[Federal Register Volume 73, Number 232 (Tuesday, December 2, 2008)]
[Proposed Rules]
[Pages 73211-73219]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-28528]



[[Page 73211]]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17
[FWS-R6-ES-2008-0111; MO 9921050083-B2]


Endangered and Threatened Wildlife and Plants; 90-Day Finding on 
a Petition To List the Black-tailed Prairie Dog as Threatened or 
Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day petition finding and initiation of status 
review.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to list the black-tailed prairie dog 
(Cynomys ludovicianus) as threatened or endangered under the Endangered 
Species Act of 1973, as amended (Act). We find that the petition 
presents substantial scientific or commercial information indicating 
that listing the black-tailed prairie dog may be warranted. Therefore, 
with the publication of this notice, we are initiating a status review 
of the species to determine if listing the species is warranted. To 
ensure that the review is comprehensive, we are soliciting scientific 
and commercial information regarding this species.

DATES: To allow us adequate time to conduct a status review, we request 
that we receive information on or before February 2, 2009.

ADDRESSES: You may submit information by one of the following methods:
     Federal rulemaking Portal: http://www.regulations.gov. 
Follow the instructions for submitting comments.
     U.S. mail or hand-delivery: Public Comments Processing, 
Attn: FWS-R6-ES-2008-0111; Division of Policy and Directives 
Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax Drive, 
Suite 222; Arlington, VA 22203.
    We will not accept e-mail or faxes. We will post all information 
received on http://www.regulations.gov. This generally means that we 
will post any personal information you provide us (see the Information 
Solicited section below for more information).

FOR FURTHER INFORMATION CONTACT: Pete Gober, Field Supervisor, South 
Dakota Fish and Wildlife Office, 420 South Garfield Avenue, Suite 400, 
Pierre, SD 54501; telephone at 605-224-8693, extension 224. If you use 
a telecommunications device for the deaf (TDD), call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION: 

Information Solicited

    When we make a finding that a petition presents substantial 
information indicating that listing a species may be warranted, we are 
required to promptly commence a review of the status of the species. To 
ensure that the status review is complete and based on the best 
available scientific and commercial information, we are soliciting 
information concerning the status of the black-tailed prairie dog. We 
request information from the public, other concerned governmental 
agencies, Tribes, the scientific community, industry, or any other 
interested parties concerning the status of the black-tailed prairie 
dog. We are seeking information regarding the species' historical and 
current status and distribution, its biology and ecology, ongoing 
conservation measures for the species and its habitat, and threats to 
the species or its habitat.
    Please note that comments merely stating support or opposition to 
the action under consideration without providing supporting 
information, although noted, will not be considered in making a 
determination, as section 4(b)(1)(A) of the Act (16 U.S.C. 
1533(b)(1)(A)) directs that determinations as to whether any species is 
a threatened or endangered species must be made ``solely on the basis 
of the best scientific and commercial data available.'' At the 
conclusion of the status review, we will issue a 12-month finding on 
the petition, as provided in section 4(b)(3)(B) of the Act (16 U.S.C. 
1533(b)(3)(B)).
    You may submit your information concerning this 90-day finding by 
one of the methods listed in the ADDRESSES section. We will not 
consider submissions sent by e-mail or fax or to an address not listed 
in the ADDRESSES section.
    If you submit information via http://www.regulations.gov, your 
entire submission--including any personal identifying information--will 
be posted on the Web site. If your submission is made via a hardcopy 
that includes personal identifying information, you may request at the 
top of your document that we withhold this information from public 
review. However, we cannot guarantee that we will be able to do so. We 
will post all hardcopy submissions on http://www.regulations.gov.
    Information and materials we receive, as well as supporting 
documentation we used in preparing this 90-day finding, will be 
available for public inspection on http://www.regulations.gov, or by 
appointment, during normal business hours, at the U.S. Fish and 
Wildlife Service, South Dakota Fish and Wildlife Office (see FOR 
FURTHER INFORMATION CONTACT).

Background

    Section 4(b)(3)(A) of the Act (16 U.S.C. 1531 et seq.) requires 
that we make a finding on whether a petition to list, delist, or 
reclassify a species presents substantial scientific or commercial 
information to indicate that the petitioned action may be warranted. We 
are to base this finding on information provided in the petition, 
supporting information submitted with the petition, and information 
otherwise available in our files at the time we make the finding. To 
the maximum extent practicable, we are to make this finding within 90 
days of our receipt of the petition and publish our notice of the 
finding promptly in the Federal Register.
    Our standard for substantial information within the Code of Federal 
Regulations (CFR) with regard to a 90-day petition finding is ``that 
amount of information that would lead a reasonable person to believe 
that the measure proposed in the petition may be warranted'' (50 CFR 
424.14(b)). If we find that substantial information was presented, we 
are required to promptly commence a review of the status of the 
species.
    In making this finding, we relied on information provided by the 
petitioners, as well as information readily available in our files at 
the time of the petition review. We evaluated the information in 
accordance with 50 CFR 424.14(b). Our process for making this 90-day 
finding under section 4(b)(3)(A) of the Act and section 424.14(b) of 
our regulations is limited to a determination of whether the 
information in the petition meets the ``substantial scientific and 
commercial information'' threshold.
    On August 6, 2007, we received a formal petition dated August 1, 
2007, from Forest Guardians (now WildEarth Guardians), Biodiversity 
Conservation Alliance, Center for Native Ecosystems, and Rocky Mountain 
Animal Defense, requesting that we list the black-tailed prairie dog 
throughout its historical range (and portions thereof) in Arizona, 
Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, 
Oklahoma, South Dakota, Texas, and Wyoming, and in Canada and Mexico. 
The petitioners also requested that, if the Service believes that 
Cynomys ludovicianus arizonensis is a distinct subspecies or population 
segment, it be listed as threatened or endangered throughout its

[[Page 73212]]

historical range as well. In addition, the petitioners requested that 
the Service designate critical habitat for the species. The petition 
clearly identified itself as a petition and included the requisite 
identification information as required in 50 CFR 424.14(a). We 
acknowledged receipt of the petition in a letter to the petitioners on 
August 24, 2007, and indicated that emergency listing of the black-
tailed prairie dog was not warranted. We also explained that we would 
not be able to address the petition until fiscal year 2009, due to 
existing court orders and settlement agreements for other listing 
actions. However, in fiscal year 2008, funding became available, and we 
began work on this petition finding.

