[Federal Register Volume 77, Number 108 (Tuesday, June 5, 2012)]
[Proposed Rules]
[Pages 33143-33155]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-13320]


-----------------------------------------------------------------------

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R6-ES-2012-0023; 4500030114]


Endangered and Threatened Wildlife and Plants; 90-Day Finding on 
a Petition To List the Southern White-Tailed Ptarmigan and the Mt. 
Rainier White-Tailed Ptarmigan as Threatened With Critical Habitat

AGENCY: Fish and Wildlife Service, Interior.

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

-----------------------------------------------------------------------

SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to list the southern white-tailed 
ptarmigan (Lagopus leucura altipetens) and the Mt. Rainier white-tailed 
ptarmigan (L. l. rainierensis) as threatened under the Endangered 
Species Act of 1973, as amended (Act), and designate critical habitat. 
Based on our review, we find that the petition presents substantial 
scientific or commercial information indicating that listing the 
southern white-tailed ptarmigan and the Mt. Rainier white-tailed 
ptarmigan may be warranted. Therefore, with the publication of this 
notice, we are initiating a review of the status of the two subspecies 
to determine if listing is warranted. To ensure that this status review 
is comprehensive, we are requesting scientific and commercial data and 
other information regarding these subspecies. Based on the status 
review, we will issue a 12-month finding on the petition, which will 
address whether the petitioned action is warranted, as provided in 
section 4(b)(3)(B) of the Act. We will make a determination on critical 
habitat for these subspecies if and when we initiate a listing action.

DATES: To allow us adequate time to conduct this review, we request 
that we receive information on or before August 6, 2012. The deadline 
for submitting an electronic comment using the Federal eRulemaking 
Portal (see ADDRESSES section, below) is 11:59 p.m. Eastern Time on 
this date. After August 6, 2012, you must submit information directly 
to the Colorado Ecological Services Field Office (see FOR FURTHER 
INFORMATION CONTACT section, below). Please note that we might not be 
able to address or incorporate information that we receive after the 
above requested date.

ADDRESSES: You may submit information by one of the following methods:
    (1) Electronically: Go to the Federal eRulemaking Portal: http://www.regulations.gov. In the SEARCH field, enter Docket No. FWS-R6-ES-
2012-0023, which is the docket number for this action. Then click on 
the Search button. You may submit a comment by clicking on ``Submit a 
Comment.''
    (2) By hard copy: Submit by U.S. mail or hand-delivery to: Public 
Comments Processing, Attn: FWS-R6-ES-2012-0023; Division of Policy and 
Directives Management; U.S. Fish and Wildlife Service; 4401 N. Fairfax 
Drive, MS 2042-PDM; Arlington, VA 22203.
    We will not accept email or faxes. We will post all information we 
receive on http://www.regulations.gov. This generally means that we 
will post any personal information you provide us (see the Request for 
Information section below for more details).

FOR FURTHER INFORMATION CONTACT: Susan Linner, Field Supervisor, U.S. 
Fish and Wildlife Service, Colorado Ecological Services Field Office, 
P.O. Box 25486, DFC Mail Stop 65412, Denver, CO 80225-0486; telephone 
(303) 236-4773; fax (303) 236-4005. If you use a telecommunications 
device for the deaf (TDD), please call the Federal Information Relay 
Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION: 

Request for Information

    When we make a finding that a petition presents substantial 
information indicating that listing a species may be warranted, we are 
required to promptly review the status of the species (status review). 
For the status review to be complete and based on the best available 
scientific and

[[Page 33144]]

commercial information, we request information on the southern white-
tailed ptarmigan and the Mt. Rainier white-tailed ptarmigan from 
governmental agencies, Native American tribes, the scientific 
community, industry, and any other interested parties. We particularly 
seek the following information regarding the southern and Mt. Rainier 
white-tailed ptarmigans:
    (1) Biology, range, and population trends, including:
    (a) Taxonomy (especially the genetics of the species and 
subspecies);
    (b) Historic and current range, including distribution patterns; 
and
    (c) Historic and current population levels, and current and 
projected trends.
    (2) Past and ongoing conservation measures and management programs 
for the species, its habitat, or both.
    (3) The potential effects of climate change on habitats.
    We also seek information on the following five threat factors used 
to determine if a species, as defined by the Act, is endangered or 
threatened under section 4(a) of the Act (16 U.S.C. 1531 et seq.):
    (a) The present or threatened destruction, modification, or 
curtailment of its 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.
    Of particular interest to us is information on the potential 
cumulative effects of the five threat factors listed above.
    If, after the status review, we determine that listing the southern 
or Mt. Rainier white-tailed ptarmigan is warranted, we will propose 
critical habitat (see definition in section 3(5)(A) of the Act), in 
accordance with section 4 of the Act, to the maximum extent prudent and 
determinable at the time we propose to list the species. Therefore, we 
also request data and information on:
    (1) What may constitute ``physical or biological features essential 
to the conservation of the species,'' within the geographical range 
currently occupied by the species.
    (2) Where these features are currently found.
    (3) Whether any of these features may require special management 
considerations or protection.
    (4) Specific areas outside the geographical area occupied by the 
species that are ``essential for the conservation of the species.''
    (5) What, if any, critical habitat you think we should propose for 
designation if the species is proposed for listing, and why such 
habitat meets the requirements of section 4 of the Act.
    We will base our 12-month finding on a review of the best 
scientific and commercial information available, including all 
information we receive during this public comment period. Please 
include sufficient information with your submission (such as scientific 
journal articles or other publications) to allow us to verify any 
scientific or commercial information you include.
    Submissions merely stating support for or opposition to the action 
under consideration without providing supporting information, although 
noted, will not be considered in making a determination. Section 
4(b)(1)(A) of the Act directs that determinations as to whether any 
species is an endangered or threatened 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.
    You may submit your information concerning this status review by 
one of the methods 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 personal identifying 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 supporting documentation that we received and used 
in preparing this 90-day finding are available for you to review at 
http://www.regulations.gov, or by appointment, during normal business 
hours, at the U.S. Fish and Wildlife Service, Colorado Ecological 
Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Background

    Section 4(b)(3)(A) of the Act requires that we make a finding on 
whether a petition to list, delist, or reclassify a species presents 
substantial scientific or commercial information indicating 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. 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 scientific or commercial 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 
scientific or commercial information was presented, we are required to 
promptly conduct a species status review, which we subsequently 
summarize in our 12-month finding.

Petition History

    On August 24, 2010, we received a petition of the same date 
prepared by Noah Greenwald for the Center for Biological Diversity 
(petitioner) requesting that we list either the U.S. population or the 
Rocky Mountains population of the white-tailed ptarmigan (Lagopus 
leucura) as threatened and to designate critical habitat. The petition 
clearly identified itself as such and included the requisite 
identification information for the petitioner, as required by 50 CFR 
424.14(a). The petition specifically requested that we list either the 
contiguous U.S. population of white-tailed ptarmigan as a distinct 
population segment or list only the Rocky Mountain population as a 
distinct population segment under the Act. On May 6, 2011, we notified 
the petitioner that we received the petition and requested copies of 
the references cited.
    In a July 20, 2011, letter we informed the petitioner that we had 
reviewed the information presented in the petition and determined that 
each of the requested distinct population segments included multiple, 
recognized subspecies of white-tailed ptarmigan. Therefore, we could 
not accurately evaluate the discreetness and significance criteria for 
the two requested population segments according to our Policy Regarding 
the Recognition of Distinct Vertebrate Population Segments Under the 
Endangered Species Act (61 FR 4722; February 7, 1996). Our letter 
provided the petitioner with an opportunity to amend or revise the 
petition based on our acceptance of the subspecific taxonomic 
designations of white-tailed ptarmigan.
    On September 1, 2011, the petitioner responded by email and 
indicated that they intended to revise their petition

[[Page 33145]]

based on the information that we provided in our July 20 letter. In a 
letter dated October 12, 2011, the petitioner revised their petition to 
request listing of the southern white-tailed ptarmigan and the Mt. 
Rainier white-tailed ptarmigan as threatened. We verified receipt of 
the revised petition by email on October 12, 2011. This finding 
addresses the revised petition.

Previous Federal Actions

    There are no previous Federal actions involving the white-tailed 
ptarmigan or any of the subspecies.

