[Federal Register: February 9, 2010 (Volume 75, Number 26)]
[Proposed Rules]
[Page 6437-6471]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr09fe10-21]
[[Page 6437]]
-----------------------------------------------------------------------
Part II
Department of the Interior
-----------------------------------------------------------------------
Fish and Wildlife Service
-----------------------------------------------------------------------
50 CFR Part 17
Endangered and Threatened Wildlife and Plants; 12-month Finding on a
Petition to List the American Pika as Threatened or Endangered;
Proposed Rule
[[Page 6438]]
-----------------------------------------------------------------------
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[FWS-R6-ES-2009-0021
MO 92210-0-0010]
Endangered and Threatened Wildlife and Plants; 12-month Finding
on a Petition to List the American Pika as Threatened or Endangered
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 12-month petition finding.
-----------------------------------------------------------------------
SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
12-month finding on a petition to list the American pika (Ochotona
princeps) as threatened or endangered under the Endangered Species Act
of 1973, as amended. After review of all available scientific and
commercial information, we find that listing the American pika, at the
species level or any of the five recognized subspecies (O. p. princeps,
O. p. saxatilis, O. p. fenisex, O. p. schisticeps, and O. p. uinta), is
not warranted at this time. However, we ask the public to submit to us
any new information that becomes available concerning the threats to
the American pika, the five subspecies, or its habitat at any time.
DATES: The finding announced in this document was made on February 9,
2010.
ADDRESSES: This finding is available on the Internet at http://
www.regulations.gov at Docket Number FWS-R6-ES-2009-0021. Supporting
documentation we used in preparing this finding is available for public
inspection, by appointment, during normal business hours at the U.S.
Fish and Wildlife Service, Utah Ecological Services Field Office, 2369
W. Orton Circle, Suite 50, West Valley City, UT 84119. Please submit
any new information, materials, comments, or questions concerning this
finding to the above address.
FOR FURTHER INFORMATION CONTACT: Larry Crist, Field Supervisor, Utah
Ecological Services Field Office (see ADDRESSES); by telephone at 801-
975-3330; or by facsimile at 801-975-3331. Persons who use a
telecommunications device for the deaf (TDD) may call the Federal
Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(B) of the Endangered Species Act of 1973, as
amended (Act) (16 U.S.C. 1531 et seq.), requires that, for any petition
to revise the Federal Lists of Endangered and Threatened Wildlife and
Plants that contains substantial scientific or commercial information
indicating that listing the species may be warranted, we make a finding
within 12 months of the date of receipt of the petition. In this 12-
month finding, we may determine that the petitioned action is either:
(1) not warranted, (2) warranted, or (3) warranted, but the immediate
proposal of a regulation implementing the petitioned action is
precluded by other pending proposals to determine whether species are
threatened or endangered, and expeditious progress is being made to add
or remove qualified species from the Federal Lists of Endangered and
Threatened Wildlife and Plants. Section 4(b)(3)(C) of the Act requires
that we treat a petition for which the requested action is found to be
warranted but precluded as though resubmitted on the date of such
finding, that is, requiring a subsequent finding to be made within 12
months. We must publish these 12-month findings in the Federal
Register.
Previous Federal Actions
On October 2, 2007, we received a petition dated October 1, 2007,
from the Center for Biological Diversity (Center) requesting that the
American pika (Ochotona princeps) be listed as threatened or endangered
under the Act. Included in the petition was a request that we conduct a
status review of each of the 36 recognized subspecies of American pikas
to determine if separately listing any subspecies as threatened or
endangered may be warranted. Specifically, the Center requested that
seven American pika subspecies be listed as endangered: the Ruby
Mountains pika (O. p. nevadensis), O. p. tutelata (no common name), the
White Mountains pika (O. p. sheltoni), the gray-headed pika (O. p.
schisticeps), the Taylor pika (O. p. taylori), the lava-bed pika (O. p.
goldmani), and the Bighorn Mountain pika (O. p. obscura). The Center
requested that the remaining subspecies be listed as threatened. We
acknowledged receipt of the petition in a letter to the Center dated
October 18, 2007. In that letter, we also stated that we could not
address its petition at that time, because existing court orders and
settlement agreements for other listing actions required nearly all of
our listing funding. We also concluded that emergency listing of the
American pika was not warranted at that time.
We received a 60-day notice of intent to sue from the Center dated
January 3, 2008. We received a complaint from the Center on August 19,
2008. We submitted a settlement agreement to the Court on February 12,
2009, agreeing to submit a 90-day finding to the Federal Register by
May 1, 2009, and, if appropriate, to submit a 12-month finding to the
Federal Register by February 1, 2010.
We received a letter from the Center, dated November 3, 2008, that
discussed and transmitted supplemental information found in recent
scientific studies that had not been included in the original petition.
We considered this additional information when making this finding.
In our 90-day finding published on May 7, 2009 (74 FR 21301), we
reviewed the petition, petition supplement, supporting information
provided by the petitioner, and information in our files, and evaluated
that information to determine whether the sources cited support the
claims made in the petition. We found that the petitioner presented
substantial information indicating that listing the American pika as
threatened or endangered under the Act may be warranted, because of the
present or threatened destruction, modification, or curtailment of its
habitat or range as a result of effects related to global climate
change. We also solicited additional data and information from the
public, other governmental agencies, the scientific community,
industry, and other interested parties concerning the status of the
American pika throughout its range. The information collection period
for submission of additional information ended on July 6, 2009. This
notice constitutes our 12-month finding on the October 1, 2007,
petition to list the American pika as threatened or endangered.
Species Information
Biology
Like other pika species, the American pika (hereafter pika, unless
stated otherwise) has an egg-shaped body with short legs, moderately
large ears, and no visible tail (Smith and Weston 1990, p. 2). Fur
color varies among subspecies and across seasons, typically with
shorter, brownish fur in summer and longer, grayish fur in winter
(Smith and Weston 1990, p. 3). The species is intermediately sized,
with adult body lengths ranging from 162 to 216 millimeters (6.3 to 8.5
inches) and mean body mass ranging from 121 to 176
[[Page 6439]]
grams (4.3 to 6.2 ounces) (Hall 1981, p. 287; Smith and Weston 1990, p.
2).
American pikas are generalist herbivores that select different
classes of vegetation (Huntley et al. 1986, p. 143) and use different
parts of the same plants when grazing versus haying (Dearing 1997a, p.
1160). Feeding (the immediate consumption of vegetation) occurs year-
round; haying (the storage of vegetation for later consumption) and the
creation of haypiles occurs only in summer months after the breeding
season (Smith and Weston 1990, p. 4). The primary purpose of haypiles
is overwintering sustenance, and individuals harvest more vegetation
than necessary for these haypiles (Dearing 1997a, p. 1156). Pikas feed
an average distance of 2 meters (m) (6.5 feet (ft)) from talus and will
travel an average distance of 7 m (23 ft) when haying (Huntly et al.
1986, pp. 141-142). Huntly et al. (1986, p. 142) found that no feeding
occurred beyond 10 m (33 ft) from talus, but haying was observed up to
30 m (98 ft).
Vegetative communities immediately adjacent to pika locations are
typically dominated by grasses (Huntly 1987, p. 275). When pikas are
excluded from grazing near talus slopes, the biomass of forbs and
sedges (Roach et al. 2001, p. 319) and cushion plants (Huntly 1987, p.
275) increases rapidly. Therefore, foraging pikas influence the
presence of specific plant classes or functional groups, vegetative
cover, and species richness (Huntly 1987, p. 274; Roach et al. 2001, p.
315), and modify habitat in their quest for food and survival (Aho et
al. 1998, p. 405). Forbs and woody plants are typically found in pika
haypiles (Huntly et al. 1986, p. 143), which provide the major source
of sustenance for the winter (Dearing 1997a, p. 1156). High phenolic
(chemical compounds characterized by high acidity) concentrations of
forbs and shrubs prevent pikas from grazing immediately on these plant
types; however, pikas cache these plants and delay consumption until
the toxins decay to tolerable levels (Dearing 1997b, p. 774).
Additionally, plants with high levels of the phenolics deter bacterial
growth and exhibit superior preservation qualities (Dearing 1997b, p.
774).
Thermoregulation is an important aspect of American pika
physiology, because individuals have a high normal body temperature of
approximately 40 [deg]C (104 [deg]F) (MacArthur and Wang 1973, p. 11;
Smith and Weston 1990, p. 3), and a relatively low lethal maximum body
temperature threshold of approximately 43 [deg]C (109.4 [deg]F) (Smith
and Weston 1990, p. 3). Most thermoregulation of individuals is
behavioral, not physiological (Smith 1974b, p. 1372; Smith and Weston
1990, p. 3). In warmer environments, such as during midday sun and at
lower elevation limits, pikas typically become inactive and withdraw
into cooler talus openings (Smith 1974b, p. 1372; Smith and Weston
1990, p. 3). Below-surface temperatures within talus openings can be as
much as 24 [deg]C (43.2 [deg]F) cooler than surface temperatures during
the hottest time of day (Finn 2009a, pers. comm.). Pikas avoid
hyperthermia (heat stroke) during summer months by engaging in short
bursts of surface activity followed by retreat to a cooler microclimate
beneath the surface (MacArthur and Wang 1974, p. 357). Pikas can be
nocturnal where daytime temperatures are stressful and restrict diurnal
activity (Smith 1974b, p. 1371).
Habitat occupied by American pikas is often patchily distributed,
leading to a local population structure that is composed of island-like
sites commonly termed a metapopulation (Smith and Weston 1990, p. 4;
Moilanen et al. 1998, pp. 531-532). A metapopulation is composed of
many largely discrete local populations, and metapopulation dynamics
are characterized by extinction and recolonization occurring within
independent local populations (Hanski 1999, cited in Meredith 2002, p.
47). Local populations that make up each metapopulation frequently
become extirpated and can be subsequently reestablished by immigration
(Smith 1974a, p. 1112; Moilanen et al. 1998, p. 532). American pikas
within metapopulations often exhibit a low emigration rate, especially
in adults. Juveniles usually have short migration distances; however,
exceptions occur (Peacock 1997, pp. 346-348).
Dynamics of American pika populations are sufficiently asynchronous
(not occurring at the same time), so that simultaneous extinction of
entire metapopulations is unlikely (Smith 1980, p. 11; Moilanen et al.
1998, p. 532). When a single population becomes extirpated, distance to
a source of colonizing pikas is an influential factor determining the
probability of recolonization (Smith 1980, p. 11). American pika
populations on small and medium-sized islands are more likely to be
extirpated, with the probability of extirpation being higher on more
distant islands (Smith 1980, p. 12).
Historically, researchers hypothesized that American pika juveniles
are philopatric (remain in or return to their birthplace), dispersing
only if no territory is available within their birth place (various
studies cited in Smith and Weston 1990, p. 6). However, Peacock (1997,
pp. 346-348) demonstrated that juvenile emigration to other population
sites occurred over both long (2 kilometers (km); 1.24 miles (mi)) and
short distances, and acted to support population stability by replacing
deceased adults. Territory availability is a key factor for dispersal
patterns, and local pika populations lack clusters of highly related
individuals (Peacock 1997, pp. 347-348).
Dispersal by American pikas is governed by physical limitations.
Smith (1974a, p. 1116) suggested that it was difficult for juveniles to
disperse over distances greater than 300 m (984 ft) in low-elevation
(2,500 m (8,200 ft)) populations. Lower elevations are warmer in summer
and represent the lower edge of the elevational range of the species
(Smith 1974a, p. 1112). While dispersal distances of 3 km (1.9 mi) have
been documented at other locations and elevational ranges (Hafner and
Sullivan 1995, p. 312), it is believed that the maximum individual
dispersal distance is probably between 10 and 20 km (6.2 and 12.4 mi)
(Hafner and Sullivan 1995, p. 312). This conclusion is based on genetic
(Hafner and Sullivan 1995, pp. 302-321) and biogeographical (Hafner
1994, pp. 375-382) analysis. Genetic analysis revealed that pika
metapopulations are separated by between 10 and 100 km (6.2 to 62 mi)
(Hafner and Sullivan 1995, p. 312). Biogeographical analysis
demonstrated that, during the warmer period of the mid-Holocene (about
6,500 years ago), the species retreated to cooler sites, and the
species subsequently expanded its range somewhat as climatic conditions
cooled (Hafner 1994, p. 381). However, the species has not recolonized
vacant habitat patches greater than 20 km (12.4 mi) from refugia sites
and has recolonized less than 7.8 percent of available patches within
20 km (12.4 mi) of those same refugia sites (Hafner 1994, p. 381). The
lack of recolonization is due to habitat becoming unsuitable from
vegetation filling in talus areas (removing pika habitat) or from
habitat becoming too dry due to environmental changes resulting from
historical changes in climate (Hafner 1994, p. 381).
Individual pikas are territorial, maintaining a defended territory
of 410 to 709 square meters (m\2\) (4,413 to 7,631 square feet
(ft\2\)), but fully using overlapping home ranges of 861 to 2,182 m\2\
(9,268 to 23,486 ft\2\) (various studies cited in Smith and Weston
1990, p. 5). Individuals mark their territories with scent and defend
the territories through
[[Page 6440]]
aggressive fights and chases (Smith and Weston 1990, p. 5).
Adults with adjacent territories form monogamous mating pairs.
Males are sexually monogamous, but make little investment in rearing
offspring (Smith and Weston 1990, pp. 5-6). Females give birth to
average litter sizes of 2.4 to 3.7 twice a year (Smith and Weston 1990,
p. 4). However, fewer than 10 percent of weaned juveniles originate
from the second litter, because mothers only wean the second litter if
the first litter is lost (various studies cited in Smith and Weston
1990, p. 4).
Adult pikas can be territorially aggressive to juveniles, and
parents can become aggressive to their own offspring within 3 to 4
weeks after birth (Smith and Weston 1990, p. 4). To survive the winter,
juveniles need to establish their own territories and create haypiles
before the winter snowpack (Smith and Weston 1990, p. 6; Peacock 1997,
p. 348). However, establishing a territory and building a haypile does
not ensure survival.
Yearly average mortality in pika populations is between 37 and 53
percent. Few pikas live to be 4 years of age (Peacock 1997, p. 346),
however, some individuals survive up to 7 years (Smith 2009, p. 2).
Taxonomy
Historically, many taxonomic forms have been identified within
Nearctic pikas, including as many as 13 species and 37 subspecies
(Hafner and Smith 2009, p. 1). Initially, 13 species and 25 subspecies
of Nearctic (a biogeographic region that includes the Arctic and
temperate areas of North America and Greenland) pikas were described
(Richardson 1828, cited in Hafner and Smith 2009). Howell (1924, pp.
10-11) performed a full taxonomic revision of the American pika and
recognized 3 species: Ochotona collaris, Ochotona princeps (16
subspecies), and Ochotona schisticeps (9 subspecies). Later, Hall
(1981, pp. 286-292) described 36 subspecies of American pika spread
throughout western Canada and the western United States. The petition
(Wolf et al. 2007) from the Center of Biological Diversity that
requested that all American pika subspecies be listed as threatened or
endangered was based on the Hall (1981, pp. 286-292) taxonomy.
These references, in addition to others (Hafner and Smith 2009, p.
5) were used as the set of authoritative resources on pika taxonomy
until genetic work identified four major genetic units of the American
pika in the northern Rocky Mountains, Sierra Nevada, southern Rocky
Mountains, and Cascade Range (Hafner and Sullivan 1995, p. 308).
Further molecular phylogenetic and morphometric studies indicate the
existence of five cohesive genetic units that have been referred to as
``distinct evolutionarily significant units'' (Galbreath et al. 2009a,
p. 17; Galbreath et al. 2009b, pp. 7, 52). These studies support a
revision of the subspecific taxonomy of the American pika to include
five recognized subspecies: Ochotona princeps princeps (Northern
Rockies), O. p. saxatilis (Southern Rockies), O. p. fenisex (Coast
Mountains and Cascade Range), O. p. schisticeps (Sierra Nevada and
Great Basin), and O. p. uinta (Uinta Mountains and Wasatch Range of
Central Utah) (Hafner and Smith 2009, pp. 16-25). The previously
described 36 subspecies (Hall 1981, pp. 286-292) are now referred to as
subspecies synonyms, with each subspecies synonym corresponding to a
subspecies described by Hafner and Smith (2009, pp. 16-25). We are
making our finding based on the most recent information that has
identified five subspecies of American pika. The petition (Wolf et al.
2007) from the Center of Biological Diversity no longer contains the
best available information on taxonomy.
Historic Distribution and Habitat
The restriction of American pikas to their current distribution
(discussed below) is relatively recent. The shift in habitat range was
shaped by long-term climate change and attendant impacts on vegetation.
The geographic distribution of American pika may have encompassed
not only the western United States and Canada during the last glacial
maximum (30,000 years ago or later), but also parts of the eastern
United States (Grayson 2005, p. 2104). Archaeological and
paleontological records for pika demonstrate that approximately 12,000
years ago, pikas were living at relatively low elevations (less than
2,000 m (6,560 ft)) in areas devoid of talus (Mead 1987, p. 169;
Grayson 2005, p. 2104). By the Wisconsinan glacial period
(approximately 40,000 to 10,000 years ago), American pikas were
restricted to the intermontane region of the western United States and
Canada.
Low-elevation populations of American pikas became extinct in the
northern half of the Great Basin between 7,000 and 5,000 years ago
(Grayson 1987, p. 370). Fossil records indicate that the species
inhabited sites farther south and at lower elevations than the current
distribution during the late Wisconsinan and early Holocene periods
(approximately 40,000 to 7,500 years ago), but warming and drying
climatic trends in the middle Holocene period (approximately 7,500 to
4,500 years ago) forced populations into the current distribution of
montane refugia (Grayson 2005, p. 2103; Smith and Weston 1990, p. 2).
During the late Wisconsinan and early Holocene, now-extirpated American
pika populations in the Great Basin occurred at an average elevation of
1,750 m (5,740 ft), which is 783 m (2,569 ft) lower than 18 extant (in
existence) Great Basin pika populations (Grayson 2005, p. 2106).
Current Distribution and Habitat
Ochotona princeps princeps is patchily distributed in cool, rocky
habitat, primarily in high-elevation alpine habitats (see below for
exceptions), from the Northern Rocky Mountains of central British
Columbia and Alberta through Idaho and Montana, several mountain ranges
of Wyoming, the Ruby Mountains of Nevada, the Wasatch Range of Idaho
and Utah, and the Park Range and Front Range of Colorado north of the
Colorado River (Hafner and Smith 2009, p.19). O. p. saxatilis occupies
habitat in the southern Rocky Mountains south of the Colorado River
(Front Range, San Juan Mountains, Sangre de Cristo Range), and isolated
highlands including the La Sal Mountains of southeastern Utah, Grand
Mesa of Colorado, and Jemez Mountains of New Mexico (Hafner and Smith
2009, pp. 21-22). O. p. schisticeps occupies habitats in volcanic peaks
of northern California, throughout the Sierra Nevada of California and
Nevada, and isolated highlands throughout the Great Basin of Nevada,
eastern Oregon (north to the Blue Mountains), and southwestern Utah
(Hafner and Smith 2009, pp. 23-24). O. p. fenisex occupies habitats
from the Coast Mountains and Cascade Range from central British
Columbia south to southern Oregon (Hafner and Smith 2009, p. 20). O. p.
uinta is patchily distributed in habitats in the Uinta Mountains and
Wasatch Range of central Utah (Hafner and Smith 2009, p. 24).
Temperature restrictions influence the species' distribution
because hyperthermia or death can occur after brief exposures (as
little as 6 hours) to ambient temperatures greater than 25.5 [deg]C
(77.9 [deg]F), if individuals cannot seek refuge from heat stress
(Smith 1974b, p. 1372). Therefore, American pika habitat progressively
increases in elevation in the southern extent of the distribution
(Smith and Weston 1990, p. 2). In the northern part of its distribution
(southwestern Canada), populations occur from sea level to 3,000 m
(9,842 ft), but in the southern extent (New Mexico, Nevada, and
[[Page 6441]]
southern California) populations rarely exist below 2,500 m (8,202 ft)
(Smith and Weston 1990, p. 2). Some exceptions exist in the southern
portion of the species' range. For example, pikas in 10 percent of 420
study sites in the Sierra Nevada Mountains, Great Basin, and Oregon
Cascade Mountains occur below 2,500 m and as low as 1,645 m (5,396 ft)
at McKenzie Pass in the Cascade Mountains of Oregon (Millar and
Westfall 2009, p. 16). Beever et al. (2008, p. 10) recently discovered
a new population of American pika in the Hays Canyon Range of
northwestern Nevada at elevations ranging from 1,914 to 2,136 m (6,280
to 7,008 ft).
American pikas primarily inhabit talus fields fringed by suitable
vegetation in alpine or subalpine areas (Smith and Weston 1990, pp. 2-
4). A generalist herbivore that does not hibernate, the species relies
on haypiles of summer vegetation stored within talus openings to
persist throughout the winter months (Smith and Weston 1990, p. 3).
Alpine meadows that provide forage are important to pika survival in
montane environments. The species also occupies other habitats that
include volcanic land features (Beever 2002, p. 26; Millar and Westfall
2009, p. 10) and anthropogenic settings such as mine tailings, piles of
lumber, stone walls, rockwork dams, and historic foundations (Smith
1974a, p. 1112; Smith 1974b, p. 1369; Lutton 1975, p. 231; Crisafulli
2009, pers. comm.; Millar and Westfall 2009, p. 10).
Pikas use talus, which can include rock-ice features, and other
habitat types for den sites, food storage, and nesting (Smith and
Weston 1990, p. 4; Beever et al. 2003, p. 39). Rock-ice features are
defined as glacial- or periglacial- (i.e., around or near glaciers)
derived landforms in high-elevation, semi-arid temperature mountain
ranges and arctic landscapes (Millar and Westfall 2008, pp. 90-91).
Talus, rock-ice feature till, and volcanic features (described below)
also provide microclimate conditions suitable for pika survival by
creating cooler, moist refugia in summer months (Beever 2002, p. 27;
Millar and Westfall 2009, p. 19-21) and insulating individuals in the
colder winter months (Smith 1978, p. 137; Millar and Westfall 2009, p.
21).
Among 420 sites surveyed by Millar and Westfall (2009, p. 10), 83
percent of the pika sites occurred in rock-ice feature till, most
notably rock-glacier and boulder-stream landforms, which contain
topographic-climatic conditions that are favored by pikas (Millar and
Westfall 2009, p. 20).
Pikas also inhabit more atypical habitats that include lava tubes,
caves, valley trenches, fault scarps, fault cracks, and cliff faces,
which provide suitable habitat and thermal refuge (Beever 2002, pp. 26,
28; Millar and Westfall 2009, p. 10). For example, in Lava Beds
National Monument in northern California and Craters of the Moon
National Monument in southern Idaho, pikas typically inhabit large,
contiguous areas of volcanic habitat (Beever 2002, p. 28). Within this
habitat type, forage vegetation is accessible within distances
comparable to dimensions of home ranges (Beever 2002, p. 28). Pikas
select habitat that includes topographical features characterized by
rocks large enough to provide necessary interstitial spaces for
underground movement and tunneling. Like talus and rock-ice features,
these habitats provide pikas with cool refugia during conditions that
may result in heat stress, which in addition to behavioral
thermoregulation mechanisms, allow pika to persist in these low-
elevation and potentially thermally challenging environments (Beever
2002, pp. 27-28).
Population Status
We relied on information from the International Union for
Conservation and Nature of Natural Resources (IUCN), NatureServe,
published literature, and public submissions during the information
collection period on our 90-day finding to evaluate the status of
American pika populations.
The IUCN Red List of Threatened Species provides taxonomic,
conservation status, and distribution information on plants and animals
(IUCN 2009, p. 2). The IUCN Red List system is designed to determine
the relative risk of extinction for species, and to catalogue and
highlight plant and animal species that are facing a higher risk of
global extinction. The IUCN identified the status of the American pika
species as Least Concern in 2008 under the Red List review process
(Beever and Smith 2008, p. 3). According to IUCN (version 3.1): ``a
taxon is Least Concern when it has been evaluated against the criteria
and does not qualify for Critically Endangered, Endangered, Vulnerable
or Near Threatened. Widespread and abundant taxa are included in this
category.'' The IUCN uses five quantitative criteria to determine
whether a taxon is threatened or not, and if threatened, which category
of threat it belongs in (i.e., critically endangered, endangered, or
vulnerable). ``To list a particular taxon in any of the categories of
threat, only one of the criteria needs to be met. The five criteria
are: (1) Declining population (past, present and/or projected); (2)
Geographic range size, and fragmentation, decline or fluctuations; (3)
Small population size and fragmentation, decline, or fluctuations; (4)
Very small population or very restricted distribution; and (5)
Quantitative analysis of extinction risk (e.g., Population Viability
Analysis) (IUCN Standards and Petitions Working Group 2008, p. 11).''
However, the IUCN (using the Hall (1981) taxonomic classification,
as Vulnerable or Near Threatened) considers eight American pika
subspecies synonyms. These subspecies synonyms are Ochotona princeps
goldmani, O. p. lasalensis, O. p nevadensis, O. p. nigrescens, O. p.
obscura, O. p. sheltoni, O. p. tutelata, and O. p. schisticeps (Beever
and Smith 2008, p. 3). A vulnerable species or subspecies is facing a
high risk of extinction in the wild. A near threatened species or
subspecies is close to qualifying as or is likely to qualify as
vulnerable in the near future (IUCN, section 3.1). Status for the eight
subspecies synonyms applies under the Hall (1981) taxonomic
classification of the American pika but may not apply to any of the
subspecies described by Hafner and Smith (2009, pp. 16-25). For
example, a status of ``vulnerable'' for O. p. goldmani does not imply
that O. p. princeps (described by Hafner and Smith 2009, pp. 17-20) is
vulnerable as well because the range of O. p. goldmani does not
constitute the entire range of O. p. princeps.
