5476 Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules

As required by section 3507(d) of the

PRA, the Secretary has submitted a copy

of this proposed rule to OMB for its

review. Comments on the information

collection requirements are specifically

solicited in order to: (1) Evaluate

whether the proposed collection of

information is necessary for the proper

performance of HHS functions,

including whether the information will

have practical utility; (2) evaluate the

accuracy of the HHS estimate of the

burden of the proposed collection of

information, including the validity of

the methodology and assumptions used;

(3) enhance the quality, utility, and

clarity of the information to be

collected; and (4) minimize the burden

of the collection of information on those

who are to respond, including the use

of appropriate automated, electronic,

mechanical, or other technological

collection techniques or other forms of

information technology.

OMB is required to make a decision

concerning the collection of information

contained in these proposed regulations

between 30 and 60 days after

publication of this document in the

Federal Register. Therefore, a comment

to OMB is best assured of having its full

effect if OMB receives it within 30 days

of publication. This does not affect the

deadline for the public to comment to

HHS on the proposed regulations.

Organizations and individuals

desiring to submit comments on the

information collection requirements

should direct them to the Office of

Information and Regulatory Affairs,

OMB. (address above).

List of Subjects in 45 CFR Part 96

Administrative practice and

procedure, Grant programs—health,

Health care.

Dated: January 31, 2000.

Donna E. Shalala,

Secretary.

For the reasons set forth in the

preamble, the Department proposes to

amend Subpart L of Part 96 of Title 45

of the Code of Federal Regulations as

follows:

PART 96—BLOCK GRANTS

Subpart L—Substance Abuse

Prevention and Treatment Block Grant

1. The authority citation for Subpart

L of Part 96 continues to read as follows:

Authority: 42 U.S.C. 300x–21 to 300x–35

and 300x–51 to 300x–64.

2. Section 96.122 (d) is revised to read

as follows:

§ 96.122 Application content and

procedure.

* * * * *

(d) The application (in substantial

compliance with the statutory and

regulatory provisions for the Block

Grant) shall for fiscal years through

fiscal year 2000, be submitted no later

than March 31 of the fiscal year for

which the State is applying. Beginning

with the fiscal year 2001 application, all

required components for a complete

application must be submitted no later

than October 1 of the fiscal year for

which Block Grant funding is being

requested. The submission date for the

report required by § 96.130(e) to be

submitted with the application and/or

the information required by § 96.134(b)

may be extended for good cause shown

in a request signed by the official

authorized to apply for the Block Grant

funding on behalf of the State, or the

Governor. The State should request an

extension for only the amount of time

necessary. In no event will an extension

be granted past December 31 of the

fiscal year for which application is

made. All requests to extend the due

date must be submitted no later than

September 1 of the prior fiscal year and

addressed to the same address as

specified for the grant application.

Extension requests must state for which

requirement an extension is sought, the

date of submission sought, why the

State is unable to meet the October 1

due date, and discuss if there are steps

the State will be able to take to avoid

requiring an extension in future years,

or if not, why not. Extension requests

complying with these requirements will

be acted upon no later than September

20 of the fiscal year prior to the year for

which application is to be made. Due

date extensions regarding the § 96.130(e)

report and regarding the § 96.134(d)

information shall only be granted in

writing. In order for an applicant to

have complied with the requirements of

section 1932(a)(1) of the Public Health

Service Act (42 U.S.C. 300x-32(a)(2)), it

is necessary that the components of the

application have been submitted by the

date indicated or as extended pursuant

to the above.

* * * * *

[FR Doc. 00–2444 Filed 2–1–00; 10:25 am]

BILLING CODE 4162–20–P

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

Endangered and Threatened Wildlife

and Plants; 12-Month Finding for a

Petition To List the Black-Tailed Prairie

Dog as Threatened

AGENCY: Fish and Wildlife Service,

Interior.

ACTION: Notice of 12-month petition

finding.

SUMMARY: We, the Fish and Wildlife

Service, announce a 12-month finding

for a petition to list the black-tailed

prairie dog (Cynomys ludovicianus) as

threatened throughout its range under

the Endangered Species Act of 1973, as

amended (Act). After reviewing all

available scientific and commercial

information, we have determined that

listing this species is warranted but

precluded by other higher priority

actions to amend the Lists of

Endangered and Threatened Wildlife

and Plants. Upon publication of this

notice of 12-month petition finding, the

black-tailed prairie dog will be added to

our candidate species list.

This decision is based on—the

number, variety, and significance of

threats affecting the species, especially

sylvatic plague (an exotic disease to

which the species has no resistance) and

inadequate regulatory mechanisms

(some areas mandate eradication);

evidence of recent general population

declines in a significant portion of the

species’ range; and cumulative

rangewide population data indicating

overall population declines since 1980.

DATES: The finding announced in this

document was made on February 4,

2000.

ADDRESSES: You may submit data,

information, comments, or questions

concerning this finding to the Field

Supervisor, U.S. Fish and Wildlife

Service, 420 South Garfield, Suite 400,

Pierre, South Dakota 57501. You may

inspect the petition finding, supporting

data, and comments by appointment

during normal business hours at the

above address. The petition finding also

will be available at the Service’s Region

6 website at <www.r6.fws.gov/

btprairiedog>.

FOR FURTHER INFORMATION CONTACT: Pete

Gober, Field Supervisor, South Dakota

Field Office (see ADDRESSES section),

telephone (605) 224–8693, extension 24,

or facsimile (605) 224–9974.

SUPPLEMENTARY INFORMATION:

Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules 5477

Background

On July 31, 1998, we received a

petition dated July 30, 1998, from the

National Wildlife Federation (National

Wildlife Federation 1998). The

Petitioner requested that we list the

black-tailed prairie dog as threatened

throughout its range. The Petitioner also

requested that the species be afforded

emergency listing. Section 4 of the Act

and regulations at 50 CFR 424 do not

provide for petitions to request the

listing of species on an emergency basis.

However, section (4)(b)(7) of the Act and

the Service’s Listing Priority Guidance

(63 FR 25502) direct that all petitions

are to be reviewed to determine if an

emergency listing is appropriate. We

determined and advised the Petitioner

by letter dated August 27, 1998, that it

would be inappropriate to list this

species on an emergency basis given its

then known status. On September 16,

1999, the Petitioner requested that we

readdress this issue based on reports of

increased control efforts (Graber,

National Wildlife Federation, in litt.

1999). We have reevaluated information

available regarding this subject and

determined that emergency listing of the

species is not appropriate at this time.

Section 4(b)(3)(A) of the Act requires

that, for any petition to revise the List

of Threatened and Endangered Species

containing substantial scientific and

commercial information that listing may

be warranted, we make a positive 90-

day finding and initiate a status review

of the species. We published a notice of

a positive 90-day finding on the subject

petition in the Federal Register on

March 25, 1999 (64 CFR 14425).

Accordingly, the subject petition

requires a 12-month administrative

finding pursuant to section 4(b)(3)(B) on

whether the petitioned action is—(I) not

warranted, (ii) warranted, or (iii)

warranted but precluded from

immediate proposal by other higher

priority efforts to revise the List of

Threatened and Endangered Species.

When we find a petition to list a species

is warranted but precluded, the species

is designated a candidate species.

We believe that sufficient information

is currently available to support a

finding that listing the black-tailed

prairie dog as threatened is warranted,

but that a proposed rule at this time is

precluded by work on other higher

priority listing actions. We will

reevaluate the status of the species in 1

year. The information contained in this

notice is a summary of the information

in the 12-month finding.

The National Wildlife Federation

petition presented extensive

information regarding the biology of the

black-tailed prairie dog. This

information included a description of

the species and its range, as well as

comments related to its population

biology and trend. The Petitioner noted

that the species still occurs

intermittently throughout most of its

historic range, although much reduced

in numbers and in the amount of habitat

that it occupies. The Petitioner

contrasted reports that the black-tailed

prairie dog once occupied as much as

100–200 million acres (ac) (40–80

million hectares (ha)) of the western

North American prairie with current

estimates of occupied habitat and

concluded that the species’ habitat has

been reduced by at least 99 percent. The

Petitioner attributed reductions in

occupied habitat to habitat loss and

degradation related to the conversion of

prairie grasslands to farmland, extensive

control, disease, urban development,

unregulated shooting, and other factors.

On August 26, 1998, we received

another petition regarding the blacktailed prairie dog from the Biodiversity

Legal Foundation, the Predator Project,

and Jon C. Sharps (Biodiversity Legal

Foundation et al. 1998). They requested

that we list the black-tailed prairie dog

as threatened throughout its known

historic range in the contiguous United

States. We accepted this second request

as supplemental information to the

National Wildlife Federation petition.

The Biodiversity Legal Foundation et al.

(1998) provided estimates of historic

and current distribution of the blacktailed prairie dog, both regionally and

by State. They noted that the species’

populations are impacted by eradication

programs, sylvatic plague, recreational

shooting, land conversion, and natural

predation. The Biodiversity Legal

Foundation (1999) also developed and

submitted a potential plan for blacktailed prairie dog conservation.

The notice of a 90-day finding that a

petition to list the black-tailed prairie

dog presented substantial information

that appeared in the Federal Register on

March 25, 1999 (64 FR 14424). In this

notice, we requested that any additional

scientific information relevant to a

proposed 12-month administrative

finding be submitted to us by May 24,

1999. We published a notice in the

Federal Register on June 4, 1999 (64 FR

29983), that reopened this period for an

additional 45 days, through July 19,

1999. On October 4, 1999, we again

published a notice that we would accept

additional information, especially

pertaining to a draft black-tailed prairie

dog Conservation Assessment and

Strategy (Strategy) developed by various

States and its effect on the status of the

species (64 FR 53655). This information

collection period closed November 3,

1999.

We received approximately 14,500

comment letters during the

development of this finding. The

following summarizes the sources and

general content of information we

received.

All State wildlife agencies within the

historic range of the black-tailed prairie

dog provided written comments on the

petition. Two State agriculture

departments (New Mexico and

Wyoming) and two State Legislatures

(North Dakota and Wyoming) also

provided comments. In general, the

States opposed listing the black-tailed

prairie dog but supported the

development of conservation measures

for the species. Most information

provided by the States focused on

policy and jurisdictional concerns

rather than on information related to the

biological status of the species.

State wildlife agencies and other

interested parties also developed a

Strategy for conservation of the blacktailed prairie dog (Van Pelt in prep.).

