pheasant* Phasianus colchicus* B/YR g,w,fr 

Wild turkey* Meleagris gallopavo* B/YR g,fr 

California quail Callipepla californica B/YR g,fr 

Gruiformes (cranes and rails) 

Yellow rail Coturnicops noveboracensis NB/A w 

Black rail Laterallus jamaicensis NB/A w 

Virginia rail Rallus limicola B/YR w 

Sora Porzana carolina B/YR w 

Common moorhen Gallinula chloropus B/YR w 

American coot Fulica americana B/YR w 

Sandhill crane Grus canadensis NB/WR w,g 

Charadriiformes (shorebirds and gulls) 

Black-bellied plover Pluvialis squatarola NB/M w 

American golden plover Pluvialis dominica NB/A w 

Snowy plover Charadrius alexandrinus NB/A w 

Semipalmated plover Charadrius semipalmatus NB/M w 

Killdeer Charadrius vociferus B/YR w,g 

Black-necked stilt Himantopus mexicanus B/YR w 

American avocet Recurvirostra americana B/YR w 

Greater yellowlegs Tringa melanoleuca NB/YR w 

Lesser yellowlegs Tringa flavipes NB/M w 

Solitary sandpiper Tringa solitaria NB/M w 

Willet Catoptrophorus semipalmatus NB/M w 

Spotted sandpiper Actitis macularia NB/M w 

Whimbrel Numenius phaeopus NB/M w 

Long-billed curlew Numenius americanus NB/M w,g 

Marbled godwit Limosa fedoa NB/M w 

Ruddy turnstone Arenaria interpres NB/A w 

K-3
Red knot Calidris canutus NB/A w 

Sanderling Calidris alba NB/A w 

Semipalmated sandpiper Calidris pusilla NB/A w 

Western sandpiper Calidris mauri NB/M w 

Least sandpiper Calidris minutilla NB/M w 

Baird's sandpiper Calidris bairdii NB/A w 

 Pectoral sandpiper Calidris melanotos NB/M w 

Dunlin Calidris alpina NB/WR w 

Ruff Philomachus pugnax NB/A w 

 Short-billed dowitcher Mimnodromus griseus NB/M w 

Long-billed dowitcher Limnodromus scolopaceus NB/M w 

Jack snipe Lymnocryptes minimus NB/A w 

Wilson's snipe Gallinago gallinago NB/M w 

Wilson's phalarope Phalaropus tricolor NB/M w 

Red-necked phalarope Phalaropus lobatus NB/M w 

Red phalarope Phalaropus fulicarius NB/A w 

Franklin's gull Larus pipixcan NB/A w 

Bonaparte's gull Larus philadelphia NB/M w 

Mew gull Larus canus NB/A w 

Ring-billed gull Larus delawarensis NB/YR w 

California gull Larus californicus NB/WR w 

Herring gull Larus argentatus NB/WR w 

Glaucous-winged gull Larus glaucescens NB/A w 

Sabine's gull Xema sabini NB/A w 

Black-legged kittiwake Rissa tridactyla NB/A w 

Caspian Tern Sterna caspia NB/SR w 

Forster's tern Sterna forsteri NB/M w 

 Black tern Childonias niger B/SR w 

Columbiformes (pigeons and doves) 

Rock pigeon* Columba livia* B/YR g,fr 

Band-tailed pigeon Patagioenas fasciata NB/A fr 

Mourning dove Zenaida macroura B/YR g,fr 

Cuculiformes (cuckoos and roadrunners) 

Western yellow-billed Coccyzus americanus 

cuckoo occidentalis B/SR fr 

Greater roadrunner Geococcyx californicius NB/A g 

Strigiformes (owls) 

Barn owl Tyto alba B/YR fr 

Western screech owl Otus kennicottii B/YR fr 

Great horned owl Bubo virginianus B/YR fr,g 

Snowy owl Bubo scandiacus NB/A g 

K-4
Northern pygmy-owl Glaucidium gnoma NB/A fr 

Burrowing owl Athene cunicularia B/YR g 

Long-eared owl Asio otus NB/A fr 

Short-eared owl Asio flammeus B/WR g 

Northern saw-whet Owl Aegolius acadicus NB/A fr 

Caprimulgiformes (goatsuckers and nighthawks) 

Lesser nighthawk Chordeiles acutipennis NB/A fr,g 

Common nighthawk Chordeiles minor NB/A fr,g 

Common poorwill Phalaenoptilus nuttallii NB/A g 

Apodiformes (swifts and hummingbirds) 

Black swift Cypseloides niger NB/A g 

Vaux's swift Chaetura vauxi NB/A g 

White-throated swift Aeronautes saxatalis NB/A g 

Black-chinned hummingbird Archilochus alexandri B/M r 

Anna's hummingbird Calypte anna B/M r 

Rufous hummingbird Selasphorus rufus NB/M r 

Allen’s hummingbird Selasphorus sasin NB/M r 

Coraciiformes (kingfishers) 

Belted kingfisher Ceryle alcyon B/YR w, fr 

Piciformes (woodpeckers) 

Lewis' woodpecker Melanerpes lewis NB/A fr 

Acorn woodpecker Melanerpes formicivorous NB/A fr 

Red-breasted sapsucker Sphyrapicus ruber NB/A fr 

Nuttall's woodpecker Picoides nuttallii B/YR fr 

Downy woodpecker Picoides pubescens NB/M fr 

Hairy woodpecker Picoides villosus NB/M fr 

Northern flicker Colaptes auratus B/YR fr 

Passeriformes 

Flycatchers 

Olive-sided flycatcher Contopus cooperi NB/A fr 

Western wood pewee Contopus sordidulus B/SR fr 

Willow flycatcher Empidonax traillii B/SR fr 

Hammond's flycatcher Empidonax hammondii NB/A fr 

Gray flycatcher Empidonax wrightii NB/A fr 

Dusky flycatcher Empidonax oberholseri NB/A fr 

Pacific-slope flycatcher Empidonax difficilis NB/M fr 

Black phoebe Sayornis nigricans B/YR fr,w 

Say's phoebe Sayornis saya NB/M g 

Ash-throated flycatcher Myiarchus cinerascens B/SR fr 

Western kingbird Tyrannus verticalis B/SR fr,g 

K-5
Shrikes 

Loggerhead shrike Lanius ludovicianus B/YR g 

Northern shrike Lanius excubitor NB/A g 

Vireos 

Cassin's vireo Vireo cassinii NB/M fr 

Hutton's vireo Vireo huttoni NB/M r 

Warbling vireo Vireo gilvus NB/M r 

Corvids 

Western scrub jay Aphelocoma californica B/YR fr 

Clark's nutcracker Nucifraga columbiana NB/A fr 

Yellow-billed magpie Pica nuttalli B/YR fr 

American crow Corvus brachyrhynchos B/YR fr 

Common raven Corvus corax B/YR g,fr 

Larks, Swallows and Chickadee 

Horned lark Eremophila alpestris NB/WR g 

Purple martin Progne subis NB/M w,fr 

Tree swallow Tachycineta bicolor B/SR fr, w 

Violet-green swallow Tachycineta thalassina NB/M fr, w 

Northern rough-winged 

swallow Stelgidopteryx serripennis NB/M w,g 

Cliff swallow Hirundo pyrrhonota B/SR w 

Barn swallow Hirundo rustica B/SR fr, w 

 Mountain chickadee Poecile gambeli NB/A fr 

Wrentit, Titmice and Bushtit 

Wrentit Chamaea fasciata NB/M fr 

Oak titmouse Baeolophus inornatus B/YR fr 

Bushtit Psaltriparus minimus B/YR fr 

Nuthatches and Creeper 

Red-breasted nuthatch Sitta canadensis NB/M fr 

White-breasted nuthatch Sitta carolinensis NB/YR fr 

Brown creeper Certhia americana NB/M fr 

Wrens 

Rock wren Salpinctes obsoletus NB/A g 

Bewick's wren Thryomanes bewickii B/SR fr 

House wren Troglodytes aedon B/SR fr 

Winter wren Troglodytes troglodytes NB/A fr 

Marsh wren Cistothorus palustris B/YR w 

Golden-crowned kinglet Regulus satrapa NB/M fr 

Ruby-crowned kinglet Regulus calendula NB/WR fr 

Blue-gray gnatcatcher Polioptila caerulea NB/M fr 

Western bluebird Sialia mexicana NB/M fr, g 

K-6
Mountain bluebird Sialia currucoides NB/A g 

Swainson's thrush Catharus ustulatus NB/M fr 

Hermit thrush Catharus guttatus NB/M fr 

American robin Turdus migratorius NB/WR fr 

Varied thrush Ixoreus naevius NB/M fr 

Northern mockingbird Mimus polyglottos B/YR fr 

Sage thrasher Oreoscoptes montanus NB/A g 

European starling* Sturnus vulgaris* B/YR fr 

American pipit Anthus rubescens NB/WR g,w 

Cedar waxwing Bombycilla cedrorum NB/WR fr 

Bohemian waxwing Bombycilla garrulus NB/A fr 

Phainopepla Phainopepla nitens NB/A fr 

Orange-crowned warbler Vermicora celata NB/M fr 

Nashville warbler Vermivora ruficapilla NB/M fr 

Northern parula Parula americana NB/A fr 

Yellow warbler Dendroica petechia NB/M fr 

Chestnut-sided warbler Dendroica pensylvanica NB/A fr 

Magnolia warbler Dendroica magnolia NB/A fr 

Yellow-rumped warbler Dendroica coronata NB/WR fr 

Black-throated gray warbler Dendroica nigrescens NB/M fr 

Townsend’s warbler Dendroica townsendi NB/M fr 

Hermit warbler Dendroica occidentalis NB/M fr 

Palm warbler Dendroica palmarum NB/A fr 

Prothonotary warbler Protonotaria citrea NB/A fr,w 

Ovenbird Seiurus aurocapilla NB/A fr,w 

Northern waterthrush Seiurus noveboracensis NB/A fr,w 

MacGillivray's warbler Oporornis tolmiei NB/M fr 

Common yellowthroat Geothlypis trichas B/YR fr,w 

Wilson's warbler Wilsonia pusilla NB/M fr 

Yellow-breasted chat Icteria virens B/SR fr 

Summer tanager Piranga rubra NB/A fr 

Western tanager Piranga ludoviciana NB/M fr 

Spotted towhee Pipilo maculatus B/YR fr 

California towhee Pipilo crissalis B/YR fr 

American tree sparrow Spizella arborea NB/A fr 

Chipping sparrow Spizella passerina NB/M r 

Brewer's sparrow Spizella breweri NB/A g 

Vesper sparrow Pooecetes gramineus NB/A g 

Lark sparrow Chondestes grammacus B/SR fr,g 

Sage sparrow Amphispiza belli NB/A g 

Savannah sparrow Passerculus sandwichensis NB/YR g 

K-7
 

Grasshopper sparrow Ammodramus savannarum NB/A g 

Fox sparrow Passerella iliaca NB/M fr 

Song sparrow Melospiza melodia NB/M fr, w 

Lincoln's sparrow Melospiza lincolnii NB/WR fr 

Swamp sparrow Melospiza georgiana NB/A w 

White-throated sparrow Zonotrichia albicollis NB/A fr,g 

Harris's sparrow Zonotrichia querula NB/A fr,g 

White-crowned sparrow Zonotrichia leucophrys NB/WR fr,g 

Golden-crowned sparrow Zonotrichia atricapilla NB/WR fr,g 

Dark-eyed junco Junco hyemalis NB/WR fr 

Chestnut-collared longspur Calcarius ornatus NB/A g 

Snow bunting Plectrophenax nivalis NB/A g 

Black-headed grosbeak Pheucticus melanocephalus B/SR fr 

Blue grosbeak Guiraca caerulea B/SR g 

Lazuli bunting Passerina amoena B/SR fr 

Indigo bunting Passerina cyanea NB/A fr 

Red-winged blackbird Agelaius phoeniceus B/YR w,g 

Tricolored blackbird Agelaius tricolor B/YR w,g 

Western meadowlark Sturnella neglecta B/YR g 

Yellow-headed blackbird Xanthocephalus xanthocephalus B/YR w 

Brewer's blackbird Euphagus cyanocephalus B/YR fr,g 

Great-tailed grackle Quiscalus mexicanus B/YR w 

Brown-headed cowbird Molothrus ater B/YR fr,g 

Hooded oriole Icterus cucullatus NB/A fr 

Bullock’s oriole Icterus bullockii B/SR fr 

Purple finch Carpodacus purpureus NB/A fr 

Cassin's finch Carpodacus cassinii NB/A fr 

House finch Carpodacus mexicanus B/YR fr 

Red crossbill Loxia curvirostra NB/A fr 

Pine siskin Carduelis pinus NB/M fr 

Lesser goldfinch Carduelis psaltria B/YR fr 

Lawrence's goldfinch Carduelis lawrencei NB/M fr 

American goldfinch Carduelis tristis B/YR fr 

Evening grosbeak Coccothraustes vespertinus NB/A fr 

House sparrow* Passer domesticus* B/YR fr 

K-8
Table 2. Mammal species occurring on Sacramento, Delevan, Colusa, or Sutter 

Refuges 

(* - non- native species). 

