BIOLOGICAL ASSESSMENT

EXF Thinning, Fuels Reduction and Research Project

Bend-Ft. Rock Ranger District, Deschutes National Forest, Bend, Oregon

August 31, 2009

Updated November 13, 2009

Prepared by: /s/ Barbara S. Webb

Wildlife Biologist, Bend-Ft. Rock Ranger District

The purpose of this biological assessment (BA) is to consult with the U.S. Fish and Wildlife Service (USFWS) 

on effects to the federally threatened northern spotted owl (Strix occidentalis caurina) from the removal of 211

acres of NRF habitat (field verified, not occupied) and resulting from the thinning of trees and subsequent 

mowing and prescribed burning.

The project would occur within the Lookout Mountain Unit of the Pringle Falls Experimental Forest on the 

Bend-Ft. Rock Ranger District of the Deschutes National Forest (Forest) in Bend, Oregon (Deschutes County). 

The entire project area is within lands allocated as Administratively Withdrawn and Late Successional Reserve 

under the Northwest Forest Plan.

The Forest completed an informal programmatic consultation on August 24, 2006 for the Joint Aquatic and 

Terrestrial Programmatic Biological Assessment for Federal Lands within the Deschutes and John Day River 

Basin’s Administered by the Deschutes and Ochoco National Forests (Programmatic BA, USDA et al. 2006, 

Consultation # 1-7-06-I-0173). This project would not fall under this programmatic document because it 

adversely impacts NRF habitat. Separate formal consultation is being pursued for this project. 

SPECIES NOT CONSIDERED

The Oregon spotted frog (Rana pretiosa) is a federal candidate species. Oregon spotted frogs are an aquatic 

species; more commonly associated with slow-moving water and wetland areas. There are no water sources 

within the project area or this unit of the experimental forest. The project activities are not expected to 

adversely affect the spotted frog or its habitat because there is no potential habitat, therefore, it is not considered 

in this BA. 

PROJECT LOCATION

The Bend/Ft. Rock District of the Deschutes National Forest is proposing to thin and underburn about 2,554

acres of ponderosa pine and mixed conifer habitat within the Pringle Falls Experimental Forest, located 25 

miles southwest of Bend, Oregon and about 35 miles southwest of Bend (Figure 1).
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Figure 1: Project Area Map
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PROJECT DESCRIPTION

The proposed action is the Study Plan as designed by the Pacific Northwest Research Station. Four treatment 

blocks with relatively homogeneous elevation, aspect, and plant association were delineated using, where 

possible, existing roads. Treatment units were then delineated within each block, also based on topography and 

roads. Each unit was randomly assigned one of four levels of treatment or no treatment. The proposed project 

area falls within the Administratively Withdrawn (AWD) and Late-Successional Reserve (LSR) allocations 

under the Northwest Forest Plan. The southeast corner of the project area is east of the spotted owl’s range and 

is allocated as Experimental Forest under the Deschutes LRMP as amended by the Eastside Screens (Table 1).

Table 1. Breakdown of Land Management Allocations.

Allocation Acres within the 

Lookout Mt. Unit 

Acres within a 

proposed unit

Late Successional 

Reserve

160 160

Matrix 0 0

Administratively 

Withdrawn

3005 2024

Private Land 0 0

Eastside 

Screens/Experimental 

Forest

370 370

Total 3,535 2554

The intensity of proposed thinning uses the Stand Density Index (SDI), which is a relative tree density 

measurement of each stand. At a certain SDI the trees in a stand will become suppressed and bark beetle 

activity will begin. This is called the upper management zone (UMZ). Where stands are denser than the UMZ, 

there is imminent risk of catastrophic loss of overstory trees to bark beetles. Treatments closer to UMZ are less 

intensive treatments; those further from UMZ (e.g. 50% of UMZ) are more intensive treatments. The SDI and 

associated UMZ were based on the ponderosa pine plant associations.

The proposed action includes vegetation management activities across approximately 2,554 acres (Figure 2)

Table 2. Alternative 2 Units with Silviculture and Fuels Prescriptions and Forest Plan Management Area.

Unit 

No. Acres Silv. Rx Fuels Rx Mgmt.

11 118 Thin to 75% UMZ Mow/Underburn Experimental Forest

12 192 Thin to 50% UMZ Mow/Underburn Experimental Forest

13 83 Thin to 75% UMZ 

w/ small openings

Mow/Underburn Experimental Forest

14 194 Thin to UMZ Mow/Underburn Experimental Forest

15 No Treat No Treat

21 106 Thin to 75% UMZ 

w/ small openings

Mow/Underburn Experimental Forest

22 206 Thin to 75% UMZ Mow/Underburn Experimental Forest

23 225 Thin to 50% UMZ Mow/Underburn Experimental Forest

24 196 Thin to UMZ Mow/Underburn Experimental Forest
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Unit 

No. Acres Silv. Rx Fuels Rx Mgmt.

25 No Treat No Treat

31 148 Thin to 50% UMZ Mow/Underburn Experimental Forest

32 164 Thin to UMZ Mow/Underburn Experimental Forest

33 335 Thin to 75% UMZ Mow/Underburn Experimental Forest / LSR

34 94 Thin to 75% UMZ 

w/ small openings

Mow/Underburn Experimental Forest

35 No Treat No Treat

41 116 Thin to 50% UMZ Mow/Underburn Experimental Forest

42 160 Thin to UMZ Mow/Underburn Experimental Forest

43 70 Thin to 75% UMZ 

w/ small openings

Mow/Underburn Experimental Forest

44 147 Thin to 75% UMZ Mow/Underburn Experimental Forest

45 No Treat No Treat

Acres are approximate. Actual acres treated would be slightly reduced to account for such things as avoidance 

of sensitive areas (e.g. where slopes exceed 30%). The control units (No Treatment) are included in the table 

because they are an important component of the research design, and the acres of no treatment will be tracked 

through the analysis. Any future entry into the control units would require additional NEPA analysis.

Table 3. Summary of Actions 

Thinning Type Acres

1- Thin to UMZ (“light thin”) 714

2- Thin to 75% UMZ

(“moderate thin”)

806

3- Thin to 50% UMZ

(“heavy thin”)

681

4- Thin to 75% UMZ & Create 

small openings (“cutting 

some large & intermediate”)

353

Total 2,554

5- No Treat (Control Units) 342

Road Closure 1 gate & temp. roads

Description of Activities

Implementation of the project is proposed to begin in 2010 because the risk of bark beetle-caused mortality 

increases each year, and the occurrence of mortality increases each year. While the risk of ignition probably 

will not change in the near-term, the risk of stand-replacement fire increases as fuels continue to accumulate. 

The study design incorporates both short-term and long-term research components. Neither can begin to 

produce the answers to the questions they were designed to address until the project is implemented. 

Each of the following activities has the potential to occur within the spotted owl breeding season (March1 –

September 30). According to Andy Youngblood, Chief Research Forester for the project, “ideally, all of the 

thinning would be implemented within a single growing season, and all of the activity fuels treated the 

following year. This is ideal from a research perspective because it reduces potentially confounding issues such 

as inter-annual variation in weather patterns and assumes that all residual vegetation is allowed to develop under 
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similar conditions. If there is a difference, is the difference due to treatment or the year in which the treatment 

is applied? There may be interesting results that develop because a portion of the area is treated in one year and 

the another portion is treated in the following year under slightly different environmental conditions, but this is 

beyond the scope of the study plan. It can get confusing when the comparison is based on pre-treatment 

compared to post-treatment at two different areas and years. Thus, timing of treatments may be critical for 

some short-term responses. The more meaningful comparison is among the different levels of treatment 

themselves. If our treatments are enough to cause detectable differences among treatments, then the baseline or 

pre-treatment conditions are unimportant and largely can be ignored. 

Thinning 

Thinning will be conducted with ground-based machinery. For treatment types 1, 2, and 3 thinning is from 

below: to reduce stand density by removing trees from the lower crown classes or smaller diameters to improve 

growth and overall forest health of trees in the upper crown classes or the larger trees. The largest trees are 

retained. Treatment type 4 (thin to 75% UMZ with small openings) will be a free thin across the entire diameter 

distribution to begin transition to an all-aged stand structure (i.e. multi-cohort). 

For all treatment types, species preference for cutting is as follows: 1) lodgepole pine, 2) grand/white fir, 3) 

small-diameter ponderosa pine, 4) small-diameter mountain hemlock, 5) small diameter Douglas-fir. 

Slash and Smaller Material Treatment

Trees with commercial value (usually greater than 7” diameter at breast height or “dbh”) will be whole-tree 

yarded, with limbs and tops attached to the landings, so slash generated from these trees will be on the landings, 

reducing the need for slash piling within the units. Tops and limbs will be utilized as market conditions allow, 

otherwise they will be burned at the landings. Smaller material (generally < 7” dbh) will be felled by hand and 

will also be utilized as market conditions allow. If it cannot be utilized, the lighter concentrations will be 

lopped and scattered and heavier concentrations grapple piled and burned. Assuming no market for smaller 

material, approximately one-half of the units will have heavier concentrations of small material piled and 

burned. This assumption is used in the analysis.

Mechanical Shrub Treatment (Mowing)

Thinning and slash treatment will be followed by mechanical shrub treatment, also known as mowing. This 

involves the use of mechanized equipment to mow, cut, chop, grind or otherwise reduce shrub or ground fuel 

vertical structure.

Underburning

Following thinning, slash treatment, and mowing, prescribed fire is planned for most areas. This is considered a 

landscape-scale burning operation where fire will be applied preferably in the fall. 

Fire lines are used to control the fire during prescribed burning operations. Existing roads will be used as much 

as possible. Line construction will be necessary at the project perimeter, around control units, and around the 

plantation in the middle of the project area (approximately 12 miles of line to be built). Lines will be built with 

an ASV, and will be approximately 3 to 4 feet wide. Handline will be constructed where necessary, such as 

with steeper slopes.