The actions identified in the current

draft of this Strategy remain tentative

and do not at this time confer any

improved status for the species. Eight of

the 11 participating State wildlife

agencies have signed a Memorandum of

Understanding for the purpose of

implementing the States’ Strategy for

the black-tailed prairie dog. At this time,

the strategy does not include

participation by the States of New

Mexico, North Dakota, and Colorado,

other State (non-wildlife) agencies,

Federal agencies, Tribal agencies, or any

private interests. We recognize the

significant effort that went into the

development of this strategy, and we

believe that the strategy is a positive

step in addressing the conservation

needs of the black-tailed prairie dog. At

this early stage in development of the

strategy, the document lacks

commitments to specific immediate

actions that would affect the status of

the species. We will continue working

with the States and other interested

parties to support the coordinated

conservation efforts of the States.

Three Tribes in South Dakota

provided written comments on the

petition—the Cheyenne River Sioux

Tribe, the Crow Creek Sioux Tribe, and

the Rosebud Sioux Tribe. Information

was provided by these Tribes regarding

distribution and abundance and existing

regulatory mechanisms on and

adjoining their respective Tribal lands.

Several Federal agencies provided

written comments on the petition. The

Bureau of Indian Affairs (BIA)

supported conservation measures and

5478 Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules

acknowledged a possible need to list the

species. The U.S. Forest Service

provided supplemental information

regarding the current status of blacktailed prairie dogs on National

Grasslands (Sidle, U.S. Forest Service,

in litt. 1999). The National Park Service

provided information on its control

efforts and noted its preference for the

development and implementation of

cooperative management strategies

among State, Tribal, and Federal

agencies rather than a listing of the

species. The Corps of Engineers Omaha

District also reviewed information

provided in the petition, but had no

specific comments.

Twenty-three county agencies (county

commissions and weed/pest councils)

in Colorado, Montana, Nebraska, South

Dakota, and Wyoming provided written

comments on the petition. All county

agencies were opposed to listing the

species. Economic considerations were

a common concern in these comment

letters. Because the Act directs that only

biological considerations are to be

addressed in the listing process, we

cannot address economic considerations

in review of this petition.

One hundred forty-four organizations

(wildlife/conservation or livestock/land

management organizations) provided

written comments on the petition.

Forty-two wildlife/conservation

organizations supported listing of the

black-tailed prairie dogs. Eighty-seven

livestock/land management

organizations were opposed to listing

the species. Fifteen organizations

provided recommendations but did not

indicate a position.

Over 14,300 individuals provided

written comments on the petition.

Approximately 90 percent of all

individuals supported listing the blacktailed prairie dog as threatened. The

issues most frequently noted in these

letters were impacts from the loss of 99

percent of the species’ habitat,

recreational shooting, control, and

disease. Individuals opposed to listing

the species most frequently expressed

the view that adequate numbers of the

species exist, the species is able to

reproduce rapidly in response to

adverse impacts, sport shooting does not

impact the species, and adverse

economic impacts can occur if the

species is not controlled.

We received approximately 9,000

letters during the third comment period

(October 4 to November 3, 1999). Of

these, 84 mentioned the States’ Strategy,

25 of which opposed the States’

Strategy, mostly due to a perceived lack

of specific conservation measures and

reliance on future, voluntary actions.

Fifty-six letters supported the States’

Strategy, most expressing the view that

the proposed measures were sufficient

to avoid listing and that State

management was preferable to Federal

management. The remaining 3 of the 84

commenters did not express a position.

Taxonomy

Five species of prairie dogs occur in

North America. Prairie dogs are rodents

within the squirrel family (Sciuridae)

and include the black-tailed prairie dog,

the white-tailed prairie dog (Cynomys

leucurus), the Gunnison’s prairie dog (C.

gunnisoni), the Utah prairie dog (C.

parvidens), and the Mexican prairie dog

(C. mexicanus) (Pizzimenti 1975). The

Utah and Mexican prairie dogs are

currently listed as threatened (49 FR

22339) and endangered (35 FR 8495),

respectively. Generally the black-tailed

prairie dog occurs east and north of the

other four species in less arid habitat.

Some scientific literature describes a

subspecies (Cynomys ludovicianus

arizonensis) of the black-tailed prairie

dog. This subspecies, found in

northeastern Mexico (Ceballos et al.

1993), is extirpated in Arizona

(Alexander 1932; Bureau of Sport

Fisheries and Wildlife 1961; Van Pelt,

Arizona Game and Fish Department, in

litt. 1998) and has a remnant population

in southwestern New Mexico (Hall and

Kelson 1959) and in the Trans-Pecos

region of Texas (Davis 1974, Hall and

Kelson 1959). A complex of this

subspecies in Chihuahua, Mexico,

comprises the largest remaining prairie

dog complex of any prairie dog species

(Ceballos and Pacheco 1997).

The remainder of the species is found

in eastern Montana, eastern Wyoming,

eastern Colorado, eastern New Mexico,

southwestern North Dakota, western

and central South Dakota, western and

central Nebraska, western and central

Kansas, western and central Oklahoma,

northwestern Texas, and southwestern

Canada. Although some literature

describes a subspecies, the research that

has focused on evolutionary divergence

(genetic segregation and differentiation

within a taxon) supports categorizing

the black-tailed prairie dog as a

monotypic species. Based on this

research we do not consider this

subspecies separation to be valid. We

consider the species as being

monotypic. For the remainder of this

notice, the use of the common name

‘‘black-tailed prairie dog’’ includes both

varieties discussed above.

Biology

Prairie dogs are small, stout ground

squirrels. The total length of an adult

black-tailed prairie dog is approximately

14–17 inches. The weight of an

individual ranges from 1 to 3 pounds.

Individual appearances within the

species vary in mixed colors of brown,

black, gray, and white. The black-tipped

tail is characteristic (Hoogland 1995).

Black-tailed prairie dogs are diurnal,

burrowing animals and spend most of

the day above ground. They do not

hibernate as do white-tailed,

Gunnison’s, and Utah prairie dogs

(Hoogland 1995, Tileston and

Lechleitner 1966). The species is very

social, living in population aggregations

called colonies, towns, or villages (King

1955). Groups of colonies comprise a

complex. Historically, they generally

occurred in large colonies that

contained thousands of individuals,

covered hundreds of thousands of acres,

and extended for miles (Bailey 1905).

This description is no longer accurate

for existing black-tailed prairie dog

populations; most colonies are now

much smaller.

The colonial behavior of prairie dogs,

especially the black-tailed prairie dog, is

a significant characteristic of the

species. Colonial behavior offers an

effective defense mechanism by aiding

in the detection of predators and

deterring predators through mobbing

behavior. It increases reproductive

success through cooperative rearing of

juveniles and aids parasite removal via

shared grooming. However, it also has

been noted that this behavior promotes

the transmission of disease, which can

significantly suppress populations

(Olsen 1981, Hoogland 1995).

Several biological factors determine

the reproductive potential of the blacktailed prairie dog. Females usually do

not breed until their second year and

live 3–4 years (Hoogland 1995, King

1955, Knowles and Knowles 1994).

Females of the species produce a single

litter, usually 4–5 pups, annually

(Hoogland 1995, Knowles and Knowles

1994). Prairie dog dispersal is usually

limited to approximately 3 miles (5

kilometers) or less, and individuals

dispersing from home colonies generally

move into an established colony rather

than attempting to initiate a new colony

(Garrett and Franklin 1988, Hoogland

1995). These limitations could restrict

recruitment of animals into small and

declining isolated populations and favor

the reestablishment of individuals in

nearby, recently abandoned colonies

over the establishment of new, more

distantly located colonies.

Ecology

The extent to which the black-tailed

prairie dog is affected by other species,

particularly ungulates, is largely

unknown. The black-footed ferret

(Mustela nigripes), swift fox (Vulpes

Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules 5479

velox), mountain plover (Charadrius

montanus), ferruginous hawk (Buteo

regalis), burrowing owl (Athene

cunicularia), and numerous other

species are dependent upon prairie dogs

to varying degrees. Although reports

vary as to those species that require

prairie dogs for their survival, at least 9

species depend directly on prairie dogs

or their activities to some extent, and

another 137 species are associated

opportunistically (Kotliar et al. 1999).

The most obligatory species of this

group is the endangered black-footed

ferret. Probably no other species has a

more clearly documented dependence

on another species than does the blackfooted ferret on the prairie dog

(Anderson et al. 1986, Biggins et al.

1986, Clark 1989, Forrest et al. 1988,

Henderson et al. 1974, Hillman 1968,

Miller et al. 1996).

Rangewide Distribution

The historic range of the black-tailed

prairie dog included portions of 11

States, Canada, and Mexico. Today it

occurs from extreme southern Canada to

northeastern Mexico and from

approximately the 100th meridian west

to the Rocky Mountains. The species is

currently present in 10 States including

Colorado, Kansas, Montana, Nebraska,

New Mexico, North Dakota, Oklahoma,

South Dakota, Texas, and Wyoming. It

has been extirpated in Arizona since as

early as 1932 (Alexander 1932). We

believe that significant range

contractions have occurred in the

southwestern portion of the species’

historic range in Arizona, western New

Mexico and western Texas, and in the

eastern portion of the species’ historic

range in Kansas, Nebraska, Oklahoma,

South Dakota, and Texas. These range

contractions represent approximately 20

percent of the species’ original range.

Only a few individuals or none remain

in these areas. Approximately 37

percent of the species’ potential habitat

in the United States has been converted

to cropland (Black-footed Ferret

Recovery Foundation, in litt. 1999). This

habitat loss is essentially permanent and

not considered a range contraction in

the usual sense occurring at the

periphery of a species’ range. Although

the species will occupy abandoned

tilled ground, these lands are generally

unavailable for use by the species

because the land is continuously

disturbed and thus the habitat is lost

permanently.

Rangewide Abundance

Historically, black-tailed prairie dogs

were one of the most conspicuous and

characteristic residents of the shortgrass and mixed-grass prairies of the

United States. Seton (1953) estimated

that, in the late 1800s, 5 billion blacktailed prairie dogs existed over their

entire range of 600,000 square miles

(384 million ac or 155.5 million ha).

Miller et al. (1996) and Mulhern and

Knowles (1995) provided a range for

historic occupied habitat by all species

of prairie dogs of 99 million-247 million

ac (40 million-100 million ha).

Anderson et al. (1986) noted that, as a

conservative estimate for the early

1900s, 104 million ac (42 million ha) of

rangeland may have been occupied by

all species of prairie dogs. Black-tailed

prairie dogs had the most extensive

range of all the species of prairie dogs

and probably occupied more area than

all other species combined (Hoogland

1995). Estimates of historic black-tailed

prairie dog occupied habitat of

approximately 79 million ac (32 million

ha) in the United States by the Blackfooted Ferret Recovery Foundation (in

litt. 1999) and of approximately 111

million ac (45 million ha ) by Knowles

(1998) provide a reasonable historic

range for black-tailed prairie dog

occupied habitat. It is apparent that

regardless of which estimate is

considered, tens of millions of acres of

occupied habitat once existed in the

United States.