Species Information

Taxonomy
    The white-tailed ptarmigan is a small bird in the order 
Galliformes, family Phasianidae, and the subfamily Tetraoninae, which 
includes the grouse, or ground-feeding game birds (Hoffman 2006, p. 11; 
NatureServe 2011, p. 1). Likely descended from ancestral rock ptarmigan 
(Lagopus muta) isolated during the last ice age (Pleistocene Epoch, 2.6 
million to 12,000 years before present), the white-tailed ptarmigan 
does not hybridize or compete for resources with either the rock or 
willow ptarmigan (L. lagopus) where ranges overlap in the northern part 
of the range (Short 1967, p. 17; Johnsgard 1973, p. 252; Gibbard and 
van Kolfschoten 2004, p. 441; Hoffman 2006, pp. 11, 36). The blue 
grouse (Dendragapus obscurus) shares breeding habitats with the white-
tailed ptarmigan, but hybridization or competition between the species 
has not been documented (Hoffman 2006, pp. 11, 36).
    There are five recognized subspecies of white-tailed ptarmigan in 
North America (American Ornithologists' Union (AOU) 1957, p. 135). The 
southern white-tailed ptarmigan (Lagopus leucura altipetens) occupies 
the Rocky Mountains in Colorado, New Mexico, and historically in 
Wyoming. The Mt. Rainier white-tailed ptarmigan (L. l. rainierensis) 
occupies the Cascade Mountains of Washington. The Kenai white-tailed 
ptarmigan (L. l. peninsularis) extends from Canada into Alaska, and the 
Vancouver white-tailed ptarmigan (L. l. saxatilis) is restricted to 
Vancouver Island in Canada. The northern white-tailed ptarmigan (L. l. 
leucurus) extends from Canada into Montana (Aldrich 1963, p. 542).
    Based on a lack of comparative work, Braun et al. (1993, p. 1) 
questioned the status and validity of the five subspecies of white-
tailed ptarmigan. After examining museum specimens, Braun et al. 
suggested that the southern, Mt. Rainier, and Vancouver white-tailed 
ptarmigans are similar in size and color, whereas the northern and 
Kenai white-tailed ptarmigan are similar in size and color (1993, p. 1; 
Hoffman 2006, p. 11). Braun et al. observed a gradation in size and 
color from south to north, with larger, darker-colored birds in the 
south (1993, p. 1). However, Braun et al. never published their 
results, and, thus, their questioning of the subspecies designations 
has not been subjected to scientific peer review.
    Multiple taxonomic authorities for birds recognize the validity of 
the five subspecies of white-tailed ptarmigan. The AOU recognized the 
five subspecies in their Checklist (1957, p. 135). Since 1957, the AOU 
has not conducted a review of its subspecific distinction and stopped 
listing subspecies as of the 6th edition in 1983. However, the AOU 
recommends the continued use of its 5th edition for taxonomy at the 
subspecific level (1997, p. xii). Based on their 1957 consideration of 
the taxon, the AOU still recognizes the southern and Mt. Rainier white-
tailed ptarmigan as valid subspecies. Additionally, the Integrated 
Taxonomic Information System (ITIS) (2011) and Clements Checklist 
(2011, Version 6.6) also recognize the five subspecies of white-tailed 
ptarmigan. Hoffman (2006, p. 11) and Storch (2007, p. 39) also 
reference the five subspecies. No scientifically peer-reviewed studies 
exist that review or analyze the subspecific designations of white-
tailed ptarmigan.
    We recognize the lack of information, particularly morphological 
and genetic data, regarding the subspecific designations of white-
tailed ptarmigan. We are aware of a proposed study by the U.S. 
Geological Survey that will use genetics to clarify the subspecific 
designations of white-tailed ptarmigan throughout its range. However, 
at the time of this evaluation, the best available scientific and 
commercial information suggests that the five subspecies identified by 
the AOU are valid. Therefore, we accept the taxonomic characterization 
of white-tailed ptarmigan as five subspecies occurring in North 
America.
    The petitioner requests that we list two of the five recognized 
subspecies of white-tailed ptarmigan as threatened: The southern white-
tailed ptarmigan and the Mt. Rainier white-tailed ptarmigan. Section 
3(16) of the Act defines the term ``species'' as any subspecies of fish 
or wildlife or plants, and any distinct population segment of any 
species of vertebrate fish or wildlife which interbreeds when mature. 
After a review of the available taxonomic information, we determine 
that the southern white-tailed ptarmigan and Mt. Rainier white-tailed 
ptarmigan are subspecies and are listable entities under the Act. 
During our status review, we will further evaluate the taxonomic 
classifications of the southern white-tailed ptarmigan and the Mt. 
Rainier white-tailed ptarmigan.
Physical Description
    The southern and Mt. Rainier white-tailed ptarmigans are physically 
similar (Braun et al. 1993, p. 1; Hoffman 2006, p. 11). Both subspecies 
of white-tailed ptarmigan are white in winter and brown in summer, the 
feathers changing color with the seasons to camouflage the birds (Braun 
et al. 1993, p. 1). Although the body feathers change color, the white-
tailed ptarmigan is named for its white tail feathers, which never 
change color. These perpetually white tail feathers distinguish the 
species from other ptarmigan species (Short 1967, p. 17; Braun et al. 
1993, p. 1; Hoffman 2006, p. 12). Males and females share similar body 
size, shape, and winter plumage, with adult body lengths up to 13.4 
inches (34 centimeters) and body masses up to 0.9 pounds (425 grams) 
(Braun et al. 1993, p. 1; Hoffman 2006, p. 12). During the winter, both 
males and females are stark white and difficult to distinguish from 
each other and from the background of snow, except for black eyes, 
black toenails, and a black beak (Braun et al. 1993, p. 1; Hoffman 
2006, p. 12). As the snow melts and the breeding season begins, males 
turn a lighter color of brown or gray than females, and have a dark 
band of feathers on the breast that resembles a necklace (Braun et al. 
1993, p. 1). Both males and females have heavily feathered feet that 
act as snowshoes to support them as they walk across the snow (Braun et 
al. 1993, p. 1).
Life History
    The southern and Mt. Rainier white-tailed ptarmigans share similar 
life histories. During the winter, the southern and Mt. Rainier white-
tailed ptarmigans congregate in flocks and travel to the lowest 
elevations in their respective ranges, seeking areas with soft snow and 
willows (Salix spp.) (Hoffman and Braun 1977, p. 110). During the 
winter, the birds feed on willows that protrude through the snow, and 
dig burrows, or roosts, in the soft snow that provide shelter from 
winter storms (Braun et al. 1993, p. 1; Hoffman 2006, pp. 17, 27). As 
alpine winters transition to spring, the southern and Mt. Rainier 
white-tailed ptarmigans migrate upwards in elevation for breeding and 
nesting to areas that are free of snow and provide access to

[[Page 33146]]

willows by mid-May (Hoffman and Braun 1975, p. 486). After breeding and 
nesting, the southern and Mt. Rainier white-tailed ptarmigans spend the 
summer at the highest elevations of their respective ranges, where 
temperatures are coolest and rocky areas provide protection from 
predators and storms. Summer forage includes willows and other plants 
(May and Braun 1972, p. 1184; Braun et al. 1993, p. 1; Hoffman 2006, p. 
27). The first snowstorm of the season forces the southern and Mt. 
Rainier white-tailed ptarmigans back down to the lower elevations of 
their respective ranges.
    The southern and Mt. Rainier white-tailed ptarmigans spend their 
entire lifecycles in alpine ecosystems and are well adapted to survive 
in cold, arid, and open alpine environments (Johnson 1968, p. 1011; 
Hoffman 2006, p. 12; Storch 2007, p. 4). The color-changing plumage 
effectively camouflages the southern and Mt. Rainier white-tailed 
ptarmigans against white snow in winter and alpine vegetation and rocks 
in the summer (Ligon 1961, p. 87; Braun et al. 1993, p. 1; Martin and 
Forbes 2004, p. 1). The color-changing plumage also alters the 
reflective and absorptive properties of the feathers according to 
season to help the birds regulate body temperature (Hoffman 2006, p. 
31). Metabolic rates are low, allowing the southern and Mt. Rainier 
white-tailed ptarmigans to gain weight during the winter (Hoffman 2006, 
p. 31). Low evaporative efficiencies prevent the loss of body heat 
(Laisiewski et al. 1966, p. 15; Johnson 1968, p. 1010; Hoffman 2006, p. 
31). Additionally, snowshoe-like, feathered feet allow the southern and 
Mt. Rainier ptarmigans to save energy by walking on top of snow rather 
than flying, which is energetically expensive (Storch 2007, p. 4).
Habitat
    The southern and Mt. Rainier white-tailed ptarmigans inhabit alpine 
ecosystems at or above treeline, a transition zone defined as the upper 
elevational edge where wind, cold, and harsh weather prevent the growth 
of trees (Wardle 1974, p. 371). Treeline occurs at elevations around 
11,500 feet (ft) (3,500 meters (m)) above sea level in New Mexico and 
southern Colorado, and 9,500 ft (2,900 m) in Wyoming (Hoffman 2006, p. 
23). Treeline is as low as 6,600 ft (2,000 m) in the North Cascades of 
Washington (Clarke and Johnson 1990, p. 652; Hoffman 2006, p. 23). 
These alpine habitats at or above treeline are characterized by high 
winds, cold temperatures, short vegetation growing seasons, low 
atmospheric oxygen concentrations, and intense solar radiation (Martin 
and Weibe 2004, p. 177; Sandercock et al. 2005, p. 13). The extreme 
topography and harsh climatic conditions of the alpine slows the growth 
of plants (Hoffman 2006, p. 22). Slow growth rates make alpine 
ecosystems sensitive to disturbance, and vegetation may take many years 
to recover from disturbance (Willard and Marr 1970, p. 257). Within 
these open and arid alpine habitats, the southern and Mt. Rainier 
white-tailed ptarmigans prefer rocky areas, dwarfed trees, and 
vegetation near snowfields and streams (Choate 1963, p. 686; Frederick 
and Guti[eacute]rrez 1992, p. 898; Hoffman 2006, p. 23). The southern 
and Mt. Rainier white-tailed ptarmigans make seasonal migrations 
between elevations. Factors affecting their distribution include cool 
temperatures and the presence of exposed rocky areas, soft snow, and 
willows (Hoffman 2006, p. 23).
Distribution, Abundance, and Trends
    Specific population distribution, abundance, and demography 
information is lacking for the white-tailed ptarmigan or any of its 
subspecies, likely a reflection of the difficulty of surveying in often 
remote, high-elevation habitats. Although, at the species level, the 
white-tailed ptarmigan still occupies most of its historical range, 
population estimates are mostly unknown, other than in localized areas 
of study (Braun et al. 1993, p. 2; Hoffman 2006, p. 16). Storch (2007, 
p. 40) estimated a rangewide, spring population of more than 200,000 
birds (for all subspecies of white-tailed ptarmigan). The North 
American Landbird Conservation Plan estimates the global population at 
2,000,000 birds (again, for all subspecies combined) (Rich et al. 2004; 
Hoffman 2006, p. 16); however, Hoffman (2006, p. 16) argues that this 
estimate is likely extremely inflated and may be a reporting error. 
Breeding densities fluctuate between years and locations, ranging from 
5 to 36 birds per square mile (sq mi) (2 to 14 birds per square 
kilometer (sq km)) (Hoffman 2006, p. 16). Most populations are probably 
stable and secure; however, localized populations may be at risk 
(Storch 2007, p. 152). NatureServe ranks the white-tailed ptarmigan as 
``secure'' rangewide (2011, p. 1). The International Union for 
Conservation of Nature (IUCN) ranks the white-tailed ptarmigan as a 
species of ``least concern'' (IUCN 2011, p. 1). Within the U.S. Forest 
Service (USFS) Rocky Mountain Region, Hoffman states that populations 
of white-tailed ptarmigan are stable, and are in no immediate jeopardy 
of declining (2006, p. 40). However, these rankings are for the species 
as a whole, and do not evaluate the status of the individual subspecies 
of the white-tailed ptarmigan.
    The white-tailed ptarmigan is endemic to alpine habitats in western 
North America and is the only species of ptarmigan whose range extends 
south of Canada (Aldrich 1963, p. 543; AOU 1998, p. 120; Hoffman 2006, 
p. 12). The southern white-tailed ptarmigan inhabits alpine areas in 
the Rocky Mountains of Colorado and New Mexico, but is likely not found 
in Wyoming (Hoffman 2006, p. 13). The Mt. Rainier white-tailed 
ptarmigan inhabits the northern Cascade Mountains of Washington, but 
there are no published accounts of the Mt. Rainier white-tailed 
ptarmigan in the Olympic Mountains in the northwestern part of the 
State (Hoffman 2006, p. 12). There are no verified records of white-
tailed ptarmigan in Idaho, Oregon, California, or Utah (Gabrielson and 
Jewett 1940, p. 602; Aldrich 1963, pp. 541, 543; Braun et al. 1993, p. 
1; Gilligan et al. 1994, p. 86; Hoffman 2006, p. 12). The historical 
absence of white-tailed ptarmigan from apparently suitable alpine 
habitats in Oregon, California, Utah, and the Olympic Mountains in 
Washington is due to long distances to the nearest occupied ranges 
(Hoffman 2006, p. 12). A lack of suitable alpine habitats explains the 
absence of ptarmigan in Idaho (Hoffman 2006, p. 12).
    In Colorado, the southern white-tailed ptarmigan lives in all 
available alpine areas, except in the Spanish Peaks and Greenhorn 
Mountain in the southern part of the State (Braun et al. 1993, p. 1). 
Colorado supports the largest population of white-tailed ptarmigan in 
the United States outside of Alaska, with a statewide breeding 
population estimated at 34,800 birds (Hoffman 2006, pp. 15, 16). At 
Rocky Mountain National Park (RMNP) and Mt. Evans in Colorado, Braun et 
al. (1993, p. 1) reported breeding densities of 11.7 to 35.0 birds per 
sq mi (4.5 to 13.5 birds per sq km) and 5.2 to 26.7 birds per sq mi 
(2.0 to 10.3 birds per sq km), respectively (Hoffman 2006, p. 11).
    In New Mexico, the southern white-tailed ptarmigan historically 
inhabited all the ridges and peaks above timberline within the Sangre 
de Cristo Mountains, but by the mid-1900s, it was found only on the 
northernmost peaks (Ligon 1961, p. 87; New Mexico Department of Game 
and Fish (NMDGF) 2008, p. 87). Following declines in the southernmost 
peaks, the NMDGF listed the white-tailed ptarmigan as endangered in 
1975 (NMGFD 2008, p. 87). Recent observations and reports