Road Closures

In an effort to protect existing research, a gate will be placed at the 4240/4245 road junction post project 

activities. The gate will restrict travel on a majority of the road system to administrative use only.

Connected Actions

Temporary road construction: Harvest operations are expected to require approximately 1 mile of temporary 

road to be developed for access to units 11, 14, 21, and 23. Temporary roads are built to facilitate ground-based 

harvest systems for the purpose of removing forest products from a treated stand. These roads are short, 

averaging less than 0.2 miles. Temporary roads will be built to low specifications that would allow equipment 

access to landing sites. These roads will be built on slopes less than 10 percent and will be constructed to the 
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lowest possible standard capable of supporting log haul in order to minimize ground disturbance. These roads 

will be closed after project activities.

Road maintenance: Approximately 35 miles of existing roads in the project area will require maintenance 

prior to use for timber haul. Maintenance is blading and shaping of the roadbed and brush removal. 

Danger tree removal: Federal and State of Oregon safety regulations require that danger trees along project area 

travel routes be felled prior to activities taking place. Roadside danger trees, rated as likely or with imminent 

potential to fail, will be felled along these travel routes (35 miles of road maintenance) and where activity units 

border the road system.

Protective Measures

1. Should a new spotted owl nest site or activity center be discovered during project implementation, 

disruptive work activities will not take place and consultation would be re-initiated. 

2. Prescribed fire managers need to use smoke management forecasts in order to minimize smoke entering 

into the Three Trappers Butte home range and to ensure that dissipation would be adequate.
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Figure 2. Proposed actions in relation to spotted owl habitat

STATUS OF THE SPECIES

NORTHERN SPOTTED OWL (STRIX OCCIDENTALIS CAURINA)

The USFWS listed the northern spotted owl (NSO) as a threatened species in Washington, Oregon, and 

California on June 26, 1990 (55 Federal Register [FR] 26114). A final draft recovery plan was released in 

January 1992 but was not finalized. A new draft recovery plan was released in April 2007 (72 FR 20865) and 

the final recovery plan was released on May 16, 2008 (USFWS 2008). Critical habitat primary constituent 

elements include forested lands that are used or potentially used for nesting, roosting, foraging, and dispersing. 

Critical habitat on 6,887,000 acres was designated on January 15, 1992 (57 FR 1796) and revised on August 12, 

2008 to include 5,312,300 acres (73 FR 47325). Current threats to NSO include previous and ongoing loss of 

suitable habitat and competition with barred owls (Strix varia) (55 FR 26114).
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Habitat and Life History

The northern spotted owl inhabits mature to old-growth mixed coniferous habitats (USFWS 1990). They will 

occupy second-growth forests if key components of mature forests are present; however, population density and 

reproductive success are usually lower than in old-growth forests (USFWS 1989). Major roosting and nesting 

areas are generally dispersed throughout a territory and their use varies seasonally (Forsman et al. 1984).

Functional nesting, roosting, and foraging (NRF) habitat for the NSO occurs in mixed conifer stands and 

riparian areas with multi-storied canopies. The canopy cover is typically greater than or equal to 40% with an 

overstory comprised of at least five percent of trees greater than 21 inches diameter breast height (dbh). Habitat 

that meets nesting and roosting requirements also provides foraging habitat, although a wider array of forest 

types are used for foraging, including more open and fragmented habitat.

Prey species on the drier East Cascades forests include a mix of arboreal and terrestrial rodents including 

northern flying squirrels, bushy-tailed woodrats, voles, and deer mice, with birds and insects as secondary prey. 

Northern flying squirrels typically use old woodpecker holes or other cavities in large trees and snags; and 

sometimes dwarf mistletoe clumps. They are a fairly large rodent thus requiring the larger trees with cavities. 

Northern flying squirrels eat truffles (Natureserve 2009, Smith 2007, Weigl, 2007). Fungi (e.g. truffles) 

usually require moist conditions to proliferate. In the forest, these can be soft, rotten logs, underneath ground 

litter, and shaded plant associations (Lehmkuhl, 2004). Bushy-tailed woodrats reach their highest densities in 

stands with soft logs, dwarf mistletoe, and large snags; rocky dens are also an important component of woodrat 

habitat (Lehmkuhl et al 2006). The experimental forest and, more specifically, the EXF project area currently 

provides some of these habitat components. There are areas with soft logs in proximity to rocky clusters. Other 

areas provide some large snags or large dying trees that will soon be snags. There are no expansive areas with 

dwarf mistletoe, although there are trees with it within the project area. Mixed conifer stands provide the best 

habitat for northern flying squirrel while lodgepole pine stands provide habitat for woodrats and deer mice.

Spotted owls primarily use cavities in the boles of dead or live trees for nesting structure. They will sometimes

build platform nests in abandoned raptor nests, broken treetops, mistletoe brooms, and squirrel nests. Large 

diameter trees with the ability to produce large limb structure or epicormic branching also provide good nesting 

structure. Relatively heavy canopy habitat with a semi-open understory is essential for effective hunting and 

movement. Nest trees on the Forest are predominately Douglas-fir, with ponderosa pine and white fir used less 

often.

Courtship behavior usually begins in February or March, and females typically lay eggs in late March or April. 

After they leave the nest in late May or June, juvenile spotted owls depend on their parents until they are able to 

hunt on their own. By late summer, the adults are rarely found roosting with their young and usually only visit 

the juveniles to feed them at night (Forsman et al. 1984). Parental feeding may continue into September after 

chicks fledge (Forsman et al. 1984). Natal dispersal of spotted owls typically begins in September and October 

with a few individuals dispersing in November and December (Miller et al. 1997, Forsman et al. 2002). Known

or suspected causes of mortality during dispersal include starvation, predation, and accidents (Forsman et al. 

2002).

Activities involving chainsaws, heavy equipment, aircraft, or blasting in specified distances during the breeding 

season (March 1 to September 30) have the potential to disrupt breeding, feeding, or sheltering which may lead 

spotted owls to flush from the nest, abort a feeding, or postpone a feeding (Damiami et al. 2007, USFWS 2003, 

Delaney et al. 1999). The sensitivity of an individual owl to disturbance is likely related to the baseline level of 

disturbance to which the individual is accustomed, the level and proximity of the disturbance, and the timing of 

the disturbance in the nesting cycle and nightly activity period. Spotted owls are likely most sensitive to 

disturbance during the earlier months of their breeding season (March-early July). 
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ENVIRONMENTAL BASELINE

A majority (2,589 ac of 3,535 ac Lookout Mt. Unit) of the project area lies within the range of the northern 

spotted owl and under management allocations of the Northwest Forest Plan (NWFP). Another 370 acres of the 

project area lies east of the range of the northern spotted owl and under management allocations of the Interim 

Management Direction – Regional Forester’s Forest Plan Amendment #2 or “Eastside Screens”. 

Approximately 160 acres of the 31,004 ac Sheridan Mountain Late Successional Reserve (LSR) (RO242) are 

within the project area. There are no Critical Habitat Units within the project area.

The action area is defined as “all areas to be affected directly or indirectly by the federal action and not merely 

the immediate area involved in the action” (50 Code of Federal Regulations 402). The proposed action area 

directly includes a 211 acre GIS-mapped NRF area and 2107 acres of dispersal habitat (proposed units east of 

the spotted owl range line were not incorporated into the dispersal acreage). 

Nesting, Roosting and Foraging Habitat

As stated within the Programmatic BA (pages 14 & 15), “spotted owls generally require mature or old-growth 

coniferous forest with complex structure including multiple canopy layers, large green trees and snags, heavy 

canopy habitat, and coarse woody material on the forest floor. A wide variety of forest types are utilized. 

Nesting, roosting, and foraging (NRF) habitat for the northern spotted owl on the Deschutes NF includes stands 

of mixed conifer, ponderosa pine with white fir understories, and mountain hemlock with subalpine fir. 

Suitable habitat on the east side of the Cascade Mountains is naturally confined to a narrow forested band below 

the high-elevation subalpine forests and above the low-elevation lodgepole (Pinus contorta)/ponderosa pine 

forests (USDI 1992a). Neither of these forest types is considered spotted owl habitat. In some areas within the 

province, suitable habitat is naturally fragmented by intrusions of lava and other forest types, as well as by 

recent harvest or wildfires. Suitable habitat is not usually found in large patches but usually occurs as 

inclusions within a larger stand. Therefore, habitat conditions are patchy within stands and across the 

landscape.” 

Field verification of suitable NRF habitat that was mapped within the experimental forest was completed in 

2008 and resulted in fewer acres of actual NRF habitat within the project area. Original maps of NRF habitat

relied on forest vegetation databases which may have over-estimated habitat in parts of the project area. 

Database queries focused on vegetative plot data using high canopy closure and large trees (see Appendix A of 

the Programmatic BA for details on data used). Some stands of mapped NRF overlapping the EXF project area 

were actually older ponderosa pine plantations, for these stands met the canopy closure minimum and the size 

of the ponderosa pine trees met the large tree requirement. However, ponderosa pine stands (and plant 

associations) are generally not managed for, nor used as, spotted owl NRF (2008 Recovery Plan states “within 

the range of dry forests, Northern Spotted Owl habitat occurs largely within Douglas-fir, grand fir, and white fir 

vegetation series” Appendix E page 103). Field verification of NRF habitat within the project area has reduced 

the amount of habitat by a total of 561 acres. Much of the remaining NRF had few potential nest trees, but had 

the structural characteristics that would allow for roosting and foraging (dispersal also, however that is 

discussed in a later section). Current mapping conventions do not separate out nesting, roosting, and foraging 

into different habitat classifications. The stands within the project area that met better foraging and dispersal 

habitat (i.e. higher canopy closure but lacked large trees), but lacked immediate nest tree availability, were 

retained as NRF because it’s anticipated that nest trees (e.g. large Douglas-fir or true firs with large cavities) 

could develop within these stand types. See Table 5 for an accounting of NRF acres across the Bend-Fort Rock 

Ranger District (an additional 48 acres of mapped NRF habitat was field-verified to not be habitat after the 

March 2008 update). 
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Appendix A contains the rationale and maps to illustrate the differing habitat variables within the NRF patches. 