At present, the black-tailed prairie

dog may be found scattered in remnant

populations throughout much of the

range that it once occupied. A

significant portion of existing occupied

habitat rangewide occurs in a few large

complexes. Approximately 36 percent of

the remaining occupied habitat for the

species in North America occurs in

seven complexes, each larger than

10,000 ac (4,000 ha). We believe that

approximately 768,000 ac (311,000 ha)

of occupied habitat currently exists

rangewide. This estimate is based on the

sum of Service estimates from various

States, from Canada, and from Mexico,

as discussed under the ‘‘Statewide

Distribution, Trends, and Abundance’’

section of this document.

Rangewide Trends

Most estimates of prairie dog

population trends are not based on

numbers of individuals, but on the

amount of occupied habitat for the

species. The actual number of animals

present depends upon the density of

animals in that locality. Estimates of

black-tailed prairie dog density across

the species’ range vary seasonally, but

range from 2 to 18 individuals per ac (5

to 45 individuals per ha) (Fagerstone

and Ramey 1996, Hoogland 1995, King

1955, Koford 1958, Miller 1996). Most

prairie dog surveys do not estimate

density because of the high effort and

cost involved. We believe that a review

of various estimates of occupied habitat

area provides the best available and

most reasonable means of determining

population trends for the species.

The U.S. Geological Survey estimated

that the black-tailed prairie dog may

occupy less than 0.5 percent of its

original range and has experienced an

estimated 98 percent decline in

population abundance throughout North

America (Mac et al. 1998). It notes that

the amount of occupied habitat has

declined from approximately 100

million ac (40.5 million ha) in the late

1800s to less than 1 million ac (0.4

million ha) at present; a decline of over

99 percent. Barko (1997), Fagerstone

and Ramey (1996), Knowles (1998),

Mulhern and Knowles (1995), and

Wuerthner (1997) concluded that a

reduction of approximately 94–99

percent in the amount of occupied

habitat within this range has occurred

since about 1900. State wildlife agencies

generally confirm this decline, but some

point out that disproportionately more

occupied habitat remains in some areas

than in others.

Some increases in the amount of

occupied habitat in some areas occurred

subsequent to the Executive Order

banning the use of compound 1080 (a

toxicant) in 1972. These increases

appear to have been limited in later

years by the use of other toxicants such

as zinc phosphide, the continuing

spread of sylvatic plague, and other

factors (Knowles 1998). Moreover, the

majority of these increases

(approximately 85 percent) occurred in

areas (Montana, South Dakota, and

Wyoming) where significant impacts

due to disease had not yet occurred.

Survey efforts in some areas have

noted significant declines in the amount

of black-tailed prairie dog occupied

habitat over the last few decades. For

example, the U.S. Forest Service has

mapped black-tailed prairie dog

colonies within the Northern Great

Plains National Grasslands in North

Dakota, South Dakota, Wyoming, and

Nebraska. These grasslands, covering

approximately 3.7 million ac (1.5

million ha), included a maximum of

86,220 ac (34,890 ha) of black-tailed

prairie dog occupied habitat in the

1970s to the 1990s. In 1997, the U.S.

Forest Service mapped 39,420 ac

(15,965 ha) of occupied habitat in the

same areas, indicating a 54 percent

decline (U.S. Forest Service 1998). Data

provided by the U.S. Forest Service in

1999 confirmed losses in occupied

habitat for the National Grasslands with

a 58 percent decline from the 1970s to

the present (Sidle, U.S. Forest Service,

in litt. 1999).

5480 Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules

Lockhart (U.S. Fish and Wildlife

Service, in litt. 1998) reported that the

recovery program for the black-footed

ferret has identified large prairie dog

complexes potentially useful for

reintroduction of the ferret. Both blacktailed and other prairie dog species are

considered. One necessary criteria for

these sites is that they contain

approximately 10,000 ac (4,000 ha) of

occupied habitat. In the late 1980s, the

Black-footed Ferret Interstate

Coordinating Committee identified

dozens of potential sites that may have

qualified as suitable for ferret recovery.

Black-tailed prairie dog populations at

these sites appear to have been reduced

by as much as 90 percent within the last

15 years. By 1994 only 16 sites were

identified, and by 1998 this number was

reduced to 10 sites (7 being black-tailed

prairie dog sites). Although the overall

trend is a large-scale reduction,

population increases have been

observed at some locales. These

declines have occurred largely in the

western portion of the species’ range

and are generally attributed to sylvatic

plague. These declines may be

representative of the overall population

dynamics of the species in many areas.

However, populations in some other

areas in the eastern portion of the

species’ range where plague is mostly

absent have increased marginally or

remained generally constant during the

same period.

Approximately 66 percent, or 300

million ac (122 million ha), of the blacktailed prairie dog range in the United

States is affected by sylvatic plague

(Black-footed Ferret Recovery

Foundation, in litt. 1999). This area

includes the western portions of the

species’ range. Another important factor

that has affected the species is the

conversion of rangeland to cropland,

especially in the eastern portion of the

species’ range. Conversion of native

prairie to cropland has largely

progressed across the species’ range

from east to west with more cropland

occurring in the eastern portion of the

species’ range. In the plague-free portion

of the species’ range, less than 33

percent of the species’ historic range is

available to the species (Black-footed

Ferret Recovery Foundation, in litt.

1999). Therefore, only approximately 10

percent of the black-tailed prairie dog

historic range is both plague-free and

available (not cropland) to the species.

The majority of plague-free, suitable

range occurs in South Dakota.

Statewide Distribution, Abundance,

and Trends

In some parts of the species’ range,

statewide population increases were

noted after 1972. However, in most

western States, populations have

declined since the 1980s, most likely

due to sylvatic plague. In the eastern

part of the range, where plague has not

yet occurred, similar declines have not

been observed. These trends are

discussed below by State. We have

evaluated all historic and current data

and information available on the

species’ abundance and trends. Several

estimates of black-tailed prairie dog

occupied habitat were available for each

State. The dates, methodologies, and

ultimately the reliability of these

estimates varied. Generally, our estimate

of current occupied habitat for each

State is the most recently reported

estimate with the most reliable

methodology (Arizona, Montana,

Nebraska, North Dakota, Oklahoma,

South Dakota, Canada, and Mexico). For

States where a range (Wyoming) or two

reliable estimates were available

(Kansas), we used the midpoint. For

States where no recent estimate with

adequate methodology was available

(Colorado, New Mexico, and Texas), we

extrapolated from older estimates. We

rounded all our estimates to the nearest

1,000 ac.

In Arizona, black-tailed prairie dogs

existed in the southeastern portion of

the State prior to eradication efforts

(Hall and Kelson 1959). The species is

extirpated at present in the State.

Approximately 2 percent of occupied

habitat in the United States may have

existed in Arizona historically. We

believe that intensive grazing at the turn

of the last century may have caused

occupied habitat to expand in Arizona

and that control may have been the

principal factor that subsequently

suppressed populations. Shrub invasion

also may have limited recovery. The

species largely disappeared from the

State prior to the documented

occurrence of sylvatic plague in the

State (Shroufe, Arizona Game and Fish

Department, in litt. 1999). However,

plague is an additional factor that could

affect the future viability of the species

in Arizona.

In Colorado, black-tailed prairie dogs

historically occurred on suitable habitat

east of the Rocky Mountain foothills

(Hall and Kelson 1959, Torres 1973).

Presently, the species appears to be

scattered in remnant populations

throughout the same area. Statewide

estimates of occupied habitat noted for

Colorado range from 7 million ac (2.8

million ha) historically to 44,000 ac

(18,000 ha) in 1998 (Knowles 1998).

We believe that occupied habitat in

Colorado has declined significantly

from historic estimates. There is a large

disparity in recent statewide estimates

of remnant occupied habitat. However,

we believe that trends at specific

locations within the State (a 50 percent

decline in Denver Metropolitan Area

from 1994 to 1998 (Seery, U.S. Fish and

Wildlife Service, pers. comm. 1998), a

70 percent decline at Rocky Mountain

Arsenal National Wildlife Refuge from

1988–1999 (Seery and Matiatos, in

press), and a 90 percent decline at

Comanche National Grasslands from

1995 to 1998 (Cully 1998), indicate that

there has likely been a statewide decline

in recent years (despite periodic limited

recovery) and that these declines may

continue. These declines have largely

been attributed to sylvatic plague. We

estimate that 93,000 ac (43,000 ha) of

black-tailed prairie dog occupied habitat

currently exist statewide.

In Kansas, black-tailed prairie dogs

historically occurred on suitable habitat

throughout the western two-thirds of the

State (Hall and Kelson 1959, Smith

1958). Presently, the species appears to

be scattered throughout generally the

same area, except that the eastern limit

of the range appears to have shifted

westward approximately 30–50 miles

(50–80 kilometers) (Vanderhoof and

Robel 1992). Statewide estimates of

occupied habitat for Kansas range from

2.5 million ac (1 million ha) historically

to 36,000 ac (15,000 ha) in 1998

(Knowles 1998). We estimate that

42,000 ac (17,000 ha) of black-tailed

prairie dog occupied habitat currently

exist statewide.

We believe that occupied habitat in

Kansas has declined significantly from

historic estimates, but has likely been

stable to slightly declining in recent

years. The most recent statewide survey

is from 1992 (Vanderhoof and Robel

1992). However, in 1996 sylvatic plague

was documented in Kansas on the

Cimarron National Grasslands (Cully,

U.S. Geological Survey, Biological

Resources Division, pers. comm. 1998).

Therefore, occupied habitat may decline

if sylvatic plague impacts continue and/

or spread to other areas of the State.

In Montana, black-tailed prairie dogs

historically occurred on suitable habitat

in the eastern two-thirds of the State

(Flath and Clark 1986), with the

exception of the northeastern corner of

the State (Hall and Kelson 1959). One of

the seven large remaining black-tailed

prairie dog complexes occurs in

Montana. Statewide estimates of

occupied habitat for Montana range

from 6 million ac (2.4 million ha)

historically (Knowles 1998) to 28,286 ac

(11,456 ha) in 1961 (Bureau of Sport

Fisheries and Wildlife 1961). The

Montana Department of Fish, Wildlife,

and Parks believes that historic

estimates are inaccurate (Graham,

Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules 5481

Montana Department of Fish, Wildlife,

and Parks, in litt. 1998). The most recent

estimate of occupied habitat is 66,000 ac

(26,000 ha) (Montana Department of

Fish, Wildlife and Parks in prep.). We

estimate that 65,000 ac (26,000 ha) of

black-tailed prairie dog occupied habitat

currently exist statewide.