ORDER/COMMON NAME SCIENTIFIC NAME 

Marsupalia (opossums) 

Virginia opossum* Didelphis virginiana* 

Insectivora (shrews and moles) 

Broad-footed mole Scapanus latimanus 

Chiroptera (bats) 

Pallid bat Antrozous pallidus 

Big brown bat Eptesicus fuscus 

Silver-haired bat Lasionycteris noctivagans 

Western red bat Lasiurus blossevilli 

Hoary bat Lasiurus cinereus 

California myotis Myotis californicus 

Western small footed bat Myotis ciliolabrum 

Western long-earred bat Myotis evotis 

Little brown bat Myotis lucifugus 

Fringed bat Myotis thysanodes 

Yuma myotis Myotis yumanensis 

Western pipistrelle Pipistrellus hesperus 

Townsend's big-eared bat Pletocus townsendii 

Western mastiff bat Eumops perotis 

Brazilian free-tailed bat Tadarida brasiliensis 

Lagomorpha (rabbits and hares) 

Desert cottontail Sylvilagus audubonii 

Black-tailed hare Lepus californicus 

Rodentia (rodents) 

California ground squirrel Spermophilus beecheyi 

Western gray squirrel Sciurus griseus 

Botta's pocket gopher Thomomys bottae 

Beaver Castor canadensis 

Western harvest mouse Reithrodontomys megalotis 

Deer mouse Peromyscus maniculatus 

California vole Microtus californicus 

Muskrat Ondatra zibethicus 

Black rat* Rattus rattus* 

Norway rat* Rattus norvegicus* 

House mouse* Mus musculus* 

Carnivora (carnivores) 

Coyote Canis latrans 

K-9
Red fox* 

Gray fox 

Ringtail 

Raccoon 

Mink 

Vulpes vulpes* 

Urocyon cinereoargenteus 

Bassariscus astutus 

Procyon lotor 

Mustela vison 

Striped skunk 

River otter 

Mephitis mephitis 

Lontra canadensis 

Feral house cat* Felis silvestris* 

Artiodactyla (hoofed mammals) 

Black-tailed deer Odocoileus hemionus hemionus 

K-10
Table 3. Amphibian and reptile species occurring on Sacramento, Delevan, Colusa, 

or Sutter Refuges. 

(* - non-native species) 

FAMILY/COMMON NAME SCIENTIFIC NAME 

AMPHIBIANS 

Hylidae (treefrogs) 

Pacific treefrog Pseudacris regilla 

Ranidae (true frogs) 

Bullfrog* Rana catesbeiana* 

REPTILES 

Emydidae (turtles) 

Slider* Trachemys scirpta* 

Clemmys marmorata 

Northwestern pond turtle marmorata 

Phrynosomatidae (iguanid lizards) 

Western fence lizard Sceloporus occidentalis 

Colubridae (Colubrid snakes) 

Western yellow-bellied racer Coluber constrictor 

Gopher snake Pituophis catenifer 

Common kingsnake Lampropeltis getulus 

Common garter snake Thamnophis sirtalis 

Giant garter snake Thamnophis gigas 

Viperidae (vipers) 

Western rattlesnake Crotalis viridis 

K-11
Table 4. Fish species occurring on Sacramento, Delevan, Colusa, or Sutter Refuges. 

(* - non- native species; A-anadromous, R-resident) 

MIGRATORY 

FAMILY/COMMON NAME SCIENTIFIC NAME STATUS 

Petromyzontidae (lamprey) 

Pacific lamprey Lampetra tridentata A 

River lamprey Lampetra ayresi A 

Western brook lamprey Lampetra richardsoni A 

Acipenseridae (sturgeon) 

White sturgeon Acipenser transmontanus A 

Green sturgeon Acipenser medirostris A 

Clupeidae (herring) 

Threadfin shad* Dorosoma petenense* A 

American shad* Alosa sapidissima* A 

Salmonidae (salmon and trout) 

Chinook salmon, Central Valley 

fall- and late-fall-run ESU Oncorhynchus tshawytscha A 

Chinnook salmon, Sacramento 

River winter-run ESU Oncorhynchus tshawytscha A 

Chinook salmon, Central Valley 

spring-run ESU Oncorhynchus tshawytscha A 

Central Valley Steelhead ESU Oncorhynchus mykiss A 

Rainbow Trout* Salmo gairdneri* A 

Brown trout* Salmo trutta* A 

Cyprinidae (minnow) 

Tui chub Gila bicolor R 

Thicktail chub Gila crassicauda R 

Lahontan redside Richardsonius egregius R 

Hitch Lavinia exilicauda R 

California roach Hesperoleucus symmetricus R 

Sacramento blackfish Orthodon microlepidotus R 

Sacramento splittail Pogonichthys macrolepidotus R 

Hardhead Mylopharodon conocephalus R 

Sacramento squawfish Ptychocheilus grandis R 

Speckled dace Rhinichthys osculus R 

Golden shiner* Notemigonus crysoleucas* R 

Fathead minnow* Pimephales promelas* R 

Goldfish* Carassius auratus* R 

Carp* Cyprinus carpio* R 

Catostomidae (sucker) 

K-12
Sacramento sucker Catostomus occidentalis R 

Ictaluridae (catfish) 

Black bullhead* Ictalurus melas* R 

Brown bullhead* Ictalurus nebulosus* R 

Yellow bullhead* Ictalurus natalis* R 

White catfish* Ictalurus catus* R 

Channel catfish* Ictalurus punctatus* R 

Poeciliidae (livebearer) 

Mosquitofish* Gambusia affinis* R 

Atherinidae ( silverside) 

Mississippi silverside* Menidia audens* R 

Gasterosteidae (stickleback) 

Threespine stickleback* Gasterosteus aculeatus* R 

Percichthyidae (temperate basses) 

Striped bass* Morone saxatilis* A 

Centrarchidae (sunfish) 

Sacramento perch Archoplites interruptus R 

Bluegill* Lepomis macrochirus* R 

Redear sunfish* Lepomis microlophus* R 

Pumpkinseed* Lepomis gibbosus* R 

Green sunfish* Lepomis cyanellus* R 

Warmouth* Lepomis gulosus* R 

White crappie* Pomoxis annularis* R 

Black crappie* Pomoxis nigromaculatus* R 

Largemouth bass* Micropterus salmoides* R 

Smallmouth bass* Micropterus dolomieui* R 

Spotted bass* Micropterus punctulatus* R 

Percidae (perch) 

Bigscale logperch* Percina macrolepida* R 

Embiotocidae (surfperch) 

Tule perch Hysterocarpus traski R 

Cottidae (sculpin) 

Prickly sculpin Cottus asper R 

Riffle sculpin Cottus gulosus R 

Staghorn sculpin Leptocottus armatus R 

K-13
VASCULAR PLANTS 

FERN ALLIES 

Equisetaceae (Horsetail Family) 

Large mosquito fern Azolla filiculoides 

Hairy water-clover Marsilea vestita 

American pill-wort Pilularia americana 

GYMNOSPERMS 

Cupressaceae (Cypress Family) 

Arizona cypress Cupressus arizonica 

Monterey cypress Cupressus macrocarpa 

DICOT FLOWERING PLANTS 

Aceraceae (Maple Family) 

Box elder Acer negundo californicum 

Aizoaceae (Fig-marigold Family) 

Slender-leaved iceplant* Mesembryanthemum nodiflorum* 

Amaranthaceae (Amaranth Family) 

Tumbleweed* Amaranthus albus* 

California amaranth Amaranthus californicus 

Red-rooted amaranth* Amaranthus retroflexus* 

Anacardiaceae (Sumac Family) 

Western poison-oak Toxicodendron diversilobum 

Apiaceae (Carrot Family) 

Bur-chervil* Anthriscus caucalis 

Poison-hemlock* Conium maculatum* 

Coyote thistle Eryngium vaseyi 

Fennel* Foeniculum vulgare* 

Alkali-parsnip Lomatium caruifolium denticulatum 

Knotted hedge-parsley* Torilis nodosa* 

Asclepiadaceae (Milkweed Family) 

Narrow-leaved milkweed Asclepias fascicularis 

Showy milkweed Asclepias speciosa 

Asteraceae (Sunflower Family) 

Blow-wives Achyrachaena mollis 

Western ragweed Ambrosia psilostachya 

Mayweed* Anthemis cotula* 

Mugwort Artemisia douglasiana 

California aster Aster chilensis 

Table 5. Plant species occurring on Sacramento, Delevan, Colusa, or Sutter Refuges. 

(* - non- native species) 

FAMILY/COMMON NAME SCIENTIFIC NAME 

K-14
Annual saltmarsh aster Aster subulatus ligulatus 

Coyote-brush Baccharis pilularis 

Sticktight Bidens frondosa 

Yellow-carpet Blennosperma nanum nanum 

Italian plumeless-thistle* Carduus pycnocephalus* 

Yellow star-thistle* Centaura solstitialis* 

Valley pineapple-weed Chamomilla occidentalis 

Common pineapple-weed Chamomilla suaveolens 

Chicory* Cichorium intybus* 

Bull thistle* Cirsium vulgare* 

South American horseweed* Conyza bonariensis* 

Canadian horseweed Conyza canadensis glabrata 

Many-flowered horseweed* Conyza floribunda* 

Common brass-buttons* Cotula coronopifolia* 

Western goldenrod Euthamia occidentalis 

California cudweed Gnaphallium californicum 

Weedy cudweed* Gnaphallium luteo-album* 

Western marsh cudweed Gnaphallium palustre 

Cotton-batting plant Gnaphallium stramineum 

Great valley gumplant Grindelia camporum 

Common sunflower Helianthus annuus 

Hayfield tarweed Hemizonia congesta 

Pappose spikeweed Hemizonia parryi 

Common spikeweed Hemizonia pungens 

Smooth cat's ear* Hypochoeris glabra* 

Willow-leaved lettuce* Lactuca saligna* 

Prickly lettuce* Lactuca serriola* 

California goldfields Lasthenia californica 

Fremont's goldfields Lasthenia fremontii 

Woolly goldfields Lasthenia minor 

Alkali goldfields Lasthenia platycarpha 

Smooth tidytips Layia chrysanthemoides 

Sierra foothills microseris Microseris acuminata 

Douglas' microseris Microseris douglasii 

Elegant microseris Microseris elegans 

Bristly oxtongue* Picris echioides* 

Dwarf wooly-marbles Psilocarphus brevissimus brevissimus 

Oregon woolly marbles Psilocarphus oregonus 

Old-man-in-the-spring* Senecio vulgaris* 

Milk-thistle* Silybum marianum* 

Spiny-leaved sow-thistle* Sonchus asper asper* 

K-15
Common sow-thistle* Sonchus oleraceus* 

Salsify* Tragopogon porrifolius* 

Spiny cocklebur Xanthium spinosum 

Cocklebur Xanthium strumarium 

Bignoniaceae (Bignonia Family) 

Trumpet-creeper* Campsis radicans* 

Boraginaceae (Borage Family) 

Bugloss fiddleneck Amsinckia lycopsoides 

Common fiddleneck Amsinckia menziesii 

Wild heliotrope Heliotropium curassavicum 

Smooth-stemmed popcorn-flower Plagiobothrys leptocladus 

Scribe's popcorn-flower Plagiobothrys scriptus 

Large-flowered stipitate popcornflower Plagiobothrys stipitatus stipitatus 

Small-flowered stipitate popcornflower Plagiobothrys stipitatus micranthus 

Brassicaceae (Mustrad Family) 

Black mustard* Brassica nigra* 

Shepherd's purse* Capsella bursa-pastoris* 

Lens-podded hoary-cress* Cardaria chalepensis* 

Western bitter-cress Cardamine oligosperma 

Wormseed mustard* Erysimum cheiranthoides* 

Mediterranean hoary-mustard* Hirschfeldia incana* 

Alkali pepper-grass Lepidium dictyotum dictyotum 

Sharp-toothed pepper-grass Lepidium dictyotum acutidens 

Broad-leved mustard* Lepidium latifolium* 

Dwarf pepper-grass Lepidium latipes latipes 

Heckard's dwarf pepper-grass Lepidium latipes heckardii 

Shining pepper-grass Lepidium nitidum nitidum 

Clasping pepper-grass* Lepidium perfoliatum* 

Pinnatifid pepper-grass* Lepidium pinnatifidum* 

Radish* Raphanus sativus* 

Oriental hedge-mustard* Sisymbrium orientale* 

Slender tropidocarpum Tropidocarpum gracile 

Callitrichaceae (Water-starwort Family) 

Winged water-starwort Callitriche marginata 

Campanulaceae (Bellflower Family) 

Hoover's downingia Downingia bella 

Harlequin downingia Downingia insignis 

Folded downingia Downingia ornatissima 

K-16
Caprifoliaceae (Honeysuckle Family) 

Blue elderberry Sambucus mexicana 

Caryophyllaceae (Pink Family) 

Sticky mouse-eared chickweed* Cerastium glomeratum* 

Herniaria* Herniaria hirsuta hirsuta* 

Western pearlwort Sagina decumbens 

White-flowered sandspurry Spergularia macrantha 

Salt-marsh sandspurry Spergularia marina 

Ruby sandspurry* Spergularia rubra* 

Common chickweed* Stellaria media* 

Ceratophyllaceae (Hornwort Family) 

Hornwort Ceratophyllum demersum 

Chenopodiaceae (Goosefoot Family) 