Previous Federal Actions

    On October 24, 1994, we received a petition from Biodiversity Legal 
Foundation and Jon C. Sharps, dated October 21, 1994, to classify the 
black-tailed prairie dog as a Category 2 candidate species. Category 2 
included taxa for which information in our possession indicated that a 
proposed listing rule was possibly appropriate, but we did not have 
available sufficient data on biological vulnerability and threats to 
support a proposed rule. We reviewed the petition, and on May 5, 1995, 
we concluded that the black-tailed prairie dog did not warrant Category 
2 candidate status.
    On July 31, 1998, we received a petition from the National Wildlife 
Federation dated July 30, 1998, to list the black-tailed prairie dog as 
threatened throughout its range. On August 26, 1998, we received 
another petition to list the black-tailed prairie dog as threatened 
throughout its range from Biodiversity Legal Foundation, Predator 
Project, and Jon C. Sharps. We accepted this second request as 
supplemental information to the National Wildlife Federation petition. 
On February 4, 2000, we announced a 12-month finding that issuing a 
proposed rule to list the black-tailed prairie dog was warranted but 
precluded by other higher priority actions (65 FR 5476), and the 
species was included in the list of candidate species. Two candidate 
assessments and resubmitted petition findings for the black-tailed 
prairie dog were completed on October 30, 2001 (66 FR 54808), and June 
13, 2002 (67 FR 40657). On August 18, 2004, we completed a resubmitted 
petition finding for the black-tailed prairie dog (69 FR 51217), which 
concluded that listing the species was not warranted, because recent 
distribution, abundance, and trend data indicated that the threats to 
the species were not as serious as earlier believed. The species was 
then removed from the candidate list.
    On February 7, 2007, Forest Guardians and others filed a complaint 
challenging the decision to remove the black-tailed prairie dog from 
the candidate list. On August 6, 2007, we received a new formal 
petition dated August 1, 2007, from Forest Guardians (now WildEarth 
Guardians), Biodiversity Conservation Alliance, Center for Native 
Ecosystems, and Rocky Mountain Animal Defense, requesting we list the 
black-tailed prairie dog throughout its historical range (and portions 
thereof) in Arizona, Colorado, Kansas, Montana, Nebraska, New Mexico, 
North Dakota, Oklahoma, South Dakota, Texas, and Wyoming and in Canada 
and Mexico. The plaintiffs filed the new petition, and withdrew their 
2007 complaint, on October 9, 2007.
    On March 13, 2008, WildEarth Guardians filed a complaint for 
failure to complete a 90-day finding on their August 1, 2007 petition. 
On July 1, 2008, a stipulated settlement and order were signed, in 
which we agreed to submit a 90-day finding to the Federal Register by 
November 30, 2008. This 90-day finding is in response to the stipulated 
settlement.

Species Information

    The black-tailed prairie dog is a member of the Sciuridae family, 
which includes squirrels, chipmunks, marmots, and prairie dogs. Prairie 
dogs constitute the genus Cynomys. Taxonomists currently recognize five 
species of prairie dogs belonging to two subgenera, all in North 
America (Hoogland 2006a, pp. 8-9). The white-tailed subgenus, 
Leucocrossuromys, includes Utah (C. parvidens), white-tailed (C. 
leucurus), and Gunnison's prairie dogs (C. gunnisoni) (Hoogland 2006a, 
pp. 8-9). The black-tailed subgenus, Cynomys, consists of Mexican (C. 
mexicanus) and black-tailed prairie dogs (Hoogland 2006a, pp. 8-9). 
Generally, the black-tailed prairie dog occurs east of the other four 
species in more mesic habitat (Hall and Kelson 1959, p. 365). Based on 
information currently available, we consider the black-tailed prairie 
dog a monotypic species (Pizzimenti 1975, p. 64). Information submitted 
by the petitioners and readily available within our files indicates 
that the black-tailed prairie dog is a valid taxonomic species and a 
listable entity under the Act. We found that Cynomys ludovicianus 
arizonensis is not considered a distinct subspecies or population 
segment (Pizzimenti 1975, p. 64).
    The Utah and Mexican prairie dogs are currently listed as 
threatened (49 FR 22330) and endangered (35 FR 8495), respectively. The 
Gunnison's prairie dog is currently a candidate species within the 
montane portion of its range (73 FR 6660). The white-tailed prairie dog 
is undergoing formal status review to consider whether listing is 
warranted.
    The black-tailed prairie dog is a burrowing, colonial mammal; brown 
in color; approximately 12 inches (30 centimeters) in length; and 
weighing 1-3 pounds (500-1,500 grams) (Hoogland 2006a, pp. 8-9). The 
black-tailed prairie dog can be distinguished from other prairie dog 
species by several key characteristics, which include having a longer 
(2-3 inches (7-10 centimeters)) black-tipped tail, being non-
hibernating, and living at lower elevations (2,300-7,200 feet (700-
2,200 meters)) (Hoogland 2006a, pp. 8-9). Overlap of the geographic 
ranges of the five species is minimal; consequently, species can be 
identified by locality (Hall and Kelson 1959, p. 365; Hoogland 2006a, 
pp. 8-9).
    The black-tailed prairie dog is considered a keystone species, that 
is, one that is an indicator of species composition within an 
ecosystem, and that is key to the persistence of the ecosystem (Kotliar 
et al. 1999, pp. 183, 185). The black-footed ferret (Mustela nigripes), 
swift fox (Vulpes velox), golden eagle (Aquila chrysaetos), and 
ferruginous hawk (Buteo regalis) utilize prairie dogs as a food source; 
the mountain plover (Charadrius montanus) and burrowing owl (Athene 
cunicularia) depend on habitat (burrows) created by prairie dogs. 
Numerous other species share habitat with prairie dogs, and rely on 
them to varying degrees (Kotliar et al. 1999, pp. 181-182).
    Several biological factors determine the reproductive potential of 
the black-tailed prairie dog. Females usually do not breed until their 
second year, live 4-5 years, and produce a single litter of an average 
of 3 pups annually (Hoogland 2001, p. 917; Hoogland 2006b, p. 38). 
Therefore, 1 female may produce 0 to 15 young in its lifetime. While 
the black-tailed prairie dog is not prolific in comparison to many 
other rodents, it is capable of rapid population increases after 
population reductions (Collins et al. 1984, p. 360; Pauli 2005, p. 17; 
Reeve and Vosburgh 2006, p. 144).
    Historically, black-tailed prairie dogs generally occurred in large 
colonies that often contained thousands of individuals, covered 
hundreds or thousands of acres, and extended for miles (Bailey 1905, p. 
90; Bailey 1932, p. 122; Ceballos et al. 1993, p. 109; Lantz 1903, p. 
2671). Currently, most

[[Page 73213]]

colonies are much smaller. Colonial behavior offers an effective 
defense mechanism by aiding in the detection of predators and by 
deterring predators through mobbing behavior (Hoogland 1995, pp. 3-6). 
It increases reproductive success through cooperative rearing of 
juveniles and aids parasite removal via shared grooming (Hoogland 1995, 
pp. 3-6).
    Colonial behavior can increase the transmission of disease (Antolin 
et al. 2002, p. 122; Biggins and Kosoy 2001, p. 911; Olsen 1981, p. 
236). Sylvatic plague is a disease foreign to North America that can 
spread from prairie dog to prairie dog through the exchange of infected 
fleas or by contact between infected mammals (Biggins and Kosoy 2001, 
p. 911) (see Threats Analysis, Factor C).