We believe that occupied habitat in

Montana has declined significantly from

historic estimates. Following a major

reduction in occupied habitat from

approximately 1900 to 1961, blacktailed prairie dog populations in the

State apparently expanded from 1961 to

1986 and then experienced significant

declines due to sylvatic plague. The

Montana Department of Fish, Wildlife,

and Parks (1998) noted that occupied

habitat declined by approximately 50

percent from the estimates of the late

1980s, largely due to sylvatic plague.

In Nebraska, black-tailed prairie dogs

historically occurred on suitable habitat

throughout most of the State west of the

97th meridian (Hall and Kelson 1959,

Knowles 1995). Presently, the species

appears to be scattered throughout the

same area, but at much reduced

numbers, especially east of the 99th

meridian. Statewide estimates of

occupied habitat noted for Nebraska

range from 6 million ac (2.4 million ha)

historically (Knowles 1998) to 30,000 ac

(12,000 ha) in 1961 (Bureau of Sport

Fisheries and Wildlife 1961). The most

recent estimate of occupied habitat is

60,000 ac (24,000 ha) (Knowles 1998).

We estimate that 60,000 ac (24,000 ha)

of black-tailed prairie dog occupied

habitat currently exist statewide.

We believe that occupied habitat in

Nebraska has declined significantly

from historic estimates and has likely

been stable to slightly declining in

recent years (Amack, Nebraska Game

and Parks Commission, in litt. 1999).

This stability may be due to the fact that

sylvatic plague does not appear to be

widespread in the State, although it has

been documented in the northwestern

portion of the State where it has

impacted some black-tailed prairie dog

populations (Virchow et al. 1992).

In New Mexico, black-tailed prairie

dogs historically occurred on suitable

habitat throughout the southern and

eastern two-thirds of the State (Bailey

1932, Hall and Kelson 1959). Presently,

the species appears to exist in remnant

populations in scattered locations,

generally east of the Pecos River

(Findley et al. 1975). Statewide

estimates of occupied habitat noted for

New Mexico range from over 6,640,000

ac (2,690,000 ha) historically (Bailey

1932) to 15,000 ac (6,000 ha) in 1998

(Knowles 1998). We estimate that

39,000 ac (16,000 ha) of black-tailed

prairie dog occupied habitat currently

exist statewide.

We believe that occupied habitat in

New Mexico has declined significantly

from historic estimates. Following the

toxicant ban in 1972, increases in

occupied habitat appear to have

occurred. However, declines in

occupied habitat have likely occurred in

more recent years (Maracchini, New

Mexico Department of Game and Fish,

in litt. 1998).

In North Dakota, black-tailed prairie

dogs historically occurred on suitable

habitat in the southwestern third of the

State, west of the Missouri River (Hall

and Kelson 1959). Presently, the species

appears to be scattered throughout the

same area. Statewide estimates of

occupied habitat for North Dakota range

from 2 million ac (810,000 ha)

historically (Knowles 1998) to

approximately 7,000 ac (2,800 ha) as a

conservative estimate in 1973 (Grondahl

1973). The most recent estimate of

occupied habitat is a preliminary

estimate of approximately 25,000 ac

(10,000 ha), based on aerial surveys

(Sidle, U.S. Forest Service, pers. comm.

1999). We estimate that 25,000 ac

(10,000 ha) of black-tailed prairie dog

occupied habitat currently exist

Statewide.

We believe that occupied habitat in

North Dakota has declined significantly

from historic estimates, but has likely

been fairly stable to increasing

(McKenna, North Dakota Game and Fish

Department, in litt. 1999) in recent

years. The amount of occupied habitat

in North Dakota is relatively small

compared to other States in the northern

Great Plains.

In Oklahoma, black-tailed prairie dogs

historically occurred on suitable habitat

in the western two-thirds of the State

(Hall and Kelson 1959). Presently, the

species is largely limited to the

panhandle (Shaw et al. 1993, Tyler

1968, Wuerthner 1997), although

scattered remnant populations occur in

the western half of the State outside of

the panhandle (Shackford et al. 1990).

Statewide estimates of occupied habitat

noted for Oklahoma range from 950,000

ac (385,000 ha) historically (Knowles

1998) to less than 8,600 ac (3,500 ha) in

1998 (Lomolino, University of

Oklahoma, in litt. 1999). We estimate

that 9,000 ac (3,600 ha) of black-tailed

prairie dog occupied habitat currently

exist Statewide.

Populations in the panhandle have

experienced significant declines in the

past 10 years, although with limited

recovery (Lomolino, University of

Oklahoma, in litt. 1999). These declines

were likely due to plague. The amount

of occupied habitat in the remainder of

the State has experienced a slow, steady

decline (Shackford et al. 1990).

Statewide, populations have been

reduced by 50 percent in the last 10

years (Lomolino, in litt. 1999).

In South Dakota, black-tailed prairie

dogs historically were found throughout

all but the eastern one-fourth of the

State (Hall and Kelson 1959, Linder et

al. 1972). Presently the species appears

to be scattered throughout the same

area, with the majority of occupied

habitat on Tribal or Federal lands west

of the Missouri River and small

scattered populations elsewhere. Four of

the seven remaining large black-tailed

prairie dog complexes occur in South

Dakota. Statewide estimates of occupied

habitat for South Dakota range from

more than 1,757,000 ac (712,000 ha)

historically, following the initiation of

intensive control efforts in 1918 (Linder

et al. 1972), to 33,000 ac (13,000 ha) in

1961 (Bureau of Sport Fisheries and

Wildlife 1961). The most recent estimate

of occupied habitat in the State is a

preliminary estimate of 147,000 ac

(60,000 ha), based on aerial surveys

(Sidle, U.S. Forest Service, pers. comm.

1999). We estimate that 147,000 ac

(60,000 ha) of black-tailed prairie dog

occupied habitat currently exist

Statewide.

We believe that occupied habitat in

South Dakota has declined significantly

from historic estimates, with notable

recovery from 1961–1980 (Bureau of

Sport Fisheries and Wildlife 1961,

Tschetter 1988). Thereafter, extensive

control efforts at Pine Ridge Reservation

and elsewhere in the 1980s resulted in

a significant decline in occupied

habitat. Subsequently, occupied habitat

has remained fairly stable. More

unoccupied, but available, habitat

appears to remain in South Dakota than

in other States.

In Texas, black-tailed prairie dogs

historically occurred on suitable habitat

throughout the northwestern one-third

of the State (Bailey 1905, Hall and

Kelson 1959). Presently, the species

occurs largely in the western portion of

the panhandle. Some scattered remnant

populations exist in the Trans-Pecos

Region of western Texas. Statewide

estimates of occupied habitat range from

58 million ac (23 million ha) historically

to 23,000 ac (9,000 ha ) in 1998

(Knowles 1998). We estimate that

71,000 ac (29,000 ha) of black-tailed

prairie dog occupied habitat currently

exist Statewide.

We believe that occupied habitat in

Texas has declined significantly from

historic estimates. However, based upon

the limited amount of information

available, we believe that occupied

habitat increased following the toxicant

5482 Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules

ban in 1972 and that populations may

have remained fairly stable since the

late 1970s (Cheatheam 1977, Lair and

Mecham 1991).

In Wyoming, black-tailed prairie dogs

historically occurred on suitable habitat

east of the Rocky Mountain foothills

(Clark 1973, Hall and Kelson 1959)

below approximately 5,500 feet (1,676

meters) elevation (Van Pelt in prep.).

Presently, the species appears to be

scattered throughout the same area. One

of the seven remaining large black-tailed

prairie dog complexes occurs in

Wyoming. Statewide estimates of

occupied habitat for Wyoming range

from 16 million ac (6.5 million ha)

historically (Knowles 1998) to 49,000 ac

(20,000 ha) in 1961 (Bureau of Sport

Fisheries and Wildlife 1961). The most

recent estimate is 70,000–180,000 ac

(28,000–73,000 ha) in 1998 (Knowles

1998). We estimate that 125,000 ac

(51,000 ha) of black-tailed prairie dog

occupied habitat currently exist

Statewide.

We believe that occupied habitat in

Wyoming has declined significantly

from historic estimates. Increases in

occupied habitat occurred following the

toxicant ban in 1972. However, we

believe that recent declines, largely due

to impacts from sylvatic plague, are

likely to continue.

Canada Distribution, Abundance, and

Trends

Historically, black-tailed prairie dogs

occurred on suitable habitat in

southernmost Saskatchewan (Hall and

Kelson 1959). Presently the species is

found in a small area along the

Frenchman River Valley. Many of these

colonies are in Canada’s Grasslands

National Park (Laing 1986). Canada

represents a very small percentage

(approximately 0.3 percent) of the

rangewide population. Estimates of

occupied habitat in Canada range from

1,244 ac (503 ha) in 1970 (Millson 1976)

to 2,318 ac (938 ha) in 1996 (Fargey,

Grasslands National Park, pers. comm.

1998). We estimate that 2,000 ac (800

ha) of black-tailed prairie dog occupied

habitat currently exists in Canada.

We believe that occupied habitat in

Canada has remained at approximately

2,000 ac (800 ha) and, in the absence of

sylvatic plague, will likely remain

stable.

Mexico Distribution, Abundance, and

Trends

Historically, black-tailed prairie dogs

occurred on suitable habitat throughout

the northern portion of the Mexican

States of Chihuahua and Sonora (Hall

and Kelson 1959). Presently, most

individuals appear to be limited to a

small region in northern Chihuahua.

The largest remaining black-tailed

prairie dog complex occurs in Mexico.

Estimates of occupied habitat in Mexico

range from 1,384,000 ac (560,000 ha)

historically (Mearns 1907 as cited in

Ceballos et al. 1993) to 90,000 ac

(36,000 ha) in 1996 (List et al. 1997). We

believe that the List et al. (1997)

estimate of 90,000 ac (36,000 ha) of

currently existing black-tailed prairie

dog occupied habitat in Mexico is

accurate.

We believe that occupied habitat in

Mexico has declined significantly from

historic estimates and that this decline

continues. Decline appears to be due

primarily to cropland conversion. From

1988 to 1996, the geographic range of

the species in Mexico contracted 80

percent and the amount of occupied

habitat decreased by 34 percent (List et

al. 1997). Colony fragmentation has

occurred in previously surveyed blacktailed prairie dog colonies, reducing the

size of towns and increasing their

isolation.