Iodine-bush Allenrolfea occidentalis 

Silverscale Atriplex argentea 

Heartscale Atriplex cordulata 

Crownscale Atriplex coronata coronata 

Brittlescale Atriplex depressa 

Ball saltbush Atriplex fruticulosa 

Variable seeded saltbush* Atriplex heterosperma* 

San Joaquin spearscale Atriplex joaquiniana 

Big saltbush Atriplex lentiformis 

Vernal-pool saltbush Atriplex persistens 

Many-fruited saltbush Atriplex polycarpa 

Tumbling oracle* Atriplex rosea* 

Australian saltbush* Atriplex semibaccata* 

Spearscale Atriplex triangularis 

Hyssop-leaved bassia* Bassia hyssopifolia* 

Lamb's-quarters* Chenopodium alnum* 

Mexican tea* Chenopodium ambrosioides* 

Nettled-leaved goosefoot* Chenopodium murale* 

Parish's pickleweed Salicornia subterminalis 

Woody pickleweed Salicornia virginica 

Russian thistle* Salsola tragus* 

Fleshy-leaved Russian-thistle* Salsola soda* 

Horned seablite Suaeda calceoliformis 

Bush seepweed Suaeda moquinii 

Convolvulaceae (Morning-glory Family) 

Bindweed* Convolvulus arvensis* 

Alkali-weed Cressa truxillensis 

Crassulaceae (Stonecrop Family) 

K-17
Water pygmyweed Crassula aquatica 

Pygmyweed Crassula connata 

Mossy pigmyweed* Crassula tillaea* 

Cuscutaceae (Dodder Family) 

California dodder Cuscuta californica 

Alkaline dodder Cuscuta salina 

Dipsacaceae (Teasel Family) 

Wild teasel* Dipsacus fullonum* 

Fuller's teasel* Dipsacus sativus* 

Elatinaceae (Waterwort Family) 

Texas bergia Bergia texana 

Ricefield waterwort* Elatine ambigua* 

California waterwort Elatine californica 

Chilean waterwort Elatine chilense 

Euphorbiaceae (Spurge Family) 

Hoover's spurge Chamaesyce hooveri 

Spotted spurge* Chamaesyce maculata* 

Thyme-leaved spurge Chamaesyce serpyllifolia 

Turkey-mullein Eremocarpus setigerus 

Fabaceae (Legume Family) 

Ferris's milk-vetch Astragalus tener 

Bird's-foot-trefoil* Lotus corniculatus* 

Spanish lotus Lotus purshianus purshianus

Wrangel lotus Lotus wrangelianus 

Pink-flowered lupine Lupinus microcarpus microcarpus 

Small-flowered lupine Lupinus polycarpus 

Common bur-clover* Medicago polymorpha* 

White sweet-clover* Melilotus alba* 

Indian sweet-clover* Melilotus indica* 

Indian clover Trifolium albopurpureum 

Deceptive notch-leaved clover Trifolium bifidum decipiens 

Foothill clover Trifolium cioliolatum 

Involucrate cowbag clover Trifolium depauperatum amplectens 

Sour clover Trifolium fucatum 

Rose clover* Trifolium hirtum* 

Small-headed clover Trifolium microcephalum 

White-tipped clover Trifolium variegatum 

Red-flowered vetch* Vicia benghalensis* 

Garden vetch* Vicia sativa sativa* 

Winter vetch* Vicia villosa varia* 

Fagaceae (Beech Family) 

K-18
 

Valley oak Quercus lobata 

Frankeniaceae (Frankenia Family) 

Alkali sea-heath Frankenia salina 

Gentianaceae (Gentian Family) 

June centaury Centaurium muehlenbergii 

Geraniaceae (Geranium Family) 

Long-beaked stork's-bill* Erodium botrys* 

Short-fruited stork's-bill* Erodium brachycarpum* 

Red-stemmed filaree* Erodium cicutarium* 

White-stemmed filaree* Erodium moschatum* 

Cut-leaved geranium* Geranium dissectum* 

Hydrophyllaceae (Water-leaf Family) 

Great valley phacelia Phacelia ciliata 

Juglandaceae (Walnut Family) 

Northern California black walnut Juglans californica hindsii 

Lamiaceae (Mint Family) 

Giraffehead* Lamium amplexicaule* 

Cut-leaved bugleweed Lycopus americanus 

Horehound* Marrubium vulgare* 

American wild mint Mentha arvensis 

Pennyroyal* Mentha pulegium* 

Sacramento pogogyne Pogogyne zizyphoroides 

Rigid hedge-nettle Stachys ajugoides rigida 

Sonoma hedge-nettle Stachys stricta 

Lentibulariaceae (Bladderwort Family) 

Humped bladderwort* Utricularia gibba* 

Limnanthaceae (Meadowfoam Family) 

Rosy meadowfoam Limnanthes douglasii 

Lythraceae (Loosestrife Family) 

Valley redstem Ammannia coccinea 

Robust redstem Ammannia robusta 

California loosestrife Lythrum californicum 

Hyssop loosestrife* Lythrum hyssopifolium* 

Slender-fruited loosetrife* Lythrum tribracteatum* 

Malvaceae (Mallow Family) 

Velvetleaf* Abutilon theophrasti* 

Rose mallow (California hibiscus) Hibiscus lasiocarpus 

Bull mallow* Malva nicaeensis* 

Little mallow* Malva parviflora* 

Alkali mallow Malvella leprosa 

K-19
Fringed checker-mallow Sidalcea diploscypha 

Hairy checkerbloom Sidalcea hirsute 

Martyniaceae (Unicorn-plant Family) 

Common unicorn-plant* Proboscidea louisianica louisinica* 

Molluginaceae (Carpet-weed Family) 

Glinus* Glinus lotoides* 

Indian chickweed* Mollugo verticillata* 

Moraceae (Mulberry Family) 

Edible fig* Ficus carica* 

White mulberry* Morus alba 

Myrtaceae (Myrtle Family) 

Red river gum* Eucalyptus camaldulensis* 

Oleaceae (Olive Family) 

Oregon ash Fraxinus latifolia 

Olive Olea europaea 

Onagraceae (Evening-primrose Family) 

 Purple clarkia Clarkia purpurea quadrivulnera 

Tall annual willowherb Epilobium brachycarpum 

Fringed willowherb Epilobium ciliatum ciliatum 

Cleistogamous spike-primrose Epilobium cleistogamum 

Smooth spike-primrose Epilobium pygmaeum 

Yellow waterweed Ludwigia peploides peploides 

Montevideo waterweed Ludwigia peploides montevidensis 

Oxalidaceae (Wood-sorel Family) 

Creeping wood-sorel* Oxalis corniculata* 

Plantaginaceae (Plantain Family) 

Cut-leaved plantain* Plantago coronopus* 

Elongate plantain Plantago elongata 

Erect plantain Plantago erecta 

English plantain* Plantago lanceolata* 

Common plantain* Plantago major* 

Polemoniaceae (Phlox Family) 

Bicolored linanthus Linanthus bicolor 

White-flowered navarretia Navarretia leucocephala 

Polemoniaceae (Phlox Family) 

Tehama navarretia Navarretia heterandra 

Polygonaceae (Buckwheat Family) 

Swamp smartweed Polygonum amphibium emersum 

Common knotweed* Polygonum arenastrum* 

Water-pepper* Polygonum hydropiper* 

Mild water-pepper Polygonum hydropiperoides 

K-20
Willow-weed Polygonum lapathifolium 

Lady's thumb* Polygonum persicaria* 

Prolific knotweed* Polygonum prolificum*

Dotted smartweed Polygonum punctatum 

Curly dock* Rumex crispus* 

Toothed dock* Rumex dentatus* 

Portulacaceae (Purslane Family) 

Redmaids Calandrinia ciliata 

Water montia Montia fontana 

Common purslane* Portulaca oleracea* 

Ranunculaceae (Buttercup Family) 

Royal larkspur Delphinium variegatum 

Tiny mousetail Myosurus minimus 

Sessile moustetail Myosurus sessilis 

Rosaceae (Rose Family) 

Pyracantha* Pyracantha koidzumii* 

California rose Rosa californica 

Rambler rose* Rosa mutiflora* 

Himalayan blackberry* Rubus discolor* 

California blackberry Rubus ursinus 

Rubiaceae (Madder Family) 

California button-willow Cephalanthus occidentalis californicus 

Wall bedstraw* Galium parisiense* 

Tiny bedstraw* Galium murale* 

Salicaceae (Willow Family) 

Fremont's cottonwood Populus fremontii 

Sandbar willow Salix exigua 

Goodding's black willow Salix gooddingii 

Red willow Salix laevigata 

Arroyo willow Salix lasiolepis 

Scrophulariaceae (Figwort Family) 

Snapdragon Antirrhinum spp. 

Round-leved water-hyssop* Bacopa rotundifolia* 

Valley-tassels Castilleja attenuata 

Purple owl-clover Castilleja exserta 

Creamsacs Castilleja rubicundula 

Palmate bird's-beak Cordylanthus palmatus 

Sharp-leaved fluellin* Kickxia elatine* 

Seep monkey-flower Mimulus guttatus 

Johnnytuck Triphysaria eriantha 

K-21
Moth mullein* Verbascum blattaria* 

Water speedwell* Veronica anagallis-aquatica* 

Purslane speedwell Veronica peregrina xalapensis 

Solanaceae (Nightshade Family) 

Tree tobacco* Nicotiana glauca* 

Sharp-leaved ground-cherry Physalis acutifolia 

Lance-leaved ground-cherry* Physalis lanceifolia* 

American black nightshade Solanum americanum 

White horsenettle* Solanum elaeagnifolium* 

Tamaricaceae (Tamarisk Family) 

Small-flowered tamarisk* Tamarix parviflora* 

Salt-cedar* Tamarix ramosissima* 

Urticaceae (Nettle Family) 

Hoary creek nettle Urtica dioica holosericea 

Verbenaceae (Vervain Family) 

Creeping lippia Phyla nodiflora nodiflora 

Rosy lippia* Phyla nodiflora rosea* 

South American vervain* Verbena bonariensis* 

Halberd-leaved vervain Verbena hastata 

Western vervain Verbena lasiostachys scabrida 

Shore vervain Verbena litoralis 

Vitaceae (Grape Family) 

California wild grape Vitis californica 

Zygophyllaceae (Caltrop Family) 

Puncture-vine* Tribulus terrestris* 

MONOCOT FLOWERING PLANTS 

Alismataceae (Water-plantain Family) 

Water-plantain Alisma plantago-aquatica 

Fringed water-plantain Damasonium californicum 

Burhead Echinodorus berteroi 

Long-lobed arrowhead Sagittaria longiloba 

Montevideo arrowhead Sagittaria montevidensis calycina 

Arecaceae (Palm Family) 

Canary Island date palm* Phoenix canariensis* 

California fan palm Washingtonia filifera 

Cyperaceae (Sedge Family) 

Santa Barbara sedge Carex barbarae 

Clustered field sedge Carex praegracilis 

Small-flowered cyperus* Cyperus difformis* 

Tall cyperus Cyperus eragrostis 

Red-rooted cyperus Cyperus erythrorhizos 

K-22
False nutsedge Cyperus strigosus 

Pale spike-rush Eleocharis macrostachya 

Engelmann's spike-rush Eleocharis obtusa engelmannii 

Little-headed spike-rush Eleocharis parvula 

Hard-stemmed tule Scirpus acutus occidentalis 

River bulrush Scirpus fluvialtilis 

Saltmarsh bulrush Scirpus maritimus 

Rough-seeded bulrush* Scripus mucronatus* 

Tuberous bulrush* Scirpus tuberosus* 

Hydrocharitaceae (Waterweed Family) 

Ricefield water-nymph* Najas graminea* 

Juncaceae (Rush Family) 

Baltic Rush Juncus balticus balticus 

Common toad rush Juncus bufonius bufonius 

Congested toad rush Juncus bufonius congestus 

Pacific rush Juncus effusus pacificus 

Lemnaceae (Duckweed Family) 

Summer duckweed Lemna aequinoctialis 

Inflated duckweed Lemna gibba 

Common duckweed Lemna minor 

Least duckweed Lemna minuta 

Turion duckweed Lemna turionifera 

Common duckmeat Spirodela polyrhiza 

Liliaceae (Lily Family) 

Clasping onion Allium amplectens 

Garden asparagus* Asparagus officinalis* 

Harvest brodiaea Brodiaea coronaria coronaria 

Elegant brodiaea Brodiaea elegans elegans 

Yellow mariposa-lily Calochortus luteus 

Muilla Muilla maritima 

Ithuriel's spear Triteleia laxa

 Fremont's death-camas Zigadenus fremontii 

Poaceae (Grass Family) 