[[Page 33147]]

suggest that the reintroduction of white-tailed ptarmigan into the 
southern peaks of the Sangre de Cristo Mountains was successful, and 
that populations have persisted on the northernmost peaks (NMDGF 2008, 
p. 87). Coordinated surveys of all suitable habitats within the Sangre 
de Cristo Mountains are needed to document the current distribution and 
abundance of white-tailed ptarmigan in New Mexico (NMDGF 2008, p. 88).
    The southern white-tailed ptarmigan appears to be absent from most 
alpine habitats in Wyoming, except possibly for the Snowy Range in the 
southern part of the State (Hoffman 2006, p. 15). Anecdotal reports 
suggest the southern white-tailed ptarmigan persists in the Snowy 
Range, but there have been no confirmed sightings since the early 1970s 
and the available habitats are limited (Hoffman 2006, p. 15). The 
Medicine Bow National Forest in southern Wyoming considers the white-
tailed ptarmigan to be present historically but currently extirpated 
from the Snowy Range (USFS 2003, pp. 3, 154; Hoffman 2006, p. 15).
    There is little information available regarding the distribution, 
abundance, or trends of the Mt. Rainier white-tailed ptarmigan in the 
Cascade Mountains of Washington (Smith et al. 1997, p. 140). No studies 
have been conducted in Washington other than general monitoring and 
surveys to determine presence or absence (Hoffman 2006, p. 8). There 
are no population estimates and no published accounts for the white-
tailed ptarmigan in the Olympic Mountains of northwestern Washington 
(Hoffman 2006, p. 12). The Mt. Rainier white-tailed ptarmigan inhabits 
the North Cascades but not the South Cascades, primarily due to the 
lack of suitable alpine areas for dispersal and colonization in the 
south (Clark and Johnson 1990, p. 652).
    Researchers successfully translocated white-tailed ptarmigan in the 
Sierra Nevada Mountains of California, the Uinta Mountains in Utah, 
Pike's Peak in Colorado, and the Pecos Wilderness in New Mexico (Braun 
et al. 1993, p. 1; Hoffman 2006, p. 13). Reports indicate that 
ptarmigans still exist in these translocation areas (Braun et al. 1978, 
p. 665; NMDGF 2006, p. 79; Hoffman 2006, p. 13). However, a 
translocation attempt in the Wallowa Mountains in northeastern Oregon 
was unsuccessful when the introduced population did not survive (Braun 
et al. 1993, p. 1; Marshall et al. 2003, p. 618; Hoffman 2006, p. 13).

Evaluation of Information for This Finding

    Section 4 of the Act (16 U.S.C 1533) and its implementing 
regulations at 50 CFR part 424 set forth the procedures for adding a 
species to, or removing a species from, 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 its 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.
    In considering what factors might constitute threats, we must look 
beyond the mere exposure of the species to the factor to determine 
whether the species responds to the factor in a way that causes actual 
impacts to the species. If there is exposure to a factor, but no 
response, or only a positive response, that factor is not a threat. If 
there is exposure and the species responds negatively, the factor may 
be a threat and we then attempt to determine how significant a threat 
it is. If the threat is significant, it may drive or contribute to the 
risk of extinction of the species such that the species may meet the 
definition of endangered or threatened under the Act. This does not 
necessarily require empirical proof of a threat. The combination of 
exposure and some corroborating evidence of how the species is likely 
impacted could suffice. The mere identification of factors that could 
impact a species negatively may not be sufficient to compel a 
substantial finding. The information shall contain evidence sufficient 
to suggest that these factors may be operative threats that act on the 
species to the point that the species may meet the definition of 
endangered or threatened under the Act.
    In making this 90-day finding, we evaluated whether information 
regarding threats to the southern white-tailed ptarmigan and the Mt. 
Rainier white-tailed ptarmigan, as presented in the petition and other 
information available in our files, is substantial, thereby indicating 
that the petitioned action may be warranted. Our evaluation of this 
information is presented below.

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

    The petitioner asserts that threats causing the present or 
threatened destruction, modification, or curtailment of habitat or 
range for the southern and Mt. Rainier white-tailed ptarmigans include 
global climate change, recreation, livestock grazing, and mining. These 
assertions are described in more detail below.
Global Climate Change
    Information Provided in the Petition--The petitioner asserts that 
global climate change is the greatest threat to the survival of the 
southern and Mt. Rainier white-tailed ptarmigans in the United States. 
The petitioner claims that the white-tailed ptarmigan depends on open 
alpine habitats, willow as its main food source, soft snow in which to 
burrow, and cool temperatures to which it is uniquely adapted. The 
petitioner also asserts that these subspecies are physiologically 
underequipped to cope with rising temperatures associated with global 
climate change. Because these are physiological effects rather than 
effects to habitat, we discuss these assertions under Factor E.
    The petitioner asserts that the loss of alpine habitats to global 
climate change threatens the southern and Mt. Rainier white-tailed 
ptarmigans, and provides several citations to support these claims. 
Foremost amongst these are the various publications of the 
Intergovernmental Panel on Climate Change (IPCC), specifically the 
four-volume IPCC Fourth Assessment Report: Climate Change 2007 and the 
Copenhagen Diagnosis, 2009: Updating the World on the Latest Climate 
Science (IPCC 2007, p. iii; 2009, p. 1). The Copenhagen Diagnosis 
summarizes research regarding the accumulation of carbon dioxide in the 
atmosphere and the resulting greenhouse effect that contributes to 
global warming. The IPCC also summarized changes in the amount, 
intensity, frequency, and type of precipitation associated with warming 
global temperatures (Trenberth et al. 2007, p. 262).
    The petitioner alleges that several of the effects of climate 
change threaten the white-tailed ptarmigan. The petition presents 
research indicating that mountaintops and their alpine ecosystems are 
especially sensitive to changes in climate (Hougton et al. 1995 and 
1996; Pepin 2000, p. 135; Beniston et al. 1997, p. 233; Kullman 2002, 
p. 68). The petitioner presents research indicating that the greater 
photosynthetic efficiency of alpine

[[Page 33148]]