NatureServe is a nonprofit organization that, in part, collects and
manages species information and data in an effort to increase our
understanding of species, ecosystems, and conservation issues
(NatureServe 2009a, p. 1). NatureServe also assesses available
scientific information to determine species status based on factors,
including population number and size, trends, and threats. NatureServe
provides comprehensive reports for species, including American pika.
The report (Nature Service 2009b, pp. 1-7) for the American pika
includes taxonomic information, conservation status information, lists
of natural heritage records, species distribution by watershed, ecology
and life history information, population delineation, population
viability, and references. The report does not contain information on
threats or a justification for designation of conservation status
within states and provinces.
In a review conducted in 1996, NatureServe assigned the American
pika a global status of secure (i.e., common; widespread and abundant)
in the United States and the Canadian provinces of
[[Page 6442]]
Alberta and British and Columbia (NatureServe 2009b, pp. 1-2; Quinlan
2009, pers. comm.). Within the United States, NatureServe considers the
species secure or apparently secure (i.e., uncommon but not rare; some
cause for long-term concern due to declines or other factors) in
Colorado, Idaho, Montana, Oregon, Washington, and Wyoming. NatureServe
assigned the American pika a status of vulnerable in California and
Utah (i.e., vulnerable in the jurisdiction due to a restricted range,
relatively few populations, recent and widespread declines, or other
factors making it vulnerable to extirpation), and a status of imperiled
in Nevada and New Mexico (i.e., imperiled in the jurisdiction, because
of rarity due to very restricted range, very few populations, steep
declines, or other factors making it very vulnerable to extirpation
from the jurisdiction).
Northern Rocky Mountain Subspecies (Ochotona princeps princeps)
The Northern Rocky Mountains subspecies (Ochotona princeps
princeps) occurs primarily in Canada, Montana, Idaho, and Wyoming, with
a smaller amount of occupied habitat in Washington, Nevada, Utah, and
Colorado. Data on status and trends of O. p. princeps are lacking for
portions of the subspecies range. Available data consists mostly of a
list of sites verified to be occupied in recent surveys. In locations
where pika surveys have been conducted, we do not have historical
information of the subspecies' at those sites for comparison.
The Canadian Endangered Species Conservation Council (2005)
assigned a ranking of secure to Ochotona princeps princeps in Alberta
and British Columbia, which are the only two provinces where this
subspecies occurs in Canada. The ranking is based upon occurrence of
large numbers of pikas in secure habitat (British Columbia Conservation
Data Centre 2009, p. 1; Court 2009, pers. comm.). Pikas are common in
suitable habitat in the mountains on both provincial lands and in
national parks (Court 2009, pers. comm.). The population is thought to
be stable in Alberta, Canada (Court 2009, pers. comm.). Greater than
100 occurrences of O. p. princeps occur within Alberta (Court 2009,
pers. comm.). We do not have population trend information for British
Columbia. We do not have any information to suggest the distribution of
the pika is changing in Canada.
In Montana, there is little historical information to assess
whether habitat loss has occurred or if populations are stable. Limited
available data does not indicate a decline. Approximately 90 percent of
available habitat in Glacier National Park is occupied (National Park
Service (NPS) 2009, p. 9). Based upon occupancy rates elsewhere (Utah
Division of Wildlife Resources (UDWR) 2009, pp. 6, 11), we conclude the
occupancy rate of pikas within Glacier National Park is high.
Limited data are available for pika distribution, abundance, and
population status in Wyoming. American pikas occur in every Wyoming
mountain range except Laramie, Wasatch, and Black Hills (Wyoming Game
and Fish Department (WGFD) 2009, p. 1). American pikas are believed to
occur in all locations where they were observed historically within the
Grand Teton National Park (NPS 2009, p. 10). The WGFD will add the
American pika to their 2010 State Wildlife Action Plan (WAP) (WGFD
2009, p. 1). They propose to treat the subspecies as having an Unknown
Native Species Status because population and distribution trends are
unknown and limiting factors are poorly understood (WGFD 2009, p. 1).
In Idaho, the subspecies is broadly distributed and occupies a
substantial number of sites throughout much of the State (Idaho
Department of Fish and Game (IDFG) 2009, p. 1). The IDFG has no
information to suggest threats exist to the subspecies. Pikas are not
identified as a Species of Greatest Conservation Need in the Idaho
Comprehensive Wildlife Conservation Strategy (CWCS) and pikas are
considered to be secure, common, and widespread based on NatureServe's
conservation status (IDFG 2005, App. A, p. 18). O. p. princeps was
studied at Craters of the Moon National Monument in Idaho (Beever 2002,
p. 25; NPS 2009, pp. 2-3), but reports did not reveal any information
related to the status of pika populations there.
Ochotona princeps princeps in Utah currently have a high occupancy
rate (96 percent) in suitable habitat (UDWR 2009, p. 7). Although there
is no historical population information, UDWR believes that the high
occupancy rate reflects stable populations (UDWR 2009, p. 11).
In Colorado, Ochotona princeps princeps is found only in the
northern part of the State. Colorado Division of Wildlife (CDOW) (2009,
p. 19) documented greater than 40 occupied sites based on historic and
recent site surveys. Reports on O. p. princeps in Colorado do not
provide any information on status (NPS 2009, p. 10-12; Ray 2009, pp. 1-
4).
Nevada and Washington have little information on the subspecies
status. American pika records collected from 1969 to 2008 from the Ruby
Mountain chain in northeast Nevada identify at least 33 pika locations
(Nevada Department of Wildlife (NDOW) 2009, pp. 2-3); however, we have
no information on the status of populations from those locations. We
have no information on the status of O. p. princeps in Washington.
As previously stated, Beever and Smith (2008, p. 3) considered
populations of O. p. goldmani, O. p. nevadensis, and O. p obscura,
which represent a portion of the range of O. p. princeps (Hafner and
Smith 2009, pp. 18-19), as vulnerable (i.e., facing a high risk of
extinction in the wild). Additionally, NatureServe (2009, p. 2)
assigned Utah pikas, which contains populations representing all
subspecies except O. p. fenisex, a status of vulnerable (i.e., a
restricted range, relatively few populations, recent and widespread
declines, or other factors making it vulnerable to extirpation).
In summary, most States and provinces that contain populations of
O. p. princeps have not determined the subspecies' status and do not
have information on population trends. Some populations within central
Idaho (O. p. goldmani), northwestern Nevada (O. p. nevadensis), north-
central Wyoming (O. p. obscura), and north-central Utah may be
vulnerable (Beever and Smith 2008, p. 3; NatureServe 2009, p. 2).
Outside of these areas, we do not have adequate information to
determine the status of O. p. princeps populations.
Sierra Nevada Subspecies (Ochotona princeps schisticeps)
The Sierra Nevada subspecies (Ochotona princeps schisticeps) occurs
primarily in California, Nevada, and Oregon with a small portion of
occupied habitat in Utah. This subspecies has received more scientific
study than any other American pika subspecies (Grayson 2005, p. 2104).
Pikas are designated as a vulnerable species as well as a species of
conservation priority in Nevada's WAP, with a declining population (WAP
Team 2006, pp. 291, 405). O. p. schisticeps status appears to be
declining within the interior Great Basin, primarily in southern Oregon
and northwestern Nevada, and some places along the eastern Sierra
Nevada Mountain Range (Beever et al. 2003, p. 44; Wilkening 2007, p.
58); however, outside of these areas there is no indication that the
subspecies is in decline (Millar and Westfall 2009, p. 25). As
identified by Beever et al. (2003, pp. 39, 44), the interior Great
Basin refers to the hydrographic definition of the Great Basin (Grayson
1993, cited in Beever et al. 2003, p. 39).
[[Page 6443]]
As previously mentioned, some isolated populations of O. p.
schisticeps have been extirpated in the interior Great Basin. Beever et
al. (2003, p. 43) did not detect pikas at 6 of 25 historical (dating
back to the early to mid-1900s) populations during surveys from 1994 to
1999 and later documented three extirpations during 2000 to 2007
(Wilkening 2007, pp. 25-27; Beever et al. 2009, p. 15).
Researchers have not systematically searched all potential pika
habitat within the Great Basin and acknowledge that other sites with
pikas may exist (Beever et al. 2009, pp. 31), particularly the Toiyabe
Mountain Range, White Mountains, Toquima Mountain Range, and the Warner
Mountains (Meredith 2002, p. 11; Beever 2009a, pers. comm.). In fact,
two new sites were discovered in the Great Basin in northwestern Nevada
from 2008 to 2009: Hays Canyon (Beever et al. 2008, p. 9) and Sheldon-
Hart National Wildlife Refuge (Collins 2009, pers. comm.). However, the
subspecies is rare in the Great Basin, and likely has been relatively
rare in the Great Basin for the past several thousand years. It is
unlikely that many additional occupied sites will be found (Beever et
al. 2008, p. 11).
Trends of pika status are mixed in other locations within the
subspecies range. Pikas occur within Sequoia and Kings Canyon National
Parks in California along the eastern edge of the Sierra Nevada
Mountain Range, however, the population status is unknown (NPS 2009, p.
6). Pikas are widely distributed throughout Lava Beds National Monument
(Ray and Beever 2007, p. 2) and populations appear to persist in warmer
and drier sites, which is contrary to expectations because pikas are
generally restricted to cool, moist habitats on higher peaks (Hafner
1993, p. 375). The lower elevation range limit of pikas in Yosemite
National Park has contracted and moved upslope by 153 m (502 ft)
(Moritz et al. 2008, p. 263), and at least one historic pika site has
been extirpated within the Park (Moritz 2007, p. 37). Despite this
extirpation, we do not know the status of the entire Yosemite National
Park pika population. Pika populations near Bodie, California, have
experienced decline as well, but not in the largest portion of the
population which contains more suitable habitat and subsequently more
pikas (Moilanen et al. 1998, p. 531; Nichols 2009, pp. 2, 5; Smith
2009, pers. comm.).
The relative number of unoccupied sites increased from the Sierra
Nevada eastward into the Great Basin ranges (Millar and Westfall 2009,
pp. 9, 11). Millar and Westfall (2009, p. 25) concluded that pika
populations in the Sierra Nevada and southwestern Great Basin are
thriving and show little evidence of extirpation or decline. Central
Great Basin populations, on the other hand, appear less viable and more
subject to disturbance from random events (Millar and Westfall 2009, p.
25).
In Utah, a population of pikas at Cedar Breaks National Monument
was extirpated sometime between 1974 and 2006 (Oliver 2007, p. 5). As
of 2009, the site still does not contain pikas (NPS 2009, p. 9). Pikas
may have disappeared from sites near Lava Point in Zion National Park
(NPS 2009, p. 13; Oliver 2007, pp. 7-8). However, pikas occur in other
nearby locations (NPS 2009, p. 9; UDWR 2009, p. 20), demonstrating that
suitable habitat capable of supporting a pika population still exists
in southern Utah. Eighty-four percent of Ochotona princeps schisticeps
suitable habitats in Utah are occupied (UDWR 2009, p. 7).
In summary, despite some of the uncertainty in trends across the
current range of O. p. schisticeps populations, it is clear that some
interior Great Basin pika populations (Beever et al. 2003, pp. 44, 53-
54; Beever et al. 2009, p. 6) are being extirpated and moving upslope
in elevation. The recent loss of low-elevation historical pika
populations near the southern edge of historical range within the Great
Basin appears to track the fossil record (see section on Historic
Distribution and Habitat). The recent rate of population loss is more
rapid than that suggested by paleontological records (Beever et al.
2003, p. 48). The majority of suitable habitat for O. p. schisticeps
occurs outside of the Great Basin in the Sierra Nevada Mountain Range
and a large study area in the Sierra Nevada Mountain Range shows the
status appears to be stable.
Southern Rocky Mountain Subspecies (Ochotona princeps saxatilis)
Even in the absence of survey data for portions of the range of the
Southern Rocky Mountain subspecies, Ochotona princeps saxatilis,
available information suggests that the subspecies is stable across the
majority of its range. Survey data are lacking for portions of the
subspecies' range.
Pikas are well distributed in high-elevation areas of Colorado,
which contains the majority of the subspecies' habitat. Fifty-eight of
62 historical sites surveyed had O. p. saxatilis populations persisting
even at relatively low-elevation 2,743 to 3,048 m (9,000 to 10,000 ft)
sites (CDOW 2009, p. 22; Peterson 2009, pers. comm.). Pika habitat is
extensive in Colorado, and connectivity between pika habitat and
populations appears sufficient to maintain a healthy population
structure (CDOW 2009, p. 22).
In Utah, 92 percent of surveyed suitable pika habitat in the La Sal
Mountains of eastern Utah was occupied (UDWR 2009, p. 7). There is no
evidence of declines of American pika populations from historical
levels in Utah (UDWR 2009, p. 11).
Density and trend data are not available for Ochotona princeps
saxatilis populations in New Mexico (New Mexico Department of Game and
Fish (NMDGF) 2009, p. 2; U.S. Forest Service (USFS) 2009, p. 1). New
Mexico's CWCS lists the Goat Peak pika (was Ochotona princeps
nigrescens, now included in O. p. saxatilis) as a subspecies of
greatest conservation need as well as vulnerable and State sensitive
(NMDGF 2006, pp. 55, 57). However, based on limited field observation,
persistence of O. p saxatilis populations within New Mexico does not
appear to reflect the pattern of recent extirpation observed within the
interior Great Basin (NMDGF 2009, p. 3). Beever and Smith (2008, p. 3)
have assigned O. p. lasalensis and O. p. nigrescens, which now belong
to the O. p. saxatilis subspecies (see Table 1; Hafner and Smith 2009,
p. 21), a status of vulnerable.
Despite some of the uncertainty in status across the range of O. p.
saxatilis in New Mexico, the subspecies appears to be well distributed
throughout the available habitat, especially in Colorado and Utah (CDOW
2009, p. 22; UDWR 2009, p. 11). There is no evidence indicating that
the subspecies is in decline across its range in Utah and Colorado.
Based on other status reviews (Beever and Smith 2008; NatureServe
2009b, p. 2), further monitoring may be warranted for O. p. saxatilis
populations in the Jemez Mountains of New Mexico and La Sal Mountains
of Utah to obtain a current status characterization of this portion of
the subspecies range.
Cascade Mountain Subspecies (Ochotona princeps fenisex)
We have no trend data available for Ochotona princeps fenisex
populations. In many locations where recent pika surveys have been
conducted, no historical information exists for purposes of comparison.
NatureServe has assigned the American pika a status of apparently
secure (i.e., uncommon but not rare; some cause for long-term concern
due to declines or other factors) in Oregon; secure (i.e., common;
widespread and abundant) in the State of Washington; and secure in the
Canadian province of British Columbia.
[[Page 6444]]
All eight survey locations in the Three Sisters Mountains and at
McKenzie Pass, (located in the Cascade Mountain Range) have evidence of
recent pika activity (Millar and Westfall 2009, p. 9). O. p. fenisex
populations also occur in low-elevation (range of 121 to 255 m (397 to
837 ft)) habitat in the Columbia River Gorge, Oregon (Simpson 2009, p.
244). We have population estimates of O. p. fenisex from Mt. St. Helens
from 1992 to 1994 (Bevers 1998, p. 42), but no information on the
population status.
Survey data are lacking for a large portion of O. p. fenisex range,
and no reports indicate population status. Based on the current pattern
of known occupancy and the NatureServe (2009b, pp. 1-2) assessment, the
subspecies is apparently secure.
Uinta Mountain Subspecies (Ochotona princeps uinta)
The Uinta Mountain subspecies, Ochotona princeps uinta, occurs
solely within the State of Utah. The species is believed to have a
relatively high occupancy rate (63 percent) with no evidence of
declines from historical levels (UDWR 2009, pp. 7, 9, 11, 20). Based on
available information, O. p. uinta populations appear stable.
Summary of American Pika Population Status
Most States and provinces that contain populations of O. p.
princeps and O. p. fenisex have not determined the subspecies' status
and do not have information on population trends. Information presented
above suggests that O. p. schisticeps populations in some areas,
primarily in the interior Great Basin, may be in decline. O. p.
saxatilis populations appear to be well distributed throughout the
majority of available habitat and O. p. uinta populations appear
stable. Recent observed trends for O. p. princeps, O. p. saxatilis, O.
p. fenisex, and O. p. uinta subspecies do not seem to mirror the loss
of occupied pika sites and upward range contraction that has been
reported for interior Great Basin populations. There is discrepancy
among reported population trends within California, southern Utah, and
New Mexico. Some information suggests that the species is vulnerable
within some areas of California, southern Utah, and New Mexico (Beever
and Smith 2008; NatureServe 2009b); however, other reports discussed
above suggest that the O. p. schisticeps subspecies is stable or not in
decline (Millar and Westfall 2009, p. 25; NMDGF 2009, p. 3; UDWR 2009,
p. 11).
Summary of Information Pertaining to the Five Factors
Section 4 of the Act and implementing regulations (50 CFR part 424)
set forth procedures for adding species to, removing species from, or
reclassifying species on the Federal Lists of Endangered and Threatened
Wildlife and Plants. Under section 4(a)(1) of the Act, a species may be
determined to be endangered or threatened based on any of the following
five factors: (1) The present or threatened destruction, modification,
or curtailment of its habitat or range; (2) overutilization for
commercial, recreational, scientific, or educational purposes; (3)
disease or predation; (4) the inadequacy of existing regulatory
mechanisms; or (5) other natural or manmade factors affecting its
continued existence. In making this finding, information pertaining to
the American pika in relation to the five factors provided in section
4(a)(1) of the Act is discussed below. In making our 12-month finding
on a petition to list the American pika or any of the five subspecies
of pika, we considered and evaluated the best available scientific and
commercial information. Below, we provide a summary of our analysis of
threats to the five recognized subspecies of the American pika and to
the species as a whole.
A. The Present or Threatened Destruction, Modification, or Curtailment
of its Habitat or Range
The following potential factors that may affect the habitat or
range of American pika are discussed in this section: (1) Climate
change; (2) livestock grazing; (3) native plant succession; (4)
invasive plant species; and (5) fire suppression.
Climate Change
Climate change is a potential threat to the long-term survival of
the American pika. Thermal and precipitation regime modifications may
cause direct adverse effects to individuals or populations. Climate
change has the potential to contribute to the loss of and change in
pika habitat and enhance negative ecological and anthropogenic effects.
The Science of Climate Change
The Intergovernmental Panel on Climate Change (IPCC) concluded that
global climate change is occurring and is caused by human activities,
such as the burning of fossil fuels and clearing of forests (Forster et
al. 2007, pp. 135-136). The IPCC is a scientific intergovernmental body
established by the World Meteorological Organization and the United
Nations Environment Programme ``to assess scientific information
related to climate change, to evaluate the environmental and socio-
economic consequences of climate change, and to formulate realistic
response strategies'' (IPCC 2007, p. iii). The publications of the
IPCC, specifically the four-volume IPCC Fourth Assessment Report:
Climate Change 2007, constitute the best available science on global
climate change. The IPCC Fourth Assessment Report: Climate Change 2007
included the findings of three working groups composed of more than 500
lead authors and 2,000 expert reviewers and provided objective
scientific guidance to policymakers on the topic of climate change
(IPCC 2007, p. iii). We believe the IPCC information is the best
available scientific information on global climate change at a broad
scale.
Historical records analyzed by the IPCC demonstrate that global
surface temperatures have risen (with regional variations) during the
past 157 years, most strongly after the 1970s (Trenberth et al. 2007,
p. 252). Globally, average surface temperatures have risen by 0.074
[deg]C plus or minus 0.018 [deg]C (0.13 [deg]F plus or minus 0.03
[deg]F) per decade during the past century (1906 through 2005) and by
0.177 [deg]C plus or minus 0.052 [deg]C (0.32 [deg]F plus or minus 0.09
[deg]F) per decade during the past quarter-century (1981 through 2005)
(Trenberth et al. 2007, p. 253).
Changes in the amount, intensity, frequency, and type of
precipitation have been summarized by the IPCC (Trenberth et al. 2007,
p. 262). The warming of global temperatures has increased the
probability of precipitation falling as rain rather than snow,
especially in near-freezing situations, such as the beginning and end
of the snow season (Trenberth et al. 2007, p. 263). In many Northern
Hemisphere regions, this has caused a reduced snowpack, which can
greatly alter water resources throughout the year (Trenberth et al.
2007, p. 263). As a result of thermal and precipitation regime changes,
the IPCC expects the snowline (the lower elevation of year-round snow)
in mountainous regions to rise 150 m (492 ft) for every 1 [deg]C (1.8
[deg]F) increase in temperature (Christenson et al. 2007, p. 886).
These predictions are consistent with regional predictions for the
Sierra Nevada in California that calculate that year-round snow will be
virtually absent below 1,000 m (3,280 ft) by the end of the 21st
century under a high emissions scenario (Cayan et al. 2006, p. 32).
Scientists at climate research institutions in the United States
and in over a dozen countries worldwide, have
[[Page 6445]]
generated projections of future climatic conditions both globally and
in the United States, which includes the range of the American pika.
These projections were assessed and synthesized in the Fourth
Assessment Report of the IPCC. The United States Global Change Research
Program (USGCRP) coordinates climate change research from 13
departments and agencies and was mandated by Congress in the Global
Change Research Act of 1990 to, ``assist the Nation and the world to
understand, assess, predict, and respond to human-induced and natural
processes of global change.'' The IPCC has predicted global average
surface warming during the 21st century is likely between 1.1 and 6.4
[deg]C (2.0 and 11.5 [deg]F), depending on the emissions scenario, and
taking into account other sources of uncertainty in the projections
(Solomon et al. 2007, p. 70, Table TS. 6). The recent USGCRP assessment
of climate impacts (Karl et al., 2009, pp. 129, 135) also adopts the
IPCC range of temperature projections for different United States
regions.
On a regional scale, North America is likely to exceed the global
mean warming in most areas (Christenson et al. 2007, p. 850).
Specifically, warming is likely to be largest in winter in northern
regions of North America, with minimum winter temperatures likely
rising more than the global average (Christenson et al. 2007, p. 850).
Across 21 global climate models using a mid-level emissions scenario,
the IPCC predicted that the average annual temperature in western North
America (covering the entire range of the American pika) will increase
between 2.1 and 5.7 [deg]C (median 3.4 [deg]C) (3.8 and 10.3 [deg]F
(median 6.1 [deg]F)) during the 21st century (Christenson et al. 2007,
p. 856). The 2009 USGCRP impacts report projects the Southwest to warm
2 to 6 [deg]C (4 to 10 [deg]F) relative to the 1960-1979 baseline (Karl
et al. 2009, p. 129) and the Northwest to warm by ``another 2 to 6
[deg]C (3 to 10 [deg]F)'' by the end of the century (Karl et al. 2009,
p. 135).
In the 20th century, the Pacific Northwest and western United
States experienced annual average temperature increases of 0.6 to 1.7
[deg]C (1.1 to 3.1 [deg]F) and 1.1 to 2.8 [deg]C (2.0 to 5.0 [deg]F),
respectively (Parson et al. 2001, p. 248; Smith et al. 2001, p. 220).
Temperature increases are expected to affect precipitation, snowpack,
and snowmelt in the range of the American pika. Climate warming
corresponds with a reduced mountain snowpack (Mote et al. 2005 and
Regonda et al. 2005 cited in Vicuna and Dracup 2007, p. 330; Trenberth
et al. 2007, p. 310) and a trend toward earlier snowmelt in western
North America (Stewart et al. 2004, pp. 217, 219, 223). The IPCC
concluded that snow-season length and depth of snowpack are very likely
to decrease in most of North America (Christenson et al. 2007, p. 850).
Leung et al. (2004, p. 75) concluded that future warming increases in
the western United States will cause increased rainfall and decreased
snowfall, resulting in reduced snow accumulation or earlier snowmelt.
Similarly, Rauscher et al. (2008, p. 4) concluded that increased
temperatures in the late 21st century could cause early-season
snowmelt-driven runoff to occur as much as 2 months earlier than
presently in the western United States.
The above information applies at large, general scales. To
understand the changes likely to occur in pika habitat, we worked with
the National Oceanic and Atmospheric Administration (NOAA) to assess
the best available climate science across the range of the American
pika (NOAA 2009, p. 4). The NOAA study reviewed historical climate
observations and climate projections of surface temperatures for 20-
year periods centered on 2025, 2050, and 2100 in alpine and subalpine
mountain areas that are habitat for the American pika. Because model
projections for precipitation are less reliable than for temperature in
this region, their report focused primarily on temperature (NOAA 2009,
pp. 10, 15). We primarily relied on this report to perform
deterministic risk assessments of increased temperature in the
foreseeable future to American pika populations throughout their range
in the western United States. In addition, we used information on
historical climate observations to supplement previous peer-reviewed
publications and other reports from the literature to assess how
temperature increases may have affected pikas in recent decades.
The NOAA's analysis (NOAA 2009, p. 9) revealed an evident warming
trend between 1950 and 2007 in the western United States. Strong
warming trends occurred across 89 percent of the western United States
and 37 to 42 percent of western United States mountain ranges (Das et
al. 2009, cited in NOAA 2009, p. 9). Within the western United States,
warming was documented and is attributable to anthropogenic climate
change (Bonfils et al. 2008, cited in NOAA 2009, p. 11). Some studies
(Barnett et al. 2008, p. 1080; Pierce et al. 2008, p. 6436) have
estimated that up to about half of the trends in temperature and
associated hydrologic variables can be attributed to anthropogenic
causes. Natural climate variability may account for the remainder of
the observed climate change in the western United States, and will
likely play a role in the future climate of that region.