Avnes bentgrass* Agrostis avenacea* 

Pacific meadow foxtail Alopecurus saccatus 

Giant-reed* Arundo donax* 

Barbed oat* Avena barbata* 

Wild oat* Avena fatua* 

Lesser quaking-grass* Briza minor* 

Ripgut brome* Bromus diandrus* 

Soft chess* Bromus hordeaceus* 

K-23
Red brome* Bromus madritensis rubens* 

Uruguayan pampasgrass* Cortaderia selloana* 

Swamp pricklegrass* Crypsis schoenoides* 

African pricklegrass* Crypsis vaginiflora* 

Bermuda grass* Cynodon dactylon* 

Annual hairgrass Deschampsia danthonioides 

Hairy crabgrass* Digitaria sanguinalis* 

Saltgrass Distichlis spicata 

Jungle-rice* Echinochloa colona* 

Water-grass* Echinochloa crus-galli* 

Blue wild-rye Elymus glaucus glaucus 

Tall wheatgrass* Elytrigia pontica* 

Tall fescue Festuca arundinacea 

Barbgrass* Hainardia cylindrica* 

Hordeum brachyantherum 

Meadow barley brachyantherum 

Low barley Hordeum depressum 

Foxtail barley Hordeum jubatum 

Mediterranean barley* Hordeum marinum gussoneanum* 

Glaucous barley* Hordeum murinum glaucum* 

Hare wall* Hordeum murinum leporinum* 

Rice cutgrass Leersia oryzoides 

Bearded sprangletop Leptochloa fascicularis 

Mexican sprangletop Leptochloa uninervia 

Annual ryegrass* Lolium multiflorum* 

Alkali ryegrass Leymus triticoides 

Hairy orcuttgrass Orcuttia pilosa 

Cultivated rice* Oryza sativa* 

Smooth witchgrass* Panicum dichotomiflorum* 

Sicklegrass* Parapholis incurva* 

Dallisgrass* Paspalum dilatatum* 

Knotgrass Paspalum distichum 

Harding-grass* Phalaris aquatica* 

Lemmon's canarygrass Phalaris lemmonii 

Lesser canarygrass* Phalaris minor* 

Paradox canarygrass* Phalaris paradoxa* 

Annual bluegrass* Poa annua* 

Mediterranean beardgrass* Polypogon maritimus* 

Annual beardgrass* Polypogon monspeliensi* 

Lesser alkaligrass Puccinellia simplex 

Perennial brstlegrass Setaria parviflora 

K-24
Yellow bristlegrass* Setaria pumial* 

Johnsongrass* Sorghum halepense* 

Greene's tuctoria Tuctoria greenei 

Foxtail fescue* Vulpia myuros hisuta* 

 Rattail fescue* Vulpia myuros myuros* 

Potamogetonaceae (Pondweed Family) 

Crispate-leaved pondweed* Potamogeton crispus 

Leafy pondweed Potamogeton foliosus 

Sago pondweed Potamogeton pectinatus 

Long-leaved pond weed Potamogeton nodosus 

Typhaceae (Cattail Family) 

Narrow-leaved cattail Typha angustifolia 

Southern cattail Typha domingensis 

Broad-leaved cattail Typha latifolia 

Zannichelliaceae (Horned-pondweed Family) 

 Horned-pondweed Zannichelliapalustris 

K-25
K-26
Appendix L. Compliance with Section 7 of 

the Endangered Species Act 

An Intra-Service Section 7 Consultation has been initiated with the Sacramento Fish and 

Wildlife Office and will be completed prior to the final approval of this CCP. In addition, a 

letter has been forward to NOAA – Fisheries requesting a review and concurrence with 

the CCP for species under their jurisdiction. 

L-1 
L-2 
Appendix M. Applicable Laws and 

Executive Orders and Relationships to 

Federal, State, and Local Policies and 

Plans 

This appendix contains an overview of laws, executive orders, polices, and plans created 

by federal, state and local agencies with jurisdiction in the vicinity of Sacramento, 

Delevan, Colusa, and Sutter National Wildlife Refuges (Refuges). Table 1 contains a list of 

applicable laws and executive orders that may affect the Refuges’ Comprehensive 

Conservation Plan (CCP) or the U.S. Fish and Wildlife Service’s implementation of the 

CCP. A brief description of the law, executive order, policy, or plan is included as well as 

how it relates to the CCP. 

1.0 Federal Government 

Table 1. Applicable Laws and Executive Orders 

Law, Regulation, or 

Guideline 

Description Relation to the CCP 

Agency Coordination 

Executive Order No. 12372, Requires that Federal agencies afford Copies of this environmental 

Intergovernmental Review other agencies review of documents assessment were sent to the 

of Federal Programs. associated with Federal programs. California State 

Clearinghouse, Federal and 

State agencies, and local 

governments. 

Human Rights Regulations 

Executive Order 12898, 

Environmental Justice. 

February 11, 1994 

Americans with Disabilities 

Act of 1990 

Requires Federal agencies to consider the 

effects of projects and policies on minority 

and lower income population. Provides for 

access to Federal facilities for the disabled. 

The proposed action will not 

have a disproportionately high 

and adverse human health or 

environmental effect on 

minority populations and lowincome populations. The 

proposed action promotes 

reasonable and appropriate 

uses of the land that preserve 

the natural character and 

protect the natural resources 

of the area. 

Cultural Resources Regulations 

Antiquities Act of 1906 This act authorizes the scientific 

investigation of antiquities on Federal 

land. It prohibits and provides penalties 

for unauthorized search for or collection of 

artifacts or other objects of scientific 

interest. The Act also authorizes the 

president to establish national monuments 

and cultural areas on Federal lands. 

The Service will continue to 

comply with this Act under the 

CCP. 

M-1 
Table 1. Applicable Laws and Executive Orders 

Law, Regulation, or 

Guideline 

Description Relation to the CCP 

Executive Order No. 11593, 

Protection and 

Enhancement of the 

Cultural Environment 

States that if the Service proposes any 

development activities that may affect 

archaeological or historical sites, the 

Service will consult with Federal and State 

Historic Preservation Officers to comply 

with Section 106 of the National Historic 

Preservation Act of 1966, as amended. 

The Service will continue to 

comply with this Order under 

the CCP. 

Native American Graves 

Protection and Repatriation 

Act of 1990 (PL 101-601; 25 

USC 3001 et seq.) 

Regulations for the treatment of Native 

American graves, human remains, funeral 

objects, sacred objects, and other objects 

of cultural patrimony. Requires 

consultation with Native American Tribes 

during Federal project planning. 

The Service will continue to 

comply with this Act under the 

CCP. 

Archaeological Resources Protects materials of archeological interest The Service will continue to 

Protection Act of 1979 (PL from unauthorized removal or destruction comply with this Act under the 

96-95; 93 STAT 722; 16 USC and requires Federal managers to develop CCP. 

470aa-47011), as amended plans to locate archeological resources. 

Executive Order 13007, Provides for access to, and ceremonial use The Service will continue to 

Indian Sacred Sites. 24 May, of, Indian sacred sites on Federal lands comply with this Order under 

1996 used by Indian religious practitioners and 

direction to avoid adversely affecting the 

physical integrity of such sites. 

the CCP. 

American Indian Religious 

Freedom Act 1978 (PL 95­

341; 92 STAT 469; 42 USC 

1996) 

Provides for freedom of Native Americans 

to believe, express, and exercise their 

traditional religion, including access to 

important sites. 

The Service will continue to 

comply with this Act under the 

CCP. 

Archaeological and Historic 

Preservation Act of 1974 

(PL 93-291; 88 STAT 174; 16 

USC 469) 

Provides for the preservation of historical 

buildings, sites, and objects of national 

significance. 

The Service will continue to 

comply with this Act under the 

CCP. 

National Historic 

Preservation Act of 1966 

(PL 89-665; 50 STAT 915; 16 

USC 470 et seq.; 36 CFR 

800), as amended 

Requires Federal agencies to consider the 

effects of any actions or programs on 

historical properties. 

The Service will continue to 

comply with this Act under the 

CCP. 

Biological Resources Regulations 

Endangered Species Act of 

1973 (16 USC 1531 et seq.), 

as amended 

Provides for protection of plants, fish, and 

wildlife that have a designation as 

threatened or endangered. 

An Intra-Service Section 7 will 

be completed with the Service 

and with NOAA-Fisheries for 

endangered and threatened 

species on the Refuges. 

National Environmental 

Policy Act of 1969 (42 USC 

4321 et seq) 

Requires analysis, public comment, and 

reporting for environmental impacts of 

Federal actions. 

The public has been notified of 

the availability of the draft 

Environmental Assessment 

and had a 45-day period to 

provide comments. 

M-2 
Table 1. Applicable Laws and Executive Orders 

Law, Regulation, or 

Guideline 

Description Relation to the CCP 

Executive Order 13186, 

Responsibilities of Federal 

Agencies to Protect 

Migratory Birds. Jan. 10, 

2001. 

Instructs Federal agencies to conserve 

migratory birds by several means, 

including the incorporation of strategies 

and recommendations found in Partners in 

Flight Bird Conservation Plans, the North 

American Waterfowl Plan, the North 

American Waterbird Conservation Plan, 

and the United States Shorebird 

Conservation Plan, into agency 

management plans and guidance 

documents. 

The Service has incorporated 

the strategies and 

recommendations of the listed 

management plans into the 

CCP to conserve migratory 

birds. The Service will 

continue to comply with this 

Order under the CCP. 

Fish and Wildlife 

Conservation Act of 1980 (16 

USC 661-667e), as amended 

Requires the Service to monitor non-game 

bird species, identify species of 

management concern, and implement 

conservation measures to preclude the 

need for listing under ESA. 

The Service will continue to 

comply with this Act under the 

CCP. 

The Bald and Golden Eagle 

Protection Act of 1940 (16 

USC 668 et seq.) 

Provides protection for bald and golden 

eagles. 

The Service will continue to 

comply with this Act under the 

CCP. 

Migratory Bird Treaty Act 

of 1918, as amended 

Provides protection for bird species that 

migrate across state and international 

boundaries. 

The Service will continue to 

comply with this Act under the 

CCP. 

Anadromous Fish 

Conservation Act of 1965 (16 

USC 757a-757g) 

To conserve, develop, and enhance 

anadromous fish and the fisheries of the 

Great Lakes and Lake Champlain. 

The Service will continue to 

comply with this Act under the 

CCP. 

Clean Air Act of 1963, as 

amended ( USC 

Provides for the protection of air quality. 

Regulates air emissions from area, 

stationary, and mobile sources. 

The Service will continue to 

comply with this Act under the 

CCP. 

The Clean Water Act of 

1972, Section 404 (33 USC 

1344 et seq.), as amended 

Provides for protection of water quality. The Service will continue to 

comply with this Act under the 

CCP. 

Fish and Wildlife Act of 

1956 (16 USC 742a-743j) 

Provides Secretary of Interior with 

authority to protect and manage fish and 

wildlife resources. 

The Service will continue to 

comply with this Act under the 

CCP. 

National Wildlife Refuge Amends the Fish and Wildlife Act of 1956 The Service will continue to 

System Volunteer and to promote volunteer programs and promote volunteer programs 

Community Partnership community partnerships for the benefit of and community partnerships 

Enhancement Act (1998) national wildlife refuges, and for other 

purposes. 

under the CCP. 

Fish and Wildlife Requires equal consideration and The Service will continue to 

Coordination Act of 1958 coordination of wildlife conservation with 

other water resource development 

programs. 

comply with this Act under the 

CCP. 

Emergency Wetlands Promotes the conservation of migratory The Service will continue to 

Resources Act of 1986 waterfowl and offsets or prevent the 

serious loss of wetlands by the acquisition 

of wetlands and other essential habitats. 

comply with this Act under the 

CCP. 

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Table 1. Applicable Laws and Executive Orders 

Law, Regulation, or 

Guideline 

Description Relation to the CCP 

Federal Noxious Weed Act 

of 1990 

Requires the use of integrated 

management systems to control or contain 

undesirable plant species, and an 

interdisciplinary approach with the 

cooperation of other Federal and State 

agencies. 

The Service will continue to 

comply with this Act under the 

CCP. 

Executive Order 13112, 

Invasive Species, 1999 

Directs federal agencies to prevent 

introduction and provide control of 

invasive species. 

The Service will continue to 

comply with this Act under the 

CCP. 

Rivers and Harbor Act of 

1899 

Requires authorization by the U.S. Army 

Corps of Engineers prior to any work in, 

on, over, and under a navigable water of 

the U.S. 

The Service will continue to 

comply with this Act under the 

CCP. 

Hazardous Materials Regulations 

Oil Pollution Act of 1990 (PL 

101-380; 33 USC 2701, et 

seq.) 

Provides oil pollution policies and 

protections. 

The Service will continue to 

comply with this Act under the 

CCP. 

Comprehensive 

Environmental Response, 

Compensation, and Liability 

Act of 1980 (PL 96-510; 42 

USC 9601, et seq.) 

Provides mechanism for hazardous waste 

clean up. 

No evidence of contaminants 

or hazardous waste was 

identified in the project area. 

Land and Water Use Regulations 

The National Wildlife 

Refuge System 

Administration Act of 1966 

(16 USC 668dd-668ee), 

National Wildlife Refuge 

System Improvement Act of 

1997 (PL 105-57) 

Administration, management, and 

planning for National Wildlife Refuges, 

Amends the National Wildlife Refuge 

System Administration Act of 1966. 

Requires development of CCPs for all 

refuges outside of Alaska. 

The Service determined that 

hunting, wildlife observation, 

photography, environmental 

education, interpretation, 

research, grazing, plant 

gathering, bicycling, 

commercial photography, and 

mosquito and other vector 

control are compatible with 

the purposes for which the 

Refuges were established. 

This document will satisfy this 

Act. 

Executive Order No. 11988, Provides for the support, preservation, and No structure that could either 

Floodplain Management enhancement of the natural and beneficial 

values of floodplains. 

be damaged by or significantly 

influence the movement of 

floodwater in the project area 

is planned for construction by 

the Service, thus the proposed 

action is consistent with this 

Order. 

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Table 1. Applicable Laws and Executive Orders 

Law, Regulation, or 

Guideline 

Description Relation to the CCP 

Executive Order No. 11990, Provides for the conservation of the The Service plans no 

Protection of Wetlands natural and beneficial values of wetlands 

and their associated habitats. 

detrimental impacts to 

wetlands but plans to preserve 

wetlands in the project area, 

thus the proposed action is 

consistent with this Order. 