plants coupled with more carbon dioxide in the atmosphere suggests that 
overall changes in vegetation will be especially dramatic in alpine 
habitats (Korner and Diemer 1994, p. 58; Hoffman 2006, p. 46). 
Additionally, warming temperatures will shift treelines upwards in 
elevation, reducing available alpine habitats (Markham et al. 1993, p. 
65; Root et al. 2003, p. 57; Hoffman 2006, pp. 3, 46). Warmer winter 
temperatures also suggest that a higher percentage of total 
precipitation will fall as rain rather than snow (Mote 2003, p. 1; Mote 
2005, p. 39; Knowles et al. 2006, p. 4545; Karl et al. 2009, pp. 24, 
135), which the petitioner argues may further reduce available alpine 
habitats for both subspecies.
    After summarizing current research on global climate change, the 
petitioner provides research that forecasts the range of the white-
tailed ptarmigan under several, predicted climate scenarios (Lawler et 
al. 2009, pp. 591-593). The petitioner predicts that the current 
northern range of the white-tailed ptarmigan will contract, and the 
species will be eliminated from the contiguous United States by year 
2061, citing Lawler et al. (2009, appendix e) to support this claim.
    Furthermore, the petitioner claims that climate change has already 
occurred and is predicted to continue within the range of the southern 
and Mt. Rainier white-tailed ptarmigans in the United States. The 
petitioner summarizes research indicating that temperatures in Colorado 
have increased significantly more than the average for the western 
United States (Ray et al. 2008, pp. 5, 10, 11, 21, 29). The references 
presented by the petitioner indicate that Colorado will experience few 
extreme cold months, more extreme warm months, with more consecutive 
warm winters (Ray et al. 2008, p. 29). The petitioner also presents 
evidence of ongoing climatic warming within the range of the Mt. 
Rainier white-tailed ptarmigan in the Cascade Mountains of Washington 
(Karl et al. 2009, pp. 135-136).
    The petitioner presents research that global climate change, 
through increasing temperatures, also will affect the elevation of 
treeline, citing studies that document the advancement of treeline 
upslope (Wang et al. 2002b, p. 82; Grace et al. 2002, p. 540; Millar et 
al. 2004, p. 181; Stohlgren and Baron 2003, p. 1; Hoffman 2006, p. 45). 
The petitioner deduces that the upslope migration of trees and the 
expansion of forest will compress and fragment white-tailed ptarmigan 
habitats (Wang et al. 2002b, p. 82; Hoffman 2006, p. 45).
    Finally, the petitioner presents research that changes will occur 
to the alpine plant communities bounded by the encroaching treeline 
because of global climate change (Hoffman 2006, p. 46; Cannone et al. 
2007, p. 360). Although the exact changes to vegetation communities are 
uncertain, the petitioner reasons that the changes will be significant 
to the alpine habitats of the white-tailed ptarmigan. The petitioner 
also suggests that changed snowfall patterns will alter and reduce the 
availability of vegetation features important to the white-tailed 
ptarmigan, such as wet meadows below late-lying snowfields that are 
used by females to raise broods (Hoffman 2006, p. 46).
    The petitioner concludes that global warming is the greatest threat 
to the survival of the white-tailed ptarmigan because of the loss and 
fragmentation of alpine habitats, the upslope advancement of treeline, 
and other changes to alpine plant communities.
    Evaluation of Information in the Petition and Available in Service 
Files--Climatic and species models referenced by the petitioner suggest 
that the white-tailed ptarmigan may be completely extirpated from its 
current range within the United States with more than a 90 percent 
model agreement under low and high carbon dioxide emission scenarios 
(Lawler et al. 2009, appendix e). Therefore, the petitioner concludes 
that global warming modifies and curtails the range of the white-tailed 
ptarmigan in the United States, restricting the species to any 
remaining alpine habitats in Alaska and Canada, resulting in local 
extirpations, and threatening both subspecies. Although the 
complexities of modeling often confound the predicted species 
distributions and loss of habitats attributed to global climate change, 
the information presented by the petition and available in our files 
indicates that global climate change may curtail the range of the 
southern or Mt. Rainier white-tailed ptarmigan, potentially resulting 
in the extirpation of both subspecies from the contiguous United 
States.
    The petitioner cites information indicating that climatic warming 
has occurred within the range of the southern and Mt. Rainier white-
tailed ptarmigans. Over the past 30 years, temperatures in Colorado 
increased by 1.9 [deg]F (1.1 [deg]C), twice the average increase for 
the entire western United States for the same time period (Ray et al. 
2008, pp. 10, 21). Ray et al. expect Colorado to warm by 3.96 [deg]F 
(2.2 [deg]C) by 2050, with winter temperatures increasing by 3.06 
[deg]F (1.7 [deg]C) (Ray et al. 2008, pp. 5, 11, 29). Summer 
temperatures also are expected to increase in Colorado, with predicted 
increases of 5.04 [deg]F (2.8 [deg]C) (Ray et al. 2008, p. 29). Climate 
models for Washington State project increases in annual average 
temperatures of 5.22 [deg]F (2.9 [deg]C) by 2080 (Littell et al. 2009, 
pp. 33, 199). This report also illustrated an increase of 1.44 [deg]F 
(0.8 [deg]C) for Washington since 1920 (Littell et al. 2009, pp. 39, 
199). In the Pacific Northwest, spring snowpack has declined by 
approximately 40 percent since the mid-20th century and is consistent 
with observed increases in global temperature (Mote 2003, p. 2). Payne 
et al. (2004, p. 243) predict further declines in the spring snowpack 
of the Cascade Mountains by as much as 40 percent by the year 2040. 
These studies indicate that temperatures are increasing, and may be a 
result of global climate change within the range of the southern and 
Mt. Rainier white-tailed ptarmigans.
    Furthermore, we evaluated the claims and references provided by the 
petitioner regarding the response of treeline to warming temperatures 
and the potential impact on alpine environments. For certain areas of 
the RMNP in Colorado, krummholz (wind-trimmed, low-growing) trees are 
moving upslope at an average rate of 3.3 ft (1 m) per 27 years 
(Stohlgren and Baron 2003, p. 1). The researchers predicted that at 
certain sites, the krummholz could develop into forests in response to 
environmental factors, such as temperature and soil moisture. If 
unchecked, the researchers predicted that the developing forests would 
invade alpine ecosystems, thereby reducing the diversity of understory 
plants and habitat for alpine wildlife (Stohlgren and Baron 2003, p. 
1). Based on predicted increases in temperature, Grace et al. (2002, p. 
540) similarly predicted the advancement of treeline upwards and the 
subsequent invasion of trees into alpine meadows. Forest expansion has 
occurred to similar alpine habitats in the Arctic and Alaska (Millar et 
al. 2004, p. 181). Available studies also suggest that small increments 
of 1.8 to 3.6 [deg]F (1 to 2 [deg]C) of warming may result in changes 
to the dynamics of vegetation communities in the alpine (Korner and 
Diemer 1994, p. 58; Hoffman 2006, p. 46; Cannone et al. 2007, p. 360). 
The response of plants to increased levels of atmospheric carbon 
dioxide and shifts in precipitation patterns may impact the 
distribution of willow and other important ptarmigan food plants 
(Hoffman 2006, p. 46).
    Although it is unclear exactly how alpine vegetation communities 
will respond to a warming climate, the cited references indicate that 
the upslope

[[Page 33149]]

migration of treeline, the expansion of subalpine forests, and changes 
to alpine plant communities may occur. Cumulatively, these changes may 
reduce the alpine habitats available to the southern and Mt. Rainier 
white-tailed ptarmigans; however, the magnitude of this loss is 
undeterminable based on our review of the information in the petition 
and in our files.
    Based on the results of the empirical studies cited by the 
petitioner and information available in our files, along with 
predictions of increasing air temperatures, decreasing snow packs, and 
predicted changes to white-tailed ptarmigan habitats and distribution 
of food plants, we find that the ranges of the southern white-tailed 
ptarmigan and the Mt. Rainier white-tailed ptarmigans and the alpine 
habitats within these ranges may decrease as a result of global climate 
change. Therefore, we find that the petition and information in our 
files present substantial information to indicate that the predicted 
changes in habitat due to the effects of climate change may be a threat 
to the southern white-tailed ptarmigan and the Mt. Rainier white-tailed 
ptarmigan. We discuss potential physiological and behavioral effects of 
a warming climate under Factor E, below.
Recreation
    Information Provided in the Petition--The petitioner asserts that 
recreational activities (specifically hiking, off-road vehicle (ORV) 
use, and skiing) destroy alpine habitats and directly disturb the 
southern and Mt. Rainier white-tailed ptarmigans. The petitioner 
provides citations indicating that various recreational activities 
occur within alpine habitats and that, in Colorado, these activities 
have increased in popularity over time (Hesse 2000, p. 68; Ebersole et 
al. 2002, p. 101). The petitioner asserts that these activities can 
adversely affect habitats of the southern and Mt. Rainier white-tailed 
ptarmigans via: (1) Hikers trampling alpine vegetation; (2) the 
erosion, slumping, soil compaction, snow compaction, and vegetation 
damage from ORV use, including snowmobiles; and (3) the compaction of 
snow and loss of willows by skiers and snowmaking machines at ski 
areas. The petitioner provides citations to several sources that 
describe the impacts of trampling and ORV use on slow-growing alpine 
vegetation (Willard and Marr 1971, p. 257; Lodico 1973, entire; 
Ebersole et al. 2002, p. 101; Hoffman 2006, p. 43). The petitioner also 
provides one reference that speaks generally to the historical impacts 
of recreation on alpine habitats (Brown et al. 1978b, pp. 23-44). The 
petitioner cites 27 biological evaluations (BEs) prepared by the USFS 
in the Rocky Mountain Region that concluded that recreational projects 
may affect individual white-tailed ptarmigan, but would not cause a 
trend towards Federal listing, a standard for BEs described by the 
USFS's operational manual regarding sensitive species (USFS 2011, p. 3, 
5).
    The petitioner suggests that hikers may wander off trails, trample 
alpine vegetation, and create new trails, with lasting damage to 
vegetation occurring (Hoffman 2006, p. 43). The petitioner also asserts 
that snowmobiles are especially dangerous to the white-tailed ptarmigan 
because they may occasionally collide with and kill the birds. 
Additionally, the petitioner stresses that noise and activity 
associated with snowmobiles may disturb the birds and cause them to 
leave their optimal feeding and roosting sites, exposing the birds to 
predation (Hoffman 2006, p. 44).
    The petitioner cites Braun et al. (1976, p. 9) to report that 
white-tailed ptarmigan exist within ski areas, but to a lesser extent, 
because of development. However, the petitioner reasons that skiers 
repeatedly displace white-tailed ptarmigans and force them to 
unnecessarily expend extra energy. Additionally, the petitioner 
suggests that skiers and grooming machines may damage willows while 
snowmaking operations may cover any remaining willows, rendering them 
inaccessible to the white-tailed ptarmigan. The petitioner argues that 
skiers and grooming machines also may compact soft snow and make it 
unsuitable for roosting (Hoffman 2006, p. 44). Finally, the petitioner 
asserts that the development of ski areas results in habitat loss and 
may increase predation, which we discuss below under Factor C.
    Evaluation of Information in the Petition and Available in Service 
Files--Recreational activities occur within the alpine habitats of the 
southern and Mt. Rainier white-tailed ptarmigans. However, the 
probability of humans interacting with either subspecies or their 
habitats remains relatively low, because the severe environment and low 
productivity of the alpine zone have deterred human use and habitation 
(Hoffman 2006, p. 41). When recreation occurs in alpine habitats, the 
effects of trampling, ORVs, skiing, and other forms of recreation on 
slow-growing alpine vegetation are well documented (Willard and Marr 
1971, p. 257; Billings 1973, p. 703; Lodico 1973, entire; Ebersole et 
al. 2002, p. 101). However, we are unaware of any information to 
indicate that recreational activities may be a threat to the habitats 
or the range of the southern or Mt. Rainier white-tailed ptarmigan.
    Although hikers may trample vegetation, ORVs may erode soils, and 
skiers or grooming machines may compact snow or cover willows, the 
references cited by the petitioner and available in our files describe 
only anecdotal and isolated impacts from recreation to the habitats of 
the southern and Mt. Rainier white-tailed ptarmigans. While 
recreational use of the alpine habitat has increased over time in 
Colorado, the references cited by the petitioner and available in our 
files do not indicate recreation is occurring at levels that impact the 
habitats or range of the southern and Mt. Rainier white-tailed 
ptarmigans. We have no specific information, nor did the petitioner 
provide any information, regarding recreational use within the range of 
the Mt. Rainier white-tailed ptarmigan in Washington. Furthermore, the 
cited references provide no information, and we found no information, 
that winter recreational activities compact soft snow to an extent that 
impedes the construction of snow roosts or limits the availability of 
willows such that the southern or Mt. Rainier white-tailed ptarmigan is 
unable to seek shelter or feed during the winter. Similarly, the cited 
references provide no information to suggest that the development of 
ski areas has destroyed, modified, or curtailed the habitats or range 
of either of the petitioned subspecies. We have no information and the 
petitioner provided no information regarding ski area development in 
Washington and potential impacts to the Mt. Rainier white-tailed 
ptarmigan.
    Additionally, while recreationists in alpine areas may interact 
with and occasionally disturb ptarmigan, the cited references and 
information in our files provide only anecdotal evidence of this 
interaction or disturbance. The references do not suggest that the 
southern and Mt. Rainier white-tailed ptarmigans abandon habitats after 
being disturbed or that ORVs kill birds in any scope or scale that 
result in population-level impacts. We found no evidence that 
ptarmigans abandon sites frequented by motorized vehicles. However, 
ptarmigans may temporarily move away if disturbed and are occasionally 
killed by collisions (Hoffman 2006, p. 44). The petitioner cites USFS 
BEs that concluded that recreation projects may affect the white-tailed 
ptarmigan in the Rocky Mountain Region, although these BEs concluded 
that the activities would not contribute to loss of viability or lead 
to a trend