Summary of Factors Affecting the

Species

Section 4 of the Act and regulations

(50 CFR part 424) promulgated to

implement the listing provisions of the

Act set forth the procedures for adding

species to the Federal lists. A species

may be determined to be an endangered

or threatened species due to one or more

of the five factors described in section

4(a)(1). These factors and their

application to the black-tailed prairie

dog are as follows:

A. The Present or Threatened

Destruction, Modification, or

Curtailment of the Species’ Habitat or

Range

We believe that habitat loss due to

cropland conversion, urbanization,

habitat modification, and fragmentation

is a factor adversely affecting blacktailed prairie dog populations

rangewide.

In the United States, approximately

37 percent of the suitable habitat within

the range of the black-tailed prairie dog

has been converted to cropland (Blackfooted Ferret Recovery Foundation, in

litt. 1999). This land use change resulted

in significant destruction of black-tailed

prairie dog habitat, particularly in

eastern portions of the species’ range

where adequate precipitation favors

farming. Cropland conversion

continues, but the amount of occupied

habitat converted annually is unknown.

In some areas cropland conversion

occurs due to continuing improvements

in intensive agricultural techniques, for

example, dryland wheat farming in

Montana (Knowles et al. 1996, Lessica

1995) and irrigated croplands in Mexico

(List et al. 1997). List et al. (1997)

reported that occupied habitat in

Mexico declined by 34 percent between

1988 and 1996, in part due to

conversion to cropland.

Habitat loss also has occurred due to

urbanization. One example of the

present and threatened destruction of

black-tailed prairie dog occupied habitat

due to urban development is apparent

along the Front Range of Colorado near

Denver. In 1994, 42,500 ac (17,200 ha)

of occupied habitat were mapped in the

Denver/Boulder/Fort Collins

metropolitan area (Skiba, Colorado

Division of Wildlife, pers. comm. 1999).

Knowles (1998) estimated that occupied

habitat has declined by approximately

8,000 ac (3,200 ha) since the initial

mapping effort, due to urbanization. An

evaluation of the specific impact of

urbanization is difficult because sylvatic

plague also has significantly affected

populations in this area in recent years

(Weber, Colorado Division of Wildlife,

pers. comm. 1998).

Habitat modification and loss due to

the absence of black-tailed prairie dogs

can be anticipated in the prairie

ecosystem where populations have been

extirpated or significantly reduced in

number. Weltzin et al. (1997)

determined that black-tailed prairie

dogs, and the herbivores and granivores

associated with their colonies, probably

maintained grassland and savanna

historically by preventing woody

species such as mesquite from

establishing or attaining dominance.

List et al. (1997) reported that control of

black-tailed prairie dogs in Mexico

resulted in the invasion of mesquite

shrubs that rendered the landscape

unsuitable for reoccupation by the

species. Davis (1974) also noted that the

removal of the species from some sites

in Texas resulted in the invasion of

brush. The fragmented nature of

remaining prairie dog colonies, barriers

to immigration and emigration, and the

lack of fire and native ungulate herds

that historically denuded the landscape

and provided opportunities for prairie

dog colonies to expand (Miller et al.

1994) accentuate habitat loss due to

vegetative succession. The degree to

which this type of grassland change and

other landscape alterations affect blacktailed prairie dog populations across

their range is unknown. Nevertheless,

these subtle habitat changes may be a

major factor in precluding the

utilization of habitat or recolonization of

former habitat by the species.

North American grasslands have

suffered among the most extensive

fragmentation and transformation of any

Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules 5483

biome on the continent (Groombridge

1992). More fragmented, more isolated,

and less connected populations usually

have higher extinction rates (Clark 1989,

Gilpin and Soule 1986, MacArthur and

Wilson 1967, Shaffer 1981, Wilcove et

al. 1986, Wilcox and Murphy 1985). List

et al. (1997) suggested that fragmented

black-tailed prairie dog colonies in

Mexico were prone to extirpation.

Miller et al. (1996) described existing

prairie dog populations as small,

disjunct, and geographically isolated.

Dispersal has been limited by barriers

created by human development that

preclude immigration or emigration.

Fragmentation and extirpation of small,

isolated colonies will result in the loss

of additional genotypes, as occurred

with the complete extirpation of the

species in portions of the eastern and

southwestern areas of its historic range.

Lost genetic diversity will inherently be

detrimental to the long-term survival of

the species.

B. Overutilization for Commercial,

Recreational, Scientific, or Educational

Purposes

We believe that overutilization of the

black-tailed prairie dog via the pet trade

is not a significant factor affecting blacktailed prairie dog populations

rangewide. Herron (Texas Parks and

Wildlife Department, pers. comm. 1999)

and others have reported that blacktailed prairie dogs are removed from the

wild for sale as pets. Herron was aware

of 3 commercial operators who

collectively removed approximately

5,000 individuals from the Texas

panhandle and other States annually in

recent years. Miscellaneous reports

indicate that this practice occurs

elsewhere in the species’ range, but the

extent of removal of individuals from

the wild for use as pets is unknown.

Recreational (sport or varmint)

shooting is impacting black-tailed

prairie dog populations in some local

areas. At present, we do not believe that

this factor is responsible for significant

rangewide declines in the species’

population; however, it may be

important locally. The popularity of

shooting has increased appreciably in

recent years. Many States do not require

hunting licenses and have no bag limits

or seasonal restrictions for taking prairie

dogs. Some areas administered by the

Bureau of Land Management and the U.

S. Forest Service have been closed to

recreational shooting over the past two

years, but recreational shooting is still

allowed on other areas administered by

these agencies. Recreational shooting is

not allowed on on lands administered

by the National Park Service or the Fish

and Wildlife Service. Knowles (1988)

reported that shooting on two blacktailed prairie dog colonies removed 69

percent of the adults. He thought that

the reduction of prairie dog populations

below a certain threshold number might

have a further negative consequence

because fewer prairie dogs were

available to watch for predators and

keep the vegetation clipped around

burrows to improve detection of

predators. Vosburgh (1996) reported that

intensive shooting can have a

statistically significant impact on the

density of local black-tailed prairie dog

colonies. He observed that during the

summer, species density declined 33

percent on colonies with shooting and

15 percent on colonies without

shooting. Prairie dogs also spent more

time in alert postures and less time

foraging on colonies where shooting

occurred.

Large, healthy populations appear to

be able to withstand considerable

removal by shooting and remain viable

(Bourland and Dupris, Cheyenne River

Sioux Tribe, in litt. 1998; Finnegan et

al., Rosebud Sioux Tribe, in litt. 1998).

Accordingly, the shooting of hundreds

of thousands of individuals across the

extensive range of the black-tailed

prairie dog where millions of

individuals occur will not likely

adversely impact the overall population

of a species where each female can

produce an average of four young

annually. Conversely, small local

populations already depressed by

disease and other adverse influences

may suffer additive losses from shooting

impacts. Shooting impacts also may

contribute to population fragmentation

and preclude or delay recovery of

colonies reduced by other factors, such

as sylvatic plague.

C. Disease or Predation

We believe that sylvatic plague is

likely the most important factor in

recent reductions of many black-tailed

prairie dog populations throughout a

significant portion of the range of the

species. Approximately 66 percent of

the species’ range has been affected by

plague (Black-footed Ferret Recovery

Foundation, in litt. 1999). Plague is an

exotic disease foreign to the

evolutionary history of North American

species (Gage, Center for Disease

Control, pers. comm. 1999). Plague was

first observed in wild rodents in North

America near San Francisco, California,

in 1908 (Eskey and Haas 1940). It spread

eastward across the continent in

subsequent years and still appears to be

expanding its range, although not as

rapidly as in its early years. The first

reported incidences of plague in blacktailed prairie dogs occurred in the 1940s

(Gage, Center for Disease Control, pers.

comm. 1999, Miles et al. 1952). Blacktailed prairie dogs show neither

effective antibodies nor immunity to the

disease. This disease is caused by the

bacterium Yersinia pestis, which fleas

acquire from biting infected rodents and

other species and then transmit via a

bite. Plague also can be transmitted

directly between animals. Cully (1989)

summarized plague reports in 76

species of 5 mammalian orders in the

United States, although plague is

primarily a rodent disease. It can

seriously affect humans, although it

responds well to modern treatment

(Center for Disease Control 1997).

Rodent species vary in their

susceptibility to plague, with some

species acting as hosts or carriers of the

disease or infected fleas and showing

little or no symptoms. Black-tailed and

Gunnison’s prairie dog populations

demonstrate nearly 100 percent

mortality when exposed to plague

(Barnes 1993, Cully 1993) and cannot be

considered carriers.

Plague, once established in an area,

becomes persistent and periodically

erupts, with the potential to extirpate

local black-tailed prairie dog

populations. After several epizootics (an

eruption of the disease that attacks a

large number of animals at the same

time), black-tailed prairie dogs at the

Rocky Mountain Arsenal National

Wildlife Refuge have neared extirpation

(Seery, U.S. Fish and Wildlife Service,

pers. comm. 1998). This phenomenon

may be occurring at other formerly large

black-tailed prairie dog complexes

across much of the western portion of

the species’ range. At Northern

Cheyenne Reservation in southeastern

Montana, a plague epizootic started in

1991 and continued through 1996

(Young 1997), removing 97 percent of

the black-tailed prairie dog population

(Fourstar, Bureau of Indian Affairs, pers.

comm. 1998). The population has begun

to recover and has increased from a low

of 378 ac (153 ha) of occupied habitat

to 963 ac (390 ha). However, Young

(University of Arizona, pers. comm.

1998) does not believe that this complex

will recover to its former status. The

effects of plague on prairie dogs may be

exacerbated in smaller, isolated colonies

where populations are not buffered by

large numbers (where some individuals

may escape infection by chance) and

where recovery may be hampered by

limited immigration from other

colonies.

We believe that predation is not likely

a major factor affecting overall blacktailed prairie dog populations, but it

may be important locally or contribute

to the effects of other factors. Little

5484 Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules

information is available to quantify the

impact of predators on prairie dog

populations.

D. The Inadequacy of Existing

Regulatory Mechanisms

We believe that inadequate regulatory

mechanisms are a contributing factor

affecting overall black-tailed prairie dog

populations. Many States, Tribes, and

Federal agencies recognize the historic

decline and ecological significance of

the black-tailed prairie dog, but few use

available regulatory mechanisms to

conserve the species. At least one

government entity in most States

promotes their reduction. However,

some limited regulatory mechanisms

exist for conservation of the species.