This effort was independent of the detection surveys. That is to say the protocol survey calling stations were 

situated to take in all previously mapped NRF habitat. Although some patches of NRF were subsequently 

dropped as habitat, the 2008 and 2009 surveys still included all of the original calling stations. The following 

table (Table 3) displays the amount of existing NRF habitat within a unit (including control units) that had been 

field-verified to be providing habitat features discussed earlier.

Table 3. Existing Spotted Owl NRF Habitat by Unit

Unit No. NRF Acres Proposed Action

32 13 Light thin, mow shrubs, prescribed burn

13 3 Thin across all age cohorts, mow shrubs, prescribe burn

12 37 Heavy thin, mow shrubs, prescribed burn

11 69 Moderate thin, mow shrubs, prescribed burn

22 33 Moderate thin, mow shrubs, prescribed burn

23 56 Heavy thin, mow shrubs, prescribed burn

25 10 Control – No treatments

TOTAL 221

Table 4. Existing Spotted Owl NRF Habitat by Allocation.

Allocation Acres within the 

entire Lookout 

Mt Unit

NRF Acres 

within the 

entire 

Lookout Mt 

Unit

NRF Acres

within a 

proposed project 

unit

Percent of NRF 

within Lookout 

Mt Unit also 

within a 

proposed unit

Late Successional 

Reserve

160 0 0 0%

Matrix 0 0 0 0%

Administratively 

Withdrawn

3005 250 221 88%

Private Land 0 0 0 0

Eastside 

Screens/Experimental 

Forest

370 N/A N/A N/A

Total 3,535 250 221 88%

Table 5. Documentation of NRF Baseline Changes in 2008.

Activity Name Type Acres

2009 Corrected NRF Baseline BEND FT ROCK 24,145

Total for Deschutes National Forest 78,110

October 2009 Edits to the Joint Aquatic and Terrestrial Programmatic BIOLOGICAL ASSESSMENT for Lands within the Deschutes 

Basin Administered by the Bureau of Land Management Prineville Office and the Deschutes and Ochoco National Forests – 08/06 –

Page B-2.

Dispersal Habitat and Connectivity

Dispersal habitat is important for spotted owl young to move from one territory to another, away from natal 

areas, or away from adults. The Programmatic BA defines dispersal habitat as a minimum of 30% canopy 
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closure regardless of plant association, and a minimum average diameter of 7 inch dbh for lodgepole pine 

stands, and 11 inch dbh for mountain hemlock, ponderosa pine and mixed conifer stands (Table 6).

Table 6. Dispersal habitat definitions (items in bold are PAGs found within the EXF Project Area)

Plant Association Group (PAG) Stand Criteria

Average dbh, Percent Canopy Cover

Mixed Conifer Wet 11” dbh, 40% CC

Mixed Conifer Dry 11” dbh, 30% CC

Ponderosa Pine 11” dbh, 30% CC

Lodgepole Pine 7” dbh, 30% CC

Mountain Hemlock 7” dbh, 30% CC

Approximately 18,392 acres of the 6th field watersheds are NSO dispersal habitat using the above criteria. In 

mapping dispersal habitat over the project area as well as the larger subwatersheds and district a two-tiered 

process was used. First, the definition of dispersal habitat detailed in the Programmatic BA was used (see 

above discussion). In trying to query existing ArcGIS databases in order to spatially display dispersal habitat 

the 2004 satellite imagery database was utilized. This database can be queried at various levels (e.g. district, 

project, and watershed boundaries), contains the vegetation data pertinent to defining habitat (e.g. tree diameter, 

canopy closure), and gives a more recent “snapshot in time” or existing condition than other vegetation 

databases, thereby eliminating the need to update features due to past harvest. Secondly, in order to query the 

satellite data, the definition of dispersal needed to be reconciled in order for it to be best displayed. Instead of 

going down to a 30% canopy closure level (as defined in the Programmatic BA for dry mixed conifer and 

ponderosa pine habitats); the database used a 40% minimum because closure breakdowns were 25-40% and 

40%+. The query then added another level whereby the tree size needed to meet at least “pole” size. In the 

satellite data this equated to 5-9” dbh; whereas in the Programmatic BA tree size ranges from 7-11” dbh. See 

Figures 4 and 5 for the results of this query at the district scale and project level, respectively. There are

approximately 2,250 acres of dispersal habitat within the Experimental forest and it is well-distributed (see 

Figures 4 and 5). 

The project area provides dispersal habitat in all directions. The Charlie Brown project (Bend-Ft Rock Ranger 

District Environmental Analysis 2002) had supported the mapping of connectivity corridors between LSRs in 

the Crane Prairie and Fall River watersheds that had been established under the Browns/Wickiup Watershed 

Analysis and Browns/Round Mountain Late-Successional Reserve Assessment (1997). These corridors were to 

be managed for late-seral characteristics and encompassed the best habitat currently meeting these 

characteristics. One of these corridors runs through the EXF Project area and encompasses suitable NRF 

habitat as well as dispersal habitat. The Fall River planning efforts (Bend Ft Rock Ranger District 

Environmental analysis 2004) also designated corridors under the “Eastside Screens” that connect to these other 

corridors from the Charlie Brown Project. These corridors are to be managed for late-seral characteristics such 

as higher canopy closures and larger trees. These corridors ensure dispersal habitat is maintained in the 

watersheds (see Figures 3-5).
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Fig. 3 Designated connectivity of late-seral and old-growth habitat throughout the watersheds.

Dispersal habitat is generally available throughout the area. Miller et al. (1997) found dispersing owls favored 

old growth structure for dispersal, but utilized many types of forest. Use of open sapling stands during dispersal 

decreased the probability of mortality, where use of clearcuts increased the probability of mortality. Miller et 

al. (1997) tied the increase of survival in sapling stands to availability of prey. The SEI report (Courtney et al. 

2004) noted that owls did not disperse across large unforested valleys but did disperse between areas through 

forested foothills.
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Figure 4. Dispersal habitat across the Bend portion of the Ranger District using the 2004 satellite imagery data
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Figure 5. Dispersal habitat and connectivity through the EXF project area and larger subwatersheds.

Critical Habitat and Late Successional Reserves

Critical Habitat Units (CHU) were established by the U. S. Fish and Wildlife Service because 1) spotted owl 

habitat is continually decreasing and becoming more fragmented, 2) the resultant increased threat of isolation of 

spotted owl populations, and 3) the exacerbation of poor habitat conditions for dispersing spotted owls. There 

are no CHUs within the project area. The closest CHU is approximately 7 air miles to the west (Cultus Mt).

Sheridan Mountain Late Successional Reserve

The Sheridan Mountain LSR is 31,004 acres and approximately 160 acres are within the EXF Project area (see 

Figure 2). This LSR has 1,908 acres of mapped NRF habitat, none of these acres are within the EXF Project 

area and have not been field verified. A decline in habitat has likely occurred in the LSR due to insects and 

disease, but this also has not been field verified. These 160 acres are made up ponderosa pine and white 

fir/Douglas-fir plant associations. The stand structure is variable with relatively small patches of larger 

diameter trees (15-20” dbh), with the higher canopy closures (>40%) concentrated in the more northern half of 

the section within the project area.

The Northwest Forest Plan established this reserve network designed to protect late-successional 

forest species. The purpose of the Late Successional Reserves (LSR) is to provide distribution, quantity, and 

quality of late successional and old growth forest habitats sufficient to avoid foreclosure of future management 

options. The objective of LSRs is to “protect and enhance the condition of late-successional/old growth forest 
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ecosystems, which serve as habitat for dependent or old growth associated species including the northern 

spotted owl.” (USDA 1994a).

The Deschutes National Forest Late Successional Reserve Overview (USDA 1995b) recognized that late 

successional reserves east of the Cascade crest function differently as well as identifying the major risks to each. 

“Climatic conditions on the eastern flank of the Cascade Range are much drier then conditions west of the crest. 

These drier climatic conditions in combination with the exclusion of fire and past timber harvest activities have 

created over stocked and stressed stands that are and have been susceptible to large scale insect and disease 

epidemics, and catastrophic fires. Within Region 6, some of the Deschutes National Forest LSRs provide 

habitat for species which rely on late structured stands maintained by frequent, low intensity fire regimes. 

These “fire climax” late successional and old growth stands provide habitats and an array of late successional 

and old growth related species not usually associated with the “climatic climax” stands on the Deschutes Forest 

or Province. Because of this mix of “westside” and “eastside” vegetation types and conditions, management 

efforts should focus on maintaining the dynamic balance of all the vegetative series, to include both climatic 

climax and fire climax ecosystems. This will provide opportunities for ecosystem maintenance and restoration 

for existing and potential natural vegetation.”(USDA 1995b).

As required by the NWFP, a Late Successional Reserve Assessment (LSRA) was completed to determine what 

management activities would be appropriate within the LSR. The LSRA was reviewed by the Regional 

Ecosystem Office (REO) and determined to be consistent by a letter dated January 27, 1997. The REO found 

the Sheridan Mountain LSRA provided sufficient framework and context for future activities within the LSR 

and was consistent with the direction found in the Record of Decision for the NWFP.