[[Page 33150]]

towards Federal listing. There is also no evidence that these impacts 
actually occurred or represent a threat to the southern white-tailed 
ptarmigan. Therefore, we find that the petition and information in our 
files do not present substantial scientific or commercial information 
to indicate that habitat impacts due to recreational activities may be 
a threat to the southern or Mt. Rainier white-tailed ptarmigan.
Livestock and Native Ungulate Grazing
    Information Provided in the Petition--The petitioner asserts that 
livestock grazing, as well as grazing by overabundant native ungulates, 
threatens the southern and Mt. Rainier white-tailed ptarmigans by 
impacting habitats and reducing the availability of food. The 
petitioner asserts that livestock grazing is the dominant land use 
within the range of the southern and Mt. Rainier white-tailed 
ptarmigans in the United States and provides references demonstrating 
that grazing can affect natural communities by removing vegetation, 
adjusting the structure of plant communities, and trampling or 
compacting soils (Fleischner 1994, p. 629; Krueper et al. 2003, p. 608; 
Hoffman 2006, p. 42). The petitioner also asserts that livestock 
grazing changes the availability of water, alters the diversity of 
plant species, and disrupts nutrient cycling and community succession; 
the petitioner presents references in support of those assertions 
(Fleischner 1994, pp. 631-634; Fleischner 2010, p. 242). The petitioner 
provides references to indicate that cattle grazing may impact the 
breeding success of nesting birds in riparian and forested ecosystems 
below treeline (Ammon and Stacey 1997, pp. 7, 11, 12; Walsberg 2005, p. 
715).
    However, the petitioner recognizes that cattle are poorly adapted 
to the alpine habitats of the white-tailed ptarmigan and are not a 
major influence on alpine areas (Alexander and Jensen 1959, pp. 680-
689; Thilenius 1975, pp. 15, 28). Where cattle cannot graze, the 
petitioner asserts that grazing by sheep has deleterious effects on 
alpine ecosystems, including the creation of trails, trampling of 
vegetation, and overgrazing, resulting in considerable damage to alpine 
habitats (Thilenius 1975, p. 28; Hoffman 2006, p. 42). Extended and 
concentrated grazing periods, coupled with the long recovery times of 
alpine ecosystems, have had a significant impact on the structure and 
function of many alpine areas (Thilenius 1975, p. 15; Hoffman 2006, p. 
42). Additionally, sheep feed on many of the same plants as the white-
tailed ptarmigan (Hoffman 2006, p. 42). As a result, the petitioner 
concludes that sheep compete with the white-tailed ptarmigan for food 
where they overlap.
    The petitioner cites 13 BEs prepared by the USFS in the Rocky 
Mountain Region that determined that grazing sheep may adversely affect 
the white-tailed ptarmigan, but would not lead to a trend towards 
Federal listing. Potential effects analyzed in the BEs included sheep 
crushing birds or eggs, disturbance or mortality caused by herds or 
working dogs, and the loss of habitat from overgrazing by sheep. The 
petitioner also reports that the southern white-tailed ptarmigan also 
may alter its movement behaviors in heavily grazed areas of the Rocky 
Mountains (Hoffman 2006, p. 26).
    Native ungulates also graze in alpine areas, and the petitioner 
asserts that, like sheep, they too may impact the habitats of the 
southern and Mt. Rainier white-tailed ptarmigans. The petitioner 
indicates that populations of elk (Cervus elaphus) have grown 
dramatically in the contiguous United States as natural predators 
disappeared and States enforced game laws (Hoffman 2006, pp. 36, 42). 
Consequently, the petitioner states that elk graze in alpine ranges 
more frequently during all seasons of the year (Hoffman 2006, p. 42). 
The petitioner cites one study that determined that willow habitats 
found below treeline that are overgrazed by elk typically convert into 
shrub-steppe habitats (Anderson 2007, pp. 401, 406). Although this 
study focused on low-elevation, riparian habitats outside of the range 
of either white-tailed ptarmigan subspecies, the petitioner predicts 
that if alpine willow habitats above treeline are overgrazed by elk, 
they too will turn into unfavorable shrub-steppe habitats.
    The petitioner concludes that grazing by livestock and native 
ungulates impacts white-tailed ptarmigan habitats, reduces the 
availability of willows, and forces changes in migration patterns.
    Evaluation of Information in the Petition and Available in Service 
Files--Although the effects of livestock grazing on natural ecosystems 
are well documented, the cited references and information in our files 
do not address the impacts of cattle grazing on the southern and Mt. 
Rainier white-tailed ptarmigans or their habitats. Cattle are not 
generally a major influence in alpine environments, and while grazing 
allotments for cattle may include alpine areas in the Rocky Mountains, 
cattle are poorly adapted to high-elevation, alpine environments and, 
therefore, are not likely to persist or overgraze in white-tailed 
ptarmigan habitats. Where cattle grazing occurs in the alpine, the 
references cited by the petitioner provide no evidence to conclude that 
cattle have negatively impacted either subspecies of white-tailed 
ptarmigan or their habitats. The petitioner provided no information and 
we have no information in our files regarding cattle grazing in 
Washington within the range of the Mt. Rainier white-tailed ptarmigan.
    Sheep are more tolerant of alpine environments than cattle and can 
graze in white-tailed ptarmigan habitats. Although the petitioner cites 
USFS BEs identifying potential impacts to white-tailed ptarmigan and 
their habitats in the Rocky Mountains from sheep grazing, these BEs 
determined that grazing would not contribute to a loss of viability or 
lead to a trend towards Federal listing. The petitioner provided no 
evidence and we have no information to indicate that the impacts 
evaluated by the BEs actually occurred or that they may threaten the 
subspecies. The petitioner provided no information and we have no 
information in our files regarding sheep grazing and the Mt. Rainier 
white-tailed ptarmigan in Washington. While sheep may feed on the same 
willows and other alpine plants as the white-tailed ptarmigan, we found 
no information to support that competition for food between sheep and 
ptarmigans negatively impacts either subspecies. Additionally, although 
the petitioner cites anecdotal observations that ptarmigans may move 
away from heavily grazed areas, the cited references and information in 
our files do not provide evidence that this movement or disruption may 
be a threat to either subspecies.
    Finally, we found no evidence to conclude that elk overgraze on 
alpine vegetation at any time of the year such that either subspecies 
may show a negative response. The petitioner asserts that elk use of 
the alpine has increased during all seasons of the year, but elk 
generally move down to lower elevations during the winter (Fitzgerald 
et al. 1994, p. 385). At these lower wintering elevations, elk are more 
removed from ptarmigans and their alpine habitats when the birds are 
congregating in their snow-covered wintering areas and feeding on 
willow. Similarly, we have no information in our files nor does the 
petitioner provide information to indicate that alpine willow habitats 
that are overgrazed by elk change into shrub-steppe habitats that may 
be unfavorable to the southern or Mt. Rainier white-tailed ptarmigan, 
or grazed to the extent to which either population of the subspecies 
may be negatively impacted. Finally, the petitioner provided no 
information and