Species Range

    The historical range of the black-tailed prairie dog included 
portions of 11 States, Canada, and Mexico (Hall and Kelson 1959, p. 
365). The black-tailed prairie dog currently exists in 10 States--
Colorado, Kansas, Montana, Nebraska, New Mexico, North Dakota, 
Oklahoma, South Dakota, Texas, and Wyoming. The species occurs from 
extreme south-central Canada to northeastern Mexico and from 
approximately the 98th meridian west to the Rocky Mountains. It has 
been extirpated from Arizona (Arizona Game and Fish Department 1988, p. 
26). Range contractions have occurred in the southwestern portion of 
the species' range in New Mexico and Texas through conversion of 
grasslands to desert shrub (Pidgeon et al. 2001, p. 1773; Weltzin et 
al. 1997, pp. 758-760). In the eastern portion of the species' range in 
Kansas, Nebraska, Oklahoma, South Dakota, and Texas, range contractions 
are largely due to habitat destruction by cropland development (Black-
footed Ferret Recovery Foundation 1999, entire).

Population Estimates

    Most estimates of black-tailed prairie dog populations are not 
based on numbers of individual animals, but on estimates of the amount 
of occupied habitat. The actual number of animals present depends upon 
the density of animals in that locality. Density of animals varies 
depending on the season, region, and climatic conditions, but typically 
ranges from 2-18 individuals per acre (ac) (5-45 individuals per 
hectare (ha)) (Fagerstone and Ramey 1996, p. 85; Hoogland 1995, p. 98; 
King 1955, p. 46; Koford 1958, p. 10-11). Density also can vary 
temporally, due to poisoning, plague, and recreational shooting as 
discussed in later sections.
    Numerous Statewide estimates of black-tailed prairie dog occupied 
habitat are available, spanning a time period from 1903 to the present. 
In Table 1, we summarize historical estimates, 1961 estimates from the 
Bureau of Sport Fisheries and Wildlife (BSFW) that resulted from a 
rangewide survey following large-scale poisoning efforts, and the most 
recent available estimates. Different methodologies were used at 
different times and in different locales to derive the various 
estimates presented; however, these estimates are the best available 
and are comparable for the purpose of determining general population 
trends on the scale of order-of-magnitude changes. Methods have 
improved in recent years with the advent of tools such as aerial 
survey, satellite imagery, and geographic information systems (GIS). 
Consequently, estimates that use these tools can be expected to be more 
accurate.

                 TABLE 1--Statewide Occupied Habitat Estimates for the Black-Tailed Prairie Dog
----------------------------------------------------------------------------------------------------------------
                                            Historical acres        1961 (BSFW) acres       Most recent acres
           State or country                    (hectares)              (hectares)              (hectares)
----------------------------------------------------------------------------------------------------------------
 Arizona..............................   650,000 (263,045) (Van                      0   0.
                                         Pelt 2007).
 Colorado.............................   3,000,000 (1,214,056)         96,000 (38,849)   631,000 (255,356); (Van
                                         (Clark 1989) 7,000,000                          Pelt 2007).
                                         (2,832,799) (Knowles
                                         1998).
 Kansas...............................   2,000,000 (809,371)           50,000 (20,234)   130,521 (52,819); (Van
                                         (Lantz 1903) 2,500,000                          Pelt 2007).
                                         (1,011,714) (Knowles
                                         1998).
 Montana..............................   1,471,000 (595,292)           28,000 (11,331)   90,000 (364,217); (Van
                                         (Flath & Clark 1986)                            Pelt 2007).
                                         6,000,000 (2,428,113)
                                         (Knowles 1998).
 Nebraska.............................   6,000,000 (2,428,113)         30,000 (12,140)   136,991 (55,428); (Van
                                         (Knowles 1998).                                 Pelt 2007).
 New Mexico...........................   >6,640,000 (2,687,112)         17,000 (6,879)   43,639 (17,660); (Van
                                         (Bailey 1932).                                  Pelt 2007).
 North Dakota.........................   2,000,000 (809,371)            20,000 (8,093)   22,396 (9,063); (Van
                                         (Knowles 1998).                                 Pelt 2007).
 Oklahoma.............................   950,000 (384,451)              15,000 (6,070)   57,677 (23,341) (Van
                                         (Knowles 1998).                                 Pelt 2007).
 South Dakota.........................   1,757,000 (711,032)           33,000 (13,354)   625,410 (253,094)
                                         (Linder et al. 1972).                           (Kempema 2007).
 Texas................................   57,600,000 (23,309,892)       26,000 (10,521)   132,515 (53,626) (Van
                                         (Bailey 1905).                                  Pelt 2007).
 Wyoming..............................   16,000,000 (6,474,970)        49,000 (19,829)   229,607 (92,918) (Van
                                         (Knowles 1998).                                 Pelt 2007).
 United States Total..................   78,700,000 (31,848,760)     364,000 (147,305)   2,100,000 (849,839).
                                         (BFFRF 1999)
                                         102,600,000
                                         (41,520,746) (sum of
                                         State average above).
 Canada...............................   2,000 (809) (Knowles     ....................   2,500 (1,011) (Everest
                                         1998).                                          & Tuckwell 2007).
 Mexico...............................   1,384,000 (560,084)      ....................   >49,000 (19,829) (List
                                         (Ceballos et al. 1993).                         2001).
 Rangewide............................   80,000,000-104,000,000   ....................   2,152,000 (870,883).
                                         (32,374,851-42,087,306).
----------------------------------------------------------------------------------------------------------------

    Several estimates of historically occupied habitat for all species 
of prairie dogs are available; the most credible estimates indicate 
that approximately 100,000,000 ac (40,000,000 ha) of occupied habitat 
existed rangewide (Anderson et al. 1986, p. 50; Miller et al. 1996, p. 
24; Nelson 1919, p. 5). If average historical

[[Page 73214]]

estimates for each State, Canada, and Mexico are summed, the rangewide 
estimate is approximately 104,000,000 ac (41,600,000 ha). Based on a 
quantification of potential habitat throughout the range of the black-
tailed prairie dog and assuming a 20 percent occupancy rate (an average 
based on historical occupation of natural short- and mixed-grass 
prairie available), approximately 80,000,000 ac (32,000,000 ha) of 
black-tailed prairie dog occupied habitat existed historically (Black-
footed Ferret Recovery Foundation 1999, entire; Ceballos et al. 1993, 
p. 109; Whicker and Detling 1988, p. 778). Therefore, a reasonable 
rangewide estimate of historically occupied habitat for the black-
tailed prairie dog is 80-100 million ac (32-40 million ha).
    In 1961, the BSFW, a predecessor of the Service, tabulated habitat 
estimates on a county-by-county basis throughout the range of all 
prairie dog species in the western United States (BSFW 1961, p. 1). 
These estimates were completed by District Agents for the Bureau who 
were familiar with the habitat due to their past control efforts. The 
survey was completed in response to concerns from within the agency 
regarding possible adverse impacts to prairie dogs following large-
scale poisoning (Oakes 2000, p. 167). Although the data are from 1961, 
they provide a rangewide estimate for a single point in time when 
prairie dogs were reduced to very low numbers by intensive government 
poisoning efforts. The survey has been cited in other seminal 
documents, including Cain et al. (1972, Appendix VIII) and Leopold 
(1964, p. 38), which resulted in significant changes in predator and 
rodent control policies in the United States, including a ban of 
Compound 1080, a highly toxic poison once widely used to control 
prairie dogs and other mammal species.
    If the most recent estimates of occupied habitat are summed for 
each of the States, Canada, and Mexico, the rangewide estimate is 
2,152,000 ac (870,883 ha). Rangewide and Statewide trends for area of 
black-tailed prairie dog occupied habitat appear to be increasing since 
the low point following a half century of coordinated rangewide control 
efforts.
    Trends from site-specific estimates are not always reflected in 
Statewide trends. Site-specific estimates are typically derived from 
field surveys related to monitoring or research, and include extensive 
ground-truthing, which provides more precise assessments. Consequently, 
site-specific estimates are often more accurate than Statewide 
estimates. However, black-tailed prairie dog monitoring and research 
are often focused on plague epizootics (outbreaks of disease that 
rapidly affect many animals in a specific area at the same time). 
Consequently, the trends available regarding site-specific occupied 
habitat estimates often include plague-affected sites (see Table 2 in 
Threats Analysis Factor C).