States

In Arizona, the Game and Fish

Department classifies all prairie dogs

native to the State as nongame

mammals. Although the species has

been extirpated in Arizona, a hunting

season was open until 1999, when it

was closed (Shroufe, Arizona Game and

Fish Department, in litt. 1999). Arizona

does not require the eradication of

prairie dogs for agricultural purposes or

promote recreational shooting of prairie

dogs (Shroufe, Arizona Game and Fish

Department, in litt. 1998). The blacktailed prairie dog is listed as endangered

on the Arizona Game and Fish

Department ‘‘Threatened Native

Wildlife’’ list (Arizona Game and Fish

Department 1988).

In Colorado, the Division of Wildlife

requires a resident or nonresident

hunting license for prairie dog shooting

unless the animals are on land owned

by the shooter. The season is yearround, with no bag or possession limit.

However, for hunt contests, no

participant may take more than five

prairie dogs during the contest. In 1999,

the Colorado State Legislature passed a

bill prohibiting the translocation of

prairie dogs and other species into a

county without the consent of the

county’s commissioners (Van Pelt in

prep.).

The State of Kansas considers blacktailed prairie dogs as agricultural pests

and mandates control if an adjoining

landowner files a complaint (Knowles

1995). In recent years, some counties

have invoked ‘‘Home Rule’’ to take over

authority for prairie dog control from

the townships and impose mandatory

control requirements on landowners.

The landowner is given the opportunity

to control prairie dogs on his land and

if he fails to do so it is done by the

county at the landowner’s expense (Van

Pelt in prep.). Shooting of prairie dogs

in Kansas is somewhat restricted since

a resident or nonresident hunting

license is required and established

methods of take are listed (Williams,

Kansas Department of Wildlife and

Parks, in litt. 1998).

In Montana, the Department of Fish,

Wildlife, and Parks requires no license

to shoot prairie dogs, and no limits on

take or season exist. Prairie dogs are

protected on two State parks as

important features of those parks

(Graham, Montana Department of Fish,

Wildlife and Parks, in litt. 1998). The

Department of Fish, Wildlife, and Parks

identifies the black-tailed prairie dog as

a State ‘‘species of special concern’’

(Flath 1998). The Department of Fish,

Wildlife, and Parks is developing a

species conservation plan for black- and

white-tailed prairie dogs in Montana

(Montana Department of Fish, Wildlife

and Parks in prep.). However, the

Montana Department of Agriculture

classifies prairie dogs as ‘‘rodents’’ and

‘‘vertebrate pests.’’ The Montana

Department of Agriculture assists

landowners in control of prairie dogs if

requested, but such assistance is not

mandated (Sullins, Montana

Department of Agriculture, pers. comm.

1999).

In Nebraska, the Game and Parks

Commission currently considers the

black-tailed prairie dog an unprotected

nongame species that can be taken in

any manner, without restrictions on

shooting or control activities. Permits

are not required for residents;

nonresidents must have a small-game

hunting permit. The Game and Parks

Commission recognizes prairie dog

shooting as an acceptable recreational

activity, but suggests that shooting be

avoided when prairie dogs have

dependent young and that shooters take

responsible measures to avoid

disturbance of other wildlife species

that use prairie dog colonies (Amack,

Nebraska Game and Parks Commission,

in litt. 1998).

In New Mexico, the Department of

Game and Fish requires a license to

shoot prairie dogs, but there are no bag

limits or restrictions (Knowles 1998).

The Petitioner reports that New Mexico

considers the prairie dog as a ‘‘rodent

pest’’ and mandates that landowners

destroy prairie dogs on notice (National

Wildlife Federation 1998).

In North Dakota, the Game and Fish

Department classifies the black-tailed

prairie dog as a nongame wildlife

species. A resident is not required to

purchase a hunting license to shoot

prairie dogs; however, nonresidents are

required to purchase one. The State sets

no bag limits or seasons for prairie dogs.

The North Dakota Game and Fish

Department has published a guidebook

to aid prairie dog shooters in finding

colonies (North Dakota Game and Fish

Department undated). The State of

North Dakota considers the black-tailed

prairie dog a pest, although the Game

and Fish Department considers it a

nongame species. The North Dakota

Department of Agriculture and the

county weed boards have regulatory

authority over control efforts (Van Pelt

in prep.).

In Oklahoma, the Department of

Wildlife Conservation classifies the

black-tailed prairie dog as a Category II

Mammal Species of Special Concern.

Prairie dog eradication is no longer

mandatory in Oklahoma but is assisted

by some State agencies and local

governments. Control and recreational

shooting of the species can occur on

private land, but the Department of

Wildlife Conservation does not promote

either activity (Duffy, Oklahoma

Department of Wildlife Conservation, in

litt. 1998). A license for recreational

shooting is required by residents and

nonresidents. The Department of

Wildlife Conservation requires that a

permit be obtained prior to any control.

Prairie dogs cannot be reduced in any

county to fewer than 1,000 individuals,

and control is not permitted on public

lands (Van Pelt in prep.).

In South Dakota, the Department of

Game, Fish, and Parks classifies the

black-tailed prairie dog as a predator/

varmint and requires that a resident or

nonresident acquire a license to shoot

prairie dogs. No seasons or bag limits

have been established. The South

Dakota Weed and Pest Control Statute

designates the species as a statewide

declared pest. Therefore, the existence

of prairie dogs constitutes an

infestation, giving the State authority to

enter private land and exterminate the

animals. If a county declares an

infestation, landowners are responsible

for the costs to control prairie dogs on

their land whether they want control or

not (Van Pelt in prep.).

In Texas, the Parks and Wildlife

Department designates black-tailed

prairie dogs as a nongame species and

is prohibited by State statute from

listing them as a State endangered

species. A license is required to hunt

prairie dogs, but no season or bag limits

have been established. In 1999, the State

established a regulation that requires a

nongame collection or dealer’s permit to

possess more than 10 live prairie dogs

or to sell prairie dogs (Van Pelt in

prep.). This law does not regulate the

killing of prairie dogs for recreational,

agricultural, or nuisance purposes

(Sansom, Texas Parks and Wildlife

Department, in litt. 1998). The Texas

Health and Safety Code authorizes

Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules 5485

counties to control prairie dogs and

gives the Texas Department of

Agriculture responsibility for providing

information regarding control to

requesting counties (Van Pelt in prep.).

The Wyoming Game and Fish

Department regards the black-tailed

prairie dog as a nongame wildlife

species and has listed it as a Species of

Special Concern. No license is required

to hunt prairie dogs, and no seasons, bag

limits, or restrictions on method of take

have been established (Van Pelt in

prep.). The Game and Fish Department

supports development of seasons and

bag limits for the black-tailed prairie

dog (Wichers, Wyoming Game and Fish

Department, in litt. 1998). The Wyoming

Department of Agriculture lists the

species as a pest. The Wyoming Weed

and Pest Control Act of 1973 authorizes

counties to enter private property to

control prairie dogs if damage has been

documented to neighboring landowners

(Knowles 1995).

Tribal

Mulhern and Knowles (1995)

estimated that 30 percent of black-tailed

prairie dog colonies occur on Tribal

lands. Four of the seven remaining large

complexes (those with 10,000 acres or

more) (Cheyenne River, Fort Belknap,

Pine Ridge, and Rosebud) occur on

Tribal lands. Two Tribes (Cheyenne

River Sioux Tribe in South Dakota and

Fort Belknap in Montana) have prairie

dog management plans in place

(Knowles 1995). No extensive control of

prairie dogs has occurred on Cheyenne

River Sioux Tribe, Fort Belknap, or

Rosebud Sioux Tribe (in South Dakota)

in recent years due to concerns related

to the conservation of black-footed

ferrets. However, active recreational

shooting programs on these and other

Tribal lands exist. The Cheyenne River

Sioux Tribe does not classify the prairie

dog as a pest and does not require or

encourage their eradication; however,

shooting of black-tailed prairie dogs

occurs year-round and without limits

(Bourland and Dupris, Cheyenne River

Sioux Tribe, in litt. 1998). Recreational

shooting is also allowed on the Crow

Creek Sioux Tribe in South Dakota, but

chemical control is not allowed. The

Tribe states that shooting appears to

have no effect on black-tailed prairie

dog numbers, and they report the

species as abundant (Miller, Crow Creek

Sioux Tribe, in litt. 1998). In 1998, the

Rosebud Sioux Tribe Department of

Natural Resources implemented a new

licensing system for black-tailed prairie

dogs in an attempt to reduce the number

of shooters. License sales were reduced

by approximately 50 percent from

approximately 4,000 licenses in 1997 to

2,000 licenses in 1998 (Finnegan,

Rosebud Sioux Tribe, pers. comm.

1999).

Federal Agencies

The BIA has a trust responsibility to

oversee management of Tribal lands.

The BIA’s involvement in prairie dog

control efforts has been principally

through management of funding for

prairie dog control programs on Tribal

lands. In the northern Great Plains, from

1978–1992, BIA funding was

responsible for the control of more

prairie dog habitat than any other

Federal agency in the country (Roemer

and Forrest 1996).

The Bureau of Land Management

(BLM) manages prairie dogs to meet

multiple-use resource objectives

including production of livestock forage

and preventing prairie dog movement to

adjacent State or private lands.

Although BLM no longer actively

conducts control, it still allows control

to occur by other agencies on its lands

and it still allows significant levels of

unregulated sport shooting (Knowles

1995). In a memorandum dated June 23,

1999, and expiring September 30, 2000,

the BLM instructed all of its State

Directors within the range of the blacktailed prairie dog to ‘‘ensure that all

actions authorized, funded or carried

out by their respective field offices do

not contribute to the need to list this

species’’ (Colby, Bureau of Land

Management, in litt. 1999). The BLM

also anticipates implementing a

mandatory restriction on prairie dog

hunting in portions of south Phillips

County, Montana, due to the lack of

success of current voluntary closures in

the area (October 18, 1999; 64 FR

56213).

We manage over 500 National

Wildlife Refuges and their satellites, but

only about 15 refuges, satellites, or

Waterfowl Production Areas have blacktailed prairie dogs. Only two refuges

have any significant amount of occupied

habitat. On the Charles M. Russell and

UL Bend National Wildlife Refuges in

Montana, we manage 5,150 ac (2,090 ha)

of black-tailed prairie dog occupied

habitat. We have treated burrows with

insecticide in an attempt to reduce fleas

and disease transmission, and we have

moved prairie dogs to recolonize vacant

or low-density towns (Matchett 1997).

The Rocky Mountain Arsenal National

Wildlife Refuge in Colorado is

attempting to recover its populations

subsequent to repeated plague

epizootics (U.S. Fish and Wildlife

Service 1998). Shooting of prairie dogs

is currently prohibited on all National

Wildlife Refuges and satellites. Limited

control has occurred on a few wildlife

refuges, primarily as a measure to

prevent the spread of prairie dogs onto

adjacent private lands. At this time, all

control efforts regarding the species

have been suspended on Service lands

(Clark, U.S. Fish and Wildlife Service,

in litt. 1999).