The Refuge Recreation Act Provides for recreation use that is The Service determined that 

of 1962, as amended compatible with the primary purpose of a 

refuge. 

hunting, wildlife observation, 

photography, environmental 

education, interpretation, 

research, grazing, plant 

gathering, bicycling, 

commercial photography, and 

mosquito and other vector 

control are compatible with 

the purposes for which the 

Refuges were established. 

This document will satisfy this 

Act. 

Fish and Wildlife Improves administration of fish and The Service will continue to 

Improvement Act of 1978 wildlife programs and amends earlier laws 

including Refuge Recreation Act, NWRS 

Administration Act, and Fish and Wildlife 

Act of 1956. Authorizes the Secretary to 

accept gifts or real and personal property 

on behalf of the U.S. Also authorizes use of 

volunteers on Service projects and 

appropriations to carry out a volunteer 

program. 

comply with this Act under the 

CCP. 

Refuge Revenue Sharing Section 401 of the Act of June 15, 1935, (49 The Service will continue to 

Act (16 U.S.C. 715s) Stat. 383) provided for payments to 

counties in lieu of taxes, using revenues 

derived from the sale of products from 

refuges. 

comply with this Act under the 

CCP. 

Land and Water 

Conservation Fund Act of 

1948 

This act provides funding through receipts 

from the sale of surplus federal land, 

appropriations from oil and gas receipts 

from the outer continental shelf, and other 

sources of for land acquisition under 

several authorities. Appropriations from 

the fund may be used for matching grants 

to states for outdoor recreation projects 

and for land acquisition by various federal 

agencies, including the Fish and Wildlife 

Service. 

The Service will continue to 

comply with this Act under the 

CCP. 

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Table 1. Applicable Laws and Executive Orders 

Law, Regulation, or 

Guideline 

Description Relation to the CCP 

Migratory Bird 

Conservation Act of 1929 

(16 U.S.C. 715-715d, 

715e,715f-715r) 

Established the Migratory Bird 

Conservation Commission. The 

Commission approves acquisition of land 

and water, or interests therein, and sets 

the priorities for acquisition of lands by the 

Secretary for sanctuaries or for other 

management purposes. 

The Service will continue to 

comply with this Act under the 

CCP. 

Wilderness Act of 1964 Directs the Secretary of the Interior to The Refuges do not contain 

(16 U.S.C. 1131-1136; 78 review, within ten years, every roadless 5,000 acres of roadless land. 

Stat. 890) area of 5,000 acres or more and every 

roadless island regardless of size within 

the National Wildlife Refuge System and 

to recommend suitability of each such area. 

2.0 Fish and Wildlife Service Plans, Policies and Programs 

Sacramento, Delevan, Colusa, and Sutter Refuges are managed as part of the National 

Wildlife Refuge System within a framework provided by legal and policy guidelines 

reviewed in Chapter 1 of this CCP. The role of the Service is introduced in Chapter 1, as 

well as the mission of the National Wildlife Refuge System. The Service’s policies on 

Compatibility, Planning, and Biological Integrity, Diversity, and Environmental Health 

mandated by the National Wildlife Refuge System Improvement Act of 1977 are also 

discussed in Chapter 1, which also provides a general overview of regulatory context. The 

Comprehensive Conservation Planning process is discussed in Chapter 2. 

The Service is actively involved in the development and implementation of a number of 

conservation plans for migratory bird species, including the Partners in Flight North 

American Landbird Conservation Plan, North American Waterfowl Management Plan, 

United States Shorebird Conservation Plan, and the North American Waterbird 

Conservation Management Plan. Regional step-down plans specific to the area are 

discussed below. 

2.1 North American Waterfowl Management Plan 

(U. S. Fish and Wildlife Service and Canadian Wildlife Service. 1986. North American 

Waterfowl Management Plan. U. S. Dept. of Int. Rep., Washington, D. C. 19 pp.) 

The North American Waterfowl Management Plan documents the strategy between the 

United States, Canada and Mexico to restore waterfowl populations through habitat 

protection, restoration and enhancement. Implementation of the plan is at the regional 

level. The Sacramento, Delevan, Colusa, and Sutter Refuges are covered by the Central 

Valley Joint Venture. The Central Valley, from Red Bluff in the north to Bakersfield in 

the south, is the single most important waterfowl wintering area in the Pacific Flyway, 

supporting 60 percent of all the total migrating population. Hundreds of thousands of 

wintering and breeding shorebirds and a host of other migratory and resident birds also 

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depend on the wetland and agricultural resources of this region for survival. The Central 

Valley Joint Venture is currently in the process of updating its implementation plan, and 

will include goals for the conservation of breeding and wintering waterfowl, breeding and 

wintering shorebirds, grassland and riparian birds, and other waterbirds. 

North American Waterfowl Management Plan Goals 

(U. S. Fish and Wildlife Service, Canadian Wildlife Service, and Mexican National 

Institute of Ecology. 1998. Expanding the vision: 1998 Update -North American 

Waterfowl Management Plan. U. S. Dept. of Int. Rep., Washington, D. C. 34 pp.) 

 Enhance the capability of landscapes to support waterfowl and other wetlandassociated species by ensuring that Plan implementation is guided by biologically 

based planning, which in turn is refined through ongoing evaluation. 

 Define the landscape conditions needed to sustain waterfowl and benefit other 

wetland-associated species, and participate in the development of conservation, 

economic, management, and social policies and programs that most affect the 

ecological health of these landscapes. 

 Collaborate with other conservation efforts, particularly migratory bird initiatives, 

and reach out to other sectors and communities to forge broader alliances in a 

collective search for sustainable uses of landscapes. 

 Maintain the current diversity of duck species throughout North America and 

achieve a continental breeding population of 62 million ducks during years with 

average environmental conditions, which would support a fall flight of 100 million. 

 Increase or reduce goose populations to sustainable levels listed in Appendix 1. 

 Reduce Western tundra swan population to 60,000, and increase Pacific Coast 

trumpeter swan population to 43,200. 

 In the Central Valley Habitat Joint Venture Area, protect 80,000 acres, restore 

120,000 acres, and enhance 735,000 acres. 

Central Valley Joint Venture 2006 Implementation Plan 

(Central Valley Joint Venture (CVJV). 2006. Central Valley Joint Venture 

Implementation Plan – Conserving Bird Habitat. U. S. Fish and Wildlife Service, 

Sacramento, CA.) 

The mission of the Central Valley Joint Venture is to work collaboratively through 

diverse partnerships to protect, restore, and enhance wetlands and associated habitats 

for waterfowl, shorebirds, waterbirds, and riparian songbirds, in accordance with 

conservation actions identified in the Implementation Plan. 

Central Valley Objectives by habitat type: 

 Protect seasonal wetlands 

 Restore 108,527 acres of seasonal wetlands 

 Enhance 23,884 acres of seasonal wetlands 

 Restore 12,500 acres of semi-permanent wetlands 

 Restore 10,000 acres of riparian areas 

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 Enhance 170,000 acres of rice cropland 

 Enhance 307,000 acres of waterfowl-friendly agricultural crops. 

2.2 Partners in Flight (PIF) Bird Conservation Plan 

(Rich, T. D., C. J. Beardmore, H. Berlanga, P. J. Blancher, M. S. W. Bradstreet, G. S. 

Butcher, D. W. Demarest, E. H. Dunn, W. C. Hunter, E. E. Iñigo-Elias, J. A. Kennedy, A. M. 

Martell, A. O. Panjabi, D. N. Pashley, K. V. Rosenberg, C. M. Rustay, J. S. Wendt, and T. C. 

Will. 2004. Partners in Flight North American Landbird Conservation Plan. Cornell Lab of 

Ornithology. Ithaca, NY.) 

North American Landbird Conservation Plan (Rich et. al 2004) summarizes geographic 

and habitat priorities for 449 species of landbirds across the continent. This plan includes, 

for the first time anywhere, estimates of continental population sizes and future 

population objectives for all landbirds. This plan will not replace Bird Conservation Plans, 

but rather will initiate a new round of dialogue on population and habitat objectives at 

continental, national, regional, state and local levels. The highest priority birds (102 

species) constitute the new PIF Watch List. Also included in the plan is a list of 

characteristic species, which include species that may not be rare or declining but which 

are integral to the biotic integrity of large habitats or regions. These species, along with 

the Watch List species, are addressed as species suites in the plan. PIF’s objective is to 

help land managers use the PIF plans, along with those from other bird initiatives, to 

undertake effective habitat conservation actions in the proper geographic context in 

North America. 

The California Partners in Flight (CalPIF) began in 1992 to promote the conservation of 

resident and migratory landbirds and their habitats in California through research, 

monitoring, education, and collaboration among public and private landowners and 

managers, government agencies, non-government organizations, and individuals and 

other bird conservation efforts. The California Partners in Flight program has completed 

six habitat and bioregion based Bird Conservation Plans (BCP's) for Riparian, Oak 

Woodlands, Coastal Scrub and Chaparral, Grasslands, Coniferous Forests, and the Sierra 

Nevada Bioregion. A Shrub steppe Plan is currently in review and a Desert Plan is in 

development. 

CalPIF initiated the Riparian Habitat Joint Venture (RHJV) project in 1994. The goal of 

the RHJV is to conserve, increase, and improve riparian habitat in order to protect and 

enhance California's native resident birds and Neotropical migratory birds. The Riparian 

Bird Conservation Plan (RHJV 2004) emphasizes a suite of 17 bird species chosen because 

of their conservation interest and as focal species representative of riparian habitats in 

the state. This Conservation Plan focuses on data concerning bird species associated with 

riparian habitat, but conservation recommendations, if implemented, should benefit many 

riparian associated species. 

The six objectives of the RHJV are: (1) Compile existing information on riparian habitat 

throughout the state to identify key riparian areas, as well as information gaps. Promote 

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and coordinate efforts to obtain the information. (2) Develop guidelines for the protection 

of existing riparian habitat on public lands and recommend alternatives for protection of 

habitat on private lands. (3) Restore riparian habitat on public and private lands using 

commonly accepted, scientifically valid restoration techniques. (4) Enhance the 

productivity and biodiversity of riparian communities using appropriate management 

techniques. (5) Establish a network of high-quality riparian habitats throughout 

California to enhance and protect native birds. (6) Educate the general public and 

resource managers about the status and value of California's riparian habitat. 

Riparian Bird Conservation Plan 

(Riparian Habitat Joint Venture (RHJV). 2004. Version 2.0. The Riparian Bird 

Conservation Plan: a strategy for reversing the decline of riparian associated birds in 

California. California Partners in Flight. http://www.prbo.org/calpif/pdfs/riparian_v-2.pdf.) 

 Increase the breeding range of native birds and safeguard healthy bird 

communities with high productivity. 

 Maximize riparian ecosystem health, promote a self-sustaining functioning system, 

and maximize the cost-effectiveness of riparian conservation activities. 

 Increase the overall breeding range and/or abundance of native riparian birds by 

designing and implementing horticultural restoration projects that mimic natural 

riparian plant diversity and “patchiness”. Such plantings will most quickly support 

a diverse community of bird species that can successfully nest in the restored 

habitat. 

 Increase the value of existing/ongoing habitat and restoration projects for bird 

species. 

 Ensure that large landscape-scale management and flood control projects 

maximize benefits to wildlife in conjunction with benefits to agriculture and urban 

populations. Achieving numerous goals simultaneously would maximize the overall 

value of such projects to the people of California. 

 Implement and time land-management activities with the goal of maximizing bird 

species productivity or “source” populations. 

 Protect, recreate, or minimize interruptions of natural processes, particularly 

hydrology and associated high-water events to allow/promote/facilitate the natural 

cycle of channel movement, sediment deposition, and scouring that results in a 

diverse mosaic of riparian vegetation classes. 

Draft Grassland Bird Conservation Plan 

(California Partners in Flight (CPIF). 2000. Version 1.0. The draft grassland bird 

conservation plan: a strategy for protecting and managing grassland habitats and associated 

birds in California (B. Allen, lead author). Point Reyes Bird Observatory, Stinson Beach, 

CA. http://www.prbo.org/calpif/plans.html.) 

The Draft Grassland Bird Conservation Plan was developed to guide conservation policy 

and action on behalf of grassland habitats and birds. The geographic scope of this plan is 

the distribution of annual and native perennial grasslands in the state, which are found 

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predominantly along the coast and in California’s Great Central Valley. The plan has focus 

on data concerning seven focal grassland bird species that are dependent on these habitat 

types. 

Conservation Action Recommendations include: 

 Monitoring/Research 

o Initiate statewide point count project. 

o Develop methods to monitor productivity and survivorship for grassland 

birds. 

o Determine sensitivity of California’s grassland birds to grassland patch size. 

o Determine grassland bird response to various grazing, burning, mowing, 

and disking regimes that occur in California. 

o Determine benefits / drawbacks of various agricultural regimes. 

o Determine if grassland birds select for or have increased productivity 

/survivorship in native grasslands vs. non-native grasslands. “Do native 

grass restorations restore native grassland birds?” 

 Habitat Restoration/Management 

o Avoid mowing and disking during the breeding season. 

o Avoid burning during the breeding season. 

 Habitat Protection 

o Identify remaining grassland areas of large patch size that have high 

species abundance and productivity for grassland birds. 

o Target unprotected areas that have been identified for protection as priority 

areas for (a) land purchases when possible, (b) conservation easements, and 

(c) the forging of partnerships with private landowners to create win-win 

situations. 

o Target areas with quality grassland habitat for protection status before 

targeting at-risk or degraded habitat. 