Specifically the objectives of any proposed management within the LSRA are 1) to prevent the loss of current 

late-successional and old-growth habitat due to large scale disturbances; and 2) to accelerate the development of 

late-seral old growth forest characteristics (e.g. snags, logs, large trees, canopy gaps).

The Sheridan Mt. LSRA defined Management Strategy Areas (MSA) throughout the LSR based on plant 

association groups and recommended treatments to reduce the risk of insect, disease, and fire (pages IV-30 & 

31). The LSRA included management options in which to reduce these risks and identified priority areas. The 

intent of the LSRA was to take a proactive approach before a stand-replacing event could occur. Therefore, it 

was intended that treatments would have occurred to reduce the effect of a wildfire or forego this type of event 

all together. 

The portion of the Sheridan Mt LSR that overlaps the EXF project area contains MSAs B, C, and J(see pages 

IV-30 (Maps 19) through IV-77 (Maps 35, 36, and 43) and Table IV-6 on page IV-31 of the LSRA for full 

descriptions). According to the LSRA, thinning and fuels reduction needs are immediate and projects that 

address these needs were recommended within the first 10 years of the assessment. Similarly, commercial 

thinning is an acceptable strategy for late-successional old growth habitat acceleration in these types of MSAs. 

In the summaries for each MSA within the LSRA (pages IV-65 through IV-77), common wildlife indicator 

species across these three MSAs include pileated woodpecker, northern goshawk, and flammulated owl. Other 

indicator species for the MSAs in this portion of the LSR include northern spotted owl, black-backed 

woodpecker, and white-headed woodpecker. Many of these species have been observed in the watershed. 

Hessburg et al. (1994 in Courtney et al. 2004) concluded that a century of fire protection has promoted a steady 

shift away from open ponderosa pine forests toward denser late-seral fir forests. These changes in the mixed 

conifer community resulted in habitat conducive to the spotted owl but have also resulted in a shift toward 

greater instability (Maffei and Tandy 2002). Much of this newly developed spotted owl habitat is relatively 

short-lived as habitat because replacement Douglas-fir and ponderosa pine nest trees are unlikely to develop 
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 16 of 42

given successional pathways. This was the case with most suitable habitat within the Sheridan Mt LSR and 

eastern portion of the Crane Prairie/western portion of the Fall River watershed. 

Recovery Plan for the Northern Spotted Owl – (USFWS, 2008). 

The final recovery plan devotes an entire appendix (Appendix E) to the managing sustainable spotted owl 

habitat in dry eastern Cascades forests, of which the EXF project is a part. In this section of the recovery plan, 

it is recognized in the dry eastside forest environments large, old, widely-spaced ponderosa pine, western larch, 

or Douglas-fir dominated the overstory. These large, fire-tolerant trees could survive low and mixed severity 

fire but large snags and logs were generally sparse. This is different than spotted owl habitat on the west-side of 

the Cascades that have infrequent fire return intervals, supporting higher densities of large snags and logs. 

Spotted owl habitat in east-side forests generally occur in Douglas-fir, white fir and grand fir vegetation series 

embedded in larger landscapes of forest vegetation series that are more indicative of high fire return intervals

(e.g. ponderosa pine, dry mixed conifer: 5-10 yr fire return interval). This picture of a landscape of dry and 

moist mixed conifer patches in a landscape of more fire-tolerant ponderosa pine closely describes the spotted 

owl habitat in the EXF project area and the adjacent portions of the Crane Prairie and Fall River Watersheds 

(especially the Sheridan Mt. LSR). Management of these habitats for spotted owl habitat would include 

identifying high quality NRF habitat (e.g. patches of mixed conifer with large Douglas-fir or white/grand fir and 

large dead wood) and placed risk reduction treatments around these key habitats. Total area of owl habitat 

patches or clusters should strive to average 30-35% of the overall landscape where applicable; with the larger 

percentages being in landscapes dominated by moist forest habitats. 

Specifically, Recovery Actions #6 and #7 include: “Identify, maintain, and restore approximately 30-35% of the 

total dry forest (ponderosa pine, Douglas-fir, and dry grand fir plant association group) habitat-capable area as 

spatially dynamic high-quality spotted owl habitat patches, and approximately 50-75% of the total moist forests 

(moist grand fir, western hemlock, and Pacific silver fir) habitat-capable areas as spatially dynamic high-quality 

spotted owl habitat patches.” and “Manage lands outside of high-quality habitat patches to restore ecological 

processes and functions and to reduce the potential for significant losses by stand replacement fires, insects, and 

disease.” Figure 6 displays the current spatial arrangement of spotted owl habitat.

Therefore, there is a need to balance the management for the spotted owl with other habitat conditions on the 

landscape. Where development of suitable spotted owl habitat best fits the landscape, additional measures will 

be incorporated to ensure that components of habitat are being managed for (i.e. prey species habitat 

requirements, dispersal, large trees, etc.). 

NSO Presence in the Action Area

Surveys according to Region 6 protocol within the Experimental Forest have occurred in 2007, 2008, and 2009. 

Detections of spotted owls occurred in 2007 and 2008 (see Appendix A Spotted Owl Survey Summary). In 

2007, the survey efforts were able to locate a pair of spotted owls; reproduction was unconfirmed because 

mousing efforts (i.e. offering the owls live mice in the hopes an adult would take it and give it to an offspring) 

were inconclusive. A nest tree was not found. A home range diameter was mapped around this pair location 

and given the name “Three Trappers Buttes” (Figure 2). Figure 6 illustrates spatially the survey points and the 

various detections received.

A majority of the Three Trappers Buttes home range lies outside of the Experimental Forest (see Figure 2). The 

EXF Project area was surveyed again in 2008 and 2009. All suitable habitat, in addition to this new activity 

center, has been surveyed to determine occupancy and use. In 2008, there were two auditory detections of a 

male calling; one from inside the project area and the other detection from outside the project area close to the 

previous year’s sightings. The owl(s) were not visually located and did not respond again on any further 
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 17 of 42

location attempts. The pair detected in 2007 has not been relocated to date. There were no spotted owl 

detections (visual or auditory) during the 2009 field season. None of the survey efforts have detected or 

observed barred owls (see Appendix B for other owl species detected).

Figure 6. Aerial spatial display (with township, range & section boundaries) of survey points with owl detections (see Legend

& appendix A), nesting, roosting, foraging habitat (in bold black-dotted polygons) and EXF project units (orange polygons). 

The eastern edge of the northern spotted owl’s range is shown in bright green.

Approximately 5 miles to the north is the home range for the Sheridan Mt Pair (1005). This site was first found 

to be active in 1989 with only a resident male observed until 1995. In 2006 a single female was heard, and this 

was the last observation made of any spotted owls in this home range. Reproduction for this pair was never 

confirmed nor inferred (i.e. no young seen). At the time of the LSRA only one spotted owl pair was known 

(Sheridan Mt). According to the LSRA this pair was already in a “take” situation because <50% and <40% of 

the 0.7 and 1.2 miles radii, respectively, was characterized as NRF habitat. This included dry mixed conifer, 

wet mixed conifer, and mountain hemlock associations. The project area does not enter the home range radius 

for this pair. The Three Trappers Pair is in a similar “take” situation, with <50% and <40% of the 0.7 and 1.2 

mile radii being classified as NRF currently; the proposed action does not enter this home range. Because the 

project area does not enter either home range, the proposed actions would not contribute to the current “take” 

situation.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 18 of 42

Due to the proximity of the Three Trappers Butte Pair with the Sheridan Mt Pair, one could theorize that this 

may be the same pair or part of the same territory (Figure 7 below).

Figure 7. Spatial display of EXF project area to spotted owl home ranges, LSRs, and connectivity.

EFFECTS OF THE ACTION

Northern Spotted Owls

NRF Habitat

This proposed project would result in the removal of 211 acres of NRF habitat. Light thinning, heavier thinning 

and thinning across all age cohorts, in combination with fuels treatments, will likely remove NRF habitat. Light 

thinning may remove some canopy components, but not necessarily the dominant canopy. The stand is still 
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 19 of 42

expected to have large trees but less than 40% canopy closure; thinning from below will reduce the multistoried aspect of stand that is conducive as spotted owl habitat and prey habitat. Thus the stand will no longer

function as NRF; there may be some foraging and dispersal habitat but not nesting. Heavy thinning and 

thinning across all age cohorts have these same effects but the effects are more exaggerated. In these 

treatments, canopy closure, multi-storied structure and larger trees (in the case of thinning across age cohorts) 

would be reduced and cause the entire stand to no longer function as NRF (e.g. reduce average tree dbh in the 

stand and reduce the canopy closure below 40%).

Prescribed burning and mowing can limit the sustainability of existing down large woody debris and snags that 

are habitat for spotted owl prey. This effect is less precise because many factors determine the amount of dead 

consumed and created. A prescribed fire can consume large logs and snags. However, it can also create large 

snags and logs by causing existing snags to fall (creating large logs), or by killing large trees (creating large 

snags). It is assumed that in order to attain research objectives, mortality of live trees would be prevented by 

mowing to reduce fuel loads, and burning under spring-like conditions. Because the prescribed burning is to be 

designed to result in small fuel consumption, and it has been shown in the Pringle Falls Unit of this 

Experimental Forest that prescribed burning can retain snags and logs. It is not expected that this action would 

contribute to the degradation of spotted owl habitat or its prey habitat that utilize snags and logs. Monitoring 

will occur before the prescribed fire in order to determine if any protection measures for large trees, snags or 

logs are warranted. Monitoring after the burn will also take place to determine the effectiveness of any 

protection measures. 

Lehmkuhl (2004), Meyer et al (2007) and Weigl (2007) have eluded to the fact that fuels reductions and 

thinning can create more open, drier microhabitats that can reduce fungi growth thereby decreasing the food on 

which the spotted owl’s prey eat. The proposed actions would create more open stands of ponderosa pine. It is 

likely that within the treated portions of the Experimental Forest, there would reduced foraging opportunities for 

the prey of northern spotted owls.