[[Page 33151]]

we have no information in our files regarding elk grazing in the alpine 
habitats of the Mt. Rainier white-tailed ptarmigan or any potential 
impacts to the subspecies. Therefore, we find that the petition and 
information in our files do not present substantial scientific or 
commercial information to indicate that habitat impacts attributed to 
grazing may be a threat to the southern or Mt. Rainier white-tailed 
ptarmigan.
Mining
    Information Provided in the Petition--The petitioner asserts that 
mining has destroyed alpine habitats and that pollutants from abandoned 
mines threaten the southern and Mt. Rainier white-tailed ptarmigans. 
Compared to recreation and grazing, the petitioner considers mining the 
most destructive human activity in alpine habitats and provides 
evidence where mining historically degraded alpine ecosystems, damaged 
soils, destroyed vegetation, and polluted watersheds in the Rocky 
Mountains (Brown et al. 1978, p. 23; Chambers 1997, p. 161; Macyk 2000, 
p. 537; Clements et al. 2000, p. 626). The petitioner also presents 
research showing that white-tailed ptarmigans are susceptible to toxic 
pollutants leeching from abandoned mines that have not been properly 
reclaimed (Larison et al. 2000, p. 181). In southwestern Colorado, the 
southern white-tailed ptarmigan exhibited calcium deficiencies, skewed 
sex ratios, and other physiological effects after eating willows 
contaminated with cadmium, a toxic heavy metal found at abandoned mines 
(Larison et al. 2000, p. 181). The petitioner also cites two BEs 
prepared by the USFS in Colorado that determined that vehicles operated 
at mines could drive over nests, crush eggs, and disturb the summer 
foraging habitats of the white-tailed ptarmigan.
    Evaluation of Information in the Petition and Available in Service 
Files--In the Rocky Mountains, historic and current mining operations 
occurred within the range of the southern white-tailed ptarmigan and 
may have reduced available habitats. However, the available information 
cited by the petitioner and available in our files does not indicate 
that these mining operations significantly reduced or fragmented 
habitats to an extent that the southern white-tailed ptarmigan has 
shown a negative population response. Although the petitioner cites 
USFS BEs that determined impacts to the white-tailed ptarmigan would 
occur at mines in the Rocky Mountain Region, these evaluations also 
determined that the mining operations would not contribute to a loss of 
viability or lead to a trend towards Federal listing. We have no 
information to indicate that these impacts actually occurred or that 
the southern white-tailed ptarmigan exhibited a negative population 
response as a result. Additionally, cadmium poisoning in white-tailed 
ptarmigan has only been observed in improperly reclaimed mines within 
the ore-belt of southwestern Colorado; there is no evidence of cadmium 
poisoning elsewhere in the Rocky Mountains or Washington (Hoffman 2006, 
p. 47). While ptarmigan in the ore-belt of southwestern Colorado may be 
poisoned after eating contaminated willows, we found no information to 
conclude that this occurs at a level that impacts the subspecies. 
Finally, the petitioner provided no information and we have no 
information regarding mining or potential effects within the range of 
the Mt. Rainier white-tailed ptarmigan in Washington. Therefore, we 
find that the petition and information in our files do not present 
substantial scientific or commercial information to indicate that 
habitat impacts due to mining activities may be a threat to the 
southern or Mt. Rainier white-tailed ptarmigan.
Summary of Factor A
    Based on the information provided in the petition, as well as other 
information readily available in our files, we find that the petition 
presents substantial scientific or commercial information indicating 
that the southern white-tailed ptarmigan and Mt. Rainier white-tailed 
ptarmigan may warrant listing due to the present or threatened 
destruction, modification, or curtailment of the species' habitat or 
range as a result of the habitat changes brought about by the effects 
of global climate change. We find that the petition does not present 
substantial scientific or commercial information indicating that the 
southern or Mt. Rainier white-tailed ptarmigan may warrant listing due 
to the present or threatened destruction, modification, or curtailment 
of the species' habitat or range from recreation, livestock grazing, or 
mining. However, we will more fully evaluate these activities in our 
status review.

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

Information Provided in the Petition
    The petitioner claims that hunting threatens the white-tailed 
ptarmigan and provides general background information on ptarmigan 
hunting regulations in the United States. Hunting of white-tailed 
ptarmigan is legal in Alaska, Colorado, Utah, and California (Hoffman 
2006, p. 47). The white-tailed ptarmigan is not hunted in New Mexico, 
Montana, Wyoming, or Washington. The petitioner reports that the 
current threat of hunting to white-tailed ptarmigan populations is 
localized, and, therefore, populations may be susceptible to 
overharvest based on a variety of factors. The petitioner indicates 
that white-tailed ptarmigans are unwary, congregate in large flocks, 
and return to habitats even after they are repeatedly disturbed. The 
petitioner asserts that this behavior may make the birds easy to hunt. 
The petitioner also explains that approximately 95 percent of the 
occupied range of the southern white-tailed ptarmigan in Colorado is 
publicly owned and open to hunting (Hoffman 2006, p. 9). Much of this 
occupied range is close to metropolitan areas and accessible to 
hunters. The petitioner also reports that declining populations of 
other grouse species are causing a renewed interest in the white-tailed 
ptarmigan among hunters. Additionally, where brood habitat is limited 
and occurs along rocky areas, female white-tailed ptarmigans may be 
easier to detect than males, easier to hunt, and more susceptible to 
hunting mortality (Sandercock et al. 2005, p. 22; Hoffman 2006, p. 47).
    The petitioner cites a dissertation that estimated a 15 to 27 
percent higher mortality rate in hunted white-tailed ptarmigan 
populations, which suggested that hunting results in additive mortality 
(Hoffman 2006, p. 47). However, the petitioner argues that population 
declines of white-tailed ptarmigan associated with hunting may not be 
readily apparent. The petitioner cites a study on willow grouse 
(Lagopus lagopus lagopus) in Sweden and a study on ruffed grouse 
(Bonasa umbellus) in Wisconsin to explain that immigration from non-
hunted or lightly hunted populations may sustain breeding densities of 
white-tailed ptarmigan in heavily hunted areas (Small et al. 1991, p. 
512; Smith and Willebrand 1999, p. 722; Hoffman 2006, p. 47). The 
petitioner reasons that because breeding densities for other species of 
grouse remain stable with immigration, the effects of hunting on white-
tailed ptarmigan populations may be difficult to detect.
Evaluation of Information in the Petition and Available in Service 
Files
    Wyoming classifies the southern white-tailed ptarmigan as a game 
bird, but does not permit hunting due to its restricted distribution 
and small population size in the State (Braun et al. 1993, p. 1; 
Hoffman 2006, p. 10). New

[[Page 33152]]

Mexico also does not permit hunting of the southern white-tailed 
ptarmigan. Similarly, Washington does not permit hunting of the Mt. 
Rainier white-tailed ptarmigan. In the States where hunting is not 
permitted, the petitioner provided no information and we have no 
information in our files to suggest that illegal hunting may be a 
threat to either the southern or Mt. Rainier white-tailed ptarmigan.
    Colorado permits the legal hunting of the southern white-tailed 
ptarmigan. In Colorado, daily bag and possession limits are 3 and 6 
birds, respectively, and the hunting season is 23 days long, commencing 
in mid-September when young ptarmigans have reached adulthood and can 
survive independently from the brood hen (Hoffman 2006, p. 10). The 
hunting season in Colorado ends before ptarmigans start congregating on 
wintering areas, when they are most susceptible to overharvest (Hoffman 
2006, p. 10). The short season and small bag limits of the hunting 
season in Colorado are designed to prevent overharvesting (Hoffman 
2006, p. 10). While ptarmigans may be unwary of humans, relatively easy 
to hunt, and found primarily on public lands, there is no information 
to suggest that illegal harvest by hunters may be a threat to the 
southern white-tailed ptarmigan in Colorado. Although immigration may 
make it difficult to detect the effects of hunting on other species of 
grouse, we have no information to suggest that hunting has resulted in 
additive mortality to the southern or Mt. Rainier white-tailed 
ptarmigan such that populations are unable to sustain viable breeding 
densities. Similarly, we have no information to suggest that hunting 
the species is currently more popular such that overharvesting may be a 
threat to the southern white-tailed ptarmigan. Therefore, we find that 
the petition and information in our files do not present substantial 
scientific or commercial information to indicate that hunting may be a 
threat to the southern or Mt. Rainier white-tailed ptarmigan. However, 
we will more fully evaluate hunting in our status review.

C. Disease or Predation

Information Provided in the Petition
    The petitioner asserts that the development of ski areas increases 
the presence of generalist predators that threaten the white-tailed 
ptarmigan in alpine habitats. As support, the petitioner cites a study 
on rock ptarmigan in Scotland that reported an increase in generalist 
predators, such as carrion crows (Corvus corone), feeding on birds and 
eggs following the development of a ski area (Watson and Moss 2004, p. 
267). In this study, the rock ptarmigans that nested closest to 
developed areas lost more nests to predation by crows or gulls and 
reared abnormally few broods compared to ptarmigans that nested farther 
away from development (Watson and Moss 2004, p. 267; Hoffman 2006, p. 
44). The petitioner argues that this study on the rock ptarmigan in 
Scotland is applicable to white-tailed ptarmigan populations in the 
United States. Although the petitioner states that specific studies 
regarding post-development increases in generalist predators and the 
potential effects on the white-tailed ptarmigan are lacking, the 
petitioner stresses that any development that increases generalist 
predators can impact the number of juvenile white-tailed ptarmigans in 
the population (Storch 2007, pp. 12, 40).
Evaluation of Information in the Petition and Available in Service 
Files
    In the presence of suitable habitats, predation is generally not a 
limiting factor for ptarmigans, as the birds have evolved closely with 
their predators and developed strategies to compensate for high 
predation rates (Hoffman 2006, p. 34). Although ski resorts or other 
human developments may attract predators, there is no information from 
the petition or our files to indicate that predation in any part of the 
range has exceeded any population-level compensation strategies to 
negatively impact southern and Mt. Rainier white-tailed ptarmigans. 
Although the petitioner provides evidence of predation of rock 
ptarmigan at ski resorts in Scotland, we have no information to 
conclude that there are more predators at ski resorts in the United 
States, that predation on white-tailed ptarmigan populations has 
increased, or that predation may be a threat to either subspecies. The 
petitioner provides no specific information regarding ski areas and the 
Mt. Rainier white-tailed ptarmigan in Washington. Ski areas and other 
forms of human development, such as roads, may enable predators to 
access alpine habitats, but there is no information in the petition or 
our files to indicate that predation within any part of the range of 
the southern or Mt. Rainier white-tailed ptarmigan may be a threat, 
regardless of the proximity of occupied habitats to development.
    The petitioner provides no information regarding any disease or 
pathogen that threatens the southern or Mt. Rainier white-tailed 
ptarmigans, and we found no evidence in our files that the subspecies 
may be at risk from any specific disease or pathogen. Therefore, we 
find that the petition and information in our files do not present 
substantial scientific or commercial information to indicate that 
disease or predation may be threats to the southern or Mt. Rainier 
white-tailed ptarmigans. However, we will more fully evaluate potential 
threats associated with disease and predation in our status review.