2.3 United States Shorebird Conservation Plan 

(Brown, S., Hickey, C., Harrington, B., and Gill, R. 2001. United States Shorebird 

Conservation Plan, Second Edition. Manomet Center for Conservation Sciences, Manomet, 

MA. 64 pp.) 

The United States Shorebird Conservation Plan was developed through a partnership 

effort by State and Federal agencies, non-government organizations (NGOs), academic 

institutions, and individuals committed to restoring and maintaining stable shorebird 

populations in the U.S. and throughout the Western Hemisphere (Brown et al. 2001). The 

Southern Pacific Coast Regional Shorebird Management Plan (Hickey et. al 2003) 

establishes regional goals and objectives for the western California Coast and Central 

Valley. Important shorebird habitats identified under this plan in the Central Valley 

include managed wetlands, agricultural fields and vernal pool rangelands. 

Southern Pacific Coast Regional Shorebird Plan 

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(Hickey, C., W. D. Shuford, G. W. Page, and S. Warnock. 2003. Version 1.1. The Southern 

Pacific Shorebird Conservation Plan: A strategy for supporting California’s Central Valley 

and coastal shorebird populations. PRBO Conservation Science, Stinson Beach, CA.) 

 Increase the wintering population of the Mountain Plover in the Central Valley. 

Create suitable open foraging habitat by managing for giant kangaroo rats 

(Dipodomys ingens) and using fire and grazing, as appropriate. 

 Increase populations of breeding and wintering Snowy Plovers and wintering 

Long-billed Curlews in the Central Valley. 

 Increase breeding and wintering populations of other shorebirds in the Central 

Valley. 

 Restore, enhance, and manage wetlands with integrated wetland management 

goals, which accommodate the needs of a greater diversity of birds, including 

shorebirds. 

 Ensure the availability of high quality water for wetlands. 

 Resist fragmentation or loss of existing wetland complexes by urban 

encroachment. 

 Promote management practices in agricultural lands and vernal pool rangelands 

that will provide for a greater diversity of birds, including shorebirds. Also, 

promote easements and other options for maintaining wildlife-friendly agricultural 

lands and vernal pool rangelands. 

 Reduce the use of contaminated agricultural evaporation ponds by shorebirds and 

other waterbirds while creating alternative uncontaminated habitats that will 

mimic historic saline playa wetlands thereby maintaining the current mix of 

waterbird communities. 

 Increase shorebird use of sewage ponds or wetlands using treated sewage effluent 

if issues of disease transmission and contaminants can be addressed. 

2.4 North American Waterbird Conservation Plan 

(Kushlan, J. A., M. J. Steinkamp, K. C. Parsons, J. Capp, M. Acosta Cruz, M. Coulter, I. 

Davidson, L. Dickson, N. Edelson, R. Elliot, R. M. Erwin, S. Hatch, S. Kress, R. Milko, S. 

Miller, K. Mills, R. Paul, R. Phillips, J. E. Saliva, B. Sydeman, J. Trapp, J. Wheeler, and K. 

Wohl. 2002. Waterbird Conservation for the Americas: The North American Waterbird 

Conservation Plan, Version 1. Waterbird Conservation for the Americas, Washington, DC, 

U.S.A., 78 pp) 

North American Waterbird Conservation Plan (NAWCP) provides an overarching 

continental framework and guide for conserving waterbirds. It sets forth goals and 

priorities for waterbirds in all habitats from the Canadian Arctic to Panama, from 

Bermuda through the U.S. Pacific Islands, at nesting sites, during annual migrations, and 

during non-breeding periods. It advocates continent-wide monitoring; provides an 

impetus for regional conservation planning; proposes national, state, provincial and other 

local conservation planning and action; and gives a larger context for local habitat 

protection. 

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The vision of the NAWCP is the distribution, diversity, and abundance of breeding, 

migratory, and non-breeding waterbirds are sustained or restored throughout North 

America, Central American, and the Caribbean. Four goals were established in the plan 

(Kushlan et. al 2002) to accomplish this vision (1) species and population goal, (2) habitat 

goal, (3) education and information goal, and (4) coordination and integration goal. A 

regional step-down plan for the Pacific Coast will focus on key species and habitats and 

develop specific goals and objectives for management, monitoring, research and outreach. 

Species and Population Strategies 

 Determine population status for all species of waterbirds throughout North 

America, Central America, and the Caribbean. 

 Institute a large scale, dispersed, partnership-based population monitoring system. 

 Initiate monitoring of demography, habitats, wintering range, and important 

threats, such as seabird bycatch, as appropriate for species and areas. 

 Develop analytical tools and analytical schemes to determine and assess population 

trends against trend thresholds for each species. 

 Define sustainable population goals for all species, at regional scales as possible 

and as needed, and eventually at the continental scale. 

 Determine the extent and root causes of public perception of waterbirds, 

particularly locally abundant species, and develop programs that help bring public 

perception in line with scientific and economic findings. 

 Energize Joint Ventures and agencies to take responsibility for setting and 

achieving population goals through appropriate management. 

 Develop a global perspective on populations to aid in interpretation of population 

trends. 

 Synthesize information to identify key factors affecting populations in order to take 

appropriate conservation action. 

Habitat Strategies 

 Identify key marine, freshwater, and terrestrial habitats for waterbirds, including 

breeding, wintering, migratory, roosting, and foraging habitats. 

 Implement conservation and management actions that secure important habitats. 

 Increase understanding of waterbird habitat requirements, threats to habitat 

quality, and habitat interaction at different scales. 

 Develop and implement habitat management plans for waterbirds for each 

planning unit. 

 Identify, inventory and document key sites that potentially qualify as global, 

continental, national, or state Important Bird Areas (IBAs) and other key sites for 

waterbirds. 

 Refine and continually update the list and description of IBAs for waterbirds. 

Education and Information Strategies 

 Ensure that information on waterbird conservation is available in a form that is 

useful for planning, implementation, and management purposes. 

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 Increase effectiveness of communication by partnering with outreach activities for 

other birds and for other environmental programs. 

 Develop relationships with educators of all levels and participate in programs that 

increase awareness and improve education. 

 Develop and widely distribute educational information on habitat conservation 

strategies. 

 Work with users of waterbird habitats to promote practices and policies that 

reduce impacts on the birds. 

Coordination and Integration Strategies 

 Establish cooperative actions with organizations concerned with the conservation, 

research, and management of waterbirds and their habitats. 

 Establish cooperative actions with other bird conservation initiatives, particularly 

through common goal setting, and multi-species approaches such as advocated by 

North American Bird Conservation Initiative (NABCI). 

 Establish cooperative linkages with other bird conservation initiatives concerned 

with aquatic habitats. 

 When initiatives for other aquatic bird groups are not underway, catalyze 

simultaneous planning and conservation of all water-dependent bird species. 

 Seek to achieve integrated bird conservation action that incorporates the needs of 

waterbirds. 

 Exchange information and expertise with international, national, regional 

state/provincial and local partners, and establish networks between 

conservationists, scientists, and habitat managers. 

 Develop waterbird plans, where appropriate, at national, regional, JV, and 

state/provincial levels. 

 Influence environmental policies and programs to positively affect waterbird 

conservation. 

 Participate in international programs in ways that enhance the conservation of 

waterbirds. 

 Increase human and financial resources available for waterbird conservation. 

.5 USFWS/CDFG Tricolored Blackbird Status Update and Management Guidelines 

(Beedy, E.C. and W.J. Hamilton 1997. Tricolored Blackbird Status Update and 

Management Guidelines. Jones and Stokes, Inc. 97-009. Sacramento, CA. Prepared 

for USFWS and CDFG. 55 pp.) 

 Maintain viable, self-sustaining populations distributed throughout the current 

range of the species. 

 Avoid losses of tricolored blackbird colonies and their reproductive effort 

throughout their range. 

 Increase the breeding opportunities on suitable public lands and on private lands 

managed for this species. 

 Enhance public awareness and support for protection of this unique species. 

2

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 Minimize losses of important foraging habitat for both nesting and wintering 

populations. 

2.6 Pacific Flyway Management Plan: Western Management Unit Mourning Dove 

Goals and Objectives 

(Pacific Flyway Council. 2003. Pacific Flyway Management Plan for Western White-winged 

Doves. U. S. Fish and Wildlife Service, Portland, Oregon. 27pp.) 

 Maintain the Western Management Unit (WMU) population of mourning doves 

and its habitat at levels consistent with optimum distribution, density, and 

recreational uses of the resources. 

 Determine the causes of mourning dove population declines in the WMU and 

establish procedures to reverse the trends. 

 Increase the population levels of WMU mourning doves to a point where call-count 

indices average no less than 16 in the Coastal subunit. 

 Increase and maintain adequate habitat to sustain the current seasonal distribution 

of WMU mourning doves throughout their range. The important habitat 

components are appropriate structures for nesting and roosting (trees), and food 

and water sources. 

 Maximize the potential for sustained consumptive and non-consumptive uses of the 

mourning dove resource in the WMU. 

2.7 Anadromous Fish Restoration Program 

The Central Valley Project Improvement Act (CVPIA) was signed into law in 1992. The 

CVPIA directed the Secretary of the Interior to amend previous authorizations of 

California's Central Valley Project to: "include fish and wildlife protection, restoration, 

and mitigation as project purposes having equal priority with irrigation and domestic use 

and fish and wildlife enhancement as a project purpose equal to power generation." 

Section 3406(b)(1) of the CVPIA directs the Secretary of the Interior to develop and 

implement a program that makes all reasonable efforts to at least double natural 

production of anadromous fish in California's Central Valley streams on a long-term, 

sustainable basis. 

The major resulting program is known as the Anadromous Fish Restoration Program 

(AFRP). The goal of the AFRP, is concurrent to section 3406(b)(1) of the CVPIA, to 

"develop within three years of enactment and implement a program which makes all 

reasonable efforts to ensure that, by the year 2002, natural production of anadromous fish 

in Central Valley rivers and streams will be sustainable, on a long-term basis, at levels not 

less than twice the average levels attained during the period of 1967-1991." Since 1995, the 

AFRP has helped implement over 195 projects to restore natural production of 

anadromous fish. 

Six general objectives need to be met to achieve this program goal: 

 Improve habitat for all life stages of anadromous fish through provision of flows of 

suitable quality, quantity, and timing, and improved physical habitat; 

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 Improve survival rates by reducing or eliminating entrainment of juveniles at 

diversions; 

 Improve the opportunity for adult fish to reach their spawning habitats in a timely 

manner; 

 Collect fish population, health, and habitat data to facilitate evaluation of 

restoration actions; 

 Integrate habitat restoration efforts with harvest and hatchery management; 

 Involve partners in the implementation and evaluation of restoration actions. 

3.0 State of California 

3.1 California Wildlife Action Plan, California Wildlife Conservation Challenges 

(California Department of Fish and Game. 2005c. California Wildlife Conservation 

Challenges California’s Wildlife Action Plan. Prepared by U. C. Davis Wildlife Health Center 

for the California Department of Fish and Game. Sacramento, CA. 624 pp.) 

Conservation actions were considered for each region, based on the stressors and 

circumstances of the regions. Statewide conservation actions are those actions that are 

important across most or all regions. The following are recommended statewide 

conservation actions: 

A. The state should develop policies and incentives to facilitate better integration of 

wildlife conservation considerations into local and regional planning and land-use 

decision-making. 

B. Permitting agencies, county planners, and land management agencies should work 

to ensure that infrastructure development projects are designed and sited to avoid 

harmful effects on sensitive species and habitats. 

C. The state should develop policies and incentives to better integrate wildlife 

conservation into state and regional transportation planning. Wildlife 

considerations need to be incorporated early in the transportation planning 

process. 

D. State and federal agencies should work with cities and counties to secure sensitive 

habitats and key habitat linkages. 

E. State and local agencies should allocate sufficient water for ecosystem uses and 

wildlife needs when planning for and meeting regional water supply needs. 

F. Federal, state, and local agencies should provide greater resources and coordinate 

efforts to control existing occurrences of invasive species and to prevent new 

introductions. 

G. Federal, state, and local agencies and nongovernmental conservation 

organizations, working with private landowners and public land managers, should 

expand efforts to restore and conserve riparian communities. 

H. Federal, state, and local agencies and nongovernmental organizations, working with 

private landowners, should expand efforts to implement agricultural and rangeland 

management practices that are compatible with wildlife and habitat conservation. 

I. In their conservation planning and ecosystem restoration work, state and federal 

wildlife agencies and land managers should consider the most current projections of 

the effects of global warming. 

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J. The state and federal governments should give greater priority to wildlife and natural 

resources conservation education. 

K. The state should strengthen its capacity to implement conservation actions and to 

assist local agencies and landowners with planning and implementation of wildlife 

and habitat restoration and conservation efforts. 

The following are recommended conservation actions for the Central Valley and BayDelta Region: 

A. The California Resources Agency, Fish and Game, the U.S. Fish and Wildlife 

Service, public land managing agencies, and local governments need to develop 

multicounty regional habitat conservation and restoration plans. 

B. While numerous private landowners are leaders in conservation, Fish and Game, 

the U.S. Fish and Wildlife Service, the USDA Natural Resources Conservation 

Service, and local resource conservation districts need to improve conservation and 

restoration on private lands by assisting private landowners. 

C. Public land managers need to continue improving wildlife habitat for a variety of 

species on public lands. 

D. Public agencies and private organizations need to work with the San Francisco Bay 

Joint Venture to protect and restore tidal habitats and baylands in San Francisco 

Bay. 

E. Public agencies and private organizations need to collaboratively protect and 

restore habitat connectivity along major rivers in the Central Valley. 