The effects of these activities within NRF habitat (i.e. degradation and removal of habitat) will adversely affect 

northern spotted owls by further limiting available habitat within the watersheds. Owl habitat on the eastern 

edge of the species’ range adds to the diversity of the species and its ability to persist (McCullough, 1996). The 

objective of the research is to investigate treatments for ponderosa pine growth and protect existing research. 

There is not a spotted owl research component to the proposal, and ponderosa pine types are generally not 

managed for spotted owl habitat. The beneficial effects to spotted owl habitat from the reduced fuel loadings 

and thinning that retains Douglas-fir are secondary to the proposed research within the project area. The 

treatments may eventually promote better foraging and dispersal opportunities rather than nesting due to the 

increased health and spacing of the trees within the stands.

One temporary road will be constructed through existing, unoccupied NRF habitat (Unit 11). It will be 

approximately 0.5 miles in length and will be closed (the roadbed will be subsoiled) after thinning is complete. 

The construction of this temporary road will contribute to the loss of NRF habitat already anticipated by the 

thinning. The closing of this temporary road may reduce future disturbance.

The removal of danger trees from the haul routes is expected to have minimal effects to NRF habitat. Generally 

these trees would be close to the roads and not favorable for spotted owl nesting because of noise disturbances 

from vehicles passing. Any effects of this aspect of the proposed action would act in conjunction with the 

thinning, mowing and burning. 

Dispersal

1,935 acres of dispersal habitat will be treated. Of these acres, 533 acres will not meet dispersal guidelines 

outlined in the Programmatic BA or the Sheridan LSRA after treatment (e.g. basal area and residual canopy 

closure; see Table 7). The affected dispersal acres occur within mixed conifer vegetation types and would 
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 20 of 42

receive the heavy thin and thin across all age cohorts with small openings prescription; specifically Units 12, 41 

and 23 which occur within the connectivity corridors analyzed under the Charlie Brown analysis effort (2000) 

and established under the Browns/Wickiup Watershed Analysis and Browns/Round Mountain LateSuccessional Reserve Assessment (1997). The corridor “CC#2” was designated to address dispersal and 

movement needs of a variety of species, past fragmentation between the LSRs and the literature then on risks to 

NSO from predators associated with edges. The goal was to provide connected dispersal habitat within a

corridor that was a minimum of 1,000 ft. wide, and an average 30% canopy closure through time (Charlie 

Brown Biological Evaluation and associated USFWS Letter of concurrence, 2000). Treatments within Units 

12, 41 and 23 would narrow this corridor to the minimum 1,000 ft. width. Loss of dispersal habitat, can 

adversely affect spotted owls because it limits the ability of young to successfully move throughout the 

landscape and establish a new territory. Loss of dispersal in conjunction with a loss of NRF habitat can prevent 

new pairs of owls from becoming established and being able to rear young. 

The 533 acres removed represents approximately 24% of the current dispersal habitat in the project area and 3% 

of the dispersal habitat in the watersheds. It is unlikely that the loss of 533 acres of dispersal habitat will form a 

barrier to movement; especially since other stands of habitat are still distributed throughout the area (e.g. control 

units, and other non-treated portions of the experimental forest). The proposed actions narrow the suitable areas 

for dispersal and can increase the risk of predation as an owl moves through the area. 

The proposed total of 1 mile of temporary road construction in three segments would take place within this 

“CC#2”. This construction contributes to the degradation and loss of dispersal habitat because it would require 

the removal of trees and brush within the road bed. Because the temporary roads would be built within 

proposed units, the dispersal habitat degraded and removed has already been accounted for in the discussion 

effects for the thinning.

Table 7. Unit specific effects to dispersal habitat

Unit Trtmt PAG

% 

Canopy 

Cover –

LSRA*

Current 

– BA**

Target 

BA**

Dispersal 

BA*

Current 

TPA**

Disp.

TPA*

Currently

Dispersal?

Will Meet 

Dispersal 

After?

In 

Corridor? Acres

11 2 MCD 40 138 76 70 103 95 Y Y Y 118

12 3 MCD 40 138 51 70 103 95 Y No Y 192

13 4 MCD 40 138 76 70 103 95 Y Y Y 83

14 1 MCD 40 138 101 70 103 95 Y Y Y 194

15 5 MCD 40 138 138 70 103 95 Y Y Y 64

21 4 MCD 40 174 83 70 85 95 Y Likely Y 106

22 2 MCD 40 174 83 70 85 95 Y Likely Y 206

23 3 MCD 40 174 56 70 85 95 Y No Y 225

24 1 MCD 40 174 111 70 85 95 Y Likely Y 196

25 5 MCD 40 174 174 70 85 95 Y Likely Y 108

31 3 MCD 40 184 70 70 101 95 N/A Y

Y - Eastside 

Screens 148

32 1

MCD/

MCW 40 184 140 70 101 95-100 Y Y Y 164

33 2 MCD 40 184 105 70 101 95 Y Y N 335

34 4 MCD 40 184 105 70 101 95 N/A Y

Y - Eastside 

Screens 94

35 5

PPD/

PPW 30-35 184 184 80-85 101 140-155 N/A Y

Y - Eastside 

Screens 109

41 3 MCD 40 154 35 70 99 95 Y No Y 116

42 1

MCD/

MCW 40 154 70 70 99 95-100 N/A Y

Y - Eastside 

Screens 160

43 4

MCW

/PPD 30-40 154 53 70-80 99 100-140 N/A No

Outside 

Owl Line 70

44 2

PPW/

PPD 30-35 154 53 80-85 99 140-155 N/A No

Y - Eastside 

Screens 147

45 5 MCW 40 154 154 70 99 100 N/A Y

Y - Eastside 

Screens 61
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 21 of 42

*Information from page III-37 and IV-25 of the LSRA

**Current stand measurements are from the Lookout Mountain Study Plan by A. Youngblood, 2009

LSR

Treatments are proposed within the Sheridan Mt LSR but as evidenced by Figures 2 and 7 no NRF within the 

LSR will be treated. The treated portion of the LSR is part of proposed Unit 33 of the EXF Project. Unit 33 is 

proposed to be treated with a “moderate thinning” strategy whereby the stand will be thinned from below to 

within 75% of the Upper Management Zone (UMZ) for ponderosa pine. This means that understory and codominant trees will be removed from the stand (i.e. unit) resulting in a less dense stand (e.g. a stand density 

index or SDI that is currently 267 trees per acre will be 152 trees per acre). The thinning will target lodgepole 

pine first, then grand fir/white fir, small diameter ponderosa pine, and lastly small diameter Douglas-fir. Unit 

33 is a mature mixed conifer stand dominated by ponderosa pine and white fir. The largest trees are ponderosa 

pine and the desired condition is to reduce the existing tree density per acre but retain the larger ponderosa pine 

and have a co-dominant canopy of Douglas-fir.

The LSRA defined Management Strategy Areas (MSA) throughout the LSR based on plant association groups. 

Unit 33 contains MSAs B, C, and J. According to the LSRA, thinning and fuels reduction needs are immediate 

and should occur within the first 0-10 years after the assessment was written and adopted (1997) in order to help 

protect old growth habitat. Similarly, according to the LSRA, commercial thinning is an acceptable strategy or 

treatment in order to develop late-successional old growth habitat in these types of MSAs. Common wildlife 

indicator species for these three MSAs include pileated woodpecker, northern goshawk, white-headed 

woodpecker, and flammulated owl. The proposed actions for Unit 33 would likely promote habitat conditions 

for these species. For other wildlife indicator species within MSAs B and C (northern spotted owl and blackbacked woodpeckers) the activities would not necessarily provide short-term habitat for these species. The 

thinning would reduce the multi-storied/structural diversity in the stands that often are a component of spotted 

owl habitat. Thinning would also improve the health of the stand and make it less susceptible to the insect 

attacks upon which black-backed woodpeckers often capitalize. 

To summarize, the proposed actions within the LSR are compatible with the LSRA completed and adopted in

1997. These proposed actions will help protect existing habitat as well as aid in the development of new habitat 

for the focal species: pileated woodpecker, white-headed woodpecker, northern goshawk, and flammulated owl. 

Although the proposed actions may help protect habitat for the spotted owl and black-backed woodpeckers

(both focal species) elsewhere in the LSR; they will not necessarily help in the development of new habitat. 

The effects of connectivity between LSRs, especially in relation to the effects of other late-successional species 

dispersing, are similar to the spotted owl.

Critical Habitat Unit (CHU) 

There will be no effects to any CHU. The closest CHU is on the western border of the Bend-Fort Ranger 

District, whereas the EXF project area lies on the eastern edge of the spotted owl’s range. Although the closest 

CHU is over 7 miles to the west, the project area does lie within a connectivity corridor (designed under the 

Browns/Wickiup Watershed Analysis, and the Charlie Brown Environmental Assessment) that connects this 

CHU with the Sheridan Mt LSR. Spotted owl dispersal to the CHU via the LSRs is discussed under dispersal 

habitat. 

Disturbance-related Effects 
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 22 of 42

Because the proposed actions have the likelihood of occurring during the spotted owl nesting season and there 

is evidence that spotted owls use the project area (albeit most likely for foraging and dispersal based on habitat 

quality), disturbance to spotted owls may occur (e.g. flushing of an adult from a tree during the day). There are 

no proposed actions within the 1.2 mile home range of a known pair; and noise disturbance is most likely to 

occur within 0.25 mile of an individual or nest, therefore there would be no disturbance effects to owls within 

known home ranges. There are proposed activities within 0.25 miles of NRF habitat that is otherwise outside of 

a unit. These NRF patches are small (<10 acres) with foraging quality being the predominant component and 

likely activity when documented (based on time of detections, see Appendix B). Potential for disturbance in 

these patches is low. Due to the amount of dispersal habitat within the project area, and the likelihood that 

project activities would be conducted in the late summer and fall; disturbance to dispersing owls is also a 

possibility.