Population Impacts

    Three major impacts, which somewhat overlap, have influenced 
historical 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 to the 1920s. The conversion of native prairie to cropland likely 
reduced occupied habitat in the United States from as much as 100 
million ac (40 million ha) of occupied black-tailed prairie dog 
colonies to about 50 million ac (20 million ha) or less (Laycock 1987, 
p. 4; Whicker and Detling 1988, p. 778). The second major impact on the 
species was large-scale poisoning efforts, conducted from approximately 
1918 to 1972, to reduce competition between prairie dogs and domestic 
livestock (BSFW 1961, p. 1). Large-scale, repeated control efforts 
likely reduced occupied habitat in the United States from about 50 
million ac (20 million ha) to approximately 364,000 ac (162,000 ha) by 
1961 (BSFW 1961). The third major impact on the species was the 
inadvertent introduction of an exotic disease, sylvatic plague, into 
North American ecosystems around 1900. The first recorded impacts on 
the black-tailed prairie dog were recorded in 1946 (Miles et al. 1952, 
p. 41).

Threats Analysis

    Section 4 of the Act (16 U.S.C. 1533) and implementing regulations 
at 50 CFR 424 set forth the procedures for adding species to the 
Federal Lists of Endangered and Threatened Wildlife and Plants. 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) of the 
Act: (A) The present or threatened destruction, modification, or 
curtailment of habitat or range; (B) overutilization for commercial, 
recreational, scientific, or educational purposes; (C) disease or 
predation; (D) the inadequacy of existing regulatory mechanisms; or (E) 
other natural or manmade factors affecting its continued existence. 
Listing actions may be warranted based on any of the above threat 
factors, singly or in combination.
    Under the Act, a threatened species is defined as a species that is 
likely to become an endangered species within the foreseeable future 
throughout all or a significant portion of its range. An endangered 
species is defined as a species that is in danger of extinction 
throughout all or a significant portion of its range. We evaluated each 
of the five listing factors to determine whether the level of threat 
identified by information in the petition or in our files was 
substantial and indicated that listing the black-tailed prairie dog as 
threatened or endangered may be warranted. Our evaluation is presented 
below.
    We placed the threats listed in the petition under the most 
appropriate listing factor. However, we recognize that several 
potential threats affecting the species might be considered under more 
than one factor. For example, poisoning can affect black-tailed prairie 
dog habitat (Factor A), and can be affected by State and Federal 
regulatory mechanisms (Factor D), but is primarily addressed in this 
finding under Factor E (other natural or manmade factors).

A. The Present or Threatened Destruction, Modification, or Curtailment 
of Its Habitat or Range

Information Provided in the Petition
    The petitioners assert that several factors are affecting black-
tailed prairie dog and its habitat, including that:
    (1) Conversion to cropland, resulting in habitat loss, is likely 
increasing due to the demand for corn-based ethanol for vehicle fuel 
and the removal of land from the Conservation Reserve Program (CRP) for 
increased corn production;
    (2) Urbanization is a threat to the species and its habitat, 
especially in the Front Range of Colorado;
    (3) Oil, gas, and mineral extraction cause habitat degradation and 
loss, and increased habitat fragmentation;
    (4) The loss of prairie dogs from shooting, plague, and poisoning 
causes a corresponding loss of habitat, primarily due to degraded 
habitat, decreased grassland productivity, and eventual burrow 
collapse; and
    (5) Livestock grazing and fire suppression negatively impact black-
tailed prairie dog habitat by allowing the proliferation of woody 
plants and noxious weeds that replace native forage species.
Response
    In some instances, black-tailed prairie dog habitat is currently 
being destroyed, modified, or curtailed by: (1) Conversion of native 
prairie habitat to cropland; (2) urbanization; (3) oil, gas, and 
mineral extraction; (4) habitat loss

[[Page 73215]]