D. The Inadequacy of Existing Regulatory Mechanisms

Information Provided in the Petition
    The petitioner claims that existing regulatory mechanisms are 
inadequate to prevent the decline of the white-tailed ptarmigan because 
global and national regulations are failing to reduce carbon emissions 
to levels that will slow global surface warming. They also assert that 
no legal mechanisms currently exist to regulate greenhouse gases on a 
national level in the United States. The petitioner argues that 
stabilizing current climatic conditions through reductions in 
greenhouse gas emissions is necessary to preserve the remaining alpine 
habitats of the white-tailed ptarmigan, as discussed under Factor A, 
above. The petitioner also argues that other regulatory mechanisms 
inadequately protect the white-tailed ptarmigan from threats other than 
climate change. The petitioner argues that changes in climate caused by 
human activities must be mitigated through stronger regulatory 
mechanisms because the existing mechanisms are inadequate.
    The petitioner stresses that legislative action is necessary to 
save the white-tailed ptarmigan because scientists warn that we are 
approaching emissions levels that would cause dangerous climate change 
(Hansen et al. 2008, pp. 217-218). The petitioner stresses that with 
current atmospheric carbon dioxide levels at approximately 390 parts 
per million (ppm), and worldwide emissions continuing to increase by 
more than 2 ppm each year, immediate reductions in greenhouse gas 
emissions are necessary to prevent the loss of species and ecosystems 
to climate change.
    The petitioner reports that the United States produces 
approximately 20 percent of worldwide carbon dioxide emissions each 
year (U.S. Energy Information Administration 2010), yet lacks adequate 
regulations to reduce the greenhouse gas emissions. The petitioner 
cites the Service's 2008 listing of the polar bear (Ursus maritimus), 
which recognized that there are no regulatory mechanisms that address 
the anthropogenic causes of climate change (e.g., greenhouse gas 
emissions) and the

[[Page 33153]]

impact of warming temperatures and altered precipitation patterns on 
diminishing sea ice (73 FR 28288, May 15, 2008). The petition also 
states that existing domestic laws which grant authority to require 
greenhouse gas emissions reductions (e.g., Clean Air Act, Clean Water 
Act, Endangered Species Act, Energy Policy and Conservation Act) are 
not fully implemented. As an example, the petitioner references the 
U.S. Environmental Protection Agency's (EPA's) implementation of the 
Clean Air Act (42 U.S.C. 7401 et seq.) to lower emissions by requiring 
improved fuel economy and higher emission standards for light-duty 
vehicles (75 FR 25324, May 7, 2010), but states that the majority of 
other Clean Air Act programs are not fully implemented to address 
greenhouse gas emissions (75 FR 17004, April 2, 2010). The petitioner 
argues that full implementation of these environmental laws would 
provide an effective and comprehensive greenhouse gas reduction 
strategy, but does not explain how the majority of these laws could be 
applied to control emissions.
    The petitioner also indicates that the international agreements 
that address greenhouse gas emissions (e.g., United Nations Framework 
Convention on Climate Change, Kyoto Protocol) rely on non-binding and 
ineffective controls (Pew 2010, p. 1; Rogelj et al. 2010, p. 464). 
Therefore, the petitioner considers international regulatory mechanisms 
inadequate to protect the white-tailed ptarmigan from climate change.
    Furthermore, the petitioner contends that other State and Federal 
regulatory mechanisms in the United States do not adequately protect 
the white-tailed ptarmigan from threats other than climate change. The 
petitioner asserts that the National Environmental Policy Act (NEPA; 42 
U.S.C. 4321 et seq.) does not prohibit Federal agencies from choosing 
project alternatives that may negatively affect individuals or 
populations of white-tailed ptarmigans. The USFS recognizes the white-
tailed ptarmigan as a sensitive species in its Rocky Mountain (Region 
2) and Southwest Region (Region 3), but the petitioner contends that 
because the NEPA does not require avoidance of harm, the sensitive 
species designation provides little regulatory protection. The 
petitioner cites 41 BEs prepared by the USFS in the Rocky Mountain 
Region within the last 10 years that evaluated activities that could 
harm ptarmigan. The petitioner also explains that the National Forest 
Management Act (16 U.S.C. 1600 et seq.) does not prohibit the USFS from 
carrying out actions that harm the white-tailed ptarmigan or its 
habitats.
    Finally, the petitioner explains that the State of New Mexico added 
the white-tailed ptarmigan to its list of endangered species in 1975, 
and as a species of greatest conservation need in 2006. The petitioner 
argues that these designations in New Mexico confer no regulatory 
authority to protect white-tailed ptarmigan habitats. The petitioner 
provides no information or analysis regarding State regulations in 
either Colorado or Washington.
    The petitioner concludes that, given the threat of climate change 
as discussed under Factor A, it is important to protect all existing 
alpine habitats in order to provide the species with the best possible 
chance to find suitable habitats in a warmer world. The petitioner 
argues that none of the existing regulatory mechanisms provide 
substantial protection for the white-tailed ptarmigan from other 
threats discussed under Factor A, such as livestock grazing, 
recreation, or mining.
Evaluation of Information in the Petition and Available in Service 
Files
    According to the IPCC, anthropogenic emissions of long-lived 
greenhouse gases, especially carbon dioxide, are currently contributing 
the largest positive radiative forcings (leading to warming of climate) 
of any climate factor (Forster et al. 2007, pp. 136-137). After 
providing scientific references in support of global climatic warming 
as discussed under Factor A, the petitioner refers to the limited 
application of the Clean Air Act by the EPA to effectively regulate 
greenhouse gas emissions. Information in our files indicates that on 
December 15, 2009, the EPA announced that current and projected 
concentration of six greenhouse gases in the atmosphere threaten the 
public health and welfare of current and future generations (74 FR 
66496). In effect, the EPA concluded that the greenhouse gases linked 
to climate change are pollutants whose emissions can be subject to the 
Clean Air Act (42 U.S.C. 7401 et seq.).
    The EPA proposed specific regulations to limit greenhouse gas 
emissions under the Clean Air Act in 2010. However, specific 
regulations to limit greenhouse gas emissions were only proposed in 
2010, and have not yet been finalized. Therefore, the Clean Air Act 
cannot, at present, be considered an existing regulatory mechanism that 
addresses greenhouse gas emissions. Nor do we have any basis to 
conclude that implementation of the Clean Air Act in the foreseeable 
future (40 years, based on global climate projections) may 
substantially reduce the current rate of global climate change through 
regulation of greenhouse gas emissions. Thus, we conclude that the 
Clean Air Act is not designed to specifically address the primary 
threats to the southern and Mt. Rainier white-tailed ptarmigans, 
including the loss of alpine habitats and other environmental changes 
associated with climate change, as discussed under Factor A.
    Given that the petition, as revised, is specifically for the 
southern and Mt. Rainier white-tailed ptarmigan, we do not consider the 
adequacy of existing international regulations, treaties, or agreements 
that do not directly apply to the United States, and to the subspecies, 
when evaluating possible threats under Factor D. There is no 
information in the petition or in our files regarding applicable 
international regulations or treaties that might alleviate threats to 
the southern and Mt. Rainier white-tailed ptarmigans in the United 
States. Also, concerning the petitioner's assertion that NEPA does not 
provide adequate regulatory protection, NEPA is a disclosure law which 
does not require subsequent minimization or mitigation measures by the 
Federal agency involved. Although Federal agencies may include 
conservation measures for sensitive species as a result of the NEPA 
process, any such measures are voluntary in nature and not required by 
the statute. Thus it is outside the scope of NEPA to provide regulatory 
protections to species. As with the Clean Air Act, NEPA is not designed 
to specifically address the specific threats to the southern and Mt. 
Rainier white-tailed ptarmigans.
    In the Rocky Mountains, approximately 95 percent of occupied 
ptarmigan habitats are on public lands, 85 percent of which are 
administered by the USFS (Hoffman 2006, p. 9). The petitioner did not 
provide information, and we found no information in our files, 
regarding the land ownership and corresponding management regulations 
for alpine habitats in Washington. Because the ptarmigan is a USFS 
sensitive species in the Rocky Mountains, the USFS actively manages it 
to avoid trends toward Federal listing and to maintain population 
viability across its range in Regions 2 and 3. The petitioner argues 
that according to BEs, 41 projects administered by the USFS within the 
last 10 years in the Rocky Mountain Region harmed the white-tailed 
ptarmigan. The petitioner previously indicated that 8 of these projects 
were associated with sheep grazing, 2 were associated with mining, and 
27 were associated with recreation. However, the USFS determined that

[[Page 33154]]

these activities would not contribute to a loss of viability or lead to 
a trend towards Federal listing, and the petitioner does not provide 
evidence these projects actually occurred or contributed to a trend 
towards listing contrary to the USFS' determination. The petitioner 
also does not provide evidence that State regulations in New Mexico are 
ineffective and may threaten the southern white-tailed ptarmigan. The 
petitioner provides no information, and we have no information in our 
files, regarding regulations or laws specific to the Mt. Rainier white-
tailed ptarmigan in Washington.
Summary of Factor D
    We are not aware of any existing regulatory mechanisms that are 
designed to address the changes described in Factor A in the southern 
and Mt. Rainier white-tailed ptarmigan habitats that are occurring or 
likely to occur in the future.
    As discussed above, there are no applicable international 
regulations or treaties that might alleviate threats to the southern 
and Mt. Rainier white-tailed ptarmigans in the United States. 
Similarly, it is beyond the scope of NEPA to provide specific 
protections to the subspecies.
    Approximately 95 percent of the occupied range of the southern 
white-tailed ptarmigan in the Rocky Mountains occurs on public lands, 
at least 85 percent of which is federally managed (Hoffman 2006, p. 9). 
Public lands are subject to several Federal laws and regulations that 
protect habitats from direct destruction or modification. There is no 
information in the petition nor readily available in our files 
regarding laws or regulations in the State of Washington and the 
effectiveness of regulations in other States, and it is uncertain 
whether Federal or State laws and regulations adequately address the 
potential threats to habitats of the white-tailed ptarmigan associated 
with climate change as discussed under Factor A. Existing regulatory 
mechanisms are not designed to, nor do they, ameliorate the threats to 
the southern or Mt. Rainier white-tailed ptarmigan. Therefore, we find 
that the petition and information in our files do not present 
substantial scientific or commercial information to indicate that the 
inadequacy of existing regulatory mechanisms may be a threat to the 
southern or Mt. Rainier white-tailed ptarmigans. We will more fully 
evaluate existing regulatory mechanisms in our status review.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