The U.S. Forest Service manages

approximately 3.7 million ac (1.5

million ha) of National Grasslands,

which support approximately 42,460 ac

(17,200 ha) of black-tailed prairie dog

occupied habitat, approximately 1.1

percent of the National Grasslands

(Sidle, U.S. Forest Service, in litt. 1999).

In response to a request from the

National Wildlife Federation and the

positive 90-day finding, the U.S. Forest

Service issued a moratorium on control

of black-tailed prairie dogs during the

current status review period on all lands

administered by the U.S. Forest Service.

The U.S. Forest Service also noted their

intention to manage for larger prairie

dog populations via new planning

efforts subject to completion and

approval (Manning, U.S. Forest Service,

in litt. 1999).

The National Park Service is involved

with prairie dog control programs

through integrated pest management

guidelines. During 1982–1992, four

National Parks in the northern Great

Plains were involved in prairie dog

control—Badlands National Park, South

Dakota; Wind Cave National Park, South

Dakota; Theodore Roosevelt National

Park, North Dakota; and Devils Tower

National Monument, Wyoming (Roemer

and Forrest 1996). In a memorandum

dated January 14, 1999, the National

Park Service instructed Superintendents

of National Parks within the Midwest

Region where prairie dogs occur

(Badlands, Fort Larned, Scotts Bluff,

Theodore Roosevelt, and Wind Cave

units) to suspend further treatment of

prairie dog colonies (with few

exceptions) until a final determination

is made on their status (Schenk,

National Park Service, in litt. 1999).

The U.S. Department of Agriculture’s

Animal and Plant Health Inspection

Service-Wildlife Services influences

prairie dog control programs through its

grant-in-aid program to States, which

provides technical assistance to other

State, Tribal, and Federal agencies, and

private landowners, and its distribution

of prairie dog toxicants. Roemer (1997)

reported that during 1990–1994, the

Animal and Plant Health Inspection

Service-Wildlife Services was involved

in control of prairie dogs over 101,660

ac (41,140 ha). Additionally, they were

involved in control programs in the

early 1980s at the Pine Ridge Indian

Reservation (Oglala Sioux Tribe), South

5486 Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules

Dakota. The Animal and Plant Health

Inspection Service-Wildlife Services has

directed and conducted research related

to the efficiency of prairie dog and other

rodent control.

The Environmental Protection Agency

deals indirectly with prairie dog control

through pesticide labeling programs

including restrictions to protect

wildlife. Presently, labeling does not

restrict prairie dog control, but does

address concerns for the endangered

black-footed ferret.

In Canada, the black-tailed prairie dog

is designated as vulnerable by the

Committee on the Status of Endangered

Wildlife in Canada. Control is

prohibited, and only private landowners

are permitted to shoot prairie dogs

(Fargey, Grasslands National Park, pers.

comm. 1998).

In Mexico, the black-tailed prairie dog

is listed as threatened by the Lista de las

Especies Amerzadas, the official

threatened and endangered species list

of the Mexican Government

(SEMARNAP 1994). List et al. (1997)

reported that in Mexico, laws exist to

stop control, but are often not enforced,

and extensive control occurs. There are

no protected areas for the black-tailed

prairie dog in Mexico (Ceballos et al.

1993).

E. Other Natural or Manmade Factors

Affecting the Species’ Continued

Existence

Control Effort

We believe that control efforts have

limited black-tailed prairie dog

populations, especially large-scale, wellorganized efforts conducted early in the

century. These control programs were

conducted in response to concerns

regarding potential forage competition

with domestic livestock. Current control

efforts are limited compared to historic

efforts, but still impact a significant

portion of occupied habitat annually. A

well-documented control effort has

occurred over most of the range of the

black-tailed prairie dog (Anderson et al.

1986, Bell 1921, Cain et al. 1972, Forrest

and Proctor in prep., Hanson 1993,

Hubbard and Schmitt 1983, Lantz 1903,

Lewis and Hassien 1973, Linder et al.

1972, Merriam 1902, Roemer and

Forrest 1996, Shriver 1965). Control

efforts resulted in extirpation of the

black-tailed prairie dog in Arizona

(Alexander 1932). Similar control efforts

in Texas resulted in the persistence of

only remnant populations in areas

where, historically, the largest known

populations of the species occurred

(Bureau of Sport Fisheries and Wildlife

1961, Cheatheam 1977, Cottam and

Caroline 1965).

Prairie dog control occurred

repeatedly in most areas, and figures

cited for acreage controlled may include

retreatment of the same areas in

subsequent years. Therefore, annual

estimates of lands treated do not always

equate to total loss of habitat. However,

control (usually in conjunction with

other factors) has led to the complete

loss of occupied habitat in many areas.

Organized prairie dog control gained

momentum from 1916 to 1920 when

prairie dogs were controlled on tens of

millions of acres of western rangeland

(Bell 1921). Federal programs were

responsible for much of this effort (Cain

et al. 1972). From 1937 to 1968,

30,447,355 ac (12,331,178 ha) of prairie

dog occupied habitat were controlled

(Cain et al. 1972). In the 1960s, several

States reached their lowest estimates of

occupied habitat (Bureau of Sport

Fisheries and Wildlife 1961). In 1972,

Compound 1080, which was used

extensively in prairie dog control

efforts, was banned by Presidential

Executive Order II 11643. Although

prairie dog control continued via other

toxicants, it was at a reduced rate.

The most extensive control efforts in

recent years have been conducted in the

Northern Great Plains (U.S. Forest

Service 1998). Roemer and Forrest

(1996) summarized recent Federal and

State control efforts on approximately

1,045,524 ac (423,437 ha) in South

Dakota, Montana, and Wyoming. From

1978 to 1992, an average of 69,701 ac

(28,229 ha) were treated annually in

these three States. These estimates did

not include estimates for private control

or control involving indirect State or

Federal assistance. Forrest and Proctor

(in prep.) estimated that in recent years

control conducted at the local level

probably affected ‘‘tens of thousands’’ of

black-tailed prairie dog occupied habitat

on an annual basis. The BIA

administered the last large-scale control

effort for black-tailed prairie dogs on the

Pine Ridge Reservation in South Dakota

in the early 1980s. This effort resulted

in the eradication of most prairie dogs

on approximately 458,618 ac (185,740

ha) from 1980 to 1984. From 1985 to

1986, 240,000 ac (97,000 ha) were

retreated (Roemer and Forrest 1996). In

1987, after these efforts, 57,281 ac

(23,199 ha) of occupied habitat

remained (Tschetter 1988). Current

estimates of occupied habitat range from

20,000 to 30,000 ac (8,000 to 12,000 ha)

(Yellowhair, Pine Ridge Sioux Tribe,

pers. comm. 1999). Following control

efforts on Pine Ridge, three additional

extensive control efforts targeted for the

Cheyenne River and Rosebud

Reservations in South Dakota and Fort

Belknap Reservation in Montana were

halted due to concerns regarding the

lack of available black-footed ferret

reintroduction sites.

Vulnerability of the Species in

Perspective

Three major impacts have had a

substantial influence on black-tailed

prairie dog populations. The first major

impact on the species was the initial

conversion of prairie grasslands to

cropland in the eastern portion of its

range from approximately the 1880s–

1920s. The conversion of native prairie

to cropland likely reduced black-tailed

prairie dog occupied habitat in the

United States from about 80 million ac

(32 million ha) to about 50 million ac

(20 million ha) or less. The second

major impact on the species was largescale control efforts conducted from

approximately 1918–1972 in efforts to

reduce competition between prairie

dogs and domestic livestock. Repeated

control efforts likely reduced blacktailed prairie dog occupied habitat in

the United States from about 50 million

ac (20 million ha) to approximately

364,000 ac (147,000 ha) by 1961 (Bureau

of Sport Fisheries and Wildlife 1961).

Some limited recovery and subsequent

declines have since occurred in these

remnant populations. The third major

impact on the species was the

inadvertent introduction of an exotic

disease from the Old World, sylvatic

plague, into North American ecosystems

in 1908, with the first recorded impacts

on the black-tailed prairie dog in the

1940s. These three factors, as well as

other additional factors impacting the

species, are discussed below.

We believe that many factors, alone,

in combination with each other, and

synergistically, have influenced and

continue to influence black-tailed

prairie dog populations. Historically,

large black-tailed prairie dog

populations successfully coped with

various depressant factors, except

plague, on a different scale; populations

were large and robust, while threats

were few with only short-term effects.

Presently, most populations are

significantly reduced and must cope

with many persistent influences that

depress populations, both temporally

and permanently. Based upon our

review of the available information, we

conclude that a general long-term,

rangewide decline has occurred, in

addition to more recent population

declines in some areas.

The persistence of the black-tailed

prairie dog as a species may appear

secure to some observers because it is

relatively abundant in absolute numbers

when compared with many other

Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules 5487

species with smaller populations that

are not thought to be vulnerable. Many

wildlife species in North America that

have experienced significant population

declines remain viable (e.g., various

game species such as the pronghorn

(Antilocapra americana)). However, the

black-tailed prairie dog is a highly social

species that, for the most part, responds

to major factors causing population

reductions (e.g., plague and control) on

the basis of entire colonies rather than

on an individual basis. Additionally,

adequate regulatory mechanisms are not

in place to protect or manage

populations of the black-tailed prairie

dog, as they are with most game species.

Therefore, populations are likely not as

viable as their absolute numbers might

suggest.

A significant portion of existing blacktailed prairie dog occupied habitat

rangewide occurs in a few large

complexes. Approximately 36 percent of

the remaining occupied habitat for the

species in North America occurs in

seven complexes, each larger than

10,000 ac (4,000 ha). These complexes

include—Buffalo Gap National

Grassland/Conata Basin, South Dakota;

Cheyenne River Reservation, South

Dakota; Fort Belknap Reservation,

Montana; Janos Nuevo Casas Grandes,

Mexico; Pine Ridge Reservation, South

Dakota; Rosebud Reservation, South

Dakota; and Thunder Basin National

Grassland, Wyoming. These complexes

are potentially vulnerable to control

efforts or plague.