The proposed actions would occur within the breeding season within the LSR. Although there is no NRF 

habitat within the LSR, there may be disturbance effects to other species utilizing the LSR.

INTERRELATED AND INTERDEPENDENT EFFECTS

Activities identified in Tables 8 and 9 were reviewed to assess whether in combination with the likely impacts 

of the EXF Project, there would be any interrelated or independent actions or effects to spotted owls. Table 8

lists the types of research that has occurred within the EXF project area, the type of activity that was used for 

the research, author, and the papers published. For a complete description of the study and its methods, one can 

refer to the publication listed. Table 9 lists the ongoing and reasonably foreseeable projects occurring in the 6th

field watersheds. Effects of past actions will not be discounted, but to the contrary, are analyzed in the 

description of the existing conditions. It is assumed the effects of past actions are best put into proper context 

when considered in the existing conditions, e.g. habitat conditions.

Interrelated and interdependent effects to spotted owls will be addressed at the 6th field watershed scale –the

Crane Prairie and Fall River watersheds because it is a large area that can cover a variety of spotted owl habitat 

conditions and the connectivity of the habitats. Based on that review, the potential interrelated or independent 

actions or effects are discussed.

Table 8. Research Projects within the Lookout Mt Unit and resulting Publications.

Activity Occurring or Occurred & 

Monitoring

Scientist Publication

Underburning for shrub control in 

1976, 1979, 1980

R. Martin Martin, 1982. Shrub control by burning 

before timber harvest

Pruning in 1941 in a 55 year old stand E. Mowat, W. 

Dahms, J. Barrett. 

J. Cahill

Barrett. 1968. Pruning of ponderosa 

pine...effects on growth. Res. Pap. 

PNW-68.

Cahill, 1991. Pruning young-growth 

ponderosa pine: product recovery and 

economic evaluation. Forest Products 

Journal 41:67-73.

Fight, Bolon, Cahill, 1992. Res. Pap. 

PNW-449.

Ponderosa pine-grand fir spacing 

study: thinning stand to defined 

spacings & Ponderosa pine-grand fir 

K. Seidel Seidel, 1985. A ponderosa pine-grand fir 

spacing study in Central Oregon: results 

after 10 years. Res. Note PNW-429
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 23 of 42

Activity Occurring or Occurred & 

Monitoring

Scientist Publication

plantation in a spacing study 

Release and thinning in a 43 year old 

suppressed grand fir and Shasta red 

(noble) fir stand

K. Seidel Seidel, 1977. Suppressed grand fir and 

Shasta red fir respond well to release. 

res. Note PNW-288

Thinning from above in 1938 in a 94 

year old stand

E. Mowat, J. 

Barrett

Barrett and Newman, 1974. High yields 

from 100-year old ponderosa pine. Res 

note PNW-220

P and L sale: commercial thinning in 

1949

E. Mowat, J. 

Sowder

Sowder, 1953. Lumber grade recovery 

from young ponderosa pine. Res. Note 

RN-88

Underburned R. Martin Evans, L. 1983. Hydrophobicity of 

cindery typic cryothents. OSU M. S. 

thesis.

Level-of-Growing-Stock established 

in 1965 in 65 year old ponderosa pine

with 6 growing stock levels

J. Barrett, P. 

Cochran, W. Oliver

Barrett, 1983. Growth of ponderosa pine 

poles thinned to different stocking levels 

in Central Oregon. Res. Pap. PNW-311.

Cochran and Barrett, 1999. Growth of 

ponderosa pine thinned to different 

stocking levels in Central Oregon: 30 

year results. Res. Pap PNW-RP-508.

Oliver, 2005. The west-wide ponderosa 

pine levels of growing stock study at age 

40. Gen. Tech. Rep. PSW-GTR-198.

Table 9. Ongoing and Reasonably foreseeable projects in the EXF Project area and in the Crane Prairie 

and Fall River 6th Field Watersheds

Ongoing & Future Foreseeable Projects in the 

Crane Prairie and Fall River 5th Field Watersheds

Unit of Measure in 

EXF Project 

Boundary

Units of measure 

within the 

watersheds

Snow Fuels Reduction 0 ~3000 ac

SIBUN Commercial firewood sale (downed wood) 0 <20 ac

EXF Biomasss Study <10ac (90 trees) <10ac (90 trees)

Midstate Electric Powerline Maintenance 0 <1ac 

Crane Prairie Resort Maintenance 0 <5ac

Irrigation District Improvements and Reservoir level 

maintenance

0 Crane Prairie Dam

County roads Right of way maintenance 0 ~20 miles

Gauging station with Oregon Water Resources 

Department

0 < 5 ac

Developed recreation site Maintenance 

Cow Meadow Campground

Crane Prairie Campground

0 <5 ac

Charlie Brown EA (Rx burning and PCT) 0 11,492 ac

Weed EIS 0 Multiple sites

Highway 42 Reconstruction 0 ~5 miles

Fall Rx Burning 0 3169
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 24 of 42

Crane Prairie Watershed

The majority of nest sites within the watershed are located within the mixed conifer plant association groups 

(PAGs). The dry mixed conifer PAGs often have an overstory of ponderosa pine and Douglas-fir that have 

survived past fire events, with a co-dominant overstory formed by white fir that has developed within more 

recent times with aggressive fire suppression. This condition most likely had the greatest influence on spotted 

owl habitat across the district due to the development of nesting, roosting, foraging stand characteristics, but in 

areas where climatically the climax association would be more open stands. This is to say, spotted owl habitat 

developed in areas where it may be difficult to sustain such habitat due to the existing fire regimes and climate. 

Activities proposed under the Snow Fuels Reduction project did not impact spotted owl habitat since suitable 

NRF habitat was avoided. Measures were incorporated to retain suitable nesting habitat, strategically place 

units to protect suitable habitat as well as reduce the risk of fire in mixed conifer stands by reducing ladder 

fuels. Under the remaining Charlie Brown treatment units, fuels treatments (e.g. piling and burning slash, 

underburning) will further provide areas that may slow a wildfire’s progression towards spotted owl habitat in 

the EXF project area. Overall, treatments proposed will improve spotted owl habitat conditions by promoting 

the development of large structure and reducing the risk of loss of existing habitat to the east from other largescale disturbances. 

Hazard trees were removed from within the Cultus Mt LSR and CHU. Although some of the trees removed 

were of the size of spotted nest trees, they were within ~150 ft. of the road. This makes it unlikely they would 

ever be used for nest trees. This project would not have interrelated and interdependent effects with the EXF 

project.

Maintenance activities within developed recreation sites will have no cumulative effects in association with the 

proposed action and no action alternatives.

Fall River Watershed

Most of this watershed lies east of spotted owl’s range. There are two home ranges (Sheridan Mt and Three 

Trapper’s Butte) within the western half and these occur within mixed conifer PAGs. Mixed conifer PAGs 

form a relatively thin band of potential and suitable spotted owl habitat within this watershed, as it quickly 

becomes ponderosa pine and lodgepole pine PAGs (not potential or suitable spotted owl habitat).

NRF habitat in this watershed has experienced some of the same ecological effects as habitat in the Crane 

Prairie Watershed. The habitat in the Fall River watershed is at greater risk to wildfire because it lies east of the 

majority of the insect mortality and high fuel concentrations that exist in the adjacent Crane Prairie watershed 

(e.g. Mt. Bachelor Roadless Area) and fires tend start in the Three Sisters Wilderness and move in a 

east/southeasterly direction (pers. commun. T. Bisby, former Assistant Fire Management Officer, Cascade 

Division, Bend-Ft Rock RD, 2008).

NRF habitat in this watershed closely resembles “late-successional forest structure embedded in a matrix of 

more fire-tolerant forest structures” described in the 2008 Recovery Plan (Appendix E page 105). That is, the 

NRF habitat tends to be relatively small stands of large Douglas-fir and white fir embedded in larger areas of 

ponderosa pine and lodgepole pine stands. Appendix B from the programmatic Biological Assessment was 

updated October 2009. This table also accounts for all previous losses of NRF habitat from other activities as 

well (e.g. timber harvest).

Because a bulk of this watershed lies east of the spotted owl range, dispersing owls would be unlikely. 

Therefore there are no interrelated or interdependent effects of this project with other actions within the 

watershed.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 25 of 42

Deschutes National Forest Baseline

Implementation of the proposed actions (Alternative 2) will have further additive effects to spotted owls. 

Alternative 2 will remove 211 acres of NRF habitat. As maintenance of treatments and protection of research 

plots continues, degraded habitat will likely stay marginal for the long-term, and removed habitat will likely not 

return in the short or long-term. Over the Deschutes national Forest, this project represents an approximate 

0.27% decline in the amount of NRF habitat. 

Table 10. Changes in Spotted Owl Baseline Habitat

Ranger District March 2008

Baseline 

(App B)

NRF Lost

(Field 

Verification, 

Harvest, Fire or 

<2 ac slivers)

October 2009

Baseline 

(App B)

Acres of NRF 

Habitat Lost by 

the EXF Project

Crescent 26,441 60 26,381 0

Sisters 33,075 5,491 27,584 0

Bend-Ft. Rock 24,231 86 24,145 211

Forest Total 83,747 78,110 77,899

CUMULATIVE EFFECTS

Cumulative effects include future State, tribal, local or private actions that are reasonably certain to occur in the 

action area. Future federal actions that are unrelated to the proposed action are not considered in this section 

because they require separate consultation pursuant to section 7.