Changes in the hydrologic cycle, including timing of snowmelt
runoff, amount of precipitation falling as snow versus rain, and spring
snow water equivalent, have been documented in the mountains of western
North American and attributed to anthropogenic causes (multiple
references cited in NOAA 2009, p. 8), with the exception of some high-
elevation areas, especially in the Rocky Mountains. Most of the
reduction in snowpack in the western United States has occurred below
about 2,500 m (8,200 ft) (Regonda et al. 2005, cited in NOAA 2009, p.
9). This elevation is near the lower limit of American pikas' elevation
range (Smith and Weston 1990, p. 2); therefore, it can be inferred that
the majority of pika habitat in mountainous areas has not experienced
the large changes in the hydrologic cycle seen at lower elevations.
Climate Change and Pika Biology
Several climate variables are relevant to persistence of American
pika populations because past and present trends in climate have been
identified as having important physiological, ecological, and
demographic consequences. These climate variables include, but may not
be limited to, number of extremely hot or cold days, average summer
temperatures, and duration of snow cover (Beever et al. 2009, pp. 5,
10, 16-18).
In general, pika biologists agree that temperatures below the
habitat surface, such as in talus crevices, better approximate the
conditions experienced by individual pikas because pikas rely on
subsurface refugia to escape hotter summer daytime temperatures and
obtain insulation in the colder winter months (Beever et al. 2009, p.
9). Therefore, surface temperature variables may not be as useful as
subsurface temperatures for predicting persistence or extirpations of
pika populations in the face of climate change. However, data on
subsurface temperatures within pika habitat vary depending on site-
specific conditions and are largely unavailable.
Beever et al. (2009, p. 18) found that average summer (June-July-
August (J-J-A)) below-talus temperature was the best predictor of pika
extirpation. They also discovered two other patterns: (1) The number of
extremely cold and hot days based on estimates of below-talus
temperatures was useful in predicting patterns of pika extirpations
(Beever et al. 2009, p. 18); and (2) the majority of pika-extirpated
sites were covered with
[[Page 6446]]
snow for only 2 weeks or less; whereas, the majority of pika-extant
sites had continuous snow cover for greater than 2 weeks and as long as
8.2 months (Beever et al. 2009, p. 16). Because American pikas are
small and do not hibernate, reduced snowpack can mean a lack of
insulation from cold winter temperatures (Morrison and Hik 2008, p.
905). Exposure to colder temperatures could have an adverse effect on
pika individuals and populations as a result of increased energy
expenditure during a time of year where food resources are limited
(Smith et al. 2004, p. 5). However, pika biologists have not determined
the actual effects of acute cold-stress on pikas (Beever et al. 2009,
p. 29).
The population collapse of a closely related pika species, the
collared pika (Ochotona collaris), was related to warmer winters that
resulted in low snow accumulation (and, therefore, poor insulation
value), increased frequency of freeze-thaw events, icing following
winter rains, and late winter snowfalls that delay the start of the
growing season (Morrison and Hik 2008, pp. 104-105, 110). Following a
decline in population abundance, populations recovered in subsequent
years, in some cases to near pre-decline levels (Morrison and Hik 2007,
pp. 902-903). Declines in snowpack and earlier montane snowmelt are
predicted to occur within the next century, and winter survival of the
American pika may consequently decrease. Alternatively, earlier
snowmelt could improve pika survival and positively affect American
pika populations (Morrison and Hik 2007, p. 905). Based on the
available information there does not appear to be a direct line of
evidence linking reduced snowpack to reductions in American pika
populations.
Several lines of evidence have been used to suggest that thermal
stress will adversely impact the American pika. Wolf et al. (2007, p.
43) pointed out that increasing temperatures will eliminate cool, moist
refugia in talus habitat, causing individuals to be unable to
thermoregulate in summer months. However, Millar and Westfall (2009, p.
25) stated that non-rock-ice features will likely become warmer and
more marginal for pikas, but environments with rock-ice features are
highly likely to remain buffered against temperature change due to the
insulation of rock features. Millar and Westfall (2009, p. 10)
documented that 83 percent of over 400 surveyed pika sites in the
Sierra Nevada and Great Basin occurred in rock-ice landforms,
indicating that pikas have a preference for these types of
environments. Therefore, we expect pika habitat that contains rock-ice
features or features that are similar to rock-ice (i.e., talus or
talus-like environments) to be buffered from rising surface
temperatures. We are not aware of any studies that have identified the
distribution of these types of features, and thus we are not able to
use that type of information to help us increase the sensitivity of our
climate change threats analysis.
Wolf et al. (2007, p. 44) also state that, even if the talus
refugia remain cool, ambient external temperatures may reduce an
individual's ability to forage during midday. They assert that if pika
individuals cannot adequately forage in the summer months, they may not
have the required body mass or haypile volume needed for winter
survival. However, pikas at low elevations restrict their activity when
temperatures exceed their thermal tolerance but are able to obtain
enough food and overwintering vegetation (hay pile) during the morning
and evening so that long-term population persistence is not affected
(Smith 1974a, pp. 1117-1118; Smith 1974b, pp. 1370-1372; Smith 2009, p.
4).
Warmer summer temperatures may affect the ability of juvenile pikas
to successfully disperse and colonize new areas (Smith 1974a, p. 1112;
Smith 1978, p. 137; Wolf et al. 2007, p. 44). Because dispersal occurs
on the habitat surface, dispersing pikas are exposed to the hottest
temperatures on the surface of their environment. Hotter surface
temperatures may decrease the distance juveniles are able to travel in
search of new habitat patches, but primarily in warmer, low-elevation
habitats. A pika metapopulation range may decline if juveniles are
unable to colonize new patches or immigrate to other populations.
Wilkening (2007, pp. 36-37) suggested that a greater depth of
available talus should be positively associated with pika persistence,
and pika populations located in habitat with shallow talus or small
diameter rocks of similar size might be susceptible to adverse effects
of increasing temperatures. With the appropriate assemblage of talus
structural features, below-talus microclimate might be less thermally
variable and more suitable for pikas (Millar and Westfall 2009, p. 21).
Studies from Lava Beds National Monument support this hypothesis by
demonstrating that talus depth (amount of insulation) was one of the
strongest predictors of pika occurrence (Ray and Beever 2007, p. 45).
Based on these data, it is likely that habitat with sub-optimal talus
characteristics would be less likely to support pika populations under
projected warming scenarios.
American Pika Responses to Climate Change
Past and Present Trends
Recent climatic change, including increased temperatures, freeze-
free periods, and changes in precipitation is an important driving
force on ecosystems and has affected a wide variety of organisms with
diverse geographic distributions (Walther et al. 2002, pp. 391-392;
Parmesan and Yohe 2003, p. 41). Many plant and animal species have
advanced the timing of spring events (e.g., plant flowering or bird
migration) and experienced a shift in latitudinal and altitudinal range
(i.e., movement to higher latitudes or higher altitude) (Walther et al.
2002, pp. 391-392).
The biology of the American pika makes the species a useful
indicator of changing climatic conditions and useful to test extinction
theory (Smith et al. 2004, p. 5; Smith 2009, p. 2). The species lives
in a very narrow ecological habitat (primarily talus) that is
frequently fragmented or patchily distributed. They are generally poor
dispersers, and thus the narrow niche may expose some populations to
negative effects associated with increasing temperatures (Smith 1974b,
p. 1372; Smith 2009, p. 2). However, pikas also may exhibit
considerable behavioral and physiological flexibility that may allow
them to persist in environmental conditions that humans perceive to be
outside of the species' ecological niche (Smith 2009, p. 4).
The distribution of American pikas from prehistoric times to the
present is a result of changing climatic conditions. Pika population
occurrences in the southern Rocky Mountains are closely tied to the
past and present distribution of alpine permafrost conditions, with
altithermal (i.e., a dry postglacial interval centered about 5,500
years ago during which temperatures were warmer than at present)
warming accounting for 66.7 percent of all post-Wisconsinan period
population extirpations (Hafner 1994, p. 375). Climate change and
subsequent impacts on vegetation determined the distribution of the
American pika in the Great Basin (Grayson 2005, p. 2103). The present
distribution of the American pika in the Great Basin is approximately
783 m (2,568 ft) higher in elevation than the distribution during the
late Wisconsinan and early Holocene periods (Grayson 2005, p. 2103),
demonstrating an elevational retreat tracking colder microclimates.
[[Page 6447]]
While these trends, acting over long timescales, demonstrate the role
of historical climate conditions in shaping pika distribution, we have
evidence that recent climate change has caused additional contractions
in the American pika's range within some localities.
NOAA (2009, pp. 11-14) analyzed past climate observations at 22
sites known to be recently or currently occupied by American pikas.
They analyzed the observations in detail for a subset of sites along
the southern Nevada/California border, southern Oregon, and northern
California, where recent pika extirpations were documented in the Great
Basin; however, NOAA's analyses were not limited to these regions (see
Figure 1 in NOAA 2009, p. 1). Along the southern Nevada/California
border, the summers of the last decade showed a pronounced warming
trend (NOAA 2009, p. 12). By comparison, nearly all extirpated sites
within the Great Basin are associated with relatively low elevations
with little suitable habitat accessible nearby at higher elevations,
which is in agreement with previous reports (Beever et al. 2003, p. 48;
Wilkening 2007, p. 32). Southern Oregon and northern California
experienced less pervasive warming over the past 75 years in these
regions when compared to Nevada (NOAA 2009, p. 14). However, the last
30 years in southern Oregon and northern California feature a
pronounced warming in the summer (NOAA 2009, p. 14). Based on
observations of climatology in areas known to contain American pikas,
it is apparent that pikas have been and currently are being exposed to
warmer temperatures, which may correlate with extirpations in Nevada,
Oregon, and California.
The American pika appears to be experiencing habitat shifts in some
areas, including an increasing rate of upslope movement (Beever 2009b,
pers. comm.); the disappearance of populations at relatively lower
elevations and hotter sites (Beever et al. 2003, pp. 45, 49; Beever et
al. 2009, pp. 16-18); and loss of populations from habitats that do not
maintain adequate snowpack levels (Smith et al. 2004, p. 5; Morrison
and Hik 2008, p. 905; Beever et al. 2009, p. 16).
A few reports have documented 20th century range contractions in
both the Great Basin and the Sierra Nevada. A study of Great Basin pika
populations found that 7 of 25 populations, which is a subset of all
pika-occupied sites within the Great Basin, appeared to have
experienced extirpations between 1994 and 1999 (Beever et al. 2003, p.
37). Of these, one site was subsequently determined to be occupied
(Wilkening 2007, p. 26). The most recent information indicates that 9
out of 25 (36 percent) historically occupied pika sites within the
Great Basin have been extirpated (Krajick 2004, p. 1602; Wilkening
2007, p. 46). These 25 sites in the Great Basin were first described in
1946 by Hall (pp. 587-593). Elevation is an important parameter in
models predicting the persistence of pika populations, and thermal
effects (because it is typically hotter at lower elevations) are the
primary reason for recent extirpations. Thermal effects have also
influenced recent persistence trajectories of Great Basin populations
of pikas (Beever et al. 2003, pp. 43, 46-47; Beever 2009, pp. 1, 3).
Other anthropogenic factors may affect persistence to a lesser degree
(Beever 2009, pp. 1, 3), such as proximity to roads, habitat size, and
livestock grazing, particularly when assessed cumulatively with
environmental conditions (Beever et al. 2003, p. 46).
Millar and Westfall (2009, p. 12) similarly documented that
unoccupied historical pika sites were associated with significantly
higher warmer maximum surface temperatures than occupied sites. In
general, their survey sites in the Great Basin had colder winter and
warmer summer temperatures than their survey sites in the Sierra Nevada
(Millar and Westfall 2009, p. 13). The authors also documented that
unoccupied pika sites were significantly more likely to be associated
with southern aspects, which receive more direct sunlight and,
therefore, may experience warmer temperatures, than occupied pika sites
(Millar and Westfall 2009, p. 11).
Long-term responses of small mammal communities to recent climate
change were studied in the Sierra Nevada (Moritz et al. 2008, pp. 261-
264). Because the study area has been protected since 1890, responses
to climate change were not confounded by land-use effects (Moritz et
al. 2008, p. 261). Range contractions were documented in high-elevation
species and upward range expansion in low-elevation species (Moritz et
al. 2008, p. 262). The lower range limit of the American pika within
their study site shifted 153 m (502 ft) upslope from approximately 1920
to present (Moritz et al. 2008, p. 263). Based on the Great Basin and
Sierra Nevada studies, temperatures provide the most likely explanation
for observed range shifts in American pika populations.
Despite the trends of increasing pika extirpations in the Great
Basin and upward range expansion as a response to increasing
temperatures, there is ample evidence suggesting the species can
survive and thrive in habitats with relatively hot surface
temperatures. American pika populations thrive at a low-elevation
(2,550 m (8,366 ft)) site in the mountains near Bodie, California,
where August daily maximum shade temperatures approach 30 [deg]C (86
[deg]F) at the hottest time of day (Smith 1974a, p. 1117; Smith 1974b,
p. 1369). Pikas persist here, because they reduce activity during hot
mid-day temperatures by retreating to significantly cooler conditions
under the talus surface (MacArthur and Wang 1974, p. 357; Finn 2009a,
pers. comm.; Millar and Westfall 2009, pp. 13-14), and perform
necessary daily activities during the cooler morning and evening
periods (Smith 1974b, p. 1370). Despite altering their behavior in
response to high temperatures, pikas maintain high birth and low
mortality rates (Smith 1974a, p. 1117).
American pikas also persist in the hot climates of Craters of the
Moon and Lava Beds National Monuments (Idaho and California,
respectively). Average and extreme maximum surface temperatures in
August at these sites are 32 [deg]C (90 [deg]F) and 38 [deg]C (100
[deg]F), respectively (Western Region Climate Center 2009, p. 1). Pika
persistence at these sites is noteworthy because the climate is an
estimated 18 to 24 percent drier and 5 to 11 percent warmer during the
hottest months of the year than experienced at the interior Great Basin
locations where pikas have been extirpated (Beever 2002, pp. 26-27).
Three habitat characteristics seem important to these two
California and Idaho populations: large, contiguous areas of rocky,
volcanic habitat; average or greater than average amounts of accessible
vegetation; and microtopography with rocks large enough for subsurface
movement and tunneling by pikas (Beever 2002, p. 28). With suitable
structural habitat, American pikas persist in climates that typically
would be considered too hot for the species.
Pikas persist at low-elevation (2,400 to 2,500 m (7,874 to 8,202
ft)), relatively warm sites in areas adjacent to human disturbance and
lacking in accessible vegetation (Smith 2009, p. 5). Pikas exist in
environments not typically viewed as suitable pika habitat. For
example, pikas were found at a low-altitude (2,400 to 2,500 m (7,874 to
8,202 ft)) site adjacent to an area of human land-use that was almost
barren of vegetation; yet, biologists found a robust haypile (Smith
2009, p. 5). This information suggests the species tolerates a wider
range of environmental conditions than previously thought.
[[Page 6448]]
Habitat structure appears to be just as or more important of a
predictor of pika population persistence as temperature. The amount of
talus habitat appears to be the strongest individual variable useful
for predicting persistence. In 17 of 18 instances, populations in
mountain ranges with moderate to large amounts of talus remained extant
(Beever et al. 2003, pp. 43, 47; Wilkening 2007, p. 33). Pika island
(patch) size was the most important persistence factor near Bodie,
California (Smith 1974a, p. 1114).
We believe recent American pika range contractions that have
occurred or are occurring in one locality or region should not be
assumed to have occurred or be occurring in other areas. For example,
American pika have been documented moving upslope in the Great Basin
and Yosemite National Park; however, populations in the Sierra Nevada
occur 650 m (2,132 ft) below historically known low-elevation pika
sites (Millar and Westfall 2009, p. 16), and therefore have not moved
upslope in this region. Given the available information we conclude
that the species range has not contracted upslope on a range-wide basis
in the recent past and changes in the elevation range of the species
appear to be site-specific. Persistence of lower elevation sites is
likely related to local climate, habitat structure, geomorphology, and
intra-talus microclimate (Millar and Westfall 2009, pp. 16-23).
Based on information we have obtained from a variety of sources, it
is apparent that American pika have responded to long-term climate
change (10,000 to 40,000 years) as seen by the current patchy
distribution of the species at generally higher elevations,
particularly in the southern portion of it range. The species also
appears to be responding to shorter term climatic change in the last
century in some locations. Some lower elevation populations in the
southern portions of the species range have been extirpated and some
have shown evidence of upslope movement in response to increased
temperatures. Responses of American pika to changing climatic
conditions are variable as a result of localized environmental
conditions.
We are unaware of any losses of American pika populations outside
the interior Great Basin as a response to climate change (see
Population Status section). We acknowledge that there is evidence that
eastern Sierra Nevada and Great Basin pikas may be responding to recent
climate change (Beever et al. 2009, p. 18). These effects are most
prevalent at low elevations.
Future Trend Projections
The timeframe over which the best available scientific information
allows us to reliably assess the effect of climate change on the
American pika is a critical component of our status review and finding.
The projections generated by NOAA (2009) for surface temperature in
pika habitat centered on 2025, 2050, and 2100, but the study concludes
that projection results over the next 30 to 50 years are more reliable
than projections over the next 80 to 100 years (NOAA 2009, p. 8).
Until about 2050, greenhouse gas emissions scenarios (reviewed in
IPCC Special Report on Emission Scenarios in 2000 as cited in NOAA
2009, p. 8), which are an essential component of any climate change
assessment, result in a similar range of projections of global and
regional climate change (NOAA 2009, p. 8). Temperature increases over
the next 30 to 50 years are relatively insensitive to the emissions
scenarios used to model the projected change. Some warming as projected
in the greenhouse gas emissions scenarios is anticipated as a result of
greenhouse gases already in the atmosphere that will influence future
climate; however, this is more so for mid-century versus late century
(Meehl et al. 2007, p. 749). For a given emissions scenario there is
still a range in the spread of the model projection. This spread is due
both to details in the formulation of the models that differ among the
individual models and to natural variability in climate that is
simulated by the models. Because increases of greenhouse gas emissions
have lag effects on climate and projections of greenhouse gas
emissions, it can be interpreted with greater confidence until
approximately mid-century, model projections for the next 30 to 50
years (centered on 2050) have greater reliability than results
projected further into future.
The range of projections for surface temperatures beyond mid-
century will partially depend on human population growth, technological
improvements, societal and regulatory changes, and economic growth
effects to greenhouse gas emissions. Reports from the IPCC Fourth
Assessment (Meehl et al. 2007, p. 749) and Mote and Salathe[aacute]
(2009, p. 30) reach a similar conclusion about the reliability of
projection results until mid-century versus results for the end of the
21st century. On the basis of NOAA's report (2009, p. 8) and other
supplemental information (Meehl et al. 2007, p. 749; Mote and
Salathe[aacute] 2009, p. 30), we have determined that climate changes
for 2025 and 2050 are more reliable than projections for the second
half (up until 2100) of the 21st century. As such, we consider the time
period from 2025 to 2050 to represent the foreseeable future for the
purposes of our evaluation and this finding. Nonetheless, it should be
noted that the IPCC projections indicate continued global and regional
warming into the second half of this century, and if emissions follow
the higher scenarios, warming in 2090 could be double that in 2050.
There are a few studies that attempt to project future pika trends.
McDonald and Brown (1992, pp. 409-415) applied the theory of island
biogeography to isolated mountaintop ranges in the Great Basin of
western North America and modeled potential extinctions brought on by
changing climatic conditions. They predicted that the American pika
would be locally extirpated within the next century from four of five
mountain ranges in the Great Basin assuming a less than 3 [deg]C (5.4
[deg]F) increase in temperature (McDonald and Brown 1992, p. 411, Table
1). Broader ecological results of the model indicate that mountain
ranges would lose 35 to 96 percent of their boreal habitat and 9 to 62
percent of boreal mammal species, depending on the mountain range in
question (McDonald and Brown 1992, p. 413). At this point, the fate of
pika populations occupying portions of the five mountain ranges
discussed in McDonald and Brown (1992) is unclear because pikas still
exist in the five mountain ranges analyzed and we are aware of only one
metapopulation that has been extirpated from one of the five mountain
ranges in the last 15 years (Wilkening 2007, p. 46).
Other researchers have used the species-climate envelope modeling
approach (Pearson and Dawson 2003, p. 361; Arau[aacute]jo et al. 2005,
p. 529), also known as ecological niche or bioclimatic envelope
modeling, to generate projections of altered American pika
distributions by the late 21st century. Essentially, a species'
ecological niche is the range of biological and physical conditions
under which an organism can survive and grow (Hutchinson 1957, cited in
Pearson and Dawson 2003, p. 362). A bioclimatic envelope model is one
that relates a species current distribution to its climatic driving
forces, and then applies scenarios of future climate change to project
a redistribution of the species' climate space (Pearson and Dawson
2003, p. 361). Bioclimatic models typically consider only climatic
variables and do not include other environmental, biotic or abiotic,
factors that influence the distribution of species. These models are
potentially
[[Page 6449]]
powerful tools for predicting the potential effects of climate change
to animal distributions, including those of American pikas; however,
Guisan and Thuiller (2005, pp. 1003-1004) and Hijmans and Graham (2006,
p. 2) state that the usefulness of these models for guiding
policymaking and conservation planning are limited.
In one such model, Loarie et al. (2009, p. 2) predicted that 9 of
427 (2 percent) extant pika sites will have an annual extirpation
probability greater than 5 percent in 2010. By 2099, they predict the
annual extinction probability of extant pika sites increases to 21
percent (range of 2 to 30 percent) under a medium emissions scenario
(Loarie et al. 2009, p. 5). They also predict that the percentage of
427 sites with a greater than 50 percent probability of persisting from
2010 through 2099 is 60 percent (range of 51 to 81 percent) under a
medium emissions scenario (Loarie et al. 2009, p. 5). In the Great
Basin, persistence probabilities in 2099 will be lower than the range-
wide average, equaling 44 percent under the medium emissions scenario.
According to this model, only 11 percent of pikas within the species
current range have a very high (95 percent) probability of surviving
from 2010 through 2099. By 2100, the areas with the highest predicted
probabilities of persistence occur primarily in the high elevations of
the southern Rocky Mountains, Yellowstone National Park region,
portions of the Northern Rocky Mountains, Uinta Mountains, Olympic
Mountains, and a small portion of the Sierra Nevada (Loarie et al.
2009, p. 13, Figure 3).
Such extensive loss of suitable pika habitat across the range of
the American pika in the United States has been projected by others as
well. Trook (2007, pp. 6-16) used a similar approach as Loarie et al.
(2009, pp. 2-5), and predicted dramatic declines in pika range over the
next 80 years for projections centered on 2090 (10-year average from
2085 to 2095). His projections estimated the amount of suitable habitat
for low, medium, and high emission scenarios would represent an 81
percent decrease, 86 percent decrease, and 98 percent decrease in
suitable habitat across the range of the species in the United States
(Trook 2007, p. 19). Under this model, areas that would experience the
greatest loss, or complete disappearance, of suitable habitat include
the Cascade Mountains, the northern Rocky Mountains, and isolated
mountain ranges within Nevada (Trook 2007, p. 19). Galbreath et al.
(2009a, pp. 13-16) also predicted extensive loss of suitable pika
habitat under a scenario where atmospheric carbon dioxide (a major
greenhouse gas) concentrations are double their current levels
(Galbreath et al. 2009, p. 20). Particular losses were projected in the
Sierra Nevada and throughout the southwestern portion of the species
range (Galbreath et al. 2009, pp. 20, 45, Figure 5c).
As stated earlier, Guisan and Thuiller (2005, pp. 1003-1004) and
Hijmans and Graham (2006, p. 2) state that the usefulness of
bioclimatic envelope models is limited for several reasons, which
include making unrealistic assumptions of species distributions being
at equilibrium with current climate, interpreting species-climate
relationships as if indicating causal mechanisms, and ignoring the
biotic interactions between species (Pearson and Dawson 2003, p. 361;
Hampe 2004, pp. 469-470). Climate can be considered a dominant factor
at the continental scale, while at more local scales factors such as
topography and land-cover type become important (Pearson and Dawson
2003, p. 368). Such is the case of the American pika, a species that is
not only generally tied to cool, moist climate, but also is reliant
upon particular topographical features and land-cover types such as
talus, rock-ice features, and volcanic substrates and the features
(such as caves or crevices) contained within them. If conditions at the
landscape level are satisfied, biotic interactions and microclimate may
become even more significant to species such as the American pika
(Pearson and Dawson 2003, p. 368). Climate forecasts of species
distributions are intended to be accurate at spatial resolutions at
much coarser levels than the resolution of field data that have been
collected for American pikas (Beever et al. 2009, p. 19).
We point out the following reasons for considering the bioclimatic
envelope models discussed above as not being useful for the American
pika status review:
(1) All three reports (Galbreath et al. 2009a, p. 14; Loarie et
al. 2009, p. 5; Trook 2007, p. 6) provide projections for beyond mid-
century; as stated earlier, we have determined that climate changes
predictions for 2025 and 2050 are more reliable than projections for
the second half (up until 2100) of the 21st century.
(2) Authors used relatively few explanatory (climate) variables in
modeling current and future suitable habitat; none of the variables
included those which are known to be important predictors of pika
persistence, such as land-cover type (e.g., talus), microclimate, or
other physical habitat features.
(3) Bioclimatic envelope models for pikas base persistence
projections on surface temperatures. However, we determined that
temperatures below the habitat surface, such as in talus crevices, are
more important for survival of individual pikas and are a better
predictor of persistence (see Climate Change and Pika Biology section).
(4) None of the models factor in the pika's documented behavioral
ability to avoid warmer temperatures during the hottest part of the
day.
Because of the problems associated with relying solely on available
bioclimatic envelope models, we partnered with NOAA to assess
temperature projections for the western United States and 22 pika-
relevant sites representing the 5 subspecies (Ochotona princeps
princeps (Northern Rockies), O. p. saxatilis (Southern Rockies), O. p.
fenisex (Coast Mountains and Cascade Range), O. p. schisticeps (Sierra
Nevada and Great Basin), and O. p. uinta (Uinta Mountains and Wasatch
Range of Central Utah) (Hafner and Smith 2009, pp. 16-25) across the
range of the species (NOAA 2009, pp. 1, 15-21). This information was
useful in our analysis to determine if pikas would experience
significant risk of extirpation within the foreseeable future.
The average projection of annual mean temperature increase for much
of the interior western United States by 2050 is approximately 2.2
[deg]C (range from 1.4 to 3.0 [deg]C (4 [deg]F (range from 2.5 to 5.5
[deg]F)) (NOAA 2009, p. 15). Summers are predicted to warm more than
winters (mean of 2.8 [deg]C (5 [deg]F) vs. 1.7 [deg]C (3 [deg]F)). In
general, the dominant precipitation pattern in North America projects a
wetter climate in northern portions of North America and a drier
climate in the southwestern United States (NOAA 2009, p. 15); however,
as previously stated, for much of the range of the American pika,
precipitation projections diverge and are not in agreement (NOAA 2009,
p. 15). The Washington Climate Change Impacts Assessment has projected
an increase in average annual Pacific Northwest temperature of 1.1
[deg]C (2.0 [deg]F) by the 2020s and 1.8 [deg]C (3.2 [deg]F) by the
2040s when compared to climate observations from 1970 to 1999 (Mote and
Salathe[aacute] 2009, p. 21). By 2050, the summer J-J-A climate has
moved northward in latitude and the climate zones of the valleys and
mountains has migrated upward in elevation (NOAA 2009, p. 16).
Projections for climate at 22 sites anchored on pika observations
tell a similar story to what is projected for the
[[Page 6450]]
western United States. Using established methods and existing gridded
temperature datasets (see NOAA 2009, pp. 15-20), NOAA generated site-
specific projections for surface temperatures within elevation bands
known to harbor pikas (Table 1). In Table 1, we present NOAA's
calculations for the J-J-A mean surface temperatures from 1950 to 1999
(Column 4) and compare them to J-J-A mean surface temperature
projections for 2050 (Column 5) using a medium emissions scenario. The
projections shown here are for the average of the climate model
projections considered. The NOAA study (2009, p. 19) also considers
high- and low- end model projections. High-end projections are
approximately 1 [deg]C (1.8 [deg]F) warmer than the multi-model
average, and would indicate increased risk at a number of sites,
including at the maximum elevations in some study areas.
For 2025 and 2050, projections from all three emissions scenarios
(low, medium, and high) are nearly the same; therefore, their datasets
reflect projected surface temperatures into the foreseeable future (a
20-year average centered on 2050). Upon calculating the J-J-A mean
historical and projected surface temperatures at a mean elevation of
the temperature gridcell (Column 2 in Table 1), NOAA (2009, pp. 26-27)
performed a simple calculation using lapse rates (the change in
temperature with changes in elevation) to determine the projected
temperatures at the mean elevation to the actual minimum and maximum
elevation of pika observations (Column 3 in Table 1) used in the
analysis.
Table 1. Historical (1950 - 1999) climatology and J-J-A projections for average daily temperature at elevation
for 22 historical American pika study areas.
Temperature range of minimum and maximum elevation sites in each study area based on a simple lapse rate
adjustment is shown in parentheses. Bold text indicates that the locations in the study area at the elevation of
the gridcell used in the temperature analysis by NOAA, or at the minimum or maximum elevations, may be at higher
risk from increased J-J-A temperature. Measure of risk is equal to or greater than 16.2 [deg]C (61.2 [deg]F).
Multi-model average projections shown here. The NOAA study (NOAA 2009) also considers high- and low- end model
projections.
----------------------------------------------------------------------------------------------------------------
Historical J-J-A Projected J-J-A
Mean Elevation of Range of Pika Mean Surface Mean Surface
SITE Temperature Observations (ft) Temperature Temperature
Analysis (ft) ([deg]C) ([deg]C)
----------------------------------------------------------------------------------------------------------------
O. p. fenisex
----------------------------------------------------------------------------------------------------------------
Crater Lake 7,121 6,436 - 7,660 10.6 (12.0 - 9.6) 13.2 (14.5 - 12.1)
----------------------------------------------------------------------------------------------------------------
Mt. Hood/Three Sisters 8,062 6,242 - 7,621 9.85 (13.5 - 10.7) 12.4 (16.0 - 13.3)
----------------------------------------------------------------------------------------------------------------
Mt. St. Helens 3,691 3,000 - 4,200 13.3 (14.3 - 12.5) 15.7 (16.7 - 14.9)
----------------------------------------------------------------------------------------------------------------
North Cascades/Mt. Baker 5,237 3,800 - 7,210 10.0 (12.9 - 6.1) 12.5 (15.4 - 8.6)
----------------------------------------------------------------------------------------------------------------
O. p. princeps
----------------------------------------------------------------------------------------------------------------
Bighorn Mtns 12,048 * 7.2 (NA) 10.2 (NA)
----------------------------------------------------------------------------------------------------------------
Clearwater Mtns 8,141 * 11.1 (NA) 14.1 (NA)
----------------------------------------------------------------------------------------------------------------
Gallatin National Forest 9,167 9,180 10.4 (NA) 13.4 (NA)
----------------------------------------------------------------------------------------------------------------
Glacier National Park 6,158 4,574 - 8,337 11.0 (14.1 - 6.7) 13.7 (16.9 - 9.4)
----------------------------------------------------------------------------------------------------------------
N. Wasatch Mtns 9,755 8,472 - 10,800 13.2 (15.7 - 11.1) 16.5 (19.0 - 14.4)
----------------------------------------------------------------------------------------------------------------
Ruby Mtns 9,676 8,664 - 10,413 14.1 (16.1 - 12.6) 17.4 (19.4 - 15.9)
----------------------------------------------------------------------------------------------------------------
Sawtooth Range 9,085 6,857 - 8,382 11.3 (15.7 - 12.7) 14.4 (18.8 - 15.8)
----------------------------------------------------------------------------------------------------------------
Wind River/Bridger-Teton 12,154 * 6.3 (NA) 9.6 (NA)
----------------------------------------------------------------------------------------------------------------
O. p. saxatilis
----------------------------------------------------------------------------------------------------------------
Sangre de Cristo Mtns 11,197 7,562 - 12,263 9.8 (17.0 - 7.7) 12.7 (19.9 - 10.6)
----------------------------------------------------------------------------------------------------------------
Southern Rockies 10,781 9,715 - 14,000 12.1 (14.2 - 5.7) 15.2 (17.3 - 8.8)
----------------------------------------------------------------------------------------------------------------
O. p. uinta
----------------------------------------------------------------------------------------------------------------
Eastern Uintas 11,916 9,810 - 12,076 7.5 (11.6 - 7.2) 10.8 (15.0 - 10.5)
----------------------------------------------------------------------------------------------------------------
O. p. schisticeps
----------------------------------------------------------------------------------------------------------------
Bodie Mtns 8,841 8,530 - 8,635 12.3 (12.9 - 12.7) 15.2 (15.8 - 15.6)
----------------------------------------------------------------------------------------------------------------
SE Oregon 7,600 5,800 - 7,925 12.8 (16.4 - 12.2) 15.9 (19.4 - 15.2)
----------------------------------------------------------------------------------------------------------------
Monitor Hills 8,250 8,105 - 8,822 13.0 (13.3 - 11.9) 16.0 (16.3 - 14.8)
----------------------------------------------------------------------------------------------------------------
Sierras/Yosemite 10,270 9,657 - 11,160 9.0 (10.2 - 7.2) 11.8 (13.0 - 10.0)
----------------------------------------------------------------------------------------------------------------
[[Page 6451]]
S. Wasatch Mtns 10,520 8,472 - 10,800 12.9 (16.9 - 12.3) 16.0 (20.0 - 15.4)
----------------------------------------------------------------------------------------------------------------
Toiyabe Mtns 9,092 7,896 - 11,023 12.4 (14.8 - 8.6) 15.5 (17.9 - 11.7)
----------------------------------------------------------------------------------------------------------------
Warner Mtns 7,326 5,429 - 8,267 14.8 (18.6 - 13.0) 17.8 (21.5 - 15.9)
----------------------------------------------------------------------------------------------------------------
* Local summit chosen as a representative site. Range of pika observations not available. NA = Not Available.
The resulting 2050 J-J-A projections for surface temperatures are
consistently higher than the recent climatology by approximately 3
[deg]C (5.4 [deg]F), which is consistent with a projected increase in
temperature on a west-wide United States basis (NOAA 2009, p. 29). The
low model projections are in most cases higher than the 90th percentile
of recent climatology, which suggests that the coolest summers of the
mid-21st century at the 22 pika sites will be warmer than the hottest
summer of the recent past (NOAA 2009, p. 19). The NOAA states that the
set of projections for surface temperatures in 2050 are statistically
different from the historical climatology.
Based on NOAA's calculations (NOAA 2009, p. 20), we compared past
versus projected climatology for each of the 22 pika sites chosen to
represent habitats for the five subspecies (Ochotona princeps princeps,
O. p. saxatilis, O. p. fenisex, O. p. schisticeps, and O. p. uinta)
across the range of the species.
Chronic heat-stress (e.g., recent average summer (J-J-A) subsurface
temperatures) was identified as the best predictor of pika extirpations
(Beever et al. 2009, p. 18). Pika-extirpated sites from the Great Basin
had warmer below-talus temperatures than pika-extant sites from time
periods 1945-1975, 1976-2006, and 2005-2006 (Beever et al. 2009, Table
1), with the strongest predictive ability of heat stress metrics being
based on recent climate during 2005-2006 (Beever et al. 2009, pp. 13,
18). For the most recent time period, below-talus (0.8 m (2.6 ft)
subsurface) temperatures from extirpated sites had a mean temperature
of 17 [deg]C (62.6 [deg]F) plus or minus one standard error of 0.8
[deg]C (1.4 [deg]F) when compared to a mean temperature of 12.4 [deg]C
(54.3 [deg]F) plus or minus one standard error of 1.0 [deg]C (1.8
[deg]F) for extant sites. Therefore, we assumed that warmer below-talus
temperatures increase the risk of extirpation to American pikas.
The following discussion analyzes the effects on pika populations
of: (1) Historical mean summer surface temperatures; (2) projected mean
summer surface temperatures; and (3) estimated subsurface temperatures.
As stated previously, below-talus temperatures from extirpated sites
had a mean temperature of 17 [deg]C (62.6 [deg]F) when compared to a
mean temperature of 12.4 [deg]C (54.3 [deg]F) for extant sites (Beever
et al. 2009, Table 1). However, we were unable to convert historical
and projected average summer surface temperatures to below-talus
temperatures at the 22 pika sites used in NOAA's analysis.
Relationships between surface and subsurface temperatures at the 22
pika sites are not known. The relationship between surface and
subsurface temperatures is not linear and is site-specific, making it
impossible to generalize across the range of a subspecies or the
species as a whole. Therefore, we used a mean surface temperature of
16.2 [deg]C (61.2 [deg]F), which is equal to 17 [deg]C (62.6 [deg]F)
minus one standard error of 0.8 [deg]C (1.4 [deg]F), as a conservative
indicator of increased risk to pika populations used in NOAA's report
(2009). We determined that any pika site that was projected to
experience a surface temperature (realizing that below-talus
temperatures can be substantially cooler than surface temperatures in
the summer) of greater than or equal to 16.2 [deg]C (61.2 [deg]F) would
be at increased risk of extirpation as a result of stress from climate
change. The sites that exceed our measure of risk are represented by
the bold numbers in Table 1 above. This temperature should not be
considered deterministic, but only a starting point, based on current
best available science, for identifying a temperature range that
represents increased risk to pikas.
Table 1 above uses our conservative measure of potential risk and
shows that historical climatology (J-J-A mean for 1950 to 1999) at the
mean elevation for NOAA's climate projections, and at higher elevations
(J-J-A mean for 1950 to 1999 at maximum elevations) known to harbor
pikas, suggests that all sites (22 of 22) across the range of species
were not at risk from average summer surface temperatures of greater
than or equal to 16.2 [deg]C (61.2 [deg]F) from 1950 to 1999. However,
historical climatology at minimum elevations (J-J-A mean 1950 to 1999
at minimum elevations) demonstrate that lower elevation pika sites (4
of 18) were at higher risk of experiencing adverse effects as a result
of increased average summer temperatures from 1950 to 1999. Pika sites
at relatively low elevations from the Sangre de Cristo Mountains,
mountains of southeastern Oregon, southern Wasatch Mountains, and
Warner Mountains were at risk from high average summer temperatures
(Table 1 above). In fact, extirpations occurred at low elevations in
areas adjacent to the Warner Mountains, in the mountains of
southeastern Oregon, and southern Wasatch Mountains (Beever et al.
2003, p. 43; Oliver 2007, p. 5; Wilkening 2007, p. 58). We are not
aware of any extirpations from the Sangre de Cristo Mountains; however,
we have no historical information to compare back to recent survey
data. Corroboration of findings between NOAA's report and other recent
reports of extirpations or higher risk areas in the Great Basin
suggests mean summer temperature is a useful variable for predicting
the relative risk of increased temperatures to pika populations.
We do not anticipate the species to be adversely affected on a
range-wide basis by increased summer temperatures. In our climate
change risk assessment, we determine that no pika site would be at risk
across its entire range of elevation, but some mid- to low-elevation
areas that contain pikas would be at risk from increased summer surface
temperature (Table 1 above). This determination, paired with the fact
there is a significant
[[Page 6452]]
amount of habitat not at risk from climate change, prevents the species
from being threatened or endangered from climate change. The relatively
low elevations within pika sites that would be at risk were distributed
among four of five subspecies, with Ochotona princeps uinta not
containing any populations that would be at risk. These relatively low-
elevation, at-risk areas do not represent a substantial amount of pika
habitat, especially since pikas primarily occupy high-elevation talus
habitat. Therefore, we conclude the entire species would not be at risk
from increased summer surface temperatures now or in the foreseeable
future. Our next analysis focuses on a climate change risk assessment
at the subspecies level as discussed below.
We determine that portions of the Sierra Nevada subspecies,
Ochotona princeps schisticeps, may be at risk of extirpation due to
potential impacts from recent and future climate change. In general,
the populations of O. p schisticeps that would be at highest risk of
extirpation represent the lower elevation sites in the Great Basin with
correspondingly higher mean temperatures. Populations at mid- to high
elevations at most sites, which are projected to be cooler than 16.2
[deg]C (61.2 [deg]F), should not be at risk of extirpation as a result
of exposure to increased summer temperatures. We expect at least
portions (primarily lower elevations) of five of seven sites for O. p.
schisticeps (Table 1 above) to be at risk from increased summer
temperatures by the year 2050.
Pika populations in the Bodie Mountains and the Sierra Nevada Range
are not at risk of extirpation. Populations in the Sierra Nevada Range
are not at risk due to the preponderance of high-elevation habitats
(2,943 to 3,402 m (9,657 to 11,160 ft)) and correspondingly cooler
environments. This conclusion is consistent with available literature
(Beever et al. 2003, pp. 43, 45; Smith 2009, p. 5), which suggests that
lower elevation sites, particularly along the southern edge of the
species' range, are at a higher risk of being extirpated from increased
temperatures.
We also determine that portions of the Northern Rocky Mountain
subspecies, Ochotona princeps princeps, may be at risk of extirpation
due to potential impacts from future climate change. We anticipate
higher risks of extirpation for low to medium elevation (below
approximately 3,048 m (10,000 ft)) of O. p. princeps populations in the
Northern Wasatch Mountains of Utah, Ruby Mountains of Nevada, lower
elevations of Glacier National Park, and Sawtooth Range in Idaho. These
higher risks are due to projected mean surface temperatures above our
16.2 [deg]C (61.2 [deg]F) measure of elevated risk (Table 1 above).
We do not anticipate an increase in mean summer temperature by 2050
will have an adverse affect on the majority of O. p. princeps
populations found in Wyoming, Idaho, and Montana; specifically in the
Bighorn Mountains, Clearwater Mountains, Gallatin National Forest, mid-
to high elevations of Glacier National Park, Wind River Range, and
Bridger-Teton National Forest. Average summer surface temperature for
these areas is projected to be below 16.2 [deg]C (61.2 [deg]F). The
NOAA was unable to generate surface temperature projections for 2050 at
minimum and maximum elevations of occupied pika sites in the Bighorn
Mountains, Clearwater Mountains, Gallatin National Forest, Wind River
Range, and Bridger-Teton National Forest. Specific locations (latitude
and longitude coordinates) for pika populations, which are necessary in
order to generate temperature projections at elevation, were not
available for these five areas. While temperature projections are not
available for these five areas, it is possible that at least some lower
elevation pika sites will be at increased risk of extirpation as a
result of exposure to summer temperatures at or above 16.2 [deg]C (61.2
[deg]F). Mid- to high-elevation sites, where pikas are usually more
common in the Northern Rocky Mountain Range, should be at a lower risk
of extirpation or experience no risk, because summer temperatures will
be cooler. Therefore, we anticipate the majority of O. p. princeps
populations will not be at risk from increased summer temperature.
We also determine that portions of the Coast Mountain and Cascade
Range subspecies, Ochotona princeps fenisex, may be adversely affected
by climate change. We anticipate risks to pika populations occurring at
lower elevations (approximately 914 m (3,000 ft or less)) at Mt. St.
Helens. Pika populations occurring above approximately 914 m (3,000 ft)
at Mt. St. Helens would likely experience a reduced risk of extirpation
from increased summer temperature. Projections for 2050 summer surface
temperature are below our measure of increased risk (16.2 [deg]C (61.2
[deg]F)) at Crater Lake, near Mt. Baker in the North Cascades Mountain
Range, and the Mt. Hood/Three Sisters Mountains; therefore, we do not
anticipate any risks to pika populations in these areas (Table 1
above). Of the 69 unique pika observations used to generate an
elevation range of O. p. fenisex, we do not anticipate risks
(temperature approximately greater than or equal to 16.2 [deg]C (61.2
[deg]F)) from increased summer temperatures occurring at 98 percent (68
of 69) of the observation points. Therefore, we determined that the
majority of O. p. fenisex populations would not be at a high risk of
extirpation from increased summer temperatures by 2050. Because a
sufficient amount of the habitat for O. p. fenisex is not at risk, we
determined that future climate change does not threaten or endanger the
subspecies.
We do not anticipate populations of Ochotona princeps uinta to be
at risk from the effects of increased summer temperatures; all
projected surface temperatures remain below our measure of elevated
risk (16.2[deg]C (61.2[deg]F)) (Table 1 above). Therefore, we do not
anticipate adverse population-level effects from increased summer
temperatures to occur in populations of this subspecies.
We do not anticipate an increase in mean summer temperature by 2050
to have an adverse effect on the majority of Ochotona princeps
saxatilis populations, because the majority (76% in Colorado) of pika
populations in the Southern Rocky Mountains occur at higher elevations
where temperatures will remain below our 16.2 [deg]C (61.2 [deg]F)
measure of elevated risk (Table 1 above; CDOW 2009, p. 21). Lower
elevation populations of O. p. saxatilis in the Sangre de Cristo
Mountains of northern New Mexico and Southern Rocky Mountains in
Colorado are at higher risk of extirpation than populations occurring
at mid- to high elevations in the Sangre de Cristo Mountains and
Southern Rocky Mountains, again due to higher mean summer temperatures
(Table 1 above). The majority of the pika populations in the Sangre de
Cristo Mountains of New Mexico and Southern Rocky Mountains of Colorado
occur at elevations near or greater than 3,353 m (11,000 ft) (CDOW
2009, p. 16; USFS 2009, pp. 2-6). We expect lower risks of extirpation
at these sites as a result of populations being exposed to relatively
lower average summer temperatures (below 16.2 [deg]C (61.2 [deg]F)).
As previously discussed, the subsurface temperatures of occupied
habitats are a better predictor of the temperatures experienced by
individual pikas and of the persistence of populations (Beever et al.
2009, pp. 9-10; Millar and Westfall 2009, p. 21). In addition to
presenting comparisons of average summer surface temperatures, we
reviewed below-surface (0.8 m (2.6 ft) below talus surface)
temperatures as a variable to compare extant to
[[Page 6453]]
extirpated sites (Beever et al. 2009, Table 1).
Summer microclimate in below-talus interstices is significantly
cooler, as much as 24 [deg]C (43.2 [deg]F) during the hottest times of
day (Finn 2009a, pers. comm.), at pika-extant sites compared to pika-
extirpated sites (Beever et al. 2009, Table 1). Millar and Westfall
(2009, p. 20) discovered that within-rock matrix (interstitial spaces
between boulders) temperatures at Sierra Nevada pika sites are as much
as 4 to 7 [deg]C (7.2 to 12.6 [deg]F) lower than adjacent bedrock or
mineral soil. Below-talus (0.8 m (2.6 ft)) temperatures from five Great
Basin pika sites were on average 6 [deg]C (10.8 [deg]F) cooler than
those recorded from the surface during the hottest time of the day
(Finn 2009a, pers. comm.), which is the time of day when pikas retreat
to subsurface areas to escape thermally stressful conditions (at least
at lower elevations sites).
Based on these data, it is evident that conditions below the talus-
surface are site-specific and likely are specific to several other
factors at a finer scale. These data suggest that pikas can persist in
relatively warm surface environments if temperatures below the talus-
surface contain favorable thermal conditions for survival (Millar and
Westfall 2009, p. 21).
Comparisons between below-talus summer temperatures and surface
summer temperatures indicate that our risk assessment for climate
change may be overly conservative because risk estimates for pika sites
were based on projections for summer surface temperatures. Because
below-talus microclimate provides pikas with cool habitat during the
hottest time of day during the summer, and pikas are dependent on these
subsurface environments for survival, heat-stress levels experienced by
pikas may be less than expected. The actual risk levels for pika
populations at these sites are likely to be lower than we estimate
above.
In summary, we anticipate that the majority of Ochotona princeps
princeps, O. p. fenisex, O. p. schisticeps, and O. p. saxatilis
populations are not now or will not be at risk of extirpation due to
increased summer temperatures resulting from climate change in the
foreseeable future. Our analysis also shows that no portions of the O.
p. uinta populations are at risk of extirpation now or in the
foreseeable future due to climate change. Increased summer temperatures
have the potential to adversely impact some lower and mid-elevation
pika populations of O. p. princeps, O. p. fenisex, O. p. schisticeps,
and O. p. saxatilis in the foreseeable future; however, this does not
equate to a significant portion of the suitable habitat for any of
these subspecies or the species collectively. American pika can
tolerate a wider range of temperatures and precipitation than
previously thought (Millar and Westfall 2009, p. 17). The American pika
has demonstrated flexibility in its behavior and physiology that can
allow it to adapt to increasing temperature (Smith 2009, p. 4). Based
on all these lines of evidence, we determine that climate change is not
a threat at the species-level or the subspecies-level now or in the
foreseeable future.
Livestock Grazing
In general, pikas forage within 50 m (164 ft) of talus. The
potential for interactions between pika and livestock in the immediate
vicinity of talus (i.e., within 50 m (164 ft)) depends on the site-
specific conditions. In some areas, steep terrain or rock formations
may largely prevent livestock from accessing talus margins (Beever et
al. 2003, p. 50); in other areas, if livestock have access to the talus
edge, effects to pikas from livestock presence may not be through
competition for food, but rather an indirect influence of trampling of
soils or vegetation affecting vegetative growth (Beever et al. 2003, p.
49). Livestock grazing also could reduce vegetation close to talus
habitat and subsequently cause pikas to forage farther from the
protective cover of talus, thus increasing energy demands and risk of
predation (Beever et al. 2003, p. 49). However, Beever et al. (2003, p.
50) noted the presence of an active haypile directly under a well-
traveled horse trail and several haypiles near other trails in Nevada,
suggesting that livestock may not affect foraging activities. Livestock
generally avoid crossing rocky talus slopes, preventing direct
interactions between livestock and pikas (Beever et al. 2003, p. 50).
If interactions are happening between pika and livestock that result in
a negative impact, we believe that these impacts occur primarily on a
local scale within few pika habitats and are not a threat to overall
pika populations.
There are few studies regarding the effects of grazing on pika
populations. Within the range of Ochotona princeps schisticeps,
extirpations at 6 of 25 sites in the Great Basin occurred primarily in
livestock-grazed areas (Beever et al. 2003, p. 43). A modeling revealed
that grazing was one of the top three predictors of the probability of
pika extirpation (Beever et al. 2003, pp. 45, 46, 49). However, the
authors stated their methods were not sufficient to determine whether a
cause-and-effect relationship existed (Beever et al. 2003, p. 47), and
they subsequently withdrew their conclusion due to errors in the
analysis (Beever 2009c, pers. comm.). Reanalysis showed that grazing
occurrence at pika sites in the Great Basin was no longer in the top
models to predict the probability of population extirpation (Beever
2009c, pers. comm.), showing there is not a significant correlation
between pika extirpations that have occurred in the Great Basin and
livestock grazing.
Additionally, it also is possible that livestock do not affect the
generalist diet of pikas. In North America, pika diet changes in the
face of changing nutrition values in available plant species by
shifting to an increase in sedges and forbs, especially in late summer
when grasses become less nutritious. In general, cattle and horses, as
ruminants, prefer grasses (graminoids) over forbs or shrubs (Shipley
1999, pp. 20-21) and can be considered specialist foragers relative to
American pikas, which are generalist foragers. Furthermore, Wilkening
(2007, p. 39) found that the relative amount of forb cover, not
graminoids, was the single greatest predictor of persistence for
Ochotona princeps schisticeps in the Great Basin. We conclude that the
potential competition for forage between pikas and livestock is low.
In summary, the potential for interactions between pika and
livestock in the immediate vicinity of talus where pikas forage depends
on the site-specific conditions. In some areas, steep, rocky terrain
may largely prevent livestock from accessing talus margins (Beever et
al. 2003, p. 50). If livestock have access to the talus edge, effects
to pikas may be indirectly influenced by trampling of soils or
vegetation (Beever et al. 2003, p. 49). However, livestock generally
avoid crossing rocky talus slopes, preventing direct interactions
between livestock and pikas (Beever et al. 2003, p. 50). Thus,
livestock may not affect foraging activities (Beever et al. 2003, p.
50). Pikas are generalist foragers while livestock specialize in
foraging on graminoids (grasses), reducing the potential competition
for forage. If interactions are happening between pika and livestock
that result in negative impacts, we believe that these impacts occur
primarily on a local scale within few pika habitats and are not a
threat to overall pika populations. We conclude that livestock grazing
is not a significant threat to any of the five subspecies of the
American pika and, therefore, is not a threat to the species now or in
the foreseeable future.
[[Page 6454]]
Native Plant Succession
Changes in vegetation, such as conifer encroachment into subalpine
or alpine meadows, could potentially affect available forage for the
American pika. Altitudinal treeline in the western North America has
rarely moved more than 100 m (330 ft) vertically during the Holocene
period, even during prolonged warm periods (Rochefort et al. 1994 cited
in Farge 2003, p. 267). Although there is no clear evidence of uniform
upward altitudinal treeline movement, tree establishment in subalpine
meadows has been documented across the range of the American pika in
areas like Glacier National Park in Montana (Bekker et al. 2000 cited
in Farge 2003, p. 267), Mount Rainer National Park (Franklin et al.
1971, p. 215) and the Olympic Mountains (Woodward et al. 1995, p. 217)
in Washington, the central Sierra Nevada mountain range in California
(Millar et al. 2004, p. 181), the White Mountains of south-central New
Mexico (Dyer and Moffett 1999, p. 444) and the Uinta Mountains in Utah
(Dyer and Moffett 1999, p. 452).
Tree establishment in subalpine meadows may affect pikas for a
number of reasons. Trees near pika territories could obstruct a pika's
ability to visually detect predators, and trees could provide perches
for avian predators (Wilkening 2007, pp. 42-43). Tree presence in
meadows also alters vegetation composition that could potentially
affect pika foraging behavior or forage availability. Relative tree
cover is negatively correlated with Ochotona princeps schisticeps
occupancy in the Great Basin (Wilkening 2007, p. 42). However, O. p.
schisticeps sites in Lava Beds National Monument in northern California
that have a low ratio of grass (graminoids) to forbs, shrubs, and trees
are more likely to be used by pikas (Ray and Beever 2007, p. 45). O. p.
schisticeps sites recently discovered on the Klamath National Forest in
northern California found pikas occurring in talus sites surrounded by
mixed conifer forests at approximately 1,800 m (6,000 ft) in elevation
and haypiles at those sites that included conifer branches (Hoyer and
Fleissner 2009, pers. comm.). Studies also have documented pika
foraging on tree saplings, which may prevent the establishment of trees
near talus areas occupied by pikas (Krear 1965 and Simpson 2001 cited
in Wilkening 2007, p. 42).
Studies on Ochotona princeps schisticeps in the Great Basin have
demonstrated that vegetation factors, specifically relative forb cover,
influence pika persistence (Wilkening 2007, p. 39) and are a strong
predictor of occupancy (Ray and Beever 2007, p. 1). Relative forb cover
is negatively correlated with mean summer temperature and average daily
summer highs (Wilkening 2007, p. 39). Wilkening's (2007, p. 40)
analysis is based on only two years of temperature data collected at
extant and extirpated sites and may not represent conditions pikas
experienced when extirpations occurred. It also is too short of a time
period to document temperature variability, and it may not be
representative of what pikas may experience in the future.
Meadow invasions during the 20th century are correlated with
climate change and other abiotic factors (Dyer and Moffett 1999, pp.
444, 452; Millar et al. 2004, p. 181). Precipitation (snow depth or
snow pack) (Rochefort and Peterson 1996, p. 52; Farge et al. 2003, p.
263) and snow-free periods in subalpine meadows (Franklin et al. 1971,
p. 215) are critical variables regulating conifer expansion. Tree
encroachment also is influenced locally by vegetation type, topographic
variation, landscape position (Rochefort and Peterson 1996, p. 58),
aspect (Dyer and Moffett 1999, p. 453), and warmer minimum temperatures
(Millar et al. 2004, p. 193) making uniform predictions difficult
across the range of the American pika. However, in general, tree and
shrub distributions in North America are likely to shift northward and
upward in elevation in response to future climate change and species
ranges (Shafer et al. 2001, p. 213).
One example of a study investigating vegetative response to climate
change occurs within the range of Ochotona princeps saxatilis in
Colorado. This study shows increased warming expected under an
atmosphere with a concentration of carbon dioxide twice that of pre-
industrial levels could change the dominant vegetation of meadow
habitat from forbs to shrubs like Artemisia tridentata (sagebrush) and
Pentaphylloides floribunda (shrubby cinquefoil) (Harte and Shaw 1995,
p. 876). However, Dearing (1996, p. 474) found both of these plant
species in abundance in pika haypiles in Colorado. While climate change
has historically and may continue to affect sagebrush and shrubby
cinquefoil distribution in Colorado in the future, it appears that
pikas are adapting locally to these vegetative changes and utilizing
these plant species in their haypiles.
Although we have data to support that climate change has the
potential to influence vegetative species distribution in the future,
the resolution at which the simulations are made is very coarse (25 km
(15.5 mi) grids in Shafer et al. 2001 (p. 202)). Very coarse data are
difficult to apply to the American pika. All species have inherent
spatial bounds on their life histories which can very extremely among
species. Considering all vertebrates, American pikas are close to the
smaller end of this spectrum. A typical pika can live its entire life
within a 0.8 km (0.5 mi) diameter circle, which, ecologically, is
bounded by the extent of a talus patch and a narrow buffer surrounding
it. Conversely, climate models are often initially constructed at much
coarser resolution - as much as 60 x 60 km (37.3 x 37.3 mi) resolution.
For each climatic parameter (average temperature, average
precipitation) there is only one value for each pixel (i.e., 60 x 60 km
(37.3 x 37.3 mi) cell) despite the known ecological variation present
in this pixel. Several techniques are available to `downscale' climate
models and downscaled maps are available (e.g., Shafer et al. 2001).
However, factors such as topography, landform, geology, and soil
properties can modify climate properties at finer resolutions. Whereas
modelers have high confidence in coarse resolution climate models
downscaled climate model interpretations becomes less reliable
especially when applied to an ecological response (i.e., pika behavior)
acting at fine resolution. Using plant species distribution models from
Shafer et al. (2001) as an example, there may be fine-resolution
factors (e.g., soil properties) affecting plant species distributions
that were not accounted for. That may be acceptable when tracking
common species range shifts but not necessarily useful to evaluate
threats to a population inhabiting a small fraction of a pixel, such as
in the case of the American pika.
Additionally, projections of vegetative changes from Shafer et al.
(2001) are for a 10-year period around 2090, a time period in which we
think drawing any conclusions would be too speculative. Pikas have a
generalist diet and manipulate vegetative species composition and
growth rates in areas where they forage. As a result of these life
history characteristics, we anticipate pikas will likely be able to
adapt the level of changes happening to vegetative communities as a
result of climate change. We have no clear trends to indicate that
native plant succession as a result of climate change represents a
significant threat to the American pika's ability to forage.
In summary, the relationship between pikas and their associated
vegetative communities are complex, multifaceted and not well
understood (Wilkening 2007, p. 40). Potential changes in native
vegetative plant communities, including
[[Page 6455]]
tree encroachment of meadows, in American pika habitat could affect
foraging. Pikas do not forage far from talus areas, and they manipulate
the vegetative species composition and growth rates where they forage,
suppressing plant succession. There are no clear trends showing that
native vegetative changes are occurring at the scale that would affect
pika foraging habitat and there is no evidence to suggest that native
plant succession is a threat to pikas. We do not believe that this
represents a significant threat to any of the five subspecies of the
American pika and is not a threat to the species as a whole now or in
the foreseeable future.
Invasive Plant Species
Nonnative plant invasions vary according to climate, elevation,
soils, and topography, as well as natural or human-mediated disturbance
(Parks et al. 2005, p. 151). Several studies in North America indicate
a negative correlation between elevation and nonnative species'
richness or abundance. Invasive species richness may decline with
increasing elevation because fewer species (native as well as
nonnative) thrive in the shorter growing seasons, cooler temperatures,
and generally more stressful environment of subalpine and alpine
ecosystems than at lower elevations (Zouhar et al. 2008, p. 28). Parks
et al. (2005, pp. 149, 154) synthesized much of the available
information on the patterns of invasive plant diversity within the
northwest mountain regions of the United States and found that alpine
and subalpine plant communities (including wilderness areas and
national parks) are still relatively unaffected by invasive plants.
This condition is due in part to the remoteness of these areas and
limited human access to these sites. However, Parks et al. (2005, p.
149) found that hay hauled into wilderness areas to support horses and
mules for hunting and pack trips is a major source of noxious weeds,
but the nonnative plant distribution along trails decreased sharply
within a few meters (feet) of the trails, indicating that wilderness
areas are not ideal habitats for nonnative plants.
Fire can result in nonnative plant invasions at high elevations.
Fire increases resource availability for invading plants, exposes
mineral soils, reduces native species dominance and vigor, and could
accelerate invasions (Zouhar et al. 2008, p. 28). Within the forests of
the western United States, the greatest increases in wildfire frequency
have been in the northern Rocky Mountains followed by the Sierra
Nevadas, and the southern Cascade Mountains and the Coast Ranges of
northern California and southern Oregon (Westerling et al. 2006, p.
941). This increase in fire frequency has occurred between 1,680 and
2,590 m (5,512 and 8,497 ft) in elevation and with the greatest
increase centered around 2,130 m (6,988 ft) (Westerling et al. 2006, p.
941). Reduced winter precipitation, early spring snow melt, warmer
spring and summer temperatures, longer dry summers, and drier
vegetation all played a role in the increased wildfire activity
(Westerling et al. 2006, p. 943). Whether the changes observed in
wildfire are the result of greenhouse gas-induced climate change or
normal climatic variability, climate model projections indicate that
warmer springs and summers will occur in the coming decades creating
conditions favoring the occurrence of large wildfires in forested areas
(Westerling et al. 2006, p. 943) which would potentially affecting the
spread of invasive plant species.
However, the pioneering nonnative species most favored in recent
burns are unlikely to persist in high-elevation environments (Zouhar et
al. 2008, p. 28). This outcome has been confirmed in fire effects
studies conducted in wilderness and national parks along the crest of
the Cascade Mountains that have not found nonnative plants (Douglas and
Ballard 1971, pp. 1061-1062; Miller and Miller 1976 and Hemstrom and
Franklin 1982 cited in Parks et al. 2005, p. 145); whether this absence
is due to lack of seed source or environmental barriers to
establishment is unknown. Therefore, we conclude that fire occurrences
at high elevations in alpine and subalpine areas are not likely to
increase nonnative plant invasions and this factor does not represent a
significant threat to pika foraging.
When we reviewed the State WAPs in the range of the American pika,
we found that invasive plants are listed as threats in some pika
habitat, but not in the species' primary alpine habitat. New Mexico's
WAP acknowledged that wet meadow habitat can be manipulated to replace
native vegetation with pasture species (NMDGF 2006, p. 183).
California's WAP (Bunn et al. 2006, p. 272) listed invasive plants as a
threat to the Modoc plateau (for example, Bromus tectorum (cheatgrass)
and Lepidium virginicum (pepper weed)), but stated that subalpine and
alpine plant communities in the Sierra Nevada and Cascades are
relatively intact, with few invasive plants (Schwartz et al. 1996 cited
in Bunn et al. 2006, p. 299). Similarly, Nevada's WAP (NDOW 2005, p.
159) did not list invasive plants as a threat to alpine and subalpine
habitats. Utah's WAP (Sutter et al. 2005, pp. 5-7, 8-7) listed invasive
plants (cheatgrass and noxious weeds) as a threat to the American
pika's secondary habitat of mountain shrub. Alpine habitats that are
the primary habitat for the American pika are not identified as a key
habitat by the State of Utah and, therefore, threats to this habitat
are not listed in the Utah WAP (Sutter et al. 2005, pp. 5-8).
The invasion of the American West by Bromus tectorum has caused
widespread modifications in the vegetation of semi-arid ecosystems
(Rowe and Brown 2008, p. 630) replacing native vegetation with a
monoculture of nonnative annual grass. Additionally, invasions of B.
tectorum and other nonnative grass species alter fuel loads, alter
fuelbed flammability, and increase fire frequency and intensity (Zouhar
et al. 2008, pp. 38-39), further promoting the spread of B. tectorum.
Generally this invasion is occurring at or below 2,000 m (6,562 ft) in
elevation; however, B. tectorum has been documented in Rocky Mountain
National Park up to 2,750 m (9,022 ft) in elevation (Rowe et al. 2007,
p. 45), suggesting that B. tectorum may be a future invader of higher
elevations.
Bromus tectorum is a relatively nutritious food plant for
herbivores in its earliest stages, but as the grass matures it presents
mechanical difficulties for digestion and has low nutritional value for
herbivores (Klemmedson and Smith 1964, p. 249). Additionally, the
period that B. tectorum is palatable and nutritious for herbivore
consumption is considerably shorter than for most native herbaceous
plants (Klemmedson and Smith 1964, p. 250). Studies have documented B.
tectorum in haypiles at Ochotona princeps princeps sites in central
Idaho (Elliot 1980, p. 208). At sites in the Great Basin, B. tectorum
was the fourth or fifth most abundant plant species in Ochotona
princeps schisticeps haypiles (Beever et al. 2008, pp. 11, 14). Even
though pikas are haying B. tectorum, studies have not documented pikas
grazing on B. tectorum nor has the nutritional value and digestibility
of B. tectorum for pikas been investigated (Wilkening 2007, p. 10;
Beever et al. 2008, p. 12).
Bromus tectorum seeds can germinate even after the mature plant is
uprooted or its stem is cut, or after seeds pass through an herbivore's
digestive system. Thus, pikas may alter the dynamics of the spread of
B. tectorum at local spatial scales (Beever et al. 2008, p. 12). The
pika's consumption and digestibility of
[[Page 6456]]
seeds is unknown; thus, the potential for seed redistribution also is
unknown. At this time, there is no data that indicate that B. tectorum
presence in pika habitat represents a significant threat to the species
or any of the five subspecies.
In summary, invasions of nonnative plants could change the
composition of meadows used for foraging by the American pika. However,
subalpine and alpine ecosystems are relatively intact and free from
invasive species. Bromus tectorum (cheatgrass) has been documented in
pika habitat below 2,750 m (9,022 ft) in elevation. Ochotona princeps
schisticeps and O. p. princeps have been documented to use this
species, but the nutritional value and digestibility of B. tectorum for
pikas is poorly understood. At this time, we have no evidence
indicating that invasive plant species pose a significant threat to any
of the five subspecies of the American pika and, therefore invasive
plant species are not a threat to the species now or in the foreseeable
future.
Fire Suppression
Fire is considered an important factor in creating and maintaining
meadow areas, and the microclimate of the fire-created openings
determines whether or how fast trees reinvade (Franklin et al. 1971, p.
221). For example, many subalpine meadows in the Olympic Mountains in
Washington were probably created by fire (Woodward et al. 1995, p.
218).
Human suppression of wildfires could allow for the establishment of
trees in subalpine meadows. However, in general, human wildfire
suppression efforts focus on protection of urban areas first and
foremost. Pikas typically occur in remote areas far from urban settings
where human access for suppression is sometimes difficult due to the
remoteness of the area and steep terrain. Additionally, in most cases,
pika occur in wilderness areas, national parks, and other federally
protected areas with specific management goals and objectives that
implement Minimum Impact Suppression Tactics (MIST). The MIST emphasize
suppressing wildland fire with the least impact to the land and use the
minimum amount of fire-fighting resources necessary to effectively
achieve the fire management protection objectives consistent with land
and resource management objectives (National Wildfire Coordinating
Group 2003, p. 1). Implementation of MIST in areas where pikas occur on
federally protected lands minimizes the potential for humans
interfering with the process of wildfires limiting tree encroachment
and creating or maintaining alpine meadows. Additionally,
implementation of MIST reduces the possibility of humans acting as
vectors for introduction of invasive plants. We conclude that there is
no evidence that indicates that human fire suppression efforts
represent a significant threat to pikas.
In summary, fire is considered an important factor in creating and
maintaining meadow areas. Human suppression of wildfires could allow
for the establishment of trees in subalpine meadows or possible
invasions from nonnative plants in pika habitat. However, pikas
typically occur in remote areas and in most cases, are occurring in
federally protected areas with specific management goals and objectives
that implement MIST. We conclude that there is no evidence to indicate
that human fire suppression efforts are a significant threat to any of
the five subspecies of the American pika; therefore, fire suppression
is not a threat to the species now or in the foreseeable future.
Summary of Factor A
In our analysis of Factor A, we identified and evaluated the
following risks to habitat of the five subspecies of the American pika
and the species as a whole: (1) Climate change; (2) livestock grazing;
(3) native plant succession; (4) invasive plant species; and (5) fire
suppression.
Increased summer temperatures as a result of climate change may
have the potential to adversely affect some lower and mid-elevation
pika populations of Ochotona princeps princeps, O. p. fenisex, O. p.
schisticeps and O. p. saxatilis in the foreseeable future; however,
this does not equate to a significant portion of the suitable habitat
for any of the five subspecies or the species collectively. American
pika can tolerate a wider range of temperatures and precipitation than
previously thought (Millar and Westfall 2009, p. 17). The American pika
has demonstrated flexibility in its behavior, such as using cooler
habitat below the surface to escape hotter summer daytime temperatures,
and physiology that can allow it to adapt to increasing temperature
(Smith 2009, p. 4). Cooler temperatures below the talus surface can
provide favorable thermal conditions for pika survival in relatively
warm surface environments. Based on all these lines of evidence, we
have determined that climate change is not a threat at the species or
the subspecies-level now or in the foreseeable future.
The potential for interactions between pika and livestock where
pikas forage depends on the site-specific conditions. If interactions
are happening between pika and livestock that result in negative
impacts, we believe that these impacts occur primarily on a local scale
within a few pika habitats and are not a threat to overall pika
populations. We conclude that livestock grazing is not a significant
threat to any of the five subspecies of the American pika and,
therefore, it is not a threat to the species now or in the foreseeable
future.
Potential changes in native vegetative plant communities, including
tree encroachment of meadows, in American pika habitat could affect
foraging. Pikas do not forage far from talus areas, and they manipulate
the vegetative species composition and growth rates where they forage,
suppressing plant succession. There are no clear trends showing that
native vegetative changes are occurring at the scale that would affect
pika foraging habitat and there is no evidence to suggest that native
plant succession is a threat to pikas. We do not believe that native
plant succession represents a significant threat to any of the five
subspecies of the American pika and, therefore, it is not a threat to
the species now or in the foreseeable future.
Invasions of nonnative plants could change the composition of
meadows used for foraging by the American pika. However, studies
document that subalpine and alpine ecosystems are relatively intact and
free from invasive species. Bromus tectorum (cheatgrass) has been
documented in pika habitat below 2,750 m (9,022 ft) in elevation.
Ochotona princeps schisticeps and O. p. princeps have been documented
to use this species, but the nutritional value and digestibility of B.
tectorum for pikas is poorly understood. At this time, we have no
evidence indicating that invasive plant species pose a significant
threat to any of the five subspecies of the American pika, and,
therefore, invasive plants are not a threat to the species now or in
the foreseeable future.
Fire is considered an important factor in creating and maintaining
meadow areas. Human suppression of wildfires could allow for the
establishment of trees in subalpine meadows or possible invasions from
nonnative plants in pika habitat. However, pikas typically occur in
remote areas and in most cases, are occurring in federally protected
areas with specific management goals and objectives that implement
MIST. We conclude that there is no evidence to indicate that human fire
suppression efforts are a significant threat to any of the five
subspecies of the American pika and, therefore, these efforts are not a
[[Page 6457]]
threat to the species now or in the foreseeable future.
Based on our review of the best available information, we find that
the present or threatened destruction, modification, or curtailment of
the American pika's habitat or range is not a threat to the five
subspecies or the species as a whole now or in the foreseeable future.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
During our review of the available information, we found no
evidence of risks from overutilization for commercial, recreational,
scientific, or educational purposes affecting any of the five
subspecies of the American pika populations. Therefore, based on the
best available scientific information, we conclude that the American
pika is not threatened by overutilization for commercial, recreational,
scientific, or educational purposes now or in the foreseeable future.
C. Disease or Predation
Disease
Pikas are known to be infected by coccidian parasites (Duszynski
1974, p. 94; Hobbs and Samuel 1974, p. 1079; Lynch et al, 2007 p.
1230); however, no information indicates these parasites affect the
persistence of the species. Nematodes (Murielus spp.) (Hoberg 2005, pp.
358, 360-362) and pinworms (Labiostomum spp.) (Hoberg 2009 et al, pp.
490-491, 497) also are known to infect pikas. Galbreath (2009, pp. 98-
100) describes seven helminth parasite species collected from pika
(Ochotona princeps) that represent five distinct genera that including
tapeworms (Schizorchis), oxyurid nematodes (Cephaluris, Labiostomum),
and strongylid nematodes (Graphidiella, Murielus). Bot fly larvae
(Cuterebra spp.) infestation and pulmonary fungus (Haplosporangium
parvum) also have been reported in pikas, but these are likely
extremely unusual cases (Carmichael 1951, pp. 606, 613, 616; Baird and
Smith 1979, p. 553).
Pikas are hosts to Rocky Mountain wood ticks (Dermacentor
andersoni) (James et al. 2006, pp. 21-22) and fleas (Megabothris
abantis, Meringis hubbardi) (Bossard 2006, pp. 261, 264, 266). Fleas
and ticks are potential vectors of disease and pathogens that may
affect the health of pikas. However, during our review of the best
available information, we only found one record of a disease-related
mortality in pika. Plague was reported in an individual pika found in
1989 at Lava Beds National Monument in northern California (Bonkrude
2009, pers. comm.), in the subspecies Ochotona princeps schisticeps.
In summary, based on the best available scientific information, we
conclude that disease does not pose a significant threat to the five
subspecies of the American pika and, therefore, disease is not a
significant threat to the species.
Predation
While pikas may be prey for numerous species, no information
indicates that predation presents a threat to the species. Potential
predators across the range of pikas include coyotes (Canis latrans),
long-tailed weasels (Mustela frenata), short-tailed weasels (M.
erminea), pine martens (Martes americana), raptors, and corvids
(Broadbooks 1965, pp. 327, 329; Lutton 1975, p. 234; Marti and Braun
1975, p. 213; Ivins and Smith 1983, pp. 277-284; Smith and Weston 1990,
p. 5; Forsman et al. 2004, p. 218; Quick 1951 and Murie 1961 in
Gustafson 2007, p. 12). Pikas averaged less than one percent of
northern spotted owl (Strix occidentalis caurina) prey found in pellets
collected from 1970 to 2003 throughout Oregon (Forsman et al. 2004, p.
219) within the range of the subspecies Ochotona princeps fenisex.
However, in Colorado within the ranges of O. p. princeps and O. p.
saxatilis, pika was the most frequent mammalian prey collected near one
nest and several roost sites of prairie falcons (Falco mexicanus)
(Marti and Braun 1975, p. 213).
Ivins and Smith (1983, p. 277) investigated the response of
Ochotona princeps saxatilis to martens and weasels in Rocky Mountain
National Park in Colorado. Weasels have been identified as the most
effective predator of pikas because of their ability to hunt within
talus interstices (rocky slopes) (Ivins and Smith 1983, p. 279). Ivins
and Smith (1983, p. 277) found that adult pikas use alarm calls to
broadcast the presence of predators, warning kin and other pikas of the
presence of a predator in the area. This may be one mechanism that has
allowed pikas to persist in Rocky Mountain National Park in the
presence of this effective predator. Another potential persistence
factor is that pikas have a relatively high reproductive rate giving
birth to average litter sizes of 2.34 to 3.68 young twice a year (Smith
and Weston 1990, p. 4).
We have considered the best available information on predation and
conclude that predation is not a significant threat to any of the five
subspecies of American pika, and, therefore, predation is not a
significant threat to the species as a whole.
Summary of Factor C
In conclusion, we found that while pikas are hosts to several
species of internal parasites, as well as species of fleas and ticks,
only one record exists of a disease-related morality of a single pika
from plague in northern California. Additionally, we note that while
pikas may be prey for numerous species, no information indicates that
predation has an overall adverse effect on the species. We find that
neither disease nor predation is a threat to any of the five subspecies
of the American pika, and, therefore, neither disease nor predation is
a threat to the species now or in the foreseeable future.
D. The Inadequacy of Existing Regulatory Mechanisms
To determine if existing regulatory mechanisms protect the five
subspecies of the American pika, we evaluated existing international
and United States conventions, agreements, and laws for the specific
protection of the American pika or their habitats.
United States
Federal Laws and Regulations
The Wilderness Act
The USFS, NPS, Bureau of Land Management (BLM), and the Service all
own lands designated as wilderness areas under the Wilderness Act of
1964 (16 U.S.C. 1131-1136). Within these areas, the Wilderness Act
states the following: (1) New or temporary roads cannot be built; (2)
there can be no use of motor vehicles, motorized equipment, or
motorboats; (3) there can be no landing of aircraft; (4) there can be
no other form of mechanical transport; and (5) no structure or
installation may be built. As shown in Table 2 below, a large amount of
suitable pika habitat occurs within Federal wilderness areas in the
United States (Wilderness.net 2009). As such, a large proportion of
existing pika habitat is protected from direct loss or degradation by
the Wilderness Act's prohibitions. Where human activity and threats are
increasing in wilderness areas that contain pika habitat, we have no
evidence to suggest that pikas are being affected or will be affected
in the foreseeable future (see Factor E).
[[Page 6458]]
Table 2. Amount (percent) of American pika habitat across land ownership by subspecies and species (Finn 2009b, pers. comm.). Measurements are given in
Acres, [Hectares], and (Percent of Total) within Range
--------------------------------------------------------------------------------------------------------------------------------------------------------
O. p. schisticeps O. p. uinta O. p. fenisex O. p. princeps O. p. saxatilis Species-wide
--------------------------------------------------------------------------------------------------------------------------------------------------------
BLM* 96,002 106,803 16 29,457 54,644 286,922
[38,852].......... [43,222].......... [6]............... [11,921].......... [22,114].......... [116,116]
(15.08%).......... (25.98%).......... (0.01%)........... (1.70%)........... (6.00%)........... (7.18%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
DOD* 3,903 2 9 23 0 3,937
[1,580]........... [1]............... [4]............... [9]............... [1,593]
(0.61%)........... (<0.01%).......... (<0.01%).......... (<0.01%).......... (0.10%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
NPS* 134,150 26,664 82,531 88,028 58,175 389,547
[54,290].......... [10,791].......... [33,400].......... [35,624].......... [23,543].......... [157,648]
(21.07%).......... (6.49%)........... (27.50%).......... (5.07%)........... (6.39%)........... (9.75%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
USFS* 370,580 237,520 213,163 1,515,056 711,626 3,047,945
[149,972]......... [96,123].......... [86,266].......... [613,135]......... [287,991]......... [1,233,486]
(58.20%).......... (57.77%).......... (71.03%).......... (87.26%).......... (78.18%).......... (76.31%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Service* 2,253 0 0 63 66 2,382
[912]............. [26].............. [27].............. [964]
(0.35%)........... (<0.01%).......... (0.01%)........... (0.06%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Misc. Fed.* 0 0 0 151 0 151
[61].............. [61]
(0.01%)........... (<0.01%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Tribal Lands 3,883 4,885 549 44,392 108 53,817
[1,571]........... [1,977]........... [222]............. [17,965].......... [44].............. [21,780]
(0.61%)........... (1.19%)........... (0.18%)........... (2.56%)........... (0.01%)........... (1.35%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Private 8,405 22,581 3,058 52,016 81,849 167,909
[3,401]........... [9,138]........... [1,238]........... [21,050].......... [33,124].......... [67,952]
(1.32%)........... (5.49%)........... (1.02%)........... (3.00%)........... (8.99%)........... (4.20%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
County 16,971 0 0 3 0 16,974
[6,868]........... [1]............... [6,869]
(2.67%)........... (>0.01%).......... (0.42%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
State 607 12,678 777 6,996 3,723 24,780
[246]............. [5,130]........... [314]............. [2,831]........... [1,506]........... [10,028]
(0.10%)........... (3.08%)........... (0.26%)........... (0.40%)........... (0.41%)........... (0.62%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total 636,755 411,133 300,104 1,736,186 910,189 3,994,367
[257,686]......... [166,380]......... [121,448]......... [702,610]......... [368,340]......... [1,616,498]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total Wilderness Within Above 295,962 19,558 192,754 514,726 178,118 1,201,118
Federal Land [119,774]......... [7,915]........... [78,006].......... [208,307]......... [72,083].......... [486,086]
(46.48%).......... (4.76%)........... (64.23%).......... (29.65%).......... (19.57%).......... (30.07%)
--------------------------------------------------------------------------------------------------------------------------------------------------------
*Federal land
National Environmental Policy Act
All Federal agencies are required to adhere to the National
Environmental Policy Act (NEPA) of 1970 (42 U.S.C. 4321 et seq.) for
projects they fund, authorize, or carry out. The Council on
Environmental Quality's regulations for implementing NEPA (40 CFR 1500-
1518) state that agencies shall include a discussion on the
environmental impacts of the various project alternatives (including
the proposed action), any adverse environmental effects which cannot be
avoided, and any irreversible or irretrievable commitments of resources
involved (40 CFR 1502). The NEPA itself is a disclosure law, and does
not require subsequent minimization or mitigation measures by the
Federal agency involved. Although Federal agencies may include
conservation measures for pika as a result of the NEPA process, any
such measures are typically voluntary in nature and are not required by
the statute. Table 2 above shows the amount of pika habitat occurring
on Federal lands; additionally, activities on non-Federal lands are
subject to NEPA if there is a federal nexus.
Federal Land Policy and Management Act
The BLM's Federal Land Policy and Management Act of 1976 (43 U.S.C.
1701 et seq.), as amended, states that the public lands shall be
managed in a manner that will protect the quality of scientific,
scenic, historical, ecological, environmental, air and atmospheric,
water resource, and archeological values, and that where appropriate,
BLM will preserve and protect certain public lands in their natural
condition, and provide food and habitat for wildlife (BLM and SOL 2001,
p. 8). Pikas and pika habitat occur on BLM lands in Oregon, California,
Nevada, Idaho, Wyoming, Colorado, and Utah. Table 2 above shows the
amount of pika habitat occurring on BLM lands. We are unaware of any
BLM-specific regulations, policies, or guidance that directly manages
threats to pikas.
[[Page 6459]]
National Forest Management Act
Under the USFS' National Forest Management Act of 1976, as amended
(16 U.S.C. 1600-1614), the USFS shall strive to provide for a diversity
of plant and animal communities when managing national forest lands.
Individual national forests may identify species of concern which are
significant to each forest's biodiversity. It is unknown what level of
protection, if any, each of the individual national forests offer for
pika. In many of the 10 States in which pikas are found, pikas occur in
wilderness areas and are thus protected under the Wilderness Act.
Outside of wilderness but still on USFS lands, pikas occur mainly in
alpine areas, which are sensitive to negative habitat alterations.
Their habitat is generally offered more protections from harvest or
road building than would otherwise be the case in lowland areas. Table
2 above shows the amount of pika habitat occurring on USFS lands.
National Park Service Organic Act
The NPS Organic Act of 1916 (16 U.S.C. 1 et seq.), as amended,
states that the NPS ``shall promote and regulate the use of the Federal
areas known as national parks, monuments, and reservations ... to
conserve the scenery and the national and historic objects and the
wildlife therein and to provide for the enjoyment of the same in such
manner and by such means as will leave them unimpaired for the
enjoyment of future generations.'' Where pikas occur in National Parks,
they and their habitats are protected from large-scale loss or
degradation due to the Park Service's mandate to ``...conserve
scenery... and wildlife...[by leaving] them unimpaired.'' Table 2 above
shows the amount of pika habitat occurring on NPS lands.
National Wildlife Refuge System Improvement Act of 1997
The National Wildlife Refuge Systems Improvement Act (NWRSIA) of
1997 (Pub. L. 105-57) amends the National Wildlife Refuge System
Administration Act of 1966 (16 U.S.C. 668dd et seq.). The NWRSIA
directs the Service to manage the Refuge System land and waters for
conservation. The NWRSIA also requires monitoring of the status and
trends of refuge fish, wildlife, and plants. The NWRSIA requires
development of a comprehensive conservation plan for each refuge and
management of each refuge consistent with the plan. Where pikas occur
on National Wildlife Refuge lands (see Table 2 above), they and their
habitats are protected from large-scale loss or degradation due to the
Service's mission to ``to administer a national network of lands... for
the conservation, management, and where appropriate, restoration of the
fish, wildlife, and plant resources and their habitats.''
Sikes Act
The Sikes Act of 1960 (16 U.S.C. 670a et seq.) authorizes the
Secretary of Defense to develop cooperative plans for conservation and
rehabilitation programs on military reservations and to establish
outdoor recreation facilities, and it provides for the Secretaries of
Agriculture and the Interior to develop cooperative plans for
conservation and rehabilitation programs on public lands under their
jurisdiction. The Sikes Act Improvement Act of 1997 required Department
of Defense (DOD) installations to prepare integrated natural resources
management plans (INRMPs). Consistent with the use of military
installations to ensure the readiness of the Armed Forces, INRMPs
provide for the conservation and rehabilitation of natural resources on
military lands and incorporate, to the maximum extent practicable,
ecosystem management principles and provide the landscape necessary to
sustain military land uses. Table 2 above shows the amount of pika
habitat occurring on DOD lands.
Clean Air Act of 1970
The petitioner claims that the American pika is threatened by a
lack of regulatory mechanisms to curb greenhouse gases that contribute
to global temperature rises (Wolf et al. 2007, p. 50). However, as
stated earlier under Factor A, our status review did not reveal
information that increased summer temperatures are a significant threat
to the five subspecies or species range-wide now or in the foreseeable
future. Nonetheless, we acknowledge that no regulatory mechanisms
adequately address global climate change.
The Clean Air Act of 1970 (42 U.S.C. 7401 et seq.), as amended,
requires the Environmental Protection Agency (EPA) to develop and
enforce regulations to protect the general public from exposure to
airborne contaminants that are known to be hazardous to human health.
In 2007, the Supreme Court ruled that gases that cause global warming
are pollutants under the Clean Air Act, and that the EPA has the
authority to regulate carbon dioxide and other heat-trapping gases
(Massachusetts et al. v. EPA 2007 [Case No. 05-1120]). The EPA
published a regulation to require reporting of greenhouse gas emissions
from fossil fuel suppliers and industrial gas suppliers, direct
greenhouse gas emitters and manufacturers of heavy-duty and off-road
vehicles and engines (74 FR 56260; October 30, 2009). The rule,
effective December 29, 2009, does not require control of greenhouse
gases; rather it requires only that sources above certain threshold
levels monitor and report emissions (74 FR 56260; October 30, 2009). On
December 7, 2009, the EPA found under section 202(a) of the Clean Air
Act that the current and projected concentrations of six greenhouse
gases in the atmosphere threaten public health and welfare. The finding
itself does not impose requirements on any industry or other entities
but is a prerequisite for any future regulations developed by the EPA.
At this time, it is not known what regulatory mechanisms will be
developed in the future as an outgrowth of the finding or how effective
they would be in addressing climate change.
Secretarial Order Number 3289
Department of the Interior Secretarial Order Number 3289, issued
September 14, 2009 (Department of the Interior (DOI) 2009), provides
guidance to bureaus and offices within DOI to work ``...with other
federal, state, tribal and local governments, and private landowner
partners to develop landscape-level strategies for understanding and
responding to climate change impacts.'' The DOI bureaus and offices
also shall ``...[c]onsider and analyze potential climate change impacts
when undertaking long-range planning exercises, setting priorities for
scientific research and investigations, developing multi-year
management plans, and making major decisions regarding potential use of
resources under the Department's purview.'' The DOI land management
plans and NEPA documents are subject to this Order. This Secretarial
Order requires that Federal agencies consider the future potential
impacts of climate change in their planning process. However, as stated
earlier under Factor A, our status review did not reveal information
that increased summer temperatures are a significant threat to the
species range-wide now or in the foreseeable future.
State Comprehensive Wildlife Conservation Strategies (CWCS) and State
Environmental Policy and Protection Acts
The pika receives some protection under State laws in Washington,
Oregon, California, Idaho, Nevada, Utah, Montana, Wyoming, Colorado,
and New Mexico. Each State's fish and wildlife agency has some version
of a CWCS in
[[Page 6460]]
place. These strategies, while not state or national legislation, can
help prioritize conservation actions within each State. Named species
and habitats within each CWCS may receive focused attention during
State Environmental Protection Act (SEPA) reviews as a result of being
included in a State's CWCS. However, only Washington, California, and
Montana appear to have SEPA-type regulations in place. In addition,
each State's fish and wildlife agency often specifically names or
implies protection of pikas in their hunting and trapping regulations.
See below for an overview of pertinent regulations for each state in
the range of the American pika.
Washington
The Washington Department of Fish and Wildlife's (WDFW) hunting
regulations name the pika as ``protected wildlife,'' meaning it is
illegal to hunt, kill, possess, or control pikas in Washington (WDFW
2009, p. 65). This designation offers adequate protection to individual
pikas from direct harm but offers no protection to pika habitat.
The WDFW does not include the pika in its CWCS. However, protection
of talus (considered a rare habitat type) is identified as a
conservation action under the CWCS (WDFW 2005, p. 293). Conservation
actions are those actions necessary to improve the conservation status
of the species or habitat in the next 10 years. Implementation of these
actions will likely require the cooperation of partners (private,
State, Federal, and so forth) and landowners.
Oregon
The Oregon Department of Fish and Wildlife (ODFW) does not include
the pika in its CWCS. However, their hunting regulations name the pika
as a ``protected mammal,'' making it illegal to be taken without a
permit (ODFW 2009, p. 82). This designation protects individual pikas
from direct harm, but does not offer protection to pika habitat.
California
The California Fish and Game Code, Section 2000, states that it is
illegal ``...to take any bird, mammal, fish, reptile, or amphibian
except as provided in the code or regulations made pursuant thereto.''
Pikas are considered a nongame mammal in California (California Fish
and Game Code, Section 4150), and as such are protected from taking or
possessing. This designation protects pikas from direct harm, but does
not offer protection to pika habitat.
A major component of the California WAP (Bunn et al. 2007) is the
identification of species of greatest conservation need in the State.
The California Department of Fish and Game (CDFG) uses the Special
Animal List, which includes Species of Special Concern (SSC), as the
primary source list of these species. Revisions to the WAP will include
threat assessments for current SSCs and their habitats, and will change
conservation actions and priorities accordingly (Bunn et al. 2007, p.
19). The pika is listed as an SSC under California's WAP (CDFG 2009, p.
46).
Being designated as an SSC is an administrative label only and
carries no formal legal status. The California Environmental Quality
Act (CEQA) (California Public Resources Code secs. 21000-21177)
requires State agencies, local governments, and special districts to
evaluate and disclose impacts to SSCs from projects in the State.
Section 15380 of the CEQA Guidelines clearly indicates that SSCs should
be included in an analysis of project impacts if they can be shown to
meet the criteria of sensitivity outlined therein. Sections 15063 and
15065 of the CEQA Guidelines guide managers in assigning ``impact
significance'' to populations of non-listed species. Analysts are to
consider factors such as population-level effects, proportion of the
taxon's range affected by a project, regional effects, and impacts to
habitat features. Because SSC designation carries no legal status, it
does not require mitigation where impacts are found to occur and as
such would not protect pika habitat with certainty.
Idaho
Under the Idaho CWCS, pikas are considered to be secure, common,
and widespread based on NatureServe's conservation status (IDFG 2005,
App. A, p. 18), and are not a species of greatest conservation need in
that State. Pikas are designated as ``protected nongame wildlife''
under Idaho's upland game hunting regulations. They may not be hunted,
taken, or possessed (IDFG 2008, p. 9). This designation protects pikas
from direct harm, but does not offer protection to pika habitat.
Nevada
Nevada Administrative Code (503.030) designates the pika as a
protected mammal. As such it is illegal to hunt them in Nevada. This
designation protects individual pikas from direct harm, but does not
offer protection to pika habitat.
Pikas are designated as a vulnerable species as well as a species
of conservation priority in Nevada's WAP, with a declining population
(WAP Team 2006, pp. 405, 291). Nevada's conservation approach is to
determine population viability, analyze demographics, confirm trends,
identify suitable unoccupied habitat, and evaluate the potential for
reintroduction. Talus slopes are identified as key elements of alpine
and tundra habitat of importance to pika (WAP Team 2006, p. 154).
Nevada's WAP Team has identified priority research needs focused on
pikas, including determining: the effects of recreation; minimum viable
population size; population demographics; factors contributing to pika
extirpation in Nevada; and long-term responses of alpine and tundra
communities to global climate change. They also intend to model
viability of individual populations and refine population trend
estimates and factors.
Utah
Under Utah's CWCS, pikas are a Tier III species (Sutter et al.
2005, pp. 5-7). The primary action for Tier III species is to gather
more information regarding their status and any threats to them or
their habitats. The UDWR considers pika to be a sensitive mammal
species and SSC due to limited distribution (Messmer et al. 1998, p.
57). The UDWR administrative rules designate pikas as nongame mammals.
A Utah certificate of registration is required in order to take nongame
mammals (UDWR 2007). Usually such certificates pertain to banding,
collection, salvage, depredation, fishing events, dog trials, or
possession of live birds or certain ungulates. We do not know how
likely it is that an applicant would be approved to kill or possess
pikas. This designation protects pikas from direct harm, but does not
offer protection to pika habitat.
Montana
Pikas are considered to be a nongame animal (MCA 2009 87-5-102), as
they are not a nuisance animal (MCA 2009 80-7-1101) or expressly
otherwise named in Montana's hunting regulations (MFWP 2009). It is
illegal to take, possess, transport, export, sell, or offer them for
sale (MCA 2009 87-5-106). This designation protects pikas from direct
harm, but does not offer protection to pika habitat.
Montana Fish, Wildlife and Parks (MFWP) has identified pika as a
species with greatest inventory need (MFWP 2005, p. 410) in their CWCS.
They are not on Montana's Animal Species of Concern list (MNHP 2009),
which is the list MFWP refers to when implementing their CWCS. Pikas
are designated as a Tier 3 species in Montana, meaning they have a
lower conservation need because
[[Page 6461]]
they are either abundant and widespread or they have adequate
conservation already in place (MFWP 2005, pp. 32, 444).
Wyoming
Pikas are not listed as a species of concern under Wyoming's CWCS
(Wyoming Department of Game and Fish 2005). Wyoming's Nongame Wildlife
Regulations (WGFD 1998, p. 20) consider pikas as ``protected animals''
which means they may only be taken after the issuance of a scientific
or educational permit. This designation protects pikas from direct
harm, but does not offer protection to pika habitat.
Colorado
The Colorado Division of Wildlife has designated pika as nongame
wildlife and ``protected'' (CDOW 2009, p. 17). Their harassment,
taking, or possession is prohibited unless permitted under a license
from the State. This designation protects pikas from direct harm, but
does not offer protection to pika habitat. Pikas are not mentioned in
Colorado's CWCS.
New Mexico
New Mexico's CWCS lists the Goat Peak pika (was Ochotona princeps
nigrescens, now included in O. p. saxatilis) as a species of greatest
conservation need as well as vulnerable and State sensitive (NMDGF
2006, pp. 55 and 57).
The New Mexico Department of Game and Fish has designated pika as a
``protected species'' (19 NMAC 36.2). As such, take of pikas is
prohibited without a permit or license from the State. This designation
protects pikas from direct harm, but do not offer protection to pika
habitat.
Summary of Factor D in the United States
In summary, American pika habitat that occurs in the United States
on public land is protected by several laws including the Wilderness
Act of 1964; the National Forest Management Act of 1976, as amended;
the Federal Land Policy and Management Act of 1976, as amended; the NPS
Organic Act of 1916; the Sikes Act of 1960; and the National Wildlife
Refuge System Improvement Act of 1997. Additionally, the American pika
receives some protection under State laws in Washington, Oregon,
California, Idaho, Nevada, Utah, Montana, Wyoming, Colorado, and New
Mexico. Each State's fish and wildlife agency has some version of a
CWCS in place. All of these States have regulations that protect pikas
from direct harm, but do not offer protection to pika habitat.
Canada
National Regulations
Parks Canada is committed to protecting the natural heritage of
their parks and ensuring that they remain healthy and whole (Parks
Canada 2002). Hunting is prohibited in all Canadian National Parks,
Regional District Parks, National Wildlife Areas, and Migratory Bird
Sanctuaries unless a special Federal permit is granted or notices to
the contrary are posted. Numerous Provincial and National Parks occur
within the range of O. p. princeps in Canada, and overlap a large
portion of the known occupied pika habitat there (BritishColumbia.com
2009; Government of Alberta 2009c). Where pikas occur in National Parks
in Canada, their habitat is likely to be protected from loss or
degradation due to the manner in which Parks are managed, and
individual pikas would be protected from direct harm. Currently, the
pika has no status under Canada's Species at Risk Act (Government of
Canada 2002).
Provincial Regulations
British Columbia
In British Columbia, all native species of animals in the province
(excluding invertebrates and fish) as well as several nonnative species
have been designated as wildlife, giving them full protection under the
Wildlife Act (Ministry of Environment British Columbia 1996, Chapter
488). These species may not be hunted, killed, captured, kept as pets,
or used for commercial purposes unless specifically allowed by
regulation or by authority of a permit from the Ministry of
Environment. This designation protects individual pikas from direct
harm, but does not offer protection to pika habitat.
Under British Columbia's Forest and Range Practices Act (Ministry
of Forests and Range 2008), it is illegal for individuals to cause
environmental damage. Updated regulations define environmental damage
to include any change to soil that adversely alters an ecosystem. Under
the new provision, individuals found to have caused environmental
damage may be fined or jailed or both. This law applies on Crown lands
as well as on private lands. This law helps to protect pika habitat
within British Columbia's portion of the Ochotona princeps fenisex and
Ochotona princeps princeps subspecies.
Alberta
In Alberta, it is illegal to hunt or trap pika because they are a
nongame species, which are illegal to hunt or trap without a special
collection permit. American pika are not listed by name in either
Alberta's hunting or trapping regulations (Government of Alberta 2009a,
2009b).
Summary of Factor D in Canada
In summary, individual pikas in Canada are protected from human-
caused direct mortality, and the majority of habitat is protected as
well. No threats have been documented to be occurring to pikas in
Canada. Therefore, we find that the level of protection in Canada
appears to be sufficient to protect the portions of the two American
pika subspecies (Ochotona princeps fenisex and O. p. princeps) that
occur within Canada.
Summary of Factor D
As described under Factor A, a factor potentially affecting four
out of the five subspecies is loss of lower elevation habitat due to
increased summer surface temperatures. While the Clean Air Act of 1970
(42 U.S.C. 7401 et seq.), as amended, requires the EPA to develop and
enforce regulations to protect the general public from exposure to
airborne contaminants that are known to be hazardous to human health,
the EPA does not have regulations in place to control the emissions of
greenhouse gases. The EPA's December 7, 2009 endangerment finding
signals that regulations might be developed in the future; however, the
contents and effectiveness of any such regulation is uncertain.
Therefore, there are no known existing regulatory mechanisms currently
in place at the local, State, national, or international level that
effectively address these types of climate-induced threats to pika
habitat. However, we determined in Factor A that climate change would
not adversely affect the American pika at the species or subspecies
level now or within the foreseeable future. Therefore, any inadequacy
of existing regulatory mechanisms to address the threat of climate
change do not now or will not result in adverse impacts to the five
subspecies or species as a whole within the foreseeable future.
Based on our analysis of the existing regulatory mechanisms, we
have found a diverse network of laws and regulations that provide
varied protections to the American pika and its habitat rangewide.
Specifically, American pika habitat that occurs in the United States on
public land is
[[Page 6462]]
protected by the Wilderness Act of 1964; the National Forest Management
Act of 1976, as amended; the Federal Land Policy and Management Act of
1976, as amended; the NPS Organic Act of 1916; the Sikes Act of 1960;
and the National Wildlife Refuge System Improvement Act of 1997.
Additionally, the American pika receives some protection under State
laws in Washington, Oregon, California, Idaho, Nevada, Utah, Montana,
Wyoming, Colorado, and New Mexico. Each State's fish and wildlife
agency has some version of a CWCS in place, and all of these States
have regulations that protect pikas from direct harm, but do not offer
protection to pika habitat. Two American pika subspecies (Ochotona
princeps fenisex and O. p. princeps) occur in Canada, and individual
pikas are protected from human-caused direct mortality, and the
majority of habitat is protected as well. No threats have been
documented to be occurring to pikas in Canada. Therefore, based on our
review of the best available scientific information, we conclude that
adequate regulatory mechanisms are in place to protect the species,
including the five subspecies, now and in the foreseeable future.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
Roads
Pika habitats, such as alpine and subalpine areas, may be sensitive
to disturbance from roads and the activities which occur on them.
Disturbance from roads may have a permanent impact on the landscape and
negative impact on pika population persistence (Beever et al. 2003, p.
45). Roads may destroy or isolate habitat, prevent dispersal and
migration, and interfere with necessary behavior. However, a study in
the Great Basin shows proximity to roads does not play a substantial
role in pika extirpations when compared to other factors, such as
elevation and maximum daily air temperatures (Beever 2009c, pers.
comm.).
Road construction can create habitat for pikas due to placement of
rubble as road grades and riprap for armoring waterways. Pikas have
established colonies in human-made rock structures where none existed
before in Oregon (Fontaine 2009, pers. comm.) and Washington State
(Bruce 2009, pers. comm.; Wagner 2009, pers. comm.). Pikas were found
to inhabit mine tailings and a rock wall in the Sierra Nevada and Great
Basin Mountains (Millar et al. 2008, p. 1). A total of 55 sites (or 32
percent of the sites surveyed) were in areas of moderate human
visitation (Millar et al. 2008, p. 1), many accessed by roads. Within
Colorado, 44 percent of historic pika locations are within 100 m (328
ft) of a jeep or hiking trail; only one of these sites is currently
unoccupied (CDOW 2009, p. 12), although the cause of unoccupancy is
unknown. Therefore, while it is possible that there could be some
localized impacts at pika sites near roads, we have no evidence to
suggest that roads constitute a significant threat to any subspecies of
pika or the American pika species as a whole.
In summary, we have documentation of pikas occurring in human-made
settings and occupying sites in areas of moderate human use, and we
have a study showing that presence of roads does not play a substantial
role in pika extirpations at sites in the Great Basin. Therefore, we
conclude that the presence of roads and their related human disturbance
do not constitute a significant threat to the continued existence of
the pika at either the species or subspecies level now or in the
foreseeable future.
Off-Highway Vehicles and Off-Road Vehicles
We determined that off-highway vehicle (OHV) and off-road vehicle
(ORV) use does not appear to be a significant threat to any subspecies
of pika or the pika species now or in the foreseeable future. We used
four lines of evidence to support this decision. As discussed in the
90-day finding, there is little evidence to support the hypothesis that
human influence in alpine communities constitutes a range wide threat
to the American pika, because the probability of direct human
disturbance to population locations remains quite low. Sensitive
habitats, where pikas often occur, are considered during the Federal
land management planning process (70 FR 68264-68291, 16 U.S.C 1131-
1136). Federal agencies monitor sensitive habitats and close roads to
protect areas containing sensitive habitat (70 FR 68264-68291, 16 U.S.C
1131-1136). Vehicle restrictions are enforced under the National OHV
Policy (36 CFR 212, 251, 261), Wilderness Act (16 U.S.C. 1131-1136),
and local regulations (e.g., Okanogan Land and Resource Management Plan
(USDA 1989, pp. 4-8) and the Wenatchee Land and Resource Management
Plan (USDA 1990, pp. IV-90-91) in Washington).
Trails
Many hikers rely on trails to enter higher, more isolated areas
inhabited by pikas. Trails can increase human activity near pika sites,
with potential effects related to habitat disturbance and noise.
However, Millar et al. (2008, pp. 1-2) found that of 173 occupied pika
sites within the range of Ochotona princeps schisticeps in the Great
Basin and Sierra Nevada mountain ranges: (1) 3 sites (2 percent) were
on human-made structures; (2) 55 (32 percent) were in areas moderately
impacted by human visitation; and (3) 3 of the occupied sites (2
percent) were within 1 m of well-used trails. Subsequent surveys
revealed a total of 28 of 420 sites (7 percent) were within 1 m (3 ft)
of active trails, and all 28 sites were occupied (Millar and Westfall
2009, p. 10).
Also, as discussed above, 27 of 62 historical sites (44 percent)
were within 100 m (328 ft) of a jeep or hiking trail; only one of these
sites was unoccupied (CDOW 2009, p. 12). Since access and disturbance
by human activity does not correlate with extirpation of pika colonies,
we conclude that disturbance by humans using trails is not a
significant threat to pika at either the species or subspecies level
now or in the foreseeable future.
Recreational Shooting
Shooting of pika is prohibited throughout most of its range.
Disturbance, including construction activities and trash dumping,
occurred at three out of seven sites and evidence of recreational
shooting at only a single site, Smith Creek, Nevada (Beever et al.
2003, p. 45). The authors mention no evidence of pika mortality, only
the presence of shell casings at a single site. We are not aware of any
other information on recreational shooting of pika. Therefore, we
conclude that while recreational shooting may occur on occasion, it is
not a significant threat to the pika at either the species or
subspecies level now or in the foreseeable future.
Summary of Factor E
In summary, we assessed the potential risks to pika populations
from other natural or manmade factors associated with nearness to
roads, nearness to trails, proximity to OHV/ORV use, and recreational
shooting, and we find that there is no evidence that indicates these
activities significantly threaten the continued existence of American
pika, at either the species or subspecies level, now or in the
foreseeable future.
Finding
As required by the Act, we considered the five factors in assessing
whether the species is threatened or endangered throughout all or a
significant portion of
[[Page 6463]]
its range. We have carefully examined the best scientific and
commercial information available regarding the past, present, and
future threats faced by the species. We reviewed the petition,
information available in our files, other available published and
unpublished information, and other information provided to us after the
90-day finding was published. We also consulted with recognized
American pika experts and other Federal, State, and tribal agencies.
In our analysis of Factor A, we identified and evaluated the risks
of the present or threatened destruction, modification, or curtailment
of the habitat or range of the five subspecies of the American pika,
and the species as a whole, from: (1) Climate change; (2) livestock
grazing; (3) native plant succession; (4) invasive plant species; and
(5) fire suppression. We determine that increased summer surface
temperature from climate change is not a significant threat to the
species as a whole. In our climate change risk assessment, we
determined that no pika site would be adversely affected across the
species' entire range of elevation, but some mid- to low elevations
that contain pikas would be at risk from increased summer temperature
(see Table 1 above). These relatively low elevations within pika sites
that would be at risk were distributed among four of five subspecies
(Ochotona princeps princeps, O. p. fenisex, O. p. schisticeps and O. p.
saxatilis), with O. p. uinta not containing any populations that would
be at risk. These relatively low elevation at-risk areas do not
represent a significant portion of the subspecies' habitat (and,
therefore, the species' habitat as a whole), especially since pikas
primarily occupy high-elevation talus habitat. Therefore, we conclude
the five subspecies and the entire species are not at risk from
increased summer temperatures now or in the foreseeable future.
Actual risk levels from increased summer surface temperatures of
pika populations at pika sites may be lower than we estimated in Factor
A. Results from comparisons between below-talus summer temperatures and
surface summer temperatures indicate that our risk assessment for
climate change may be overly conservative because risk estimates for
pika sites were based on projections for summer surface temperatures.
Because below-talus microclimate provides pikas with cool habitat
during the hottest time of day during the summer, and pikas are
dependent on these subsurface environments for survival, heat-stress
levels experienced by pikas may be less than expected and are likely to
be lower than we estimated. There is also evidence indicating the
American pika can tolerate a wider range of temperatures and
precipitation than previously thought (Millar and Westfall, p. 17). The
American pika demonstrates flexibility in its behavior and physiology
that allows it to adapt to the degree of increasing temperature that we
expect within the foreseeable future. We have evidence that suggests
the five American pika subspecies have persisted through climatic
oscillations in the past (Hafner 1994, p. 375; Grayson 2005, p. 2103),
which indicates that the species-wide pool of genetic diversity should
not be greatly diminished by ongoing climate change.
We investigated the potential effects to the American pika and its
habitat from interactions with domestic livestock, native plant
succession, nonnative plant invasions and human fire suppression. We
concluded that interactions with domestic livestock, native plant
succession, nonnative plant invasions, and human fire suppression do
not represent a significant threat to any of the five subspecies of the
American pika and, therefore, these are not a threat to the species now
or in the foreseeable future. Based on our review of the best available
information, we find that the present or threatened destruction,
modification, or curtailment of the American pika's habitat or range is
not a threat to the five subspecies or the species as a whole now or in
the foreseeable future.
During our review of the available information, we found no
evidence of risks from overutilization for commercial, recreational,
scientific, or education affecting any of the five subspecies of the
American pika populations or the species as a whole. Therefore, we
conclude that the American pika is not threatened by overutilization
for commercial, recreational, scientific, or educational purposes now
or in the foreseeable future.
We found that while pikas are hosts to several species of internal
parasites as well as species of fleas and ticks, only one record exists
of a disease-related morality of a single pika from plague in northern
California. Additionally, we note that, while pikas may be prey for
numerous species, no information indicates that predation has an
overall adverse effect on the species. We find that neither disease nor
predation is a threat to any of the five subspecies of the American
pika and, therefore, neither disease nor predation is a significant
threat to the species now or in the foreseeable future.
Based on our analysis of the existing regulatory mechanisms, we
have found a diverse network of laws and regulations that provide
protections to the American pika and its habitat on Federal lands in
the United States. There are no known existing regulatory mechanisms
currently in place at the local, State, national, or international
level that effectively address climate-induced threats to pika habitat.
However, we determined that climate change would not adversely affect
the American pika at the species or subspecies level now or within the
foreseeable future. Additionally, the American pika receives some
protection under State laws in Washington, Oregon, California, Idaho,
Nevada, Utah, Montana, Wyoming, Colorado, and New Mexico. Each State's
fish and wildlife agency has some version of a CWCS in place, and all
of these States have regulations that protect pikas from direct harm,
but do not offer protection to pika habitat. Two American pika
subspecies (Ochotona princeps fenisex and O. p. princeps) occur in
Canada, and individual pikas are protected from human-caused direct
mortality, and the majority of habitat is protected as well. No threats
have been documented to be occurring to pikas in Canada. Therefore,
based on our review of the best available scientific information, we
conclude that adequate regulatory mechanisms are in place to protect
the species and the five subspecies now and in the foreseeable future.
We also assessed the potential risks to pika populations from other
natural or manmade factors associated with nearness to roads, trails,
and OHV/ORV use, and associated with recreational shooting, and we find
that there is no evidence that indicates these activities significantly
threaten the continued existence of American pika, at either the
species or subspecies level, now or in the foreseeable future.
Our review of the best available scientific and commercial
information pertaining to the five factors does not support the
assertion that there are threats of sufficient imminence, intensity, or
magnitude as to cause substantial losses of population distribution or
viability of the American pika or any of its five subspecies.
Therefore, we do not find that the American pika is in danger of
extinction (endangered), nor is it likely to become endangered within
the foreseeable future (threatened) throughout its range. As a result,
we determine that listing the American pika at the species or
subspecies level, as endangered or threatened under the Act is not
warranted at this time.
[[Page 6464]]
Distinct Vertebrate Population Segments (DPSs)
After assessing whether the species and subspecies are endangered
or threatened throughout their range, we next consider whether any DPS
of American pika meets the definition of endangered or is likely to
become endangered in the foreseeable future (threatened). In this case,
because we have determined that portions of the Ochotona princeps
fenisex subspecies, O. p. princeps, O. p. saxatilis subspecies, and
portions within the Great Basin of the O. p. schisticeps subspecies are
likely to experience increased extirpations of pika within the
forseeable future, we analyzed whether any of these areas meet the
definition of a DPS.
Distinct Vertebrate Population Segments
Under the Service's Policy Regarding the Recognition of Distinct
Vertebrate Population Segments Under the Endangered Species Act (61 FR
4722, February 7, 1996), three elements are considered in the decision
concerning the establishment and classification of a possible DPS.
These are applied similarly for an addition to or a removal from the
Federal List of Endangered and Threatened Wildlife. These elements
include: (1) The discreteness of a population in relation to the
remainder of the taxon to which it belongs; (2) the significance of the
population segment to the taxon to which it belongs; and (3) the
population segment's conservation status in relation to the Act's
standards for listing, delisting (removal from the list), or
reclassification (i.e., whether the population segment is endangered or
threatened).
In our analysis of Factor A, we partnered with NOAA to assess
historical and future temperature projections for the western United
States. In the assessment, 22 pika sites were identified for analysis
representing the five subspecies across the range of the species. We
determined that certain populations of Ochotona princeps schisticeps,
O. p. fenisex, O. p. princeps, and O. p. saxatilis are currently at
risk or would be at risk in the foreseeable future from the threat of
increased summer temperature (see Table 1 above). These subpopulation
include: (1) Southeastern Oregon, Monitor Hills, southern Wasatch
Mountains, Toiyabe Mountains, and Warner Mountains for Ochotona
princeps schisticeps; (2) Mt. St. Helens for O. p. fenisex; (3) Glacier
National Park, Northern Wasatch Mountains, Ruby Mountains, and Sawtooth
Mountain Range for O. p. princeps; and (4) Sangre de Cristo Mountains
and Southern Rockies for O. p. saxatilis. Because we have identified
climate change as being a potential factor that may influence the
future distribution of the four subspecies listed above, we analyzed
these areas to determine whether they meet our DPS policy.
Discreteness
Under the DPS policy a population segment of a vertebrate taxon may
be considered discrete if it satisfies either one of the following
conditions: (1) It is markedly separated from other populations of the
same taxon as a consequence of physical, physiological, ecological, or
behavioral factors. Quantitative measures of genetic or morphological
discontinuity may provide evidence of this separation; and (2) It is
delimited by international governmental boundaries within which
differences in control of exploitation, management of habitat,
conservation status, or regulatory mechanisms exist that are
significant in light of section 4(a)(1)(D) of the Act. We begin our
analysis of discreteness by addressing the first condition listed above
(markedly separate).
Ochotona princeps schisticeps in southeastern Oregon, Monitor Hills,
southern Wasatch Mountains, Toiyabe Mountains, and Warner Mountains
American pikas are distributed across a subset of Great Basin
mountain ranges, including the mountains of southeastern Oregon,
Monitor Hills, southern Wasatch Mountains, Toiyabe Mountains, and
Warner Mountains (hereafter, O. p. schisticeps subpopulation or Great
Basin subpopulation) and typically found at high elevations within this
geographic area. Geographical features, such as broad desert valleys,
are effective at isolating these patches and serve as barriers to gene
flow between pika metapopulations belonging to the same subspecies
(Meredith 2002, pp. 47-48, 53; Grayson 2005, p. 2104). In the numerous
``sky islands'' of the Great Basin, American pikas are isolated
(greater than the maximum estimated individual dispersal distance (10
to 20 km; 6.2 to 12.4 mi) of the species from the nearest extant
population by these geographic barriers (Hafner 1994, pp. 376-378).
These barriers eliminate dispersal of pikas between and among mountain
ranges. Because temperatures in these valleys often exceed the
physiological constraints of pikas (e.g., valley temperatures often are
greater than or equal to 28 [deg]C (82.4 [deg]F)), pikas are unable to
disperse to other mountain ranges and are now confined to a subset of
ranges within the Great Basin.
We would expect a higher probability of long-distance dispersal in
suitable habitat containing favorable climate conditions within
mountain ranges occupied by the O. p. schisticeps subpopulation. Within
cool habitat, such as high elevation talus slopes, populations
separated by less than 20 km (12.4 mi) might experience occasional
contact (Hafner 1993, p. 378; Hafner 1994, p. 380). Unsuitable, low-
elevation habitat ranging from 3 to 8 km (1.9 to 5.0 mi) can act as a
complete barrier to gene flow in Great Basin pika populations (Meredith
2002, p. 54). In low elevations, distances of as little as 300 m (984
ft) can be effective barriers to pika dispersal (Smith 1974a, p. 1116).
Therefore, given the current distribution and the physiological and
physical limitations of the species, we expect few successful dispersal
events from populations within the O. p. schisticeps subpopulation to
adjacent habitats outside of this subpopulation.
Analyses of genetic similarity among pikas of increasing geographic
separation demonstrate that metapopulations are separated by somewhere
between 10 and 100 km (Hafner and Sullivan 1995, p. 312). More
substantial gene flow occurs within mountain ranges containing
continuous or semi-continuous habitat than between mountain ranges that
may be separated by geographical barriers to dispersal (Peacock 1997,
p. 346; Meredith 2002, p. 48). Genetic substructure within subspecies
and discontinuity among metapopulations is evident within the American
pika. However, the genetic distinctiveness of population segments below
the subspecies level is not necessarily correlated with biological and
ecological significance, especially when it is not clear which
populations contain relatively higher genetic variability. Geneticists
have suggested resolution of genetic structure and connectivity below
the subspecies level is required before management at finer scales
below the subspecies level is warranted (Galbreath et al. 2009b, p.
33). Great Basin pika populations separated by geographic barriers to
dispersal can develop distinct genetic signatures (Meredith 2002, pp.
37, 44, 46). Analyses of genetic distance demonstrate population
differentiation as well (Hafner and Sullivan 1995, p. 306).
Additionally, we have genetic information that provides evidence of
this separation, such as the Great Basin subpopulation having
mitochondrial deoxyribonucleic acid (DNA) haplotypes (a combination of
forms of a
[[Page 6465]]
gene at multiple specific locations on the same chromosome) that are
different from other O. p. schisticeps populations (Galbreath et al.
2009a, Figures 1 and 2; Galbreath et al. 2009b, p. 19, Figures 1, 4,
and 5). These lines of genetic evidence indicate that the Great Basin
O. p. schisticeps subpopulation is markedly separated from other O. p.
schisticeps populations.
In summary, physical barriers to dispersal within the Great Basin
O. p. schisticeps subpopulation, such as warmer valleys, and
physiological factors limit the connectivity of pikas between and among
isolated sites. Genetic analyses demonstrate that geographic barriers
to dispersal can isolate pikas and cause populations to form distinct
genetic signatures over ecological time. Therefore, we determined that
the Great Basin O. p. schisticeps subpopulation under threat of climate
change is markedly separate from other O. p. schisticeps populations as
a consequence of physical, physiological, and ecological factors. We
also have genetic information that demonstrates evidence of this
separation, although we believe it is of limited use with respect to
its correlation with biological and ecological significance for the
subpopulation. We conclude that the O. p. schisticeps subpopulation is
discrete under the Service's DPS policy.
Ochotona princeps fenisex at Mt. St. Helens
Similar physical, physiological, and ecological factors that we
determined markedly separate the Great Basin O. p. schisticeps
subpopulation from other O. p. schisticeps populations also play a role
in separating the Mt. St. Helens subpopulation from other O. p. fenisex
populations. These factors include: (1) Physical barriers to dispersal;
(2) physiological restraints, such as sensitivity to high temperatures,
that limit dispersal; and (3) the patchy nature of the subspecies'
distribution typically at high elevations. Additionally, we have
genetic information that provides evidence of this separation, such as
the Mt. St. Helens subpopulation having mitochondrial DNA haplotypes
that are different from other O. p. fenisex populations (Galbreath et
al. 2009a, Figures 1 and 2; Galbreath et al. 2009b, p. 19, Figures 1,
4, and 5).
We determined that the Mt. St. Helens subpopulation under threat of
climate change is markedly separate from other Ochotona princeps
fenisex populations as a consequence of physical, physiological, and
ecological factors. We also have genetic information that demonstrates
evidence of this separation, although we believe it is of limited use
with respect to its correlation with biological and ecological
significance for the subpopulation. We conclude that the Mt. St. Helens
subpopulation is discrete under the Service's DPS policy.
Ochotona princeps princeps in Glacier National Park, Northern Wasatch
Mountains, Ruby Mountains, and Sawtooth Mountain Range
Similar physical, physiological, and ecological factors that we
determined markedly separate the Great Basin Ochotona princeps
schisticeps subpopulation from other O. p. schisticeps populations also
play a role in separating the Glacier National Park, Northern Wasatch
Mountains, Ruby Mountains, and Sawtooth Mountain Range population
segment (here after, O. p. princeps subpopulation) from other O. p.
princeps populations. These factors include: (1) Physical barriers to
dispersal; (2) physiological restraints, such as sensitivity to high
temperatures, that limit dispersal; and (3) the patchy nature of the
subspecies' distribution typically at high elevations. Additionally, we
have genetic information that provides evidence of this separation,
such as the Ruby and Northern Wasatch Mountains populations having
mitochondrial DNA haplotypes that are different from other O. p.
princeps populations (Galbreath et al. 2009b, p. 19, Figures 1, 2, and
5).
We determined that the Ochotona princeps princeps subpopulation
under threat of climate change is markedly separate from other O. p.
princeps populations as a consequence of physical, physiological, and
ecological factors. We also have genetic information that demonstrates
evidence of this separation, although we believe it is of limited use
with respect to its correlation with biological and ecological
significance for the subpopulation. We conclude that the O. p. princeps
subpopulation is discrete under the Service's DPS policy.
Ochotona princeps saxatilis in the Sangre de Cristo Mountains and
Southern Rockies
Similar physical, physiological, and ecological factors that we
determined markedly separate the Great Basin Ochotona princeps
schisticeps subpopulation from other O. p. schisticeps populations also
play a role in separating the Sangre de Cristo Mountain and Southern
Rockies subpopulation (here after, O. p. saxatilis subpopulation) from
other O. p. saxatilis populations. These factors include: (1) Physical
barriers to dispersal; (2) physiological restraints, such as
sensitivity to high temperatures, that limit dispersal; and (3) the
patchy nature of the subspecies' distribution typically at high
elevations. Additionally, we have genetic information that provides
evidence of this separation, such as the Sangre de Cristo Mountains and
Southern Rocky Mountains populations having mitochondrial DNA
haplotypes that are different from other O. p. saxatilis populations
(Galbreath et al. 2009b, p. 19, Figure 1, 2 and 5).
We determined that the Ochotona princeps saxatilis subpopulation
under threat of climate change is markedly separate from other O. p.
saxatilis populations as a consequence of physical, physiological, and
ecological factors. We also have genetic information that demonstrates
evidence of this separation, although we believe it is of limited use
with respect to its correlation with biological and ecological
significance for the subpopulation. We conclude that the O. p.
saxatilis subpopulation is discrete under the Service's DPS policy.
Significance
If a population segment is considered discrete under one or more of
the conditions described in the Service's DPS policy, its biological
and ecological significance will be considered in light of
Congressional guidance that the authority to list DPSs be used
``sparingly'' while encouraging the conservation of genetic diversity.
In making this determination, we consider available scientific evidence
of the discrete population segment's importance to the taxon to which
it belongs. Since precise circumstances are likely to vary considerably
from case to case, the DPS policy does not describe all the classes of
information that might be used in determining the biological and
ecological importance of a discrete population. However, the DPS policy
describes four possible classes of information that provide evidence of
a population segment's biological and ecological importance to the
taxon to which it belongs. As specified in the DPS policy (61 FR 4722),
this consideration of the population segment's significance may
include, but is not limited to, the following:
(1) Persistence of the discrete population segment in an ecological
setting unusual or unique to the taxon;
(2) Evidence that loss of the discrete population segment would
result in a significant gap in the range of a taxon;
(3) Evidence that the discrete population segment represents the
only
[[Page 6466]]
surviving natural occurrence of a taxon that may be more abundant
elsewhere as an introduced population outside its historic range; or
(4) Evidence that the discrete population segment differs markedly
from other populations of the species in its genetic characteristics.
A population segment needs to satisfy only one of these conditions
to be considered significant. Furthermore, other information may be
used as appropriate to provide evidence for significance.
Persistence of the population segment in an ecological setting that is
unusual or unique for the taxon
We evaluated all discrete population segments (described as
subpopulations under Discreteness) to determine if any population
segment persists in an ecological setting this is unusual or unique for
the species. Our analysis for each subpopulation is provided below.
Pikas occupying habitat in the Ochotona princeps schisticeps
subpopulation in the Great Basin are found in what has been described
as talus or rockslides (Smith and Weston 1990, p. 4), where talus can
be more specifically described as rock-ice or non-rock-ice features
(Millar and Westfall 2009, pp. 6, 18). Talus fields are typically
fringed by suitable vegetation for foraging. Great Basin pika sites
have been associated with diverse vegetation associations (Millar and
Westfall 2009, p. 10) and a pika's generalist diet can include a wide
variety of plant material (Huntly et al. 1986, p.143; Beever et al.
2008, p. 14). Pika populations in the Great Basin not only occur
adjacent to alpine meadow habitat, but also have been documented at
relatively lower elevations persisting under a diet consisting of
plants that commonly include Elymus cinereus (Great Basin wild rye),
Artemisia tridentata (sagebrush), Rosa woodsii (wild rose), and Bromus
tectorum (cheatgrass) (Beever et al. 2008, p. 14; Collins 2009 pers.
comm.).
Pikas inhabiting the Mt. St. Helens subpopulation of Ochotona
princeps fenisex are found in talus, rockslides, or in the case of 2 of
8 populations, they can be found in log piles (Bevers 1998, pp. 68, 70-
71). The studies on Mt. St. Helens suggest that pikas are more
opportunistic in habitat use than has been previously described (Bevers
1998, p. 72). Populations from Mt. St. Helens were associated with
forage items that include forbs, trees, and ferns (Bevers 1998, p. 75).
Pikas inhabiting the Ochotona princeps princeps subpopulation are
found in talus or rockslides generally at high elevations (Meredith
2002, p. 8; UDWR 2009, p. 8; USFS 2009b, pp. 2-6). We do not have
information to the specific type of ecological setting that is occupied
by the populations inhabiting these segments, but we expect the
habitats to contain features that have been previously described for
the species.
Pikas inhabiting the Ochotona princeps saxatilis subpopulation are
described as occupying talus slopes situated in cool, moist habitats of
the alpine tundra and subalpine forests (Fitzgerald et al. 1994 cited
in CDOW 2009, p. 3). We do not have information to the specific type of
ecological setting that is occupied by this subpopulation, but we
expect the habitats to contain features that have been previously
described for the species.
For the purposes for determining significance in a DPS analysis, we
look at whether the settings occupied in the area under consideration
are unique or unusual to the taxon in question, and whether the
persistence of the population in the unique or unusual ecological
setting may provide a behavioral or physiological adaptation that would
be significant to the taxon as a whole. Thus, for this analysis, we
analyzed whether the discrete population segments constitute an unusual
or unique ecological setting for each of the four subspecies of the
pika under consideration. Pikas select habitat that includes
topographical features characterized by rocks or other surface
features, such as log piles, large enough to provide necessary
interstitial spaces for subsurface movement and microclimate conditions
suitable for pika survival by creating cooler refugia in summer months
and insulating individuals in colder, winter months (Beever 2002, p.