Extant populations of black-tailed

prairie dogs may or may not be large

enough to be resilient to ongoing or

future environmental challenges and

related potential declines. Quammen

(1996) provided examples of species

that were abundant, but suddenly

became very rare. For example, he

reported that the passenger pigeon

(Ectopistes migratorius) numbered in

the billions around 1810 and in the low

millions by the 1880s, yet was extinct in

the wild by 1900. Habitat destruction

and over-harvesting depressed

passenger pigeon numbers to a few

million, a level too low for a highly

social and colonial species to function

(Halliday 1980). The black-tailed prairie

dog numbered in the billions around

1900, exists as a few million at present,

and appears to be declining in a

significant portion of its range. The

advantages of sociality (e.g., breeding,

feeding, predator defense) may no

longer offset its modern disadvantages

(e.g., vulnerability to an exotic disease

and control efforts). Accordingly, the

vulnerability of the black-tailed prairie

dog to population reductions is likely

related less to its absolute numbers than

to the number of colonies in which it

exists, their size, their geospatial

relationship, existing barriers to

immigration and emigration, and

ultimately the number and nature of the

remaining direct threats to the species.

Finding

After a thorough review of the best

available scientific and commercial

information, we find that sufficient

information is currently available to

support a determination that listing the

black-tailed prairie dog as threatened is

warranted. This action is appropriate

because of the number and variety of

threats that act in concert to adversely

affect the species. A significant recent

decline in occupied habitat has

occurred due to several factors, the most

influential of which is the widespread

occurrence of plague, an exotic and

lethal disease to the species. In concert

with plague, the loss of suitable habitat

and inadequate regulatory mechanisms

have adversely affected remnant

fragmented populations. The available

information indicates that the species is

likely to become endangered throughout

all or a significant portion of its range

in the foreseeable future.

A major decline in historic blacktailed prairie dog occupied habitat has

occurred (perhaps as much as 99

percent). Sixty percent of the species’

remnant occupied habitat is vulnerable

or very vulnerable to the effects of

habitat loss or modification, disease,

inadequate regulatory mechanisms, and

other factors (Black-footed Ferret

Recovery Foundation, in litt. 1999).

Based on our review of the available

distribution data, we estimate that

approximately 30 percent of the historic

range no longer supports any

appreciable number of black-tailed

prairie dogs, and that these reductions

occurred at the periphery of the historic

range. However, reductions in occupied

habitat have also occurred throughout

the historic range; approximately 37

percent of the suitable habitat within

the historic range in the United States

has been fundamentally modified via

conversion to cropland and is not

available for use by the species (Blackfooted Ferret Recovery Foundation, in

litt. 1999). Additionally, habitat in

approximately 66 percent of the historic

range of the species has been degraded

by the occurrence of plague (Blackfooted Ferret Recovery Foundation, in

litt. 1999). These estimates are not

additive inasmuch as several factors can

affect any given portion of the range.

Recent, widely separated, site-specific

declines across the area where 60

percent of the current occupied blacktailed prairie dog habitat now exists

appear to be indicative of a general

population decline. The overall decline

may be similar to the specific decline

observed across the State of Montana

from 1986 to 1998 when approximately

50 percent of all occupied habitat was

lost, largely due to plague (Montana

Department of Fish, Wildlife, and Parks

1998). Plague has incrementally

extended its range and impacts on

black-tailed prairie dogs since it was

first documented in the species. It may

likely continue to expand into the

eastern portions of the species’ range in

the immediate future, as evidenced by

recent reports of predator species’

exposure to plague in previously

unaffected portions of the black-tailed

prairie dog range. A decline of similar

magnitude has occurred with

populations in Mexico (12 percent of

current occupied habitat); however, the

decline in Mexico is due to cropland

conversion, not plague.

At present, occupied habitat has

decreased over the past century by two

orders of magnitude (or 99 percent, from

approximately 100 million ac to less

than 1 million ac). If the magnitude of

decline that we have observed due to

plague or cropland conversion persists

in western portions of the species’

range, and manifests itself in eastern

portions of the species’ range, over the

next 30 years existing occupied habitat

could decline another order of

magnitude to as low as approximately

10 percent of current estimates, or

approximately 0.1 percent of historic

estimates.

We have evaluated the magnitude and

immediacy of threats to the black-tailed

prairie dog. The following provides a

summary of these evaluations.

Habitat loss and fragmentation are

considered a threat of moderate

magnitude. The species has lost an

estimated 99 percent of its historic

occupied habitat, much of it through

cropland conversion, largely in the

eastern portion of the species’ range.

However, a considerable amount of

potential unoccupied habitat remains,

especially in the western portion of the

species’ range. This unoccupied habitat

could be utilized if other factors such as

disease and control efforts were not

present or were carefully managed via

adequate regulatory mechanisms. This

threat is considered imminent because

habitat loss continues at present in

various parts of the species’ range from

a variety of activities, including

cropland conversion, urbanization,

change in vegetative communities, and

fragmentation.

Overutilization via commercial use of

the species as a pet is not considered a

threat because of the apparent low

5488 Federal Register / Vol. 65, No. 24 / Friday, February 4, 2000 / Proposed Rules

number of individuals utilized.

Overutilization via recreational shooting

is considered a threat of low magnitude.

Local populations may be impacted by

shooting; however, significant

rangewide population declines due to

this factor are not likely. This threat is

considered imminent because it is

ongoing.

Disease is considered a threat of

moderate magnitude. Plague has

markedly reduced some populations,

but has not affected all populations at

once. Some population recovery may

occur, largely via unaffected adjacent

populations, before plague

reoccurrence. Plague has impacted the

species and its conspecifics throughout

a significant portion of their ranges.

Black-tailed prairie dog populations

demonstrate nearly 100 percent

mortality when exposed to plague. An

epizootic may affect an entire complex

similar to a pathogen affecting an

individual animal. The spread of plague

in black-tailed prairie dog populations

underscores the likelihood that areas as

yet unaffected may experience

outbreaks in the future. This threat is

considered imminent because it is

ongoing. Predation is not considered a

threat.

Existing regulatory mechanisms are

inadequate and considered a threat of

moderate magnitude. All States within

the current range of the black-tailed

prairie dog classify the species as a pest

for agricultural purposes and either

allow or require its eradication

(Mulhern and Knowles 1995). Few

regulatory mechanisms exist to aid in

conserving the species. This threat is

considered imminent because it is

ongoing. State wildlife agencies and

other interested parties are developing a

conservation plan for the species. While

we support the States’ efforts and will

cooperate in conservation actions for the

black-tailed prairie dog, at this early

stage of development, the conservation

assessment and strategy document lacks

commitments to specific immediate

actions that would affect the status of

the species.

Control programs conducted largely

in response to concerns related to

potential forage competition with

domestic livestock are considered a

threat of moderate magnitude. Control

programs have had significant impacts

on population levels in the past. Control

efforts resulted in extirpation of the

black-tailed prairie dog from Arizona

and significant reductions in other

States. Current control efforts may

impact 10–20 percent of the species’

overall population annually (Forrest and

Proctor, in prep.). This threat is

considered imminent because it is

ongoing. Control efforts in some areas

could likely be accommodated if

adequate regulatory mechanisms were

in place that balanced agricultural and

wildlife conservation interests.

We conclude that the overall

magnitude of threats to the black-tailed

prairie dog throughout its range is

moderate and the overall immediacy of

these threats is imminent. The blacktailed prairie dog is considered a species

without subspecies classification.

Pursuant to the Service’s Listing Priority

Guidance (48 FR 43098), a species for

which threats are moderate and

imminent is assigned a Listing Priority

Number of 8. Region 6 currently has

nine Candidate species or subspecies

that have lower Listing Priority

Numbers and, therefore, are in more

immediate need of protection. Region 6

also has four species proposed as

endangered or threatened, and two

species for which proposed rules are

under review. Therefore, while we have

concluded that the listing of the blacktailed prairie dog as threatened is

warranted, an immediate proposal to list

is precluded by other, higher priority

actions to amend the Lists of

Endangered and Threatened Wildlife

and Plants.

References Cited

A complete list of references cited in

this notice is available upon request

from the South Dakota Field Office (see

ADDRESSES section).

Author: The primary author of this

document is Pete Gober (see ADDRESSES

section).

Authority: The authority for this action is

the Endangered Species Act of 1973 as

amended (16 U.S.C. 1532 et seq.).

Dated: February 1, 2000.

Jamie Rappaport Clark,

Director, Fish and Wildlife Service.

[FR Doc. 00–2593 Filed 2–3–00; 8:45 am]

BILLING CODE 4310–55–U

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric

Administration

50 CFR Part 648

[I.D. 012400B]

Fisheries of the Northeastern United

States; Atlantic Sea Scallop Fishery

AGENCY: National Marine Fisheries

Service (NMFS), National Oceanic and

Atmospheric Administration (NOAA),

Commerce.

ACTION: Notice of intent to prepare a

Supplemental Environmental Impact

Statement (SEIS) and notice of scoping

process; request for comments.

SUMMARY: The New England Fishery

Management Council (Council)

announces its intention to prepare

Amendment 10 to the Atlantic Sea

Scallop Fishery Management Plan

(FMP) to develop an area based

management system that would, among

other things, close areas with high

concentrations of small scallops and

open them later when the scallops are

bigger. The Council also announces its

intent to prepare an SEIS for the

Atlantic Sea Scallop FMP in accordance

with the National Environmental Policy

Act of 1969 to analyze the impacts of

any management alternatives. The

Council will hold public scoping

meetings in Fairhaven, MA; Virginia

Beach, VA; and Cape May, NJ; to

determine the scope of issues to be

addressed and for identifying the

significant issues related to the

management alternatives.

DATES: Written comments on the intent

to prepare the SEIS must be received on

or before 5:00 p.m., local time, March 1,

2000. The meetings will held between

Tuesday, February 15, 2000, and

Thursday, February 18, 2000. See

SUPPLEMENTARY INFORMATION for specific

dates and times.

ADDRESSES: Written comments should

be sent to Paul J. Howard, Executive

Director, New England Fishery

Management Council, 50 Water Street,

Mill 2, Newburyport, MA 01950.

Comments may also be sent via fax to

(978) 465–0492. The meetings will be

held in Fairhaven, MA; Virginia Beach,

VA; and Cape May, NJ. See

SUPPLEMENTARY INFORMATION for specific

locations. Comments will not be

accepted if submitted via e-mail or

Internet.

FOR FURTHER INFORMATION CONTACT: Paul

J. Howard, Executive Director, New

England Fishery Management Council

(978) 465–0492. Requests for special

accommodations should be addressed to

the New England Fishery Management

Council, 50 Water St., Mill 2,

Newburyport, MA 01950; telephone:

(978) 465–0492.

SUPPLEMENTARY INFORMATION:

Background

Amendment 4 to the Atlantic Sea

Scallop FMP established a limited

access program and a schedule of

annual day-at-sea (DAS) allocations for

full-time, part-time, and occasional

vessels with limited access permits.

Although Amendment 4 changed the

restrictions on fishing gear and limited

the number of crew aboard limited