caused by loss of prairie dogs; and (5) livestock grazing, fire 
suppression, and weeds. However, extensive rangeland remains available 
for potential expansion of black-tailed prairie dog occupied habitat.
    The most substantial cause of habitat destruction that we are able 
to quantify is cropland development. Conversion of the native prairie 
to cropland has largely progressed across the species' range from east 
to west; the most intensive agricultural use is in the eastern portion 
of the species' range. By 1999, approximately 37 percent of the 
historical suitable habitat within the species' range had been 
converted to cropland uses (Black-footed Ferret Recovery Foundation 
1999, entire). The Natural Resources Conservation Service quantified 
land cover and use changes from 1982 to 1997; the 11 States within the 
historical range of the species experienced an estimated 2 percent loss 
of rangeland during this time period (U.S. Department of Agriculture 
2000, pp. 18-24). When the 2 million ac (1.6 million ha) of currently 
occupied habitat is contrasted with the 342 million ac (139 million ha) 
of remaining non-Federal rangeland (statistics for Federal land were 
unavailable), it appears that sufficient potential habitat still occurs 
in each of the 11 States within the historical range of the species to 
accommodate large expansions of black-tailed prairie dog populations. 
This estimate of potential habitat includes rangeland Statewide, but 
does not include pasture or CRP lands, because these areas were not 
included in the analysis. However, prairie dogs do use pasture, and 
therefore this estimate is considered conservative.
    Urbanization is occurring within portions of the black-tailed 
prairie dog range, particularly the Front Range of Colorado. However, 
on a larger Statewide or rangewide context, loss of habitat due to 
urbanization is not significant, given the recent Statewide estimates 
of occupied habitat in Colorado and elsewhere (Table 1). The accuracy 
of the 2004 Colorado Division of Wildlife (CDOW) estimate of 631,000 ac 
(255,000 ha) of occupied habitat in Colorado is questioned by the 
petitioners. Other recent estimates of occupied habitat available for 
Colorado include: 461,000 ac (187,000 ha), calculated from Tipton et 
al. (2008, p. 1002); a minimum of 788,000 ac (319,000 ha) of occupied 
habitat (CDOW 2007, entire); and a minimum of 215,000 ac (87,000 ha) of 
active occupied habitat (EDAW 2000, p. 20). Each of these estimates for 
Colorado indicates a substantial increase in occupied habitat since 
1961.
    Oil, gas, and mineral extraction are occurring within portions of 
the black-tailed prairie dog range. However, no information provided by 
the petitioners or readily available in our files quantifies the 
impacts. Additionally, population trends do not suggest that oil, gas, 
and mineral extraction are a limiting factor for the species.
    Black-tailed prairie dogs do affect their own habitat. The loss or 
reduction of prairie dogs in areas can result in that habitat becoming 
degraded. However, documentation of prairie dog effects on habitat is 
mixed. Black-tailed prairie dogs can have a positive effect on habitat 
(Johnson-Nistler et al. 2004, p. 641; Koford 1958, pp. 43-62; Kotliar 
et al. 1999, p. 178; Lantz et al. 2006, p. 2671); positive effects have 
been particularly notable in the southwestern portion of the species' 
range where the foraging and clipping habits of prairie dogs destroy 
seedlings of undesirable shrub and tree species that may invade and 
eventually convert grasslands, and aeration of soil from burrow 
construction increases growth of grasses (Davis 1974, p. 156; 
Fagerstone and Ramey 1996, p. 89; Koford 1958, pp. 43-62; List et al. 
1997, p. 150; Weltzin et al. 1997, pp. 758-760). Black-tailed prairie 
dogs also may have a neutral habitat effect, i.e., a balance between 
clipping vegetation that could be forage for cattle and improving the 
protein content of remaining grass, or negative habitat effect by 
reducing grass species and causing conversion to forb species 
undesirable for cattle (Bonham and Lerwick 1976, p. 225; Fagerstone and 
Ramey 1996, p. 88; Johnson-Nistler et al. 2004, p. 641; Klatt and Hein 
1978, p. 316; Koford 1958, pp. 43-62). No information provided by the 
petitioners or readily available in our files quantifies the overall 
impact that black-tailed prairie dogs have on their own habitat. 
However, extensive rangeland remains available for potential expansion 
of black-tailed prairie dog habitat (U.S. Department of Agriculture 
2000, pp. 18-24).
    Information exists regarding the increase of nonnative plant 
species in the presence of overgrazing and the absence of fire. 
However, the impact of plant composition on habitat suitability for 
black-tailed prairie dogs is contradictory (Cerovski 2004, p. 101; 
Detling 2006, p. 115; Koford 1958, pp. 43-62; Uresk et al. 1981, p. 
200; Vermeire 2004, p. 691). Available information indicates that 
livestock grazing typically encourages black-tailed prairie dog 
expansion (Andelt 2006, p. 131; Fagerstone and Ramey 1996, p. 88; 
Forest 2005, p. 528; Groombridge 1992, p. 290; Hubbard and Schmitt 
1983, p. 30; Koford 1958, p. 68; Marsh 1984, p. 203; Osborn and Allan 
1949, p. 330; Snell 1985, p. 30; Snell and Hlavachick 1980, p. 240; 
Uresk et al. 1981, p. 200; U.S. Forest Service 1995, p. 5; U.S. Forest 
Service 1998, p. 4; Wuerthner 1997, pp. 460-461). Additionally, 
extensive rangeland remains available for potential expansion of 
occupied habitat (U.S. Department of Agriculture 2000, pp. 18-24).
Summary of Factor A
    On the basis of our evaluation of the most recent Statewide 
estimates of occupied habitat and the amount of potential habitat 
available for expansion, we determined that the petition does not 
present substantial information indicating that listing the black-
tailed prairie dog may be warranted due to the present or threatened 
destruction, modification, or curtailment of its habitat or range. The 
threat to prairie dogs presented by sylvatic plague is addressed under 
Factor C, and the threat presented by poisoning is addressed under 
Factor E.

B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

Information Provided in the Petition
    The petitioners assert that recreational shooting of black-tailed 
prairie dogs and collecting for the pet trade are threats to the black-
tailed prairie dog; they indicate that shooting is of special concern 
because of the cumulative effect of localized extirpation across the 
species' range. The petitioners indicate that shooting causes both 
direct effects (mortality) and indirect effects such as behavioral 
changes, diminished reproduction and body condition, and emigration. 
The petitioners indicate that the number of shooters is increasing, and 
the technology available to them is advancing.
    The petitioners do not believe that collecting for the pet trade 
has as great an impact as several other factors, but suggest that pet 
prairie dogs infected with an exotic disease could be released into the 
wild, which could pose a risk to wild black-tailed prairie dogs.
Response
    Recreational shooting of black-tailed prairie dogs can reduce 
population densities, cause behavioral changes, diminish reproduction 
and body condition, increase emigration, and cause extirpation in 
isolated circumstances (Knowles 1988, p. 54; Pauli 2005, p. 1; Reeve 
and Vosburgh 2006, p. 144; Stockrahm 1979, pp. 80-

[[Page 73216]]

84; Vosburgh 1996, pp. 13, 15, 16, and 18; Vosburgh and Irby 1998, pp. 
366-371). However, available information indicates that populations can 
recover from very low numbers following intensive shooting (Cully and 
Johnson 2006, pp. 6-7; Dullum et al. 2005, p. 843; Knowles 1988, p. 12; 
Pauli 2005, p. 17; Vosburgh 1996, pp. 16, 31). Based on the research 
cited in this paragraph, it appears that a typical scenario is that 
either: (1) Once populations have been reduced, shooters go elsewhere 
and populations are allowed to recover; or (2) shooting maintains 
reduced population size at specific sites. Research does not further 
clarify or quantify these factors, and shooting, investigated 
separately from other threat factors, does not appear to have a 
significant impact on black-tailed prairie dogs, overall. We do not 
have an analysis on rangewide impacts of shooting on prairie dogs.
    Many landowners maintain prairie dog populations and derive income 
from charging people for recreational shooting. Monetary gain from 
shooting fees may motivate landowners to preserve prairie dog colonies 
for future shooting opportunities, which is currently an alternative to 
eradicating them by poisoning (Reeve and Vosburgh 2006, pp. 154-155; 
Vosburgh and Irby 1998, pp. 366-371).
    Substantial information is not presented by the petitioners or 
available in our files to evaluate potential effects of collecting or 
the spread of disease resulting from the pet trade.
Summary of Factor B
    Recreational shooting of prairie dogs can cause localized effects. 
However, much of the literature documenting effects from shooting of 
prairie dogs also describes subsequent rebounds in local populations; 
extirpations, while documented, are rare and, therefore, not a 
significant threat to the species. Recent Statewide estimates of 
occupied habitat further reinforce this observation by documenting 
population increases in areas subject to shooting. We conclude that 
neither shooting nor the pet trade is a threat to the black-tailed 
prairie dog. On the basis of our evaluation, we determined that the 
petition does not present substantial information indicating that 
listing the black-tailed prairie dog may be warranted due to 
overutilization for commercial, recreational, scientific, or 
educational purposes.