F. Public agencies and private organizations need to collaboratively protect and 

restore upland linkages among protected areas in the San Joaquin Valley. 

G. Public agencies and private organizations need to collaboratively protect and 

restore lowland linkages in San Francisco Bay. 

H. Public agencies and private organizations need to collaboratively protect upland 

linkages and reduce the risk of habitat isolation in the eastern and northern San 

Francisco Bay area. 

I. Water management agencies need to secure dependable and adequate amounts 

and quality of water for wildlife. 

J. Water management agencies need to reestablish and maintain more natural river 

flows, flooding patterns, water temperatures, and salinity conditions to support 

wildlife species and habitats. 

K. Water management agencies need to restore gravel supply in sediment-starved 

rivers downstream of reservoirs to maintain functional riverine habitats. 

L. Public agencies and private organizations should protect, restore, and improve 

water-dependent habitats (including wetland, riparian, and estuarine) throughout 

the region. Design of these actions should factor in the likely effects of accelerated 

climate change. 

M. Water management agencies, state and federal wildlife agencies, and other public 

agencies and private organizations need to collaboratively improve fish passage by 

removing or modifying barriers to upstream habitat. 

M-16 
N. To support healthy aquatic ecosystems, public agencies and private organizations, 

in collaboration with the California Bay-Delta Authority, need to improve and 

maintain water quality in the major river systems of this region. 

O. Regional water quality boards, in collaboration with other public agencies and 

private organizations, need to improve and maintain water quality in streams and 

tidal waters of San Francisco Bay. 

P. Fish and Game should expand funding and coordinate efforts to prevent the 

establishment of invasive species and to reduce the damage of established invasive 

species. 

Q. State and federal agencies should expand law enforcement funding and staffing 

and coordinate efforts to enforce regulations to prevent the degradation of rivers 

and streams and to detect, prevent and take actions to protect water quality. 

4.0 County 

The Sacramento, Delevan, Colusa, and Sutter Refuges include parts of Colusa, Glenn, and 

Sutter counties. Each county is a multi-purpose government structure directed by an 

elected Board of Supervisors. There are also numerous special districts within each 

county, which are limited-purpose governmental agencies, such as fire districts, mosquito 

and vector control districts, irrigation districts and reclamation districts. Local land use 

policies are established in the general plans of each county, which are adopted by the 

respective Boards of Supervisors. The three counties’ general plans designate the 

Refuges as follows: 

 Glenn County General Plan (1993) – The Refuge is entirely within the 

“Recreation” Land use designation and the “RZ (Recreational Zone)” Zoning 

District. The General Plan is primarily directed to the support of agricultural use 

in the rural area and there is also a policy specifying early consultation for projects 

involving Wildlife Management Agencies. 

 Colusa County General Plan (1989) - The land use policies of the County General 

Plan is primarily directed to the support of agricultural use in the rural area and 

there are also policies regarding the value of natural resources. 

 Sutter County General Plan (1996) – The Refuge is entirely within the “Open 

Space” land use designation. The land use policies of the County General Plan are 

primarily directed to the support of agricultural use in the rural area and there are 

also policies regarding the value of natural resources. 

The local land use polices of Glenn, Colusa, and Sutter counties that relate to management 

of the Refuges are summarized in Table 2 below. 

M-17 
Table 2. Summary of Local Land Use Policies that relate to Refuge Management. 

County Category Land Use Policy 

Glenn County 5.1.1 As the most extensive land use in the county, 

General Plan Agricultural/ agriculture constitutes a significant component of the 

(1993) Soils local economy. Agricultural land also provides valuable 

open space and important wildlife habitat. It is 

important that the County take steps to preserve its 

agricultural land from both economic and 

environmental perspectives. 

...Converting prime agricultural land to nonagricultural uses is considered an irreversible loss of 

resources. ...With the primary goal being that of 

preserving the county’s valuable agricultural 

resources, a variety of preservation tools can be 

used.... 

NR Goal-1: Preservation of agricultural land 

Glenn County 5.1.2 Water The abundant supplies of surface and groundwater 

General Plan Resources within Glenn County make the county "water rich". A 

(1993) statewide demand for water for both domestic and 

agricultural: water use and recent State and federal 

requirements to ensure that adequate supplies of 

water are available in rivers, streams and other 

natural areas to sustain wildlife result in strong 

competition for available water. 

NR Goal-2: Protection and management of local water 

resources. 

Glenn County 5.1.3 The conservation, development and utilization of 

General Plan Biological natural resources, including fisheries and wildlife, are 

(1993) Resources the purpose of the conservation element. 

NR Goal-3: Preservation and enhancement of the 

county's biological resources in a manner compatible 

with a sound local economy. 

Glenn County 6.7 For all projects, with the exception of those associated 

General Plan Coordination with sites low in wildlife value, early consultation with 

(1993) with Wildlife 

and Land 

Management 

Agencies 

wildlife agencies should occur. 

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Table 2. Summary of Local Land Use Policies that relate to Refuge Management. 

County Category Land Use Policy 

Integrated The unincorporated communities within Colusa 

Resources County include Arbuckle, College City, Grimes, 

Management Maxwell, Princeton, and Stonyford. Incorporated cities 

Program for in Colusa County include Colusa and Williams. The 

Flood Control county also contains small settlement areas with 

in the Colusa permanent populations of less than 100 people. Land 

Basin (Colusa uses in Colusa County are typical of the rural counties 

Basin of California. 

Drainage 

District and 

U.S. Bureau of 

Reclamation 

2000) 

The eastern half of the county is dominated by large 

farms with much of the privately owned land following 

square-mile section lines. This portion of the county is 

relatively flat and use for the cultivation of rice, 

orchards, and row crops. The western half of the 

county contains the Coastal Range foothills, which are 

often used as rangeland. 

Colusa County Land Use The Land Use Element encourages a balanced mix of 

General Plan Element land uses, which reflect the need of the local 

(1989) population. Additionally, agricultural land will be 

conserved and protected through a variety of 

strategies including taxation, zoning, and general 

planning. 

Colusa County Resource The Resource Conservation Element encourages 

General Plan Conservation conservation of fish and wildlife habitat throughout the 

(1989) Element county. Preservation of the natural qualities of rivers 

and streams is also encouraged. Zoning, planning, and 

taxation policies should preserve watershed areas, as 

well as agricultural lands and hillside areas. 

Development in the Sacramento River floodway and 

ecologically sensitive areas is discouraged. 

Colusa County Open Space The Open Space and Recreation Element encourages 

General Plan and the preservation of open space and opportunities for 

(1989) Recreation 

Element 

recreational and leisure time activities. 

M-19 
Table 2. Summary of Local Land Use Policies that relate to Refuge Management. 

County Category Land Use Policy 

Colusa County “Current land use within the eastern one-half of 

Interim Colusa County is primarily “irrigated farmland” with 

Farmland 1996 small pockets of “non-irrigated farmland,” “urban and 

(California built-up land”, and “other land” (primarily wildlife 

Department of preservation areas). The central area of the county 

Conservation consists primarily of “non-irrigated farmland” and the 

1998) westernmost section of the county is primarily “other 

land” (i.e., Mendocino National Forest). Water bodies 

in the county include Funks Reservoir and East Park 

Reservoir, which are located in the northern and 

western centers respectively. 

Sutter County Section 1 Goal 1.F: To minimize conflicts between agricultural 

General Plan Land Use and non-agricultural uses. 

(1996) Goal 1.G: To preserve and protect open space and 

natural resources and reduce pollution. 

Goal 1.H: To preserve and protect the visual and scenic 

resources of the area. 

Sutter County Section 4 Goal 4.B: To protect wetland and riparian wetlands 

General Plan Conservation throughout Sutter County. 

(1996) /Open Space 

– Natural 

Resources 

Goal 4.C: To protect and enhance habitats that support 

fish and wildlife species. 

Goal 4.D: To preserve and protect vegetation 

resources of Sutter County. 

Goal 4.E: To conserve, protect, and enhance open 

space lands and natural resources in Sutter County. 

Sutter County Section 5 Goal 5.A: To provide adequate park and open space 

General Plan Conservation areas for passive and active recreational, social, 

(1996) /Open Space 

– Recreation 

and Cultural 

Resources 

educational and cultural opportunities for the residents 

of Sutter County. 

Sutter County 

General Plan 

(1996) 

Section 6 

Agricultural 

Resources 

Goal 6.A: To preserve high quality agricultural land for 

agricultural purposes. 

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Appendix N. List of Planning Team 

Members and Persons Responsible for 

Preparing this Document 

U.S. Fish and Wildlife Service 

Core Planning Team 

Kevin Foerster Project Leader, Sacramento NWRC 

J. Greg Mensik Deputy Refuge Manager, Sacramento NWRC 

Steven Emmons Refuge Manager, Sacramento and Delevan NWRs 

Michael Peters Refuge Manager, Colusa and Sutter NWRs 

Michael Wolder Supervisory Wildlife Biologist, Sacramento NWRC 

Denise Dachner Outdoor Recreation Planner, Sacramento NWRC 

Jacqueline Ferrier Refuge Planner, Sacramento NWRC 

Expanded Team Members 

Andy Atkinson Wildlife Habitat Supervisor, California Dept. of Fish and Game 

Nancy Hoffman Asst. Refuge Supervisor, Region 8 

Michael Carpenter Wildlife Biologist, Sacramento NWRC 

Paul Hofmann Wildlife Biologist, California Dept. of Fish and Game 

Rob Holbrook Central Valley Joint Venture Science Coordinator, FWS 

Jennifer Isola Wildlife Biologist, Sacramento NWRC 

Richard Kuyper Fish and Wildlife Biologist, FWS – Sacramento FWO 

Dan Meier Fish and Wildlife Program Manager, Bureau of Reclamation 

Miriam Morrill Wildland Urban Interface Coordinator, NorCal 

Dale Shippelhoute Fire Management Officer, Sacramento NWRC 

Joseph Silveira Wildlife Biologist, Sacramento NWRC 

Michelle Tovar Fish and Wildlife Biologist, FWS – Sacramento FWO 

Robert Trost Pacific Flyway Representative, Migratory Bird Management 

Reviewers 

David Bergendorf Refuge Planning, Region 8 

Margaret Kolar Assistant Regional Director for Refuges, Region 8 

Mark Pelz Chief of Refuge Planning, Region 8 

Anan Raymond Chief of Cultural Rescources, Region 1 

Patricia Roberson NEPA/Policy Coordinator, Region 8 

Art Shine Chief of Visitor Services, Region 8 

Richard Smith Refuge Planning, Region 8 

Scott Stevens Chief of Refuge Law Enforcment, Region 8 

Doug Waggoner Fire Management Coordinator, Region 8 

Dan Walsworth Refuge Supervisor, Region 8 

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N-2 
Appendix O. Wilderness Review 

Introduction 

The purpose of a wilderness review is to identify and recommend for Congressional 

designation National Wildlife Refuge System (Refuge System) lands and waters that 

merit inclusion in the National Wilderness Preservation System (NWPS). Wilderness 

reviews are a required element of comprehensive conservation plans (CCPs) and 

conducted in accordance with the refuge planning process outlined in 602 FW 1 and 3, 

including public involvement and the National Environmental Policy Act (NEPA) 

compliance. 

There are three phases to the wilderness review: (1) inventory, (2) study; and (3) 

recommendation. Lands and waters that meet the minimum criteria for wilderness are 

identified in the inventory phase. These areas are called wilderness study areas (WSAs). 

WSAs are evaluated through the CCP process to determine their suitability for 

wilderness designation. In the study phase, a range of management alternatives are 

evaluated to determine if a WSA is suitable for wilderness designation or management 

under an alternate set of goals and objectives that do not involve wilderness designation. 

The recommendation phase consists of forwarding or reporting recommendations for 

wilderness designation from the Director through the Secretary and the President to 

Congress in a wilderness study report. 

If the inventory does not identify any areas that meet the WSA criteria, we document our 

findings in the administrative record for the CCP, fulfilling the planning requirement for 

a wilderness review. We inventoried U.S. Fish and Wildlife Service (Service) lands and 

waters within the Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges 

(Refuges) and found no areas that meet the eligibility criteria for a WSA as defined by the 

Wilderness Act. This appendix summarizes the wilderness inventory for the Refuges. 

Inventory Criteria 

The wilderness inventory is a broad look at the planning area to identify WSAs. These are 

roadless areas that meet the minimum criteria for wilderness identified in Section 2(c) of 

the Wilderness Act. 

"A wilderness, in contrast with those areas where man and his works dominate the 

landscape, is hereby recognized as an area where the earth and its community of life 

are untrammeled by man, where man himself is a visitor who does not remain. An 

area of wilderness is further defined to mean in this Act an area of undeveloped 

Federal land retaining its primeval character and influence, without permanent 

improvements or human habitation, which is protected and managed so as to 

preserve its natural conditions, and which: (1) generally appears to have been 

affected primarily by the forces of nature, with the imprint of man’s work 

substantially unnoticeable; (2) has outstanding opportunities for solitude or a 

primitive and unconfined type of recreation; (3) has at least five thousand acres of 

land or is of sufficient size as to make practicable its preservation and use in an 

O-1 
unimpaired condition; and (4) may also contain ecological, geological or other 

features of scientific, educational, scenic, or historical value." 

A WSA must be a roadless area or island, meet the size criteria, appear natural, and 

provide outstanding opportunities for solitude or primitive recreation. The process for 

identification of roadless areas and islands in Refuges and application of the wilderness 

criteria are described in the following sections. 