    In their petition, the petitioner presented information regarding 
potential physiological effects of a warming climate on the southern 
and Mt. Rainier white-tailed ptarmigans under Factor A. Because these 
are physiological effects, we discuss these assertions below. The 
petitioner also claims that population isolation and limited dispersal 
distances threaten the white-tailed ptarmigan.
Physiological Response to Climate Warming
    Information Provided in the Petition--The petitioner cites a study 
conducted in the RMNP, Colorado, as evidence that warming temperatures 
have had a negative effect on the population dynamics of white-tailed 
ptarmigan (Wang et al. 2002, pp. 81-86). The petitioner also explains 
that increased temperatures may not only decrease population growth 
rates of the white-tailed ptarmigan, but also may directly impact 
individual ptarmigans because of their inability to cope with the 
stress caused by warming temperatures. The petitioner explains that the 
southern and Mt. Rainier white-tailed ptarmigans are well adapted to 
their seasonally cold alpine habitats, but are not physiologically 
adapted to high ambient air temperatures (Hoffman 2006, p. 24). To 
support this claim, the petitioner cites several studies that 
determined that the white-tailed ptarmigan has low mean body 
temperatures, a wide temperature-tolerance zone, excellent insulation 
to trap body heat, and low evaporative efficiencies (Veghte and Herreid 
1965, p. 267; Lasiewski et al. 1966, p. 445; Johnson 1968, p. 1003; 
Hoffman 2006, pp. 24, 45). The petitioner argues that southern and Mt. 
Rainier white-tailed ptarmigans are susceptible to heat stress and 
underequipped to adapt to the warming temperatures associated with 
climate change.
    The petitioner explains that white-tailed ptarmigans modify their 
behaviors to avoid overheating, but this may not be sufficient to 
compensate for a warming climate. While nesting, female white-tailed 
ptarmigans take incubation breaks to forage, but they may take fewer 
breaks if temperatures are high. With less food, as a result of fewer 
foraging breaks, the health of nesting females may deteriorate, and 
they may abandon the nest (Hoffman 2006, p. 46). Additionally, the 
petitioner suggests that warming temperatures may force females to nest 
in shaded, denser vegetation, where they may be more susceptible to 
predation (Hoffman 2006, p. 46). Therefore, the petitioner concludes 
that behavioral adaptations that ptarmigans employ to avoid overheating 
may be ineffective with a warming climate.
    Evaluation of Information in the Petition and Available in Service 
Files--Empirical studies show that warm ambient temperatures negatively 
affected the population dynamics of the southern white-tailed ptarmigan 
in Colorado by depressing population growth rates and skewing hatch 
dates (Wang et al. 2002, p. 81). This study reported that increases in 
April and May temperatures between years 1975 through 1999 at RMNP 
significantly advanced the median hatch dates of ptarmigan eggs and 
depressed the population growth rate of ptarmigans in RMNP (Wang et al. 
2002, p. 85). Additionally, a population model anticipated that warming 
resulted in population decreases from 30 to 40 birds to 2 to 3 birds in 
RMNP (Wang et al. 2002, p. 84-85). This study concluded that there is a 
clear population-level response in white-tailed ptarmigans to climate 
change, and that predicted temperature increases in RMNP may accelerate 
population declines and increase the probability of local extinction 
(Wang et al. 2002, p. 86).
    As discussed under Factor A, global climate change may result in an 
increase in temperatures within the habitats of the southern and Mt. 
Rainier white-tailed ptarmigans; and the effect of increasing 
temperatures may decrease population growth rates. Additionally, the 
southern and Mt. Rainier white-tailed ptarmigans are physiologically 
well adapted to conserve heat and tolerate the cold temperatures of 
their alpine environments. However, available information suggests that 
these adaptations are detrimental to the white-tailed ptarmigan in warm 
temperatures, with heat stress developing quickly when the birds are 
unable to cool off (Johnson 1968, p. 1012; Hoffman 2006, pp. 24, 31). 
Although the birds seek cooler microclimates with shade and cover to 
escape warm temperatures, climatic warming may reduce the number of 
these cooler microclimates available, and the southern and Mt. Rainier 
white-tailed ptarmigans may be incapable of avoiding heat stress. If 
physiologically unable to cool body temperatures through evaporation, 
guttural fluttering, bathing in snow, or relocating to cooler 
microclimates, heat stress aggravated by climate change may be a threat 
to the southern or Mt. Rainier white-tailed ptarmigan. However, the 
petitioner did

[[Page 33155]]

not provide information, and we found no evidence in our files to 
indicate, that the birds are more susceptible to predation in cooler 
microclimate areas or that females will take fewer foraging breaks so 
that malnutrition eventually reduces breeding success eventually 
resulting in a negative population response. But, as discussed above, 
we still find that warming temperatures associated with climate change 
may be a threat by depressing population growth rates and aggravating 
heat stress. Therefore, we find that the information presented in the 
petition and information in our files presents substantial scientific 
or commercial evidence to indicate the physiological response of the 
southern or Mt. Rainier white-tailed ptarmigan to climate warming may 
be a threat.
Population Isolation and Limited Dispersal Distances
    Information Presented in the Petition--The petitioner claims that 
isolation, small populations, low densities, and limited dispersal 
distances render the southern and Mt. Rainier white-tailed ptarmigans 
particularly vulnerable to extinction. To support this claim, the 
petitioner cites a species account for the Vancouver Island white-
tailed ptarmigan, the subspecies endemic to Vancouver Island, which 
indicates that this subspecies exists in low densities with stochastic 
population dynamics and environmental conditions (Martin and Forbes 
2004, pp. 4-5). The petitioner also provides the USFS sensitive species 
designation for the white-tailed ptarmigan in the Rocky Mountain Region 
as evidence that population isolation and limited dispersal distances 
are a threat (USFS 2005, p. 1). The petitioner also explains that 
alpine habitats are isolated and geographically separated by expanses 
of unsuitable habitats, and that distances between habitats exceed the 
maximum recorded travel distances for the white-tailed ptarmigan 
(Martin et al. 2000, p. 514). Therefore, the petitioner concludes that 
as climate change modifies and reduces available habitats, distances 
between suitable habitats will increase, further isolating populations 
and threatening the subspecies.
    Evaluation of Information in the Petition and Available in Service 
Files--While the Vancouver Island white-tailed ptarmigan may be 
susceptible to population extirpations because of their low densities, 
patchy habitats, and stochastic environment, we found no information in 
the petition nor available in our files that these variables may be 
threats to either the southern or the Mt. Rainier white-tailed 
ptarmigan. Contrary to the Vancouver Island white-tailed ptarmigan 
study, a study in the Rocky Mountains suggested that small population 
sizes, low densities, relatively low fecundity, and high annual 
variation in most population parameters did not appear to threaten the 
white-tailed ptarmigan population (Martin et al. 2000, p. 512). 
Additional information suggests that a well-developed system of 
population exchange and recruitment allows ptarmigans to persist in 
isolated, small populations, even during regional stochastic events in 
Colorado (Martin et al. 2000, pp. 512, 514). The petitioner provided no 
information regarding maximum distances between alpine habitats that 
may hinder population exchange or recruitment, and we have no 
information indicating that the current distances between alpine 
habitats may impede interchange for the southern or Mt. Rainier white-
tailed ptarmigans. While climate change may increase the distance 
between alpine habitats, the petitioner did not provide information, 
and we have no information in our files, that distances between alpine 
habitats may threaten either subspecies. Additionally, the USFS 
sensitive species recommendation and evaluation for white-tailed 
ptarmigan summarizes potential threats, but provides no supporting 
information regarding population isolation or dispersal distances. 
Therefore, we find that the petition and information in our files do 
not present substantial scientific or commercial information to 
indicate that isolated populations or limited dispersal distances may 
be threats to the southern and Mt. Rainier white-tailed ptarmigans.
Summary of Factor E
    We find that the information presented in the petition regarding 
population growth rates and physiological response to a warming climate 
presents substantial scientific or commercial evidence to indicate that 
the petitioned action may be warranted. We find that the petition does 
not present substantial scientific or commercial information to 
indicate that population isolation or limited dispersal distances may 
be threats to the southern and Mt. Rainier white-tailed ptarmigans. We 
will evaluate population isolation and limited dispersal distances more 
fully during our status reviews.

Finding

    On the basis of our determination under section 4(b)(3)(A) of the 
Act, we have determined that the petition presents substantial 
scientific or commercial information indicating that listing the 
southern and Mt. Rainier white-tailed ptarmigans throughout the entire 
ranges of both subspecies may be warranted. This finding is based on 
information provided under factors A and E. The information provided in 
the petition and available in our files under factors B, C, and D is 
not substantial. During the status review, we will fully address the 
cumulative effects of threats discussed under each factor.
    Because we have found that the petition presents substantial 
information indicating that listing the southern and Mt. Rainier white-
tailed ptarmigans may be warranted, we are initiating a status review 
to determine whether listing these subspecies under the Act is 
warranted.
    The ``substantial information'' standard for a 90-day finding 
differs from the Act's ``best scientific and commercial data'' standard 
that applies to a status review to determine whether a petitioned 
action is warranted. A 90-day finding does not constitute a status 
review under the Act. In a 12-month finding, we will determine whether 
a petitioned action is warranted after we have completed a thorough 
status review of the subspecies, which is conducted following a 
substantial 90-day finding. Because the Act's standards for 90-day and 
12-month findings are different, as described above, a substantial 90-
day finding does not necessarily mean that the 12-month finding will 
result in a warranted finding.

References Cited

    A complete list of references cited is available on the Internet at 
http://www.regulations.gov and upon request from the Colorado 
Ecological Services Field Office (see FOR FURTHER INFORMATION CONTACT).

Authors

    The primary authors of this notice are staff members of the 
Colorado Ecological Services Field 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: May 21, 2012.
Gregory E. Siekaniec,
Deputy Director, U.S. Fish and Wildlife Service.
[FR Doc. 2012-13320 Filed 6-4-12; 8:45 am]
BILLING CODE 4310-55-P