C. Disease and Predation

Information Provided in the Petition
    The petitioners assert that sylvatic plague causes mortality rates 
approaching 100 percent in infected colonies. They indicated that 
evidence is too preliminary to say that high levels of exposure are 
necessary before prairie dogs contract plague, or to say that prairie 
dogs have a limited immune response to plague. The petitioners 
challenge studies indicating that isolated, low density populations are 
protected from plague, and indicating that some sites have recovered to 
pre-plague levels. They note that in recent years several epizootics 
have occurred, and that plague has expanded into South Dakota. They 
also note that although not a rangewide threat, prairie dogs also are 
susceptible to tularemia and monkeypox.
Response
    Plague is an exotic disease foreign to the evolutionary history of 
North American prairie dogs. It is caused by the bacterium Yersinia 
pestis, which fleas acquire by biting infected animals, and 
subsequently transmit via a bite to other animals. The disease also can 
be transmitted through pneumonic (airborne) or septicemic (blood) 
pathways from infected to disease-free animals (Barnes 1993, p. 28; 
Cully et al. 2006, p. 158; Ray and Collinge 2005, p. 203; Rocke et al. 
2006, p. 243; Webb et al. 2006, p. 6236). Plague was first observed in 
wild rodents in North America near San Francisco, California in 1903 
(Eskey and Haas 1940, p. 1), and was first documented in black-tailed 
prairie dogs in Texas in 1946 (Miles et al. 1952, p. 41).
    Black-tailed prairie dogs are very sensitive to plague, and 
mortality frequently reaches 100 percent (Barnes 1993, p. 28). Two 
patterns of die-offs are typically described for black-tailed prairie 
dogs: (1) A rapid and nearly 100 percent die-off with incomplete 
recovery, such as has occurred at the Rocky Mountain Arsenal and the 
Comanche National Grassland in Colorado (Cully and Williams 2001, pp. 
899-903); and (2) a partial die-off resulting in smaller, but stable, 
populations and smaller, more dispersed colonies, such as has occurred 
at the Cimarron National Grassland (Cully and Williams 2001, pp. 899-
903). Several researchers have suggested that the response of black-
tailed prairie dogs to plague may vary based on population density or 
degree of colony isolation (Cully 1989, p. 49; Cully and Williams 2001, 
pp. 899-903; Lomolino et al. 2003, pp. 118-119). Table 2 illustrates 
die-offs and extent of recovery for several well-studied sites that 
have experienced plague epizootics.

                      Table 2--Site-Specific Estimates of Occupied Black-Tailed Prairie Dog Habitat Over Time (in acres (hectares))
--------------------------------------------------------------------------------------------------------------------------------------------------------
                Site                      1st Estimate            2nd Estimate            3rd Estimate           4th Estimate           5th Estimate
--------------------------------------------------------------------------------------------------------------------------------------------------------
Comanche NG, CO....................  5,000 (2,023) in 1995   1,600 (647) in 1999     10,700 (4,330) in      3,000 (1,214) in 2006  .....................
                                      (Augustine et al.       (PP) (Augustine et      2005 (Augustine et     (PP) (Augustine et
                                      2008).                  al. 2008).              al. 2008).             al. 2008).
Pueblo Chemical Depot, CO..........  4,333 (1,753) in 1998   67 (27) in 2000 (PP)    3,423 (1,385) in 2005  2,712 (1,097) in 2006  .....................
                                      (Young 2008).           (Young 2008).           (Young 2008).          (PP) (Young 2008).
Rocky Mtn Arsenal, CO..............  4,574 (1,851) in 1988   247 (99) in 1989 (PP)   2,429 (982) in 1994    22 (8) in 1995 (PP)    1,646 (666) in 2000
                                      (Seery 2001).           (Seery 2001).           (Seery 2001).          (Seery 2001).          (Seery 2001).
N. Cheyenne Res., MT...............  10,720 (4,338) in 1990  378 (152) in 1995 (PP)  3,300 (1,335) in 2001  3,913 (1,585) in 2003  5,683 (2,299) in 2006
                                      (Larson 2008).          (Fourstar 1998).        (Vosburgh 2003).       (Vosburgh 2003).       (Larson 2008).
Kiowa/Rita Blanca NG, TX, OK, NM...  1,600 (647) in 1999     6,800 (2,751) in 2003   4,500 (1,821) in 2004  3,000 (1,214) in 2005  .....................
                                      (Cully & Johnson        (Cully & Johnson        (PP) (Cully &          (PP) (Cully &
                                      2006).                  2006).                  Johnson 2006).         Johnson 2006).
Thunder Basin NG, WY...............  16,300 (6,596) in 2001  1,600 (647) in 2002     9,000 (3,642) in 2003                         .....................
                                      (Cully & Johnson        (PP) (Cully & Johnson   (Byer 2003).
                                      2006).                  2006).
--------------------------------------------------------------------------------------------------------------------------------------------------------
PP = post-plague.


[[Page 73217]]

    Some studies have documented the development of antibodies in 
black-tailed prairie dogs surviving a plague epizootic. In one Colorado 
site, over 50 percent of survivors developed antibodies (Pauli 2005, 
pp. 1, 71). Recent laboratory research indicates that, at low levels of 
exposure, a small percentage of black-tailed prairie dogs show some 
immune response and consequently some resistance to plague, indicating 
that a plague vaccine may be developed in the future (Creekmore et al. 
2002, pp. 32, 38). Preliminary work has demonstrated significantly 
higher antibody titers and survival rates in vaccinated black-tailed 
prairie dogs that were challenged with the plague bacterium (Mencher et 
al. 2004, pp. 5, 8-9). Oral vaccination may be effective for managing 
plague epizootics in free-ranging prairie dog populations by reducing 
mortality in exposed individuals (Mencher et al. 2004, pp. 8-9).
    Since the black-tailed prairie dog was removed from the candidate 
list in 2004, plague has expanded its range into South Dakota, 
previously the only State where plague had not been documented in 
prairie dogs (Service 2005, p. 1). Despite 3 years of dusting prairie 
dog burrows in portions of the area with insecticide, in 2008, the 
disease reached the black-footed ferret recovery area in Conata Basin 
(Larson 2008, entire). Approximately 9,000 ac (3,600 ha) have been 
affected through June 2008 in Conata Basin (Griebel 2008, entire). 
Conata Basin is one of the largest remaining black-tailed prairie dog 
complexes, and is the most successful recovery site in North America 
for the endangered black-footed ferret. Plague also has been documented 
on Pine Ridge and Cheyenne River Reservations in South Dakota (Mann-
Klager 2008, entire). The establishment of sylvatic plague in South 
Dakota could have a significant impact on both the black-tailed prairie 
dog and the black-footed ferret (Creekmore et al. 2002, p. 38).
    Tularemia and monkeypox are diseases that have had impacts on 
captive black-tailed prairie dogs associated with the pet trade; 
however, we have no information to indicate that either of these 
diseases are a concern for wild prairie dogs.
Summary of Factor C
    Some encouraging information regarding plague is available, 
particularly the development of a vaccine to improve management of 
plague in prairie dog populations. However, information indicates that 
plague has expanded its range in recent years and has caused population 
declines at several sites. On the basis of our evaluation, we 
determined that the petition presents substantial information to 
indicate that listing the black-tailed prairie dog as a threatened or 
endangered species may be warranted due to sylvatic plague.
    On the basis of our evaluation, we determined that the petition 
does not present substantial information indicating that listing the 
black-tailed prairie dog may be warranted due to tularemia or 
monkeypox.