Identification of Roadless Areas and Roadless Islands 

Identification of roadless areas and roadless islands required gathering and evaluating 

land status maps, land use and road inventory data, and aerial photographs for the 

Refuges. “Roadless” refers to the absence of improved roads suitable and maintained for 

public travel by means of motorized vehicles primarily intended for highway use. Only 

lands currently owned by the Service in fee title were evaluated. 

Evaluation of the Size Criteria 

Roadless areas or roadless islands meet the size criteria if any one of the following 

standards apply. 

 An area with over 5,000 contiguous acres. State and private lands are not included 

in making this acreage determination. 

 A roadless island of any size. A roadless island is defined as an area surrounded by 

permanent waters or that is markedly distinguished from the surrounding lands by 

topographical or ecological features. 

 An area of less than 5,000 contiguous Federal acres that is of sufficient size as to 

make practicable its preservation and use in an unimpaired condition, and of a size 

suitable for wilderness management. 

 An area of less than 5,000 contiguous Federal acres that is contiguous with a 

designated wilderness, recommended wilderness, or area under wilderness review 

by another Federal wilderness managing agency such as the Forest Service, 

National Park Service, or Bureau of Land Management. 

Evaluation of the Naturalness Criteria 

In addition to being roadless, a WSA must meet the naturalness criteria. Section 2(c) 

defines wilderness as an area that “... generally appears to have been affected primarily 

by the forces of nature with the imprint of man’s work substantially unnoticeable.” The 

area must appear natural to the average visitor rather than “pristine.” The presence of 

historic landscape conditions is not required. An area may include some human impacts 

provided they are substantially unnoticeable in the unit as a whole. Significant humancaused hazards, such as the presence of unexploded ordnance from military activity, and 

the physical impacts of refuge management facilities and activities are also considered in 

evaluation of the naturalness criteria. An area may not be considered unnatural in 

appearance solely on the basis of the “sights and sounds” of human impacts and activities 

outside the boundary of the unit. 

O-2 
 

Evaluation of Outstanding Opportunities for Solitude or Primitive and Unconfined 

Recreation 

In addition to meeting the size and naturalness criteria, a WSA must provide outstanding 

opportunities for solitude or primitive recreation. The area does not have to possess 

outstanding opportunities for both solitude and primitive and unconfined recreation, and 

does not need to have outstanding opportunities on every acre. Further, an area does not 

have to be open to public use and access to qualify under this criteria; Congress has 

designated a number of wilderness areas in the Refuge System that are closed to public 

access to protect resource values. 

Opportunities for solitude refer to the ability of a visitor to be alone and secluded from 

other visitors in the area. Primitive and unconfined recreation means non-motorized, 

dispersed outdoor recreation activities that are compatible and do not require developed 

facilities or mechanical transport. These primitive recreation activities may provide 

opportunities to experience challenge and risk, self reliance, and adventure. 

These two “opportunity elements” are not well defined by the Wilderness Act but, in most 

cases, can be expected to occur together. However, an outstanding opportunity for 

solitude may be present in an area offering only limited primitive recreation potential. 

Conversely, an area may be so attractive for recreation use that experiencing solitude is 

not an option. 

Evaluation of Supplemental Values 

Supplemental values are defined by the Wilderness Act as “...ecological, geological, or 

other features of scientific, educational, scenic, or historic value.” These values are not 

required for wilderness but their presence should be documented. 

Inventory Findings 

As documented below, none of the parcels in the Refuges meet the criteria for a WSA. 

Roadless Areas and Roadless Islands 

None of the Refuges are roadless areas. Each of the Refuges has multiple access roads 

that accommodate motorized access to the refuge units. Sacramento Refuge has a paved 

entrance road to the Refuge Headquarters, a six mile graveled auto tour route, and 

multiple graveled management roads and parking areas. Colusa Refuge has a three mile 

graveled auto tour route, and multiple graveled management roads and parking areas. 

Delevan and Sutter Refuges also have multiple graveled management roads and parking 

areas. The public has year-round access to the entrance roads and auto tour routes. 

During the hunting season, the public also has access to various graveled management 

roads on all four Refuges to get to designated hunter parking areas and check stations. 

O-3 
Size Criteria 

A total of 23,973 acres of Service owned-land are included within the Refuges. The 

Refuges do not contain 5,000 contiguous roadless acres, nor do the Refuges have any units 

of sufficient size to make their preservation practicable as Wilderness. 

Naturalness Criteria 

The wetland and riparian habitats within the Refuges appear natural to the refuge visitor. 

However, there are approximately 270 separate management units on the Refuges 

(USFWS 1989-2007). Intensively managed wetlands comprise the majority of those units. In 

order to more effectively maintain, manage, and monitor these Refuges, a habitat 

management system was implemented in the early 1980’s (Mensik and O’Halloran 1990). The 

system, which has evolved with several modifications and additions, along with some 

upgraded technology, has been used successfully at Sacramento Refuge Complex for over 

20 years. For a description of the refuge environment, see Chapter 3 of the CCP (USFWS 

2008). 

The Refuges’ lands have been substantially affected by humans, particularly through 

agriculture and urban development. As a result of the extensive modification of natural 

habitats and ongoing manipulation of natural processes, adopting a wilderness 

management approach for the Refuges would not facilitate the restoration of a pristine or 

pre-settlement condition, which is a goal of wilderness designation. 

Outstanding Opportunities for Solitude or Primitive and Unconfined Recreation 

The Refuges are located immediately adjacent to the communities of Willows, Maxwell, 

Colusa, Sutter, and Yuba City. Although the Refuges do provide opportunities for escape 

from the urban environment, the sites and sounds of urbanization are always present just 

beyond the Refuge boundary. 

Supplemental Values 

The wetland and riparian habitats on the Refuges provide scenic and regionally 

significant ecological value. 

References Cited: 

Mensik, J.G. and P. O’Halloran. 1990. Monitoring marsh management of the Sacramento 

National Wildlife Refuge Complex. Transactions of the Western Section of the 

Wildlife Society 26:24–28. 

U. S. Fish and Wildlife Service. 1988-2007. Refuge Management Plans for Sacramento, 

Delevan, Colusa, and Sutter National Wildlife Refuges, Sacramento National 

Wildlife Refuge files, Willows, CA. 

O-4 
USFWS. 2008. Sacramento, Delevan, Colusa, and Sutter National Wildlife Refuges Draft 

Comprehensive Conservation Plan. U.S. Fish and Wildlife Service, 

California/Nevada Office. 

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O-6 
Appendix P. Tree Reduction Operations 

Plan – Tract 1, Sutter National Wildlife 

Refuge 

 

Background 

Established in 1945, the Sutter National Wildlife Refuge (Refuge) consists of 2,591 acres, the 

majority of which (85 percent) are located within the Sutter Bypass (Bypass), a flood channel 

designed to reroute high water from the Sacramento River. Sutter Refuge acreage is managed 

primarily as wetlands (73 percent) in order to support a diversity of migratory and resident 

wetland dependant wildlife species (Figure 1). The remaining acreage is comprised of riparian and 

upland habitat, roads, water delivery ditches and shop/hunter check station facilities and parking 

lots. Given the rich alluvial soil and relatively high water table, Refuge management within the 

Bypass produces a variety of vegetation, including tall emergent wetland plants such as cattail and 

hardstem bulrush. In addition, a number of tree species including willows, cottonwoods, and some 

oaks, have been “volunteering” throughout the Bypass portions of Sutter Refuge. This tree 

growth, both in number and eventually their size, has been of concern due to their potential for 

impeding flood flows that could impact the design capacity of the Bypass. As a result, and in 

cooperation with the California Department of Water Resources (DWR), the Refuge has been 

removing trees from within the center of the Bypass since 2001(see Figure 2 and attached 

pictures). Required follow-up maintenance (mowing, disking, herbicide application) has been 

accomplished annually to ensure that resprouting and regrowth is kept to a minimum. 

Tract 1 “Northwest Grove” 

Tract 1 is an upland area located within the Bypass on the north end of Sutter Refuge. A number 

of large oak and a few cottonwood trees have been present in the western portion of the unit 

(referred to as the “northwest grove”) since the early 1960’s. While it was once mostly a sparse 

oak savanna, over the years the density of woody plants in this location has increased 

substantially. Though the “northwest grove’s” perimeter has not expanded into the Bypass 

significantly, it has filled-in (including some new species) to become a forest with a nearly 

complete canopy closure. The “northwest grove” is now comprised of an older, taller overstory of 

Valley Oaks and Fremont’s cottonwoods; with a mid-story of box elders, Oregon Ash, willows 

(black and sandbar), younger Valley oak and Cottonwoods; and an under-story that includes 

Himalayan Blackberry, poison oak, wild rose, and young saplings of the above tree species. 

Ground vegetation includes low growing (i.e. < 2 feet tall) grasses, sedges, and herbaceous 

broadleaved species. 

Management Strategy: 

In an effort to address the potential for impedance of floodwater flows within the Sutter Bypass, 

the Refuge will reduce the volume of woody vegetation and Himalaya Berry within the “northwest 

grove”. The focus will be on removing the majority of the understory plants and small trees. Some 

large trees will be left in place. For management purposes, and based upon existing topographic 

features, the area will be divided into five zones (Figure 3). For each zone, Refuge staff will 

evaluate the vegetative species composition and design an appropriate prescription for removal. 

As work is completed, Zones 1-4 will require annual maintenance treatments, such as livestock 

grazing, mowing, prescribed burning or herbicide applications, in order to suppress regrowth of 

trees, shrubs, and vines. 

P-1 
Zone 1: 

Vegetation: Moderate density overstory, and light density mid-story and understory 

shrubs. A narrow slough with dense box elder trees exists along the west edge. 

Treatment: Remove most (i.e., over 95 percent) of the willow, box elder, and Oregon ash 

trees. Remove 90-95 percent of oaks and cottonwoods less than 20 inches diameter at 

breast height (DBH). Limb-up remaining oaks and cottonwoods to a height (15 feet) in 

order to lessen impacts to high water flows. Remove all understory shrubs and vines. 

Post-treatment conditions/maintenance: Grassland with a few scattered mature oak and 

cottonwood trees. Employ one or more of the following: livestock grazing, mowing, 

prescribed burning, or herbicide application; for control of undesirable plant species. 

Zone 2: 

Vegetation: Moderate density overstory, mid-story, and understory shrubs. 

Treatment: Remove most (over 95 percent) of the willow, box elder, and Oregon ash trees. 

Remove 80-90 percent of the oak and cottonwood trees less than 20 inches DBH. Limb-up 

remaining oaks and cottonwoods to a height (15 feet) in order to lessen impacts to high 

water flows. Remove most of the understory shrubs and vines. 

Post-treatment conditions/maintenance: Grassland with a few cottonwoods, several mature 

oaks and a few smaller oaks. Employ one or more of the following: livestock grazing, 

mowing, prescribed burning, or herbicide application; for control of undesirable plant 

species. 

Zone 3: 

Vegetation: A lower elevation slough area (capable of ponding water) 

with a moderate overstory, a heavy midstory and understory of box elder, Oregon ash and 

shrubs. 

Treatment: Remove most (over (90 percent) of the willow, box elder, and Oregon ash trees. 

Remove 70-80 percent of the oak and cottonwood trees less than 20 inches DBH. Limb-up 

remaining oaks and cottonwoods to a height (15 feet) in order to lessen impacts to high 

water flows. Remove most of the understory shrubs and vines 

Post-treatment conditions/maintenance: Relatively open slough channel with a few 

cottonwoods, and several mature oaks on the adjacent high ground. Employ one or more of 

the following: livestock grazing, mowing, prescribed burning or herbicide application, for 

control of undesirable plant species. 

Zone 4: 

Vegetation: Mixed riparian forest that includes an overstory dominated by Valley Oak and 

relatively heavy understory of blackberry and poison oak, with some smaller trees. 

Treatment: Remove most (over 90 percent) of the willow, box elder, and Oregon ash trees. 

Remove 70-80 percent of the oak and cottonwood trees less than 15 inches DBH. Limb-up 

P-2 
remaining oaks and cottonwoods to a height (15 feet) in order to lessen impacts to high 

water flows. Remove most of the of the shrub/vine understory. 

Post-treatment conditions/maintenance: Oak and cottonwood savanna with understory 

dominated by grasses and sedges. Employ one or more of the following: livestock grazing, 

mowing, prescribed burning or herbicide application; for control of undesirable plant 

species. 

Zone 5: 

Vegetation: Mixed riparian forest with heavy understory, comparable to the edge areas 

along the west side of Sutter Refuge down to Hughes Road. This is a northern extension of 

the forested west edge of the Bypass Channel, which helps to protect the levee from wave 

action. 

Treatment: Remove hazardous limbs and trees near access road. 

Post-treatment conditions/maintenance: Monitor conditions and treat as necessary. 

Implementation: 

Once planning is accomplished, cooperative efforts with DWR and others will begin. While a high 

Refuge priority, progress will likely be incremental due to availability of funding and personnel. 

Our Refuge goal is to have all zone 1-4 vegetation reduction prescriptions completed within the 

next 2-3 years. 

As to what should be expected, we have included representative/illustrative “Before and After” 

photo examples of previous work (see Figure 4). 

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P-4 
P-5 
P-6 
Figure 4. Representative “before and after” pictures illustrating the overall concepts of 

the Tree Reduction Operations Plan objectives. 

Tract 1, cell 1 west of lift pump before. 

Tract 1, cell 1 west of lift pump after. 

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P-8