There are no cumulative effects anticipated to occur in the action area. 

CONCLUSION

Alternative 2 will directly reduce 211 acres of NRF habitat. Based on current detections and field verification 

within mapped NRF habitat, this existing habitat appears to have greater foraging and dispersal quality, with 

evidence of perhaps nesting outside of the project area. The project is not designed to develop future spotted 

owl NRF habitat. The founding objectives for the Lookout Mountain Unit of the Pringle Falls Experimental 

Forest were silvicultural and focused on ponderosa pine development and maintenance. The project is designed 

to protect current research and provide a platform for new research along these silvicultural objectives. 

Treatments however may provide spotted owl dispersal habitat in the long-term, and a measure of protection for 

NRF habitat immediately surrounding the Lookout Mt Unit.

Table 11. Summary of Effects to Spotted Owl Habitat
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 26 of 42

Prior to the late 1980s, loss of suitable habitat was limited to timber harvest. Recent harvest activities are aimed 

at reducing risk to existing habitat and promoting desired species composition to develop and maintain habitat. 

The effect of these more recent treatments have yet to be realized in the form of spotted owl occupancy. Barred 

owls, an identified threat to spotted owls and a more generalist species for nesting habitat needs, may be able to 

more rapidly occupy the treated stands within the EXF project area. There have been no observations of barred 

owls within or near the Lookout Mt. Unit, although barred owls have been observed in the western portion of 

the Crane Prairie watershed.

There are limited plant associations that can produce NRF habitat on the eastern edge of the owl’s range. 

Within the eastern portion of the Crane Prairie watershed and the western portion of the Fall River watershed 

there are the largest blocks of dry mixed conifer associations (similarly wet ponderosa pine associations) that 

may be able to develop large Douglas-fir trees and subsequent NRF habitat. All of the stands classified as NRF 

or that have had historical or recent spotted owl observations in these portions of the watershed all have 

contained elements of large Douglas-fir. The Experimental Forest was not established to provide for large

Douglas-fir, although the thinning prescriptions proposed favor retaining Douglas-fir with the result of 

improving growing conditions for this species. There is a possibility that the area may support limited NRF 

habitat in the future, although the emphasis within the Experimental Forest will be Douglas-fir only as it is codominant with ponderosa pine.

Proposed actions will impact spotted owl habitat. In the long term, higher quality habitat should develop due to 

tree growth and preferences for fire resistant Douglas-fir; but NRF habitat would continue to be relatively 

scarce within this landscape on the eastern edge of the species’ range. In the short term, current habitat outside 

of the Experimental Forest would be better protected from a wildfire perspective by the strategic placement of 

units. Dispersal habitat will remain throughout the watersheds; however the proposed actions will remove some 

dispersal and degrade the connectivity corridor established to facilitate old-growth dependent species between 

LSRs. Dispersal will still occur, for the proposed action would not cause a barrier to movement. The stands 

will appear more open due to the thinning and may also provide better access for spotted owl predators (e.g. 

other birds of prey). 

Implementation of the Proposed Action, May Effect, and is likely to Adversely Affect spotted owls because 

of actions proposed that will likely further reduce available NRF habitat and degrade dispersal habitat.

There will be No Effect to Critical Habitat Units as a result of the proposed actions. 

Alternative 2

Proposed Action

Acres of NRF Habitat degraded 0

Acres of NRF habitat removed 211

Acres of Dispersal Habitat degraded 1594

Acres of Dispersal Habitat removed 341

Home Range Affected (acres):

0.7 mile NRF

0.7 mile Dispersal

1.2 mile NRF

1.2 mile Dispersal

Three Trappers Butte

0

0

0

0
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 27 of 42

Communication with U.S. Fish and Wildlife Service (USFWS): 

An initial consultation meeting with Jennifer O’Reilly, Wildlife Biologist in the USFWS Bend Field Office took 

place April 29, 2008 at the Bend Fort Rock Ranger District office. The purpose of the meeting was to introduce 

the purpose and need for the project and the preliminary impacts it may have on spotted owls. Furthermore, in 

June 2008, October 2, 2008 and on July 16, 2009 meetings in the field (and an office conference call on July 31, 

2009) were held with the same representative of the USFWS to discuss the condition of the spotted owl habitat

and the proposed actions.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 28 of 42

LITERATURE

Courtney, S. P., A. C. Carey, M. L. Cody, K. Engel, K. E. Fehring, J. F. Franklin, M. R. Fuller, R. J. Gutierrez, 

J. F. Lehmkuhl, M. A. Hemstrom, P. F. Hessburg, S. L. Stephens, L. A. Sztukowski, and L. Young. 2008. 

Scientific Review of the Draft Northern Spotted Owl Recovery Plan and Reviewer Comments. Sustainable 

Ecosystems Institute. www.sei.org 150 pages.

Courtney, S.P., J.A. Blakesley, R.E. Bigley, M.L. Cody, J.P. Dumbacher, R.C. Fleischer, A.B. Franklin, J.F. 

Franklin, R.J. Gutierrez, J.M. Marzluff, and L. Sztukowski. 2004. Scientific evaluation of the status of the 

northern spotted owl. Sustainable Ecosystems Institute. Portland, OR. 

Damiami, C., D.C. Lee, and S.L. Jacobson. 2007. Effects of noise disturbance on northern

spotted owl reproductive success. USDA Forest Service, Pacific Southwest Research Station, Redwood 

Sciences Laboratory, Arcata, California.

Delaney, D., T. Grubb, P. Beier, L. Pater, and M.H. Reiser. 1999. Effects of helicopter noise on Mexican 

spotted owls. Journal of Wildlife Management 63(1): 60-76.

Forsman, E.D., C.E. Mellow, and H.M. Wight. 1984. Distribution and biology of the spotted owl in Oregon. 

Wildlife Monographs 87:1-64.

Forsman, E.D., R.G. Anthony, J.A. Reid, P.J. Loschl, S.G. Sovern, M. Taylor, B.L. Biswell, A. Ellingson, E.C. 

Mellow, G.S. Miller, K.A. Swindle, J.A. Thrailkill, F.F. Wagner, and D. E. Seaman. 2002. Natal and breeding 

dispersal of northern spotted owls. Wildlife Monographs 149:1–35.

Hessburg, P.F., R.G. Mitchell, and G.M. Filip. 1994. Historical and current roles of insects and pathogens in 

eastern Oregon and Washington forested landscapes. Gen. Tech. Rep. PNW-GTR-327. USDA Forest Service. 

Pacific Northwest Research Station. Portland, OR.

Lehmkuhl, J. F., L. E. Gould, E. Cazares, and D.R. Hosford. 2004. Truffle abundance and mycophagy by 

northern flying squirrels in eastern Washington forests. Forest Ecology and Management 200: 49-65.

Lehmkuhl, J.F, K. D. Kistler, and J. S. Begley. 2006. Bushy-tailed woodrat abundance in dry forests of eastern 

Washington. J. Mammology. 87(2):371-379.

Maffei, H. and B. Tandy. 2002. Methodology for modeling the spatial and temporal effects of vegetation 

management alternatives on late successional habitat in the Pacific Northwest. USDA Forest Service 

Proceedings RMRS-P-25.

McCullough, D. R. ed. 1996. Metapopulations and Wildlife Conservation. Island Press, Washington DC. 429 

pages.

Meyer, M. D., D.A. Kelt, and M. P. North. 2007. Microhabitat associations of northern flying squirrels in 

burned and thinned forest stands of the Sierra Nevada. Am. Midl. Nat. 157:202-211.

Miller, G.S., R.J. Small, and E.C. Meslow. 1997. Habitat selection by spotted owls during natal dispersal in 

western Oregon. Journal of Wildlife Management 61:140–150.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 29 of 42

Smith, W. P. 2007. The northern flying squirrel: a biological portrait of a forest specialist in post-European 

Settlement North America. J. Mammal. 88(4): 837-839.

USDA Forest Service. 1990. Deschutes National Forest Land and Resource Management Plan.

USDA Forest Service. 1993. Protocol for surveying for spotted owls in proposed management activity areas 

and habitat conservation areas.

USDA Forest Service. 1994. Northwest Forest Plan.

USDA Forest Service. 1995. Deschutes National Forest: A Late Successional Reserve Overview. Deschutes 

National Forest. Bend, OR. 

USDA Forest Service, Bend/Ft. Rock Ranger District. 1996. Cultus Mountain Sheridan Mountain LateSuccessional Reserve Assessment. Bend, OR. 

USDA Forest Service, Bend/Ft. Rock Ranger District. 1997. Brown’s/Wickiup Watershed Analysis and 

Brown’s/Round Mountain Late-Successional Reserve Assessment. Bend, OR. 

USDA Forest Service, Bend/Ft. Rock Ranger District. 2000. Charlie Brown Project Environmental Analysis 

and associated Assessment. Bend, OR. 

USDA Forest Service, Bend/Ft. Rock Ranger District. 2004. Fall Project Environmental Analysis and 

associated Assessment. Bend, OR. 

USDA Forest Service. 2006. The Joint Aquatic and Terrestrial Programmatic Biological Assessment for Federal 

Lands within the Deschutes and John Day River Basin’s Administered by the Deschutes and Ochoco National 

Forests, August 2006-August 2009.

USFWS. 1989. The Northern spotted owl status review supplement. U.S. Fish and Wildlife Service, Portland, 

Oregon.

USFWS. 1990. Endangered and threatened wildlife and plants; determination of threatened status for the 

northern spotted owl. Federal Register 55:26114–26194.

USFWS. 2003. Biological opinion and letter of concurrence for effects to bald eagles, marbled murrelets, 

northern spotted owls, bull trout, and designated critical habitat for marbled murrelets and northern spotted owls 

from Olympic National Forest program of activities for August 5, 2003 to December 31, 2008.