D. The Inadequacy of Existing Regulatory Mechanisms

Information Provided in the Petition
    The petitioners assert that regulatory actions influencing habitat 
loss, shooting, the pet trade, sylvatic plague, and chemical control 
are inadequate to mitigate impacts from these threats. They indicate 
that: (1) Most of the regulations that promote black-tailed prairie dog 
conservation, enacted after the 1998 petitions to list the species, 
have been rescinded or weakened; (2) Federal, State, and Tribal 
regulations and local statutes and policies enacted since removal of 
the black-tailed prairie dog from the candidate list in 2004 favor 
killing rather than preserving the species; and (3) regulatory 
mechanisms pertaining to oil and gas development on Federal lands are 
inadequate and lack safeguards for black-tailed prairie dogs.
Response
    Many of the regulations promoting prairie dog conservation enacted 
after the 1998 petitions to list the black-tailed prairie dog have been 
rescinded or weakened. Regulations enacted since removal of the black-
tailed prairie dog from the candidate list in 2004 have not favored 
preservation of the species. Several notable examples are presented in 
the petition or readily available in our files, including:
    (1) The U.S. Environmental Protection Agency (EPA) has not provided 
annual records to the Service on the amount of acreage poisoned with 
zinc phosphide or the amount of chemical sold, despite this reporting 
being included as a ``Reasonable and Prudent Alternative'' in a 1993 
Biological Opinion (Service 1993, p. II-107). EPA did not agree to 
collect or provide this data in response to the Biological Opinion. On 
April 25, 2002, we sent a letter to EPA requesting any records on the 
amount of zinc phosphide sold or acres poisoned; EPA responded that 
they were not obligated to provide this information. Having records of 
this information would enable us to monitor the rangewide effects of 
poisoning on black-tailed prairie dogs, and the endangered black-footed 
ferret, whose primary prey is the black-tailed prairie dog.
    (2) The EPA has not initiated additional formal consultation, 
following the 1993 Biological Opinion, regarding the recent permitting 
of chlorophacinone and diphacinone (both anticoagulants) to poison 
prairie dogs, despite their statement that additional consultation may 
be necessary if any new uses of these pesticides are proposed (EPA 
1998, p. 109). Use of these two chemicals constitutes new uses because 
neither poison was registered for field use on prairie dogs at the time 
of the 1993 Biological Opinion. Secondary poisoning has been documented 
in the field in a badger and a bald eagle; additionally, many other 
species, including the black-footed ferret, are known to be highly 
susceptible to both chlorophacinone and diphacinone.
    (3) The U.S. Forest Service weakened their restrictions on 
poisoning by rescinding a 2000 policy letter regarding control of 
black-tailed prairie dogs (Manning 2004, entire), which allowed for 
expansion of poisoning on their lands.
    (4) The State of Montana changed the dual status of the species 
from ``nongame wildlife in need of management'' and ``vertebrate pest'' 
to the single status of ``vertebrate pest'' (Hanebury 2007, entire), 
which eases restrictions on prairie dog poisoning.
    (5) The State of South Dakota weakened the designation of ``species 
of management concern'' for the black-tailed prairie dog by designating 
it as a pest if: Plague is reported east of the Rocky Mountains, the 
Statewide population is greater than 145,000 ac (59,000 ha), or the 
species is colonizing within a 1-mile (1.6-kilometer) buffer around 
concerned landowners (South Dakota State Legislature 2005, entire). 
Currently all of these criteria are being met; therefore, the species 
is considered a pest in South Dakota, which eases restrictions on 
prairie dog poisoning.
    (6) Since 2004, State agricultural departments have issued permits 
authorizing the use of chlorophacinone for poisoning prairie dogs in 
Colorado, Kansas, Nebraska, Oklahoma, Texas, and Wyoming.
    (7) Since 2004, State agricultural departments have issued permits 
authorizing the use of diphacinone for poisoning prairie dogs in 
Colorado, Kansas, Nebraska, Texas, and Wyoming.
    Following the 1998 petitions to list the black-tailed prairie dog, 
representatives from each State wildlife agency within the historical 
range of the

[[Page 73218]]

species formed the Prairie Dog Conservation Team. The Team developed 
``A Multi-State Conservation Plan for the Black-tailed Prairie Dog, 
Cynomys ludovicianus, in the United States'' (Luce 2002, p. 2). The 
purpose of this Multi-State Plan was to provide standards for future 
prairie dog management within the 11 States. The Multi-State Plan 
endorsed the following minimum 10-year target objectives: (1) Maintain 
at least the currently occupied acreage of black-tailed prairie dog 
habitat in the United States; (2) increase to at least 1,693,695 ac 
(685,946 ha) of occupied black-tailed prairie dog acreage in the United 
States by 2011; (3) maintain at least the current black-tailed prairie 
dog occupied acreage in the 2 complexes greater than 5,000 ac (2,025 
ha) that now occur on and adjacent to Conata Basin-Buffalo Gap National 
Grassland, South Dakota, and Thunder Basin National Grassland, Wyoming; 
(4) develop and maintain a minimum of 9 additional complexes greater 
than 5,000 ac (2,025 ha), with each State managing or contributing to 
at least one complex greater than 5,000 ac (2,025 ha) by 2011; (5) 
maintain at least 10 percent of total occupied acreage in colonies or 
complexes greater than 1,000 ac (400 ha) by 2011; and (6) maintain 
distribution over at least 75 percent of the counties in the historical 
range, or at least 75 percent of the historical geographic 
distribution. Objectives 3, 4, 5, and 6 have not yet been met; however, 
objectives 4 and 5 need not be met until 2011.
    States also agreed to draft Statewide management plans. Colorado 
has finalized a conservation plan for grassland species that supports 
and meets the objectives of the Multi-State Plan. Kansas, Oklahoma, and 
Texas have finalized management plans that support the Multi-State Plan 
objectives, but have not yet met all of those objectives. Montana, New 
Mexico, North Dakota, and South Dakota have finalized management plans 
that do not support or meet all of the objectives of the Multi-State 
Plan. Arizona, Nebraska, and Wyoming have draft plans that were not 
approved by their Wildlife Commissions.
Summary of Factor D
    On the basis of our evaluation, we determined that the petition 
presents substantial information to indicate that listing the black-
tailed prairie dog as a threatened or endangered species may be 
warranted due to the inadequacy of existing regulatory mechanisms, 
particularly regarding poisoning, which is discussed further under 
Factor E.

