[Federal Register: December 2, 2008 (Volume 73, Number 232)]
[Proposed Rules]
[Page 73211-73219]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02de08-23]
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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
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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).
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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