USFWS. 2008. Final Recovery Plan for the Northern Spotted Owl, Strix occidentalis caurina. U.S. Fish and 

Wildlife Service, Portland, Oregon.

Weigl, P. D. 2007. The northern flying squirrel (Glaucomys sabrinus): A conservation challenge. J. Mammal. 

88(4): 897-907.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 30 of 42

Appendix A: Spotted Owl Nesting Roosting & Foraging (NRF) Habitat Field 

Verification Rationale

Spotted Owl NRF Habitat verification was initiated in the fall of 2007. The mapped NRF habitat patches at the 

time were field-visited to determine if the stands contained the elements of NRF. Features that support nesting 

and roosting habitat typically include a moderate to high canopy (60 to 90 percent); a multi-layered, multispecies canopy with large [> 30 inches diameter at breast height] overstory trees; a high incidence of large trees 

with various deformities (e.g., large cavities, broken tops, mistletoe infections, and other evidence of 

decadence); large snags; large accumulations of fallen trees and other woody debris on the ground; and 

sufficient open space below the canopy for owls to fly (Thomas et al. 1990). Foraging habitat generally consists 

of attributes similar to those in nesting and roosting habitat, but may not always support successfully nesting 

pairs (USDI 1992b). Dispersal habitat, at minimum, consists of stands with adequate tree size and canopy 

closure to provide protection from avian predators and at least minimal foraging opportunities: there may be 

variations over the owl’s range (e.g., drier sites in the east Cascades or northern California) (USDI FWS 

1992b).”

Using the NRF descriptions as a guide, each NRF patch was evaluated on the following bases: 

1. Was it multi-layered (yes/no). 

2. Average canopy closure (%). 

3. Average tree dbh (range in inches). 

4. Presence of >30”dbh trees, deformities, mistletoe for potential nest trees (yes/no). 

5. Amount and size of decadence (average diameter of downed logs, size and presence of snags/broken tree 

tops).

6. Understory brushy? (yes/no). 

7. Green limbs low to ground, small open areas on ground, or well-decayed logs for foraging? (yes/no). 

8. Would it provide NRF habitat or more likely foraging or dispersal habitat? 

Some examples of the NRF patches that were dropped include a single-storied stand with an average canopy 

closure of 25%, large ponderosa pine, high branches and high brush cover. An example of a stand mapped as 

NRF but met criteria for foraging better was multi-storied, 40% canopy closure, average tree diameter was 15-

28” with some 30+” dbh ponderosa pines, but these did not have large limbs or decay and limbs in the upper 

canopy. An example of a stand that was retained as NRF was multi-storied, 50% canopy closure, contained 

Douglas-fir and ponderosa pine 12-48” dbh, contained decayed elements although many logs still firm, and 

brush level was low to moderate. If a mapped stand contained portions whereby NRF may be met, the whole 

stand was retained for further analysis. This is to say, through the verification process if there was uncertainty 

whether or not to call a stand NRF, we erred on the side of retaining it as NRF.

The following maps use the 2004 satellite vegetation database to give an overview of how some of the elements 

are distributed across the project area (blue or yellow outlined feature) and outside of the project area but within 

the general spotted owl survey area.
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Map 1. This illustrates the distribution of large trees. The red, lavender, and purple areas reflect a multi-storied 

presence and an average tree diameter of 15-20”. Yellow areas are single-storied stands with an average tree 

diameter of 15-30”. The Sheridan Mt LSR is the hatched area, the NRF patches are outlined in black and the 

closest spotted owl home range (Three Trappers Buttes) is shown. The EXF project units are outlined in blue, 

and the green line shows the eastern edge of the Northwest Forest Plan boundary.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 32 of 42

Map 2. This illustrates the distribution of plant association groups. Orange areas reflect the ponderosa pine and 

ponderosa pine/lodgepole pine groups. Blue areas reflect associations with a fir component (ponderosa 

pine/Douglas-fir, white fir/Douglas-fir, Subalpine fir/white fir). Green areas reflect associations with mountain 

hemlock. Purple are areas dominated by lodgepole pine, and Dark Blue reflect more alpine associations of 

mountain hemlock with subalpine fir. The Sheridan Mt LSR is the hatched area, the NRF patches are outlined 

in black and the closest spotted owl home range (Three Trappers Buttes) is shown. The EXF project units are 

outlined in blue, and the green line shows the eastern edge of the Northwest Forest Plan boundary.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 33 of 42

Map 3. This illustrates the canopy closure distribution. The lavender areas reflect an average of 55-70% canopy 

closure; green equal 40-55% canopy closure; and yellow equals 70-100% canopy closure. The Sheridan Mt 

LSR is the hatched area, the NRF patches are outlined in black and the closest spotted owl home range (Three 

Trappers Buttes) is shown. The EXF project units are outlined in blue, and the green line shows the eastern 

edge of the Northwest Forest Plan boundary.
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The following “on-the-ground” figures illustrate the rationale discussed above:

Figure A1 represents the lower elevation portion of Unit 32. This portion had been mapped as NRF habitat but 

based on field reviews it is evident that it is dominated by ponderosa pine, heavy shrub cover and no evidence 

of large (>30” dbh) trees with decadence to provide for immediate nesting structure. Note: two other NRF 

patches within this unit were retained as NRF habitat.

Figure A1. Taken 16 June 2008. 
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 35 of 42

The following photos taken within Unit 23 illustrate the variability within a Unit and mapped NRF patch. This 

entire stand of mapped NRF was analyzed as NRF because of portions with a heavier fir dominance and fewer 

shrubs in the understory (Figures A2 and A3). Whereas, Figures A4 and A5 illustrate the more open ponderosa 

pine dominance of some of the lower elevation areas of this same NRF stand.

Figure A2. Taken 16 June 2008

Figure A3. Taken 28 October 2009. Note lack of brush, multi-story, ponderosa pine still dominates the large overstory.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 36 of 42

Figure A4. Taken 16 June 2008. The lower slope of the NRF patch in Unit 23. Note the single-storied ponderosa pine; 

although the canopy closure if higher and there is a component of white fir. This illustrates the better quality foraging and 

dispersal habitat than perhaps the nesting components.

A5. Taken 16 June 2008. Again, the ponderosa pine dominance with heavy shrub understory.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 37 of 42

Unit 11 is nearly completely overlain by a mapped NRF stand. The NRF mapped within this unit was 

particularly challenging to field verify because of the more variable nature within the Unit. Figures A6 and A7 

were taken within portions of the NRF stand that contain many of the features that classify NRF (e.g. multistory, multi-species in overstory, large downed wood); whereas Figures A8 and A9 that are part of the same 

NRF stand illustrate the opposite for nesting habitat (e.g. open canopy, heavy shrub cover, ponderosa pine 

dominance).

Figure A6. Taken 16 June 2008

Figure A7. Taken 16 July 2009.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 38 of 42

Figure A8. Taken 28 October 2009

Figure A9. Taken 16 June 2008.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

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Unit 12 also shared the same stand of mapped NRF as illustrated with Unit 11. This Unit 12 portion differs in 

that it is higher elevation and more consistently contains features that classify NRF habitat as shown in Figures 

A10-A12.

Figure A10. Taken 16 June 2008. Unit 12 NRF. Note the lack of ponderosa pine in overstory, multi-layered canopy, little to 

no brush cover.

Figure A11. Taken 16 July 2009. Unit 12 NRF. Note the decadence within ponderosa pine overstory and the dominance of fir 

in the overstory as well as the downed wood, multi-story and high canopy closure.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 40 of 42

Figure A12. Taken 16 July 2009. Unit 12 NRF illustrating a more open area with ponderosa pine and fir as the overstory , 

large down logs, and lack of brush cover.
Biological Assessment, EXF Thinning, Fuels Reduction and Research Project, Deschutes National Forest, 

Bend-Ft. Rock Ranger District, November 13, 2009 – Page 41 of 42

Appendix B: EXF Spotted Owl Survey Summary

Survey Year Date Station # Species

Approx. Direction 

(degrees) Comments

2007 22-May 22 GLGN 105

18-Jun 24 STOC 292 2 Adults @23:42

OTFL 224

33 OTFL 224

STOC 98 1 Adult @ 22:46

2 OTFL 295

21 OTFL 288

22 OTFL 170

18 OTFL 35

19-Jun 24 NR Follow Up to Jun 18

20-Jun 33 NR Follow Up to Jun 18

26-Jun 24 STOC 70-100

Moving adult 

male@21:28

27-Jun 24 STOC Pair @17:24

24 STOC

Follow up to Pair: ate 3 

mice, lost 2 no indication 

of young

30-Jul 24 NR Further Follow up to Pair

2008 3-Jun 39 OTKE 135

36 AEAC 220

8-Jun 35 GLGN 190

11-Jun 27 OTKE 35

26-Jun 23 STOC 50 Adult heard @ 23:30

27-Jun 23 NR Follow Up to Jun 26

2-Jul 17 BUVI? 180

Call was difficult to ID 

accurately

23-Jul 17 STOC 220 Adult male @00:27

8 OTFL 170

39 OTKE

25-Jul 17 NR Follow up to July 23

2009 26-May 40 Unk Owl

27-May 18 OTFL 322

1-Jun 40

Bald 

Eagle 310 early evening response

3-Jun 27

Cooper's 

Hawk seen at station

8-Jun 10 GLGN 144

18-Jun 24 NR

Continued to call points 

near where the pair was 

heard in 2007 with no 

response

Key: 

NR = No Response

STOC = Spotted Owl

GLGN = Pygmy Owl

AEAC = Saw-whet Owl

OTFL = Flammulated Owl

OTKE = Western Screech 

Owl

BUVI = Great-Horned Owl
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