[Federal Register Volume 76, Number 196 (Tuesday, October 11, 2011)]
[Proposed Rules]
[Pages 62900-62926]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2011-25522]
[[Page 62899]]
Vol. 76
Tuesday,
No. 196
October 11, 2011
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 Tehachapi Slender Salamander as Endangered or
Threatened; Proposed Rule
Federal Register / Vol. 76 , No. 196 / Tuesday, October 11, 2011 /
Proposed Rules
[[Page 62900]]
-----------------------------------------------------------------------
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[FWS-R8-ES-2008-0087]
Endangered and Threatened Wildlife and Plants; 12-Month Finding
on a Petition To List the Tehachapi Slender Salamander as Endangered or
Threatened
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 Tehachapi slender salamander
(Batrachoseps stebbinsi) as threatened or endangered, under the
Endangered Species Act of 1973, as amended (Act). After review of all
available scientific and commercial information, we find that listing
the Tehachapi slender salamander is not warranted. However, we ask the
public to submit to us any new information that becomes available
concerning threats to the Tehachapi slender salamander or its habitat
at any time.
DATES: The finding announced in this document was made on October 11,
2011.
ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R8-ES-2008-0087 and at http://www.fws.gov/ventura. 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, Ventura
Fish and Wildlife Office, 2493 Portola Road, Suite B, Ventura, CA
93003; telephone 805-644-1766; facsimile 805-644-3958. Please submit
any new information, materials, or questions concerning this finding to
the above address or via electronic mail (e-mail) at tss@fws.gov.
FOR FURTHER INFORMATION CONTACT: Michael McCrary, Listing and Recovery
Program Coordinator, U.S. Fish and Wildlife Service, Ventura Fish and
Wildlife Office (see ADDRESSES) by telephone at 805-644-7166; or by
facsimile at 805-644-3958. 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 Species that
contains substantial scientific or commercial information that listing
the species may be warranted, we make a finding within 12 months of the
date of receipt of the petition. In this finding, we will determine
that the petitioned action is: (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 Species. 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 February 28, 2006, we received a petition, dated February 17,
2006, from Mr. Jeremy Nichols of Denver, Colorado, requesting that the
Tehachapi slender salamander (Batrachoseps stebbinsi) be listed as
threatened or endangered in accordance with section 4 of the Act. The
petition clearly identified itself as such and contained the name,
address, and signature of the petitioning private citizen, as required
in 50 CFR 424.14(a).
In response to the petition, we sent a letter to the petitioner
dated April 20, 2006, explaining that we would not be able to address
the petition until fiscal year 2007. The reason for this delay was that
responding to existing court orders and settlement agreements for other
listing actions expended our listing funding. We also concluded in our
April 20, 2006, letter that emergency listing of the Tehachapi slender
salamander was not warranted. We were delayed in responding to the
petition until funding became available.
On April 22, 2009, the Service issued its 90-day finding (74 FR
18336), concluding that the petition presented substantial scientific
or commercial information to indicate that listing the Tehachapi
slender salamander may be warranted. We also announced the initiation
of a status review to determine if listing the species is warranted and
solicited information to be provided in connection with the status
review.
We contracted with Robert Hansen, a recognized scientific expert on
the Tehachapi slender salamander, editor of the Herpetological Review,
and author of peer-reviewed papers on the species (Hansen 1980, pp. 1-
50; Hansen and Stafford 1994, pp. 252-255; Hansen and Wake 2005, pp.
693-695), to develop a technical report (Hansen 2009, pp. 1-30)
addressing the species' range and distribution relative to current and
foreseeable land uses to assess effects of habitat alteration on the
salamander. This notice constitutes our 12-month finding on the
February 28, 2006, petition to list the Tehachapi slender salamander as
threatened or endangered.