E. Other Natural or Manmade Factors Affecting Continued Existence

Information Provided in the Petition
    The petitioners assert that several other threat factors are 
affecting the black-tailed prairie dog, including that:
    (1) The historical loss of approximately one-third of the species' 
potential habitat has resulted in black-tailed prairie dog populations, 
particularly in the eastern portion of the species' range, remaining 
vulnerable to stochastic events.
    (2) The agricultural industry has put pressure on elected officials 
to increase both the methods and public financial assistance available 
to eradicate prairie dogs, promoting intolerance of the species, and 
that these officials have, in turn, put pressure on public land and 
wildlife managers to eradicate prairie dogs and halt initiatives to 
protect them; the majority of States with black-tailed prairie dogs 
have supported increased lethal control of prairie dogs, including the 
approval of anticoagulants;
    (3) While drought is a natural phenomenon, its effects are 
exacerbated by the other stressors affecting the species; and
    (4) Climate change may contribute to invasion of noxious weeds and 
exacerbate the effects of habitat fragmentation.
Response
    The black-tailed prairie dog evokes strong emotions in many people, 
which may affect regulations, recreational shooting, and poisoning. 
However, no information presented by the petitioners, or available in 
our files, quantifies the effects of intolerance separately from the 
actual threat factors. Therefore, we only address the latter.
    The information presented by the petitioners and available in our 
files indicates that, in States with recent data available, including 
South Dakota and Wyoming, the extent of poisoning may have increased 
since the black-tailed prairie dog was removed from the candidate list 
in 2004 (Cerovski 2004, p. 101; Kempema 2007, p. 8). Table 3 includes 
the total sales of zinc phosphide bait by the South Dakota bait station 
in the 4 years prior to candidate removal. South Dakota is the only 
State that has been permitted by EPA to manufacture and sell zinc 
phosphide. Sales from the South Dakota bait station are largely limited 
to South Dakota, Wyoming, and Nebraska. The States of Colorado, Kansas, 
Montana, New Mexico, North Dakota, Oklahoma, and Texas acquire zinc 
phosphide from various manufacturers, but no recent information 
regarding sales has been made available to us. Additionally, as 
described in Factor D, other methods of prairie dog control have 
expanded since 2004, because the anticoagulants chlorophacinone and 
diphacinone were approved for use in Colorado, Kansas, Nebraska, 
Oklahoma, Texas, and Wyoming.

 Table 3--Sales of Zinc Phosphide Bait Prior (Fridley 2003, Entire) and
 Subsequent to (Kempema 2007, p. 8; Larson 2008, Entire) Removal of the
            Black-Tailed Prairie Dog From the Candidate List
------------------------------------------------------------------------
    Amount of bait sold in pounds
             (kilograms)                             Year
------------------------------------------------------------------------
42,400 (19,323).....................                                2000
26,775 (12,145).....................                                2001
42,500 (19,278).....................                                2002
97,950 (44,429).....................                                2003
                                          Species removed from candidate
                                                                   list.
334,900 (151,908)...................                                2004
191,775 (86,988)....................                                2005
307,900 (139,661)...................                                2006
241,625 (109,599)...................                                2007
------------------------------------------------------------------------

    If all of the bait sold by the South Dakota bait station were 
applied at the recommended rate of 1/3 pound per acre (Hygnstrom et al. 
1994, p. B-89), this would equate to approximately 128,000 ac (52,000 
ha) poisoned in

[[Page 73219]]

2000, 80,000 ac (33,000 ha) in 2001, 128,000 ac (52,000 ha) in 2002, 
294,000 ac (119,000 ha) in 2003, 1,005,000 ac (407,000 ha) in 2004, 
575,000 ac (233,000 ha) in 2005, 924,000 ac (374,000 ha) in 2006, and 
725,000 ac (294,000 ha) in 2007. To provide some perspective, if the 
current estimate from Table 1 of approximately 2.1 million ac (850,000 
ha) of occupied habitat in the United States is used, enough poison has 
been sold by this single facility since 2004 to poison all occupied 
habitat in the United States with enough remaining to poison an 
additional 1 million ac (400,000 ha). This scenario does not include 
the possibility of individuals stockpiling poison, or applying it at 
rates greater than 1/3 pound per acre.
    Prairie dogs were extirpated from Arizona through poisoning 
campaigns that occurred in the early 1900s (Van Pelt 2007). As noted in 
the Population Estimates section of this document, that extirpation 
took place during a relatively unregulated period of large-scale 
extermination efforts using a highly toxic poison (Compound 1080).
    Drought is a natural and cyclical occurrence within the range of 
the black-tailed prairie dog to which the animal has adapted (Forrest 
2005, p. 528). It has been noted that, in at least some instances, 
occupied habitat tends to increase during periods of drought, and 
densities decrease, because animals spread out in search of food (Young 
2008, p. 5). However, no information presented by the petitioners, or 
in our files, quantifies the effect of drought, singly or in 
conjunction with other threats, on the species rangewide.
    The impacts of stochastic events and climate change on prairie dog 
populations are speculative. No information presented by the 
petitioners, or available in our files, quantifies these effects. No 
information on the direct relationship between climate change and 
population trends is available. Currently, black-tailed prairie dogs 
occupy, in fragmented populations, 2.1 million acres across 11 States; 
therefore, it is unlikely that stochastic events pose a threat to the 
species. In addition, extensive rangeland remains available for 
potential expansion of black-tailed prairie dog habitat (U.S. 
Department of Agriculture 2000, pp. 18-24). Therefore the threat of 
stochastic events does not appear to be significant.
Summary of Factor E
    On the basis of our evaluation, we determined that the petition 
presents substantial information to indicate that listing the black-
tailed prairie dog as a threatened or endangered species may be 
warranted due to poisoning of black-tailed prairie dogs.
    We determined that the petition does not present substantial 
information indicating that listing the black-tailed prairie dog may be 
warranted due to intolerance to or misconceptions about prairie dogs. 
We also determined that the petition does not present substantial 
information indicating that listing the black-tailed prairie dog may be 
warranted due to stochastic events, drought, or climate change.
Finding
    We have assessed information provided by the petitioners and 
readily available in our files. On the basis of our evaluation, we find 
that the petition presents substantial information indicating that 
listing the black-tailed prairie dog under the Act may be warranted 
based on threats associated with Factor C (sylvatic plague), Factor D 
(inadequate Federal and State regulations), and Factor E (poisoning). 
Therefore, we are initiating a status review to determine whether 
listing the black-tailed prairie dog under the Act is warranted.
    We determined that an emergency listing is not warranted at this 
time, because available information regarding Statewide populations 
indicates stable to increasing trends since 1961. However, if at any 
time we determine that emergency listing of the black-tailed prairie 
dog is warranted, we will initiate an emergency listing.
    The petitioners also request that critical habitat be designated 
for the species concurrent with final listing under the Act. We 
consider the need for critical habitat designation when listing 
species. If we determine in our 12-month finding following the status 
review of the species that listing the black-tailed prairie dog is 
warranted, we will address the designation of critical habitat in the 
subsequent proposed rule.
References Cited
    A complete list of all references cited in this document is 
available, upon request, from the South Dakota Fish and Wildlife Office 
(see FOR FURTHER INFORMATION CONTACT).
Author
    The primary authors of this notice are the staff members of the 
U.S. Fish and Wildlife Service, South Dakota Fish and Wildlife Office 
(see FOR FURTHER INFORMATION CONTACT).
Authority
    The authority for this action is the Endangered Species Act of 
1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: November 23, 2008.
Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. E8-28528 Filed 12-1-08; 8:45 am]
BILLING CODE 4310-55-P ?>