27; Millar and Westfall 2009, pp. 19-21). Pikas also select habitats
that contain forage vegetation that is accessible within distances
comparable to dimensions of home ranges (Beever 2002, p. 28). Occupied
habitats within the population segments under consideration do not
constitute an unusual or unique setting for the pika because they fall
within the species' typical ecological niche, and there does not appear
to be any behavioral or physiological differences in these population
segments that result from ecological pressures in their specific
geographic areas. Additionally, the food resources used by pika in
these areas are similar to those found elsewhere throughout the range.
No information indicates that American pika habitat in the four
population segments under consideration constitutes an unusual or
unique ecological setting for the species.
Evidence that loss of the discrete population segment would result in a
significant gap in the range of taxon
We evaluated all discrete population segments (described as
subpopulations under Discreteness) to determine if loss of any
population segment would result in a significant gap in the range of
the subspecies to which the population segment belongs. Our analysis
for each subpopulation is provided below.
Ochotona princeps schisticeps or Great Basin Subpopulation
Pika sites potentially at risk of extirpation in the foreseeable
future from increased summer surface temperatures from climate change
within the O. p. schisticeps subpopulation (see Table 1 above) occur at
relatively low elevations. Pika sites within this same subpopulation at
higher elevations, where pikas more typically occupy suitable talus
habitat, are not at risk from climate change now or in the foreseeable
future. Therefore, within the subpopulation, not all pika sites are
potentially at risk from the effects of climate change, and results
from comparisons between below-talus summer temperatures and surface
summer temperatures indicate that our risk assessment for climate
change may be conservative because risk estimates for pika sites were
based on projections for summer surface temperatures. As stated under
Discreteness, in the numerous ``sky islands'' of the Great Basin,
American pikas are isolated (greater than the maximum estimated
individual dispersal distance (10 to 20 km, or 6.2 to 12.4 mi of the
species from the nearest extant population) by these geographic
barriers (Hafner 1994, pp. 376-378). These barriers eliminate dispersal
of pikas between and among mountain ranges. Because temperatures in
these valleys often exceed the physiological constraints of pikas
(e.g., valley temperatures often exceed greater than or equal to 28
[deg]C (82.4 [deg]F)), pikas are unable to disperse to other mountain
ranges and are now confined to a subset of ranges within the Great
Basin, thereby creating many gaps between pika populations in the Great
Basin. Because there is no opportunity for populations to interact
between these barriers, the loss of a pika site potentially at risk
from increased summer surface temperatures may potentially create an
additional gap in the range of the subspecies, however, we have
determined that the possible loss of the pika occurrence would not
result in the creation of a significant gap
[[Page 6467]]
in the range of the subspecies. Our basis for this determination is
that loss of the pika occurrence would not result in a gap that is
biologically significant for subspecies since they are already highly
fragmented throughout the Great Basin. Additionally, the amount of
suitable habitat and number of pika populations in the O. p.
schisticeps subpopulation is small when compared to the Sierra Nevada
Mountain Range in the remainder of the range of the subspecies.
Therefore, the contribution of the Ochotona princeps schisticeps
subpopulation to the subspecies as a whole is small, and loss of the
population segment would not result in a significant gap in the range
of the subspecies.
Ochotona princeps fenisex or Mt. St. Helens Subpopulation
One out of a total of eight known pika populations on Mt. St.
Helens (Bevers 1998, pp. 68, 70-71) is potentially at risk of
extirpation from increased summer surface temperatures from climate
change within the O. p. fenisex subpopulation in the foreseeable future
(see Table 1 above) and occurs at relatively low elevations. Pika sites
within this same subpopulation at higher elevations, where pikas more
typically occupy suitable talus habitat, are not at risk from climate
change now or in the foreseeable future. Therefore, within the
subpopulation, not all pika sites are potentially at risk from the
effects of climate change, and results from comparisons between below-
talus summer temperatures and surface summer temperatures indicate that
our risk assessment for climate change may be conservative because risk
estimates for pika sites were based on projections for summer surface
temperatures.
Of the 69 unique pika observations used to generate an elevation
across the range of O. p. fenisex, we do not anticipate risks from
increased summer temperatures occurring at 98 percent (68 of 69) of the
observation points. As such, the amount of suitable habitat in the Mt.
St. Helens subpopulation segment when compared to the rest of the range
of the subspecies is small.
Therefore, the contribution of the Mt. St. Helens subpopulation to
the subspecies as a whole is small and provides a nominal contribution
ecologically and biologically to the subspecies, such that loss of the
population segment would not result in a significant gap in the range
of the subspecies.
Ochotona princeps princeps Subpopulation
Pika sites potentially at risk of extirpation in the foreseeable
future from increased summer surface temperatures from climate change
within the O. p. princeps subpopulation (see Table 1 above) occur at
relatively low elevations. Pika sites within this same subpopulation at
mid- to higher elevation talus habitat, where pikas currently occupy
suitable talus habitat, are not at risk from climate change now or in
the foreseeable future. Best available information suggests that pikas
more frequently occupy the highest elevation talus slopes in the
Northern Rocky Mountains, and based on the NOAA projected surface
temperatures (see Table 1 above), these habitats are not at risk from
climate change now or in the foreseeable future. Therefore, within the
subpopulation, not all pika sites are potentially at risk from the
effects of climate change and results from comparisons between below-
talus summer temperatures and surface summer temperatures indicate that
our risk assessment for climate change may be conservative because risk
estimates for pika sites were based on projections for summer surface
temperatures.
Therefore, the contribution of the Ochotona princeps princeps
subpopulation to the subspecies as a whole is small and provides a
nominal contribution ecologically and biologically to the subspecies,
such that loss of the subpopulation would not result in a significant
gap in the range of the subspecies.
Ochotona princeps saxatilis Subpopulation
Pika sites potentially at risk of extirpation in the foreseeable
future from increased summer surface temperatures from climate change
within the O. p. saxatilis subpopulation (see Table 1 above) occur at
relatively low elevations. Pika sites within this same subpopulation at
mid- to higher elevation talus habitat, where pikas currently occupy
suitable talus habitat, are not at risk from climate change now or in
the foreseeable future. Therefore, within the subpopulation, not all
pika sites are potentially at risk from the effects of climate change
and results from comparisons between below-talus summer temperatures
and surface summer temperatures indicate that our risk assessment for
climate change may be conservative because risk estimates for pika
sites were based on projections for summer surface temperatures. Pikas
inhabiting the Ochotona princeps saxatilis subpopulation in the
Southern Rockies in Colorado are described as occupying talus slopes
situated in cool, moist habitats of the alpine tundra and subalpine
forests at or above 3,000 m (10,000 ft) (Fitzgerald et al. 1994 cited
in CDOW 2009, p. 3). These habitats are extensive in Colorado and the
topography of Colorado is described as follows: ``Roughly three
quarters of the Nation's land above 10,000 feet altitude lies within
its borders. The State has 59 mountains 14,000 feet or higher, and
about 830 mountains between 11,000 and 14,000 feet in elevation''
(Doesken et al. 2003 cited in CDOW 2009, p. 3).
Therefore, the contribution of the Ochotona princeps saxatilis
subpopulation to the subspecies as a whole is small and provides a
nominal contribution ecologically and biologically to the subspecies,
such that loss of the population segment would not result in a
significant gap in the range of the subspecies.
Evidence that the discrete population segment represents the only
surviving natural occurrence of a taxon that may be more abundant
elsewhere as an introduced population outside its historical range
The American pika survives naturally throughout much of British
Columbia, Alberta, and the western United States. As such, this
consideration is not applicable to any population segment of the
American pika or the subspecies under consideration in the finding.
Evidence that the discrete population segment differs markedly from
other populations of the species in its genetic characteristics
A recent extensive genetic analysis has determined there are five
major genetic lineages of American pikas (Galbreath et al. 2009b, p.
7), which have since been interpreted as subspecies (Hafner and Smith
2009, p. 16). Galbreath et al. (2009b, p. 18) determined it is unlikely
that additional deeply divergent lineages (i.e., subspecies) of
American pika remain to be identified. Minor differences in genetic
signatures can occur within each subspecies. For example,
metapopulations separated by geographic barriers to dispersal can
develop distinct genetic signatures (Meredith 2002, pp. 37, 44, 46).
Additionally, as discussed under the Discreteness section above,
mitochondrial DNA haplotypes are unique to each American pika
population (Galbreath et al. 2009b, p. 19). However, each of the
smaller genetic units (i.e., populations) can be linked back to one of
five major genetic lineages. Geneticists have suggested
[[Page 6468]]
resolution of genetic structure and connectivity below the subspecies
level is required before management at finer scales below the
subspecies level is warranted (Galbreath et al. 2009b, p. 33).
Genetic substructure within subspecies and discontinuity among
metapopulations is evident within the American pika. However, the
genetic distinctiveness of population segments below the subspecies
level is not necessarily correlated with biological and ecological
significance, especially when it is not clear which populations contain
relatively higher genetic variability. We consider genetic differences
among subspecies to be markedly different. However, as indicated by
Galbreath et al. (2009b, p. 33), information concerning the utility of
genetic differences at the subspecific level for pika are lacking for
use in conservation management actions. As a consequence, even though
we have used the information that demonstrates apparent genetic
discontinuity between the different population segments to support our
arguments for discreteness under the DPS policy, for the reasons stated
above, we believe that this information is of limited use with respect
to its correlation with biological and ecological significance for the
population and therefore the taxon as a whole and, hence, conservation
value.
We determine, based on review of the best available information,
that no population segment below the subspecies level is significant in
relation to the remainder of the taxon. Therefore, no population
segments (as described previously under Discreteness) qualify as a DPS
under our 1996 DPS policy and none are a listable entity under the Act.
Because we found that the Ochotona princeps schisticeps, O. p. fenisex,
O. p. princeps, and O. p. saxatilis subpopulations do not meet the
significance criterion of the DPS policy, we need not proceed with an
evaluation of the threats to pikas in any of the population segments.
Significant Portion of the Range Analysis
Having determined that the American pika at the species and
subspecies level do not meet the definition of an endangered or
threatened species under the Act and no populations qualify under our
policy, we must next consider whether there are any significant
portions of the range where the species is in danger of extinction or
is likely to become endangered in the foreseeable future.
The Act defines an endangered species as one ``in danger of
extinction throughout all or a significant portion of its range,'' and
a threatened species as one ``likely to become an endangered species
within the foreseeable future throughout all or a significant portion
of its range.'' The term ``significant portion of its range'' is not
defined by the statute. For the purposes of this finding, a significant
portion of a species' range is an area that is important to the
conservation of the species because it contributes meaningfully to the
representation, resiliency, or redundancy of the species. The
contribution must be at a level such that its loss would result in a
decrease in the ability to conserve the species.
In determining whether a species is endangered or threatened in a
significant portion of its range, we first identify any portions of the
range of the species that warrant further consideration. The range of a
species can theoretically be divided into portions an infinite number
of ways. However, there is no purpose to analyzing portions of the
range that are not reasonably likely to be significant and endangered
or threatened. To identify only those portions that warrant further
consideration, we determine whether there is substantial information
indicating that: (1) The portions may be significant, and (2) the
species may be in danger of extinction there or likely to become so
within the foreseeable future. In practice, a key part of this analysis
is whether the threats are geographically concentrated in some way. If
the threats to the species are essentially uniform throughout its
range, no portion is likely to warrant further consideration. Moreover,
if any concentration of threats applies only to portions of the
species' range that are not significant, such portions will not warrant
further consideration.
If we identify portions that warrant further consideration, we then
determine whether the species is endangered or threatened in this
portion of its range. Depending on the biology of the species, its
range, and the threats it faces, the Service may address either the
significance question or the status question first. Thus, if the
Service considers significance first and determines that a portion of
the range is not significant, the Service need not determine whether
the species is endangered or threatened there. Likewise, if the Service
considers status first and determines that the species is not
endangered or threatened in a portion of its range, the Service need
not determine if that portion is significant. However, if the Service
determines that both a portion of the range of a species is significant
and the species is endangered or threatened there, the Service will
specify that portion of the range as endangered or threatened under
section 4(c)(1) of the Act.
The terms ``resiliency,'' ``redundancy,'' and ``representation''
are intended to be indicators of the conservation value of portions of
the range. Resiliency of a species allows the species to recover from
periodic disturbance. A species will likely be more resilient if large
populations exist in high-quality habitat that is distributed
throughout the range of the species in such a way as to capture the
environmental variability found within the range of the species. A
portion of the range of a species may make a meaningful contribution to
the resiliency of the species if the area is relatively large and
contains particularly high-quality habitat, or if its location or
characteristics make it less susceptible to certain threats than other
portions of the range. When evaluating whether or how a portion of the
range contributes to resiliency of the species, we evaluate the
historical value of the portion and how frequently the portion is used
by the species, if possible. In addition, the portion may contribute to
resiliency for other reasons--for instance, it may contain an important
concentration of certain types of habitat that are necessary for the
species to carry out its life-history functions, such as breeding,
feeding, migration, dispersal, or wintering.
Redundancy of populations may be needed to provide a margin of
safety for the species to withstand catastrophic events. This does not
mean that any portion that provides redundancy is necessarily a
significant portion of the range of a species. The idea is to conserve
enough areas of the range such that random perturbations in the system
act on only a few populations. Therefore, each area must be examined
based on whether that area provides an increment of redundancy that is
important to the conservation of the species.
Adequate representation ensures that the species' adaptive
capabilities are conserved. Specifically, the portion should be
evaluated to see how it contributes to the genetic diversity of the
species. The loss of genetically based diversity may substantially
reduce the ability of the species to respond and adapt to future
environmental changes. A peripheral population may contribute
meaningfully to representation if there is evidence that it provides
genetic diversity due to its location on the margin of the species'
habitat requirements.
We evaluated the American pika's current range in the context of
the most
[[Page 6469]]
significant factor(s) affecting the species (in this case, only climate
change) to determine if there is any apparent geographic concentration
of potential threats. As identified under the threats assessment in
Table 1 above, the threat of recent, current, and future increased
summer surface temperature from climate change is primarily
concentrated in portions of the range of Ochotona princeps schisticeps,
O. p. fenisex, O. p. princeps and O. p. saxatilis. We defined the
portion of the range for these subpopulation to include: (1) The lower
elevation portions of southeastern Oregon, Monitor Hills, southern
Wasatch Mountains, and Toiyabe Mountains, and the low- and mid-
elevations of the Warner Mountains for O. p. schisticeps; (2) the low-
elevation portion of Mt. St. Helens for O. p. fenisex; (3) the low-
elevation portion of Glacier National Park and the Sawtooth Mountain
Range, and low- to mid-elevation portion of the Northern Wasatch
Mountains and Ruby Mountains for O. p. princeps; and (4) the low-
elevation portion of the Sangre de Cristo Mountains and Southern
Rockies for O. p. saxatilis.
Ochotona princeps schisticeps
As stated above, we defined the portion of the range for Ochotona
princeps schisticeps as the lower elevation portions of the Great Basin
in southeastern Oregon, Monitor Hills, southern Wasatch Mountains, and
Toiyabe Mountains, and the low and mid-elevations of the Warner
Mountains. As stated under Discreteness in the DPS section of this
finding, in the numerous ``sky islands'' of the Great Basin, American
pikas are isolated (greater than the maximum estimated individual
dispersal distance (10 to 20 km; 6.2 to 12.4 mi) of the species from
the nearest extant population) by these geographic barriers (Hafner
1994, pp. 376-378). These barriers eliminate dispersal of pikas between
and among mountain ranges. Because temperatures in these valleys often
exceed the physiological constraints of pikas (e.g., valley
temperatures often exceed greater than or equal to 28 [deg]C (82.4
[deg]F)), pikas are unable to disperse to other mountain ranges and are
now confined to a subset of ranges within the Great Basin, thereby
creating many gaps between pika populations in the Great Basin.
However, there are pika populations in suitable habitat at mid- to high
elevations on the ``sky islands'' of the Great Basin that are not at
risk of extirpation from increased summer temperatures from climate
change, ensuring adequate redundancy and resiliency across the portion
of the range under consideration.
Additionally, the amount of suitable habitat and number of pika
populations in the Great Basin portion when compared to the range of
the rest of the subspecies in the Sierra Nevada Mountain Range is
small. There are larger, contiguous blocks of suitable habitat in the
Sierra Nevada Mountains, none of which was identified as potentially at
risk from climate change. Approximately 64 percent of the subspecies'
suitable habitat occurs in the Sierra Nevada (Finn 2009, pp. 1-2),
ensuring adequate redundancy and resiliency across the subspecies.
Galbreath et al. (2009b, pp. 20-21) demonstrated that three
distinct mitochondrial DNA clades (genetically similar groups that
share a common ancestor) are evident within Ochotona princeps
schisticeps; however, Galbreath (2009, pers. comm.) also states there
is not sufficient evidence at this point to distinguish among the three
subregions of O. p. schisticeps as distinct evolutionary significant
entities. Genetic substructure at the nuclear DNA level needs to be
elucidated before northern (eastern Oregon/northern California),
central (Sierra Nevada Range and central Nevada), and eastern (western
Utah) subclades are evident. Therefore, at this point, there are no
subclades (genetically different groups) associated with O. p.
schisticeps (Galbreath et al. 2009b, p. 55, Figure 5). Hafner and Smith
(2009, pp. 12-14) recently performed analyses of morphometric variation
among American pikas, but did not make any conclusions about morphology
differences between O. p. schisticeps populations. Therefore, based on
the best available information, we have determined that this portion of
the range does not contribute to the diversity of genetic,
morphological, or physiological diversity of the subspecies, and there
is adequate representation across the portion of O. p. schisticeps
under consideration and the rest of the range of the subspecies.
For these reasons, we conclude that no portions of the Ochotona
princeps schisticeps' range warrant further consideration as a
significant portion of the range. We do not find that the O. p.
schisticeps is in danger of extinction (endangered) now, nor is it
likely to become endangered within the foreseeable future (threatened)
throughout all or a significant portion of its range.
Ochotona princeps fenisex
As stated above, we defined the portion of the range for Ochotona
princeps fenisex as the low-elevation portion of Mt. St. Helens. One
out of a total of eight known pika populations on Mt. St. Helens
(Bevers 1998, pp. 68, 70-71) is potentially at risk of extirpation from
increased summer surface temperatures from climate change within the O.
p. fenisex subpopulation in the foreseeable future (see Table 1 above)
and occurs at relatively low elevations. Pika sites on Mt. St. Helens
at higher elevations, where pikas more typically occupy suitable talus
habitat, are not at risk from climate change now or in the foreseeable
future, ensuring adequate redundancy and resiliency across the portion
of the range under consideration. Therefore, not all pika sites on Mt.
St. Helens are potentially at risk from the effects of climate change,
and as stated under Factor A, results from comparisons between below-
talus summer temperatures and surface summer temperatures indicate that
our risk assessment for climate change may be conservative because risk
estimates for pika sites were based on projections for summer surface
temperatures.
Of the 69 unique pika observations used in our analysis to generate
an elevation across the range of O. p. fenisex, we do not anticipate
risks from increased summer temperatures occurring at 98 percent (68 of
69) of the observation points. As such, the amount of suitable habitat
in the Mt. St. Helens subpopulation segment when compared to the rest
of the range of the subspecies is small. There are larger, contiguous
blocks of suitable habitat in the Coast and Cascade Mountains, none of
which was identified as potentially at risk from climate change,
ensuring adequate redundancy and resiliency across the range of the
subspecies.
Galbreath et al. (2009b, p. 19) demonstrated Cascade Range
populations also were closely related, though they did not form an
unambiguous clade (group) descending from an ancestor. However,
Galbreath (2009, pers. comm.) also states there is not sufficient
evidence at this point to distinguish among O. p. fenisex as distinct
evolutionary significant entities. Therefore, at this point, there are
no subclades (genetically different groups) associated with O. p.
fenisex (Galbreath et al. 2009b, Figure 5). Hafner and Smith (2009, pp.
12-14) recently performed analyses of morphometric variation among
American pikas, but did not make any conclusions about morphology
differences between O. p. fenisex populations. Therefore, based on the
best available information, we have determined that this portion of the
range does not contribute to the diversity of
[[Page 6470]]
genetic, morphological, or physiological diversity of the subspecies,
and there is adequate representation across the portion of O. p.
fenisex under consideration and the rest of the range of the
subspecies.
For these reasons, we conclude that no portions of the Ochotona
princeps fenisex's range warrant further consideration as a significant
portion of the range. We do not find that the O. p. fenisex is in
danger of extinction (endangered) now, nor is it likely to become
endangered within the foreseeable future (threatened), throughout all
or a significant portion of its range.
Ochotona princeps princeps
As stated above, we defined the portion of the range for Ochotona
princeps princeps as the low-elevation portion of Glacier National Park
and Sawtooth Mountain Range, and low- to mid-elevation portion of the
Northern Wasatch Mountains and Ruby Mountains. Pika sites at higher
elevations on the same mountains, where pikas more typically occupy
suitable talus habitat, are not at risk from climate change now or in
the foreseeable future, ensuring adequate redundancy and resiliency
across the portion of the range under consideration. Therefore, not all
pika sites in this portion under consideration are potentially at risk
from the effects of climate change, and results from comparisons
between below-talus summer temperatures and surface summer temperatures
indicate that our risk assessment for climate change may be
conservative because risk estimates for pika sites were based on
projections for summer surface temperatures.
This portion of the range includes the southwestern and parts of
the central portion of the subspecies' range. However, the amount of
suitable habitat in this portion of the range when compared to the rest
of the range of the subspecies that will not be at risk from climate
change in the foreseeable future is small. There are larger, contiguous
blocks of suitable habitat in the northern Rocky Mountains, none of
which was identified as potentially at risk from climate change,
ensuring adequate redundancy and resiliency across the range of the
subspecies.
The Ochotona princeps princeps lineage is partitioned into
northwestern and southeastern genetic phylogroups (type of pika group)
(Galbreath et al. 2009b, pp. 19-20, 55). Pika populations in the
Northern Wasatch and Ruby Mountains make up a portion of the
southeastern phylogroup, and Glacier National Park and Sawtooth Range
pika populations make up a small portion of the northwestern
phylogroup. All suitable habitat in Wyoming and northern Colorado,
which are not part of the portion of the range under consideration,
make up a substantial portion of the southeastern phylogroup.
Additionally, the majority of the northwestern phylogroup is made up of
pika populations occurring outside the portion of the range at risk
from climate change.
Although there are some genetic (mitochondrial DNA) differences
between phylogroups, there is not sufficient evidence at this point to
distinguish among O. p. fenisex as distinct evolutionary significant
entities beyond the subspecies level (Galbreath et al. 2009b, Figure
5). Hafner and Smith (2009, pp. 12-14) recently performed analyses of
morphometric variation among American pikas, but did not make any
conclusions about morphology differences between O. p. princeps
populations. Therefore, based on the best available information, we
have determined that this portion of the range does not contribute to
the diversity of genetic, morphological, or physiological diversity of
the subspecies, and there is adequate representation across the portion
of O. p. princeps under consideration and the rest of the range of the
subspecies.
For these reasons, we conclude that no portions of the Ochotona
princeps princeps' range warrant further consideration as a significant
portion of the range. We do not find that the O. p. princeps is in
danger of extinction (endangered) now, nor is it likely to become
endangered within the foreseeable future (threatened), throughout all
or a significant portion of its range.
Ochotona princeps saxatilis
As stated above, we defined the portion of the range for Ochotona
princeps saxatilis as the low-elevation portion of the Sangre de Cristo
Mountains and Southern Rockies. Pika sites at higher elevations where
there are larger, contiguous blocks of suitable habitat, where pikas
more typically occupy suitable talus habitat, are not at risk from
climate change now or in the foreseeable future, ensuring adequate
redundancy and resiliency across the portion of the range under
consideration and the range of the subspecies. Therefore, not all pika
sites in this portion under consideration are potentially at risk from
the effects of climate change, and as stated under Factor A, results
from comparisons between below-talus summer temperatures and surface
summer temperatures indicate that our risk assessment for climate
change may be conservative because risk estimates for pika sites were
based on projections for summer surface temperatures.
Galbreath et al. (2009b, pp. 20-21) demonstrated populations south
of the Colorado River were closely related genetically, although sites
closer to the Colorado River exhibited some morphological similarities
to pikas north of the Colorado River, which is the dividing line
between Ochotona princeps saxatilis and O. p. princeps. However,
Galbreath et al. (2009b, Figure 5) also states there is not sufficient
evidence at this point to distinguish among O. p. saxatilis as distinct
evolutionary significant entities. Therefore, based on the best
available information, we have determined that this portion of the
range does not contribute to the diversity of genetic, morphological,
or physiological diversity of the subspecies, and there is adequate
representation across the portion of O. p. saxatilis under
consideration and the rest of the range of the subspecies.
For these reasons, we conclude that no portions of the Ochotona
princeps saxatilis' range warrant further consideration as a
significant portion of the range. We do not find that the O. p.
saxatilis is in danger of extinction (endangered) now, nor is it likely
to become endangered within the foreseeable future (threatened),
throughout all or a significant portion of its range.
We request that you submit any new information concerning the
status of, or threats to, this species to our Utah Ecological Services
Field Office (see ADDRESSES section) whenever it becomes available. New
information will help us monitor this species and encourage its
conservation. If an emergency situation develops for this species or
any other species, we will act to provide immediate protection.
References Cited
A complete list of references cited is available on the Internet at
http://www.regulations.gov and upon request from the Utah Ecological
Services Field Office (see ADDRESSES section).
Author(s)
The primary authors of this notice are the staff members of the
Utah Ecological Services Field Office.
Authority
The authority for this action is section 4 of the Endangered
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).
[[Page 6471]]
Dated: January 26, 2010.
Signed: James W. Kurth,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2010-2405 Filed 2-5-10; 16:15 pm]
BILLING CODE S