Species Description
Like others in the Family Plethodontidae (the lungless
salamanders), the Tehachapi slender salamander breathes through its
smooth, thin skin. Species in the Batrachoseps genus tend to have
elongated bodies and tails, and shorter limbs. Compared to other
species of attenuate Batrachoseps, the Tehachapi slender salamander has
a relatively broad head, long legs, large feet, long toes, a robust
body, and a short tail. Both front and hind feet contain four toes and
are more webbed than other Batrachoseps species. The dorsal color may
be dark red, brick red, or light or dark brown with light-tan or black
patches that often form a band-like pattern. The Tehachapi slender
salamander is characterized by 19 intercostal grooves on each side of
the body (Brame and Murray 1968, p. 19). The Tehachapi slender
salamander is sexually dimorphic. The average size of adult females is
2.24 inches (in) (57 millimeters (mm), and adult males average 2.13 in
(54 mm) snout-to-vent length. Brame and Murray (1968, p. 18) first
described the species in 1968.
The Tehachapi slender salamander belongs in the genus Batrachoseps,
one of 25 genera in the subfamily Bolitoglossinae (Jockusch in litt.
2009a, p. 2; Jockusch in litt. 2009b, p. 1). The subgenus Batrachoseps
(under the genus Batrachoseps) consists of four groups or clades (a
nontaxonomic rank based on genetic or morphological comparisons)
comprising 16 species and a few undescribed taxa all of which are
adapted to fossorial (subterranean) and semifossorial existences
(Jockusch and Wake 2002, pp. 362, 380). The four groups are attenuatus,
nigriventris, pacificus, and relictus (Jockusch in litt. 2009a, p. 1).
The Tehachapi slender salamander belongs in the nigriventris group,
along with the black-bellied
[[Page 62901]]
slender salamander (B. nigriventris), gregarious slender salamander (B.
gregarious), and Kern Canyon slender salamander (B. simatus) (Jockusch
in litt. 2009c, p. 1; Jockusch and Wake 2002, p. 363). Based on genetic
studies, the Tehachapi slender salamander is considered to be closely
related to the Kern Canyon slender salamander (Hansen and Stafford
1994, p. 252; Jockusch and Wake 2002, p. 364).
There are two known populations of Tehachapi slender salamander,
the Caliente Canyon population and the Tehachapi Mountains population,
both of which are described in detail below under the Range and
Distribution section. We examined information suggesting that the two
populations may represent separate species. We evaluated information
discussed by Jockusch (1996, pp. 1-231) and Jockusch and Wake (2002,
pp. 361-391), regarding the large amount of genetic and morphological
differences between the two populations (Nichols 2006, p. 5). Hansen
and Wake (2005, p. 694) also suggest that the two may eventually be
classified as separate species based on genetic and morphological data.
However, based on subsequent genetic research, Jockusch (in litt.
2009d, p. 1) concluded that considering the two populations separate
species was not warranted at this time. Hansen (2009a, pers. comm.)
believes there are not enough differences between the two populations
to classify them as separate species or subspecies. Therefore, we
conclude at this time that the two populations of Tehachapi slender
salamanders are a single species.
Biology and Natural History
Western species of plethodontid salamanders, including the
Tehachapi slender salamander, are completely terrestrial amphibians and
do not need standing or flowing water for any stage of their life cycle
(Zug et al. 2001, p. 383). Because their entire life cycle occurs on
land, they are vulnerable to desiccation. Thus, the Tehachapi slender
salamander, like other plethodontids, requires moist microhabitats. As
such, its above-surface activity is greatly reduced outside of the
rainy season (Feder 1983, pp. 295-296).
Peak periods of surface activity for the nocturnal Tehachapi
slender salamander occur during the rainy season, typically February
through March, but may occur earlier depending on the timing of late-
fall/early-winter rains (Hansen and Wake 2005, p. 694; Hansen in litt.
2009a, p. 2). During wetter years, peak activity may extend to April or
early May at higher elevations (Hansen and Wake 2005, p. 694). These
salamanders retreat to underground refugia (up to 3 feet (ft) (0.9
meters (m)) below the surface) during the warmer months or during
periods of freezing temperatures and are believed to aestivate during
this time (Hansen and Wake 2005, p. 694; Hansen in litt. 2009b, p. 1;
Hansen 2010 pers. comm.).
Specific information on the reproductive biology and behavior of
the Tehachapi slender salamander is unknown. There is no reported
information on the size and age at sexual maturity, nesting behavior,
clutch size, or timing of egg hatching for the Tehachapi slender
salamander (Hansen and Wake 2005, p. 694). However, Hansen and Wake
(2005, p. 694) suggest that eggs are likely laid underground well below
the talus and leaf litter material. The Tehachapi slender salamander
cannot dig its own burrows, so it uses spaces dug in leaf litter or
talus by other animals, or spaces that result from decaying vegetation
(Hansen 2009b, pers. comm.; Hansen and Stafford 1994, p. 254). Jockusch
and Mahoney (1997, p. 699) suggest that oviposition in Tehachapi
slender salamanders occurs after the first rains in the fall or winter,
and only once per season, based on their observations of oviposition
occurring in November in the related black-bellied slender salamander.
Little is known about the behavior of Batrachoseps species, but
feeding and reproduction are assumed to occur during brief periods of
surface activity (Hansen in litt. 2009b, p. 1). The low metabolic rate
of plethodontid salamanders enables them to sustain themselves on their
energy reserves when surface conditions are not suitable for foraging.
They are believed to be inactive (i.e., do not forage) while
underground (Feder 1983, pp. 304-306). The Tehachapi slender salamander
has been observed to capture prey, consisting of small terrestrial
invertebrates, with its projectile tongue (Hansen and Wake 2005, p.
694). Hansen and Stafford suggest that the diet of the Tehachapi
slender salamander is likely to be similar to other related
Batrachoseps, consisting of small spiders, mites, and insects (Hansen
and Stafford 1994, p. 254). Predators of this species are not well
known. Other salamander species are known to be preyed upon by birds,
such as American crows (Corvus brachyrhynchos), common ravens (Corvus
corax), and jays, as well as raccoons (Procyon lotor), skunks, opossums
(Didelphis virginiana), and snakes (HumboldtHerps 2010, p. 2; Kuchta
2005, p. 266). The only documented predator of the Tehachapi slender
salamander that we know of is a ring-necked snake (Diadophis punctatus)
(Burkhardt et al. 2001, p. 245). We are not aware of any information
about parasites or diseases affecting this species or information about
symbiotic or mutualistic interactions with other organisms.
Habitat Characteristics
Tehachapi slender salamanders are restricted to seasonally mesic
microhabitats on north-facing slopes in otherwise dry regions of the
Tehachapi Mountains and the southern end of the Sierra Nevada Mountains
(Hansen and Wake 2005, p. 694). Suitable habitat consists typically of
shaded, north-facing slopes containing talus substrates or areas with
considerable leaf litter or downed wood (Jockusch and Wake 2002, p.
362; Hansen and Wake 2005, p. 693; Hansen 2009, p. 2). These heavily
shaded, north-facing slopes generally occur on the lower reaches of a
hillside where sun exposure is the most limited (Hansen in litt. 2010b,
p. 1). The species has most often been found to occur on slopes with
limestone talus, scattered rocks, fissured rock outcrops, fallen logs,
leaf litter under tree canopy cover where moisture and humidity are
high compared to nearby sites with reduced canopy cover or greater
slope exposure (Hansen and Wake 2005, p. 694; CaliforniaHerps 2008, p.
2; Hansen 2009, p. 2). The species was also recently found on an
atypical, more exposed north-facing slope in a new location (Silver
Creek) in the northeast corner of its range under large rocks; talus
mixed with soil; logs; and in some cases, dead Yucca spp. plants
(family Asparagaceae) (see Figure 1) (Sweet in litt. 2011, p. 1).
Habitat that meets the requirements of the Tehachapi slender salamander
in the two areas (Caliente Canyon and Tehachapi Mountains areas; see
``Range and Distribution'' section below) where the species occurs is
sparse and patchily distributed. These patches of suitable habitat are
dominated by Aesculus californica (California buckeye), Platanus
racemosa (California sycamore), and Quercus chrysolepis (canyon live
oak). Based on survey photographs (Sweet 2011, pp. 8-10), the atypical
Silver Creek location in the northeast corner of the range also
includes abundant junipers (Juniperus californica). The species has
been documented to occur from 1,804 to 4,825 ft (550 to 1,471 m) in
altitude throughout its range (Hansen 2009, p. 2; Sweet in litt. 2011,
p. 1).
Movement patterns, individual dispersal, and home range size of the
[[Page 62902]]
Tehachapi slender salamander are unknown. However, genetic studies of
related Batrachoseps species (Jockusch 1996, p. 80; Hansen and Wake
2005, p. 694) indicate that female movement is limited (Jockusch and
Wake 2002, p. 381). Jockusch (1996, p. 80) observed genetic differences
over short geographic distances (ranging from 1.6 to 25 miles (mi) or
2.5 to 40 kilometers (km)) within a population of a closely related
species, the black-bellied slender salamander, indicating that the
females had not moved between populations for millions of years. No
quantitative studies on movement patterns, individual dispersal, and
home range size have been completed for species of Batrachoseps except
for the California slender salamander (Batrachoseps attenuatus).
Anderson (1960, p. 369) observed that the California slender salamander
movements were limited to approximately 5 ft (2 m), and Maiorana (1978,
p. 1020) observed that individuals of the same species stay within a
6.6-ft (2-m) area, on average. Based on the limited data on the
California slender salamander, we infer that individual Tehachapi
slender salamanders are likely to stay within an area of a few meters
during their lifetime (Hansen in litt. 2009b, p.1; Hansen in litt.
2009c, p. 1).
Range and Distribution
The Tehachapi slender salamander is endemic to Kern County,
California (Stebbins 2003, p. 185; Hansen and Wake 2005, p. 693). The
general range of the species in the Tehachapi Mountains extends from
the Piute Mountains in the north to Fort Tejon State Historic Park
(SHP) in the south.
Since the publication of our 90-day finding (74 FR 18336; April 26,
2009), we have obtained additional data regarding the distribution of
the Tehachapi slender salamander. In this finding, we have updated the
description of the distribution of the Tehachapi slender salamander
presented in the 90-day finding to reflect the best available
scientific information. As stated above, we relied extensively on
Hansen's technical report on the Tehachapi slender salamander in the
preparation of this review because it provides the most comprehensive
information on confirmed species occurrences throughout the species'
range. An occurrence refers to a small patch of habitat (rather than a
specific point location), where one or more individuals of the species
was observed and verified. Hansen's 2009 report incorporates his past
work, information gathered from the September 2008 habitat assessment,
all vouchered museum specimen occurrences, and confirmed reports of
occurrences from Jockusch and Wake (2002), other species experts, and
the California Natural Diversity Database (CNDDB 2007). This report
also documents current land uses and land ownership at sites where this
species has been reported, assesses habitat quality, and reviews
potential threats to the species based on its distribution and natural
history. We also report new locations not included in any of the above
that were recently found by Christopher Evelyn and Dr. Sam Sweet
(University of California, Santa Barbara) in the northeastern portion
of the species' range (Sweet 2011, pp. 8-10; Sweet in litt. 2011, p.
1).
The current known range of the Tehachapi slender salamander
consists of two disjunct areas that are separated by approximately 13
mi (21 km) of dry, rugged, mountainous terrain. We consider these two
disjunct areas as separate populations, the Caliente Canyon and
Tehachapi Mountains populations. The Caliente Canyon population is
located northeast of State Highway 58 and west of the Piute Mountains,
and lies in the southern foothills of the Sierra Nevada Mountains,
south of Kern Canyon. The Tehachapi Mountains population is located
southwest of State Highway 58 and extends to Fort Tejon State Historic
Park (SHP) (Hansen and Stafford 1994, p. 255). This population lies in
the Tehachapi Mountains and the San Emigdio/Mount Pinos area of Kern
County, on both sides of Interstate Highway 5. Until recently, the
species was known from 21 occurrences (from northeast to southwest), 14
in Caliente Canyon, 6 in the Tehachapi Mountains (including 5 on Tejon
Ranch and 1 on Fort Tejon SHP), and 1 near Highway 58 (Tehachapi Pass
location, see Figure 1 below) (Hansen 2009, pp. 8-10; ICF Jones and
Stokes 2009, p. 4.4-156 and Figure 4.4-8). The 21 previously known
occurrence records span a period from 1957 through 2007; most recorded
occurrences are on private land. In addition to the 21 previously known
occurrences, Christopher Evelyn and Dr. Sam Sweet found 4 new locations
in the northeastern portion of the species' range (Sweet 2011, pp. 1-
13; Sweet in litt. 2011, p. 1), bringing the total known occurrences to
25, including one that is extirpated.
We have defined the ranges of the two populations of the Tehachapi
slender salamander as the canyons with known occurrences. Based on the
presence of at least one known occurrence, we infer that the habitat
up- and downcanyon from the occurrence is likely to be suitable and
occupied. By using the best available aerial photographs, we determined
the boundaries of each occupied segment based on the up- and downcanyon
extent of vegetation that could support the species. We have not
calculated the actual acreage of each canyon segment because we cannot
determine the actual width of the suitable habitat, but in many cases
it probably only extends about 50-100 ft (15-30 m) upslope from the
canyon bottom. Instead, each occupied segment includes the approximate
linear extent of contiguous suitable habitat within each canyon that
has documented occurrences.
The known range of the Caliente Canyon population is based on 18
occurrences (including 4 newly discovered occurrences) and consists of
5 canyon segments totaling approximately 9 linear mi (14.5 km) (Figure
1), including: Caliente Canyon (14 occurrences, 7 linear mi (11.3-km)),
Tollgate Canyon (1 occurrence, 0.8 linear mi (1.3 km)), Indian Creek (1
occurrence, 0.5 linear mi (0.8 km)), an unnamed canyon south of Indian
Creek (1 occurrence, 0.4 linear mi (0.6 km)), and Silver Creek (1
occurrence, 0.3 linear mi (0.5 km)).
Tehahcapi slender salamanders were first discovered in Caliente
Canyon in 1967 (Brame and Murray 1968, p. 18), and Hansen included
Caliente Canyon is his 2008 habitat assessment (Hansen 2009, pp. 1-30).
However, Hansen's 2009 report does not include any information on the
four new occurrences outside Caliente Canyon, which were discovered in
2011. The 14 occurrences in Caliente Canyon closely follow Caliente
Creek between the junction of Bealville Road and California Bodfish
Road (10 mi (16 km) west of Loraine) and the unincorporated community
of Loraine (see Figure 1). Caliente Canyon runs roughly from east to
west and has a number of seasonally moist areas on the steep north-
facing slopes bordering Caliente Canyon Road. Tehachapi slender
salamander habitat in Caliente Canyon is patchily distributed and
discontinuous because slope aspect throughout the canyon varies as a
result of the natural bends in the canyon and the occurrence of side
canyons. Twelve of the 14 occurrences (approximately 85 percent) in
Caliente Canyon occur on private land and 2 (approximately 15 percent)
occur on Bureau of Land Management (BLM) land (Hansen 2009, p. 3).
Suitable habitat for the species may also occur on north-facing slopes
of unnamed side canyons that stem from Caliente Canyon (Hansen 2008a,
b, pers. comm.; Sweet in litt. 2009, p. 2).
[[Page 62903]]
Information is limited for the four newly discovered occurrences of
the Caliente Canyon population at this time. The new occurrences range
from about 5.75 to 7 mi (9.3 to 11.3 km) south and southeast of the the
easternmost occurrence in Caliente Canyon (Figure 1). Based on photos
of the new areas taken when the species was first found there (Sweet
2011, pp. 1-13), the habitat in the vicinity of the occurrences in
Tollgate Canyon, Indian Creek, and the unnamed canyon south of Indian
Creek is typical of Tehachapi slender salamanders--steep, shaded, tree-
covered, north-facing slopes, with talus and fallen logs. Although the
Silver Creek occurrence is also on a north-facing slope, it is atypical
for the species in that it is more exposed than other occurrences, with
Juniperus california and Pinus spp. (pines) predominating instead of
Quercus chrysolepis and Aesculus californica. Three of the four new
occurrences for the Caliente Canyon population occur on private land
and one occurs on BLM land.
[GRAPHIC] [TIFF OMITTED] TP11OC11.005
The Tehachapi slender salamander was reported along the Tehachapi
Pass, 8 mi (13 km) southwest of Caliente Canyon in 1957, but has not
been reported in that area since (Hansen 2009, p. 9). At the Tehachapi
Pass location (see Figure 2), the species was observed on the north
side of Black Mountain, between State Highway 58 and the Southern
Pacific rail line (Hansen 2009, pp. 3, 21). We have no information to
indicate whether surveys have been conducted for this species in this
area since 1957. Because we do not have current information indicating
that the species still occupies this area, whether that habitat still
remains, or which population this occurrence belongs to, we do not
discuss this historical occurrence further in this review.
The known range of the Tehachapi Mountains population, which is
based on six occurrences (Dudek 2008, p. 5-14; Hansen 2009, pp. 9-10),
consists of five canyon segments totaling approximately 10.2 linear mi
(16.4 km). Four of the five occupied canyons (five of the known
occurrences) within this region are on the privately owned Tejon Ranch
(see Figure 2), and span from Tejon Canyon in the northeast, to Monroe
Canyon 17.5 linear mi (28.2 km) to the southwest. The occupied canyons
on Tejon Ranch are in Bear Trap Canyon (two occurrences; approximately
2.7 linear mi (4.3 km)); the Tejon Creek drainage of Tejon Canyon (one
occurrence; approximately 5 linear mi (8 km)); an unnamed canyon near
the Edmond G. Brown Tunnel between Bear Trap Canyon and Geghus Ridge
(one occurrence; approximately 0.5 linear mi (0.8 km)); and the
recently discovered occupied location (Dudek 2008, p. 5-14) at Monroe
Canyon (one occurrence; approximately 1.5 linear mi (2.3 km). Hansen
(2009, p. 4) described the occupied habitat on Tejon Ranch (Bear Trap
Canyon specifically) as having moist, loamy soil on north-facing talus
slopes with canyon live oak, Quercus kelloggii (black oak), Q.
wislizenii (interior live oak), Calocedrus decurrens (incense cedar)
and Aesculus californica (California buckeye).
The one confirmed occurrence in the Fort Tejon SHP area
(approximately 0.5 linear mi (0.8 km)) is located on the west side of
Interstate Highway 5, approximately 3 mi (4.8 km) northwest of the
unincorporated community of Lebec, California (Hansen 2009, p. 10;
CNDDB 1997).
[[Page 62904]]
[GRAPHIC] [TIFF OMITTED] TP11OC11.006
A few reports of Tehachapi slender salamanders have not been
confirmed or have been determined to be other species of slender
salamander. In 1973, Richman reported the presence of Tehachapi slender
salamander in Tulare County (Richman 1973, p. 97). Richman stated that
two adult specimens fitting the description of the Tehachapi slender
salamander were found under a Pinus jeffreyi (Jeffrey pine) log on an
east-facing slope in the Sequoia National Forest, Tulare County,
California. In a 1980 report to the State of California Resources
Agency, Hansen (1980, p. 38) disagreed with Richman's claim that the
range of the Tehachapi slender salamander extended to Tulare County.
Based on his own collections at the site described by Richman, Hansen
(1980, p. 38) stated that the specimens are definitively not
Batrachoseps stebbinsi, and later found that what Richman described was
the first sighting of the Kern Plateau salamander (B. robustus)
(AmphibiaWeb 2009, p. 4; Hansen and Wake 2005, p. 695; Wake et al.
2002, p. 1016). BLM also reported the species occurring in Tulare
County (BLM 2009, p. 1); however, this report could not be confirmed
(Verner in litt. 2008, p. 1). The U.S. Forest Service reported that
there are no known occurrences of the species within the lands of the
National Forest System (U.S. Forest Service 2009, p. 2). Based on this
information, we currently do not believe that the range of the
Tehachapi slender salamander extends beyond Kern County.
Potential Suitable Habitat
Although we do not include any potentially suitable habitat outside
the canyons that are known to be occupied for the reasons described
below, researchers have speculated that suitable habitat occurs in
other canyons and that other canyons may be occupied. During his 2008
habitat assessment, Hansen (pers. comm. 2008b; 2009, pp. 5-6)
identified additional areas of suitable habitat along Caliente Creek
Road between the junction of Bodfish Road and the community of Loraine,
and in the southwest reaches of the Fort Tejon SHP in Johnson Canyon,
near the border with Los Padres National Forest. Hansen's report
identified five general areas containing mesic north-facing slopes as
potential habitat for the Tehachapi slender salamander, including: (1)
Along Indian Creek Road, southeast of Loraine in Caliente Canyon; (2)
drainages in Cummings and Bear Valleys; (3) canyons on Tejon Ranch
connected to Clear, Sycamore, Cedar, Chanac, Tunis, and El Paso Creeks;
(4) areas in Johnson Canyon within Fort Tejon SHP near the border with
Los Padres National Forest; and (5) the northern slopes of the San
Emigdio Mountains (e.g., Black Bob Canyon) (Hansen 2009, pp. 5-6).
Hansen (2009) did not provide a quantitative estimate of potential
habitat. Subsequent to Hansen's 2009 report, Indian Creek has been
found to be occupied by the salamander (Sweet in litt., p. 1).
In addition to Hansen's work, Dr. Sweet identified suitable habitat
in several tributary canyons extending south of Caliente Canyon (Sweet
in litt. 2009, pp. 1-2). Within this estimated 30-square-mile (7,770-
ha) area, Sweet (in litt. 2009, pp. 1-2) described the presence of
steep, north-facing slopes containing patches of oak trees, springs and
seepages, and areas containing talus. In his 2009 letter, Sweet (in
litt. 2009, p. 2) stated that he had seen the Tehachapi slender
salamander in this area and suggested that they may be widespread in
these tributary canyons stemming from Caliente Creek. However, at that
time, Sweet was unable to provide the Service with specific occurrence
information. Subsequently, Christopher Evelyn and Dr. Sweet verified
that at least a few of these canyons are occupied (Sweet 2011, pp. 1-
13).
[[Page 62905]]
Although other canyons may have some habitat characteristics
similar to those that are known to be occupied, we are not speculating
here as to either their suitability for Tehachapi slender salamanders
or the likelihood that they may be occupied. Although not studied in
detail, the species' habitat requirements appear to be highly specific
(e.g., specific soil type; narrow range of soil moisture and
temperature; substrate type and density; over- and understory
structure; presence of appropriate refugia) and habitat that may have
the general appearance of being suitable (e.g., north-facing slope with
an overstory) may be lacking one or more essential components. Also,
the species has seldom been found when these areas of apparently
suitable habitat have been searched. For example, on April 5, 2009, as
a followup to the 2009 report, Hansen (2009), with assistance from
Service biologists, conducted a survey for Tehachapi slender
salamanders in San Emigdio Canyon (within the privately owned Wind
Wolves Preserve located on the south side of Interstate Highway 5 and
northwest of Fort Tejon) and in Johnson Canyon of Fort Tejon SHP.
Although these areas included north-facing slopes that visually
appeared similar to habitat at known occurrences, no Tehachapi slender
salamanders were found. Also, during an extensive study on Tejon Ranch,
only one individual Tehachapi slender salamander was found in the 77
drainages surveyed (Dudek 2008, p. 6-5). The one individual that was
found in Monroe Canyon is a new occurrence of the species.
The lack of success in finding salamanders in potentially suitable
habitat may simply be a function of the species not being at the
surface on the day the search was conducted. However, it is also likely
that the habitat was not actually occupied because it only had the most
general habitat requirements but was missing some important feature
required by the species. Therefore, we believe that it is overly
speculative to assume that suitable habitat can be readily identified
and that habitat that appears to be suitable is in fact occupied.
Population Sizes and Trends
The populations of occupied canyons have not been determined, and
we are not aware of any information on actual population trends. The
best available information indicates that the number of occurrences has
remained relatively stable (Hansen 2009, pp. 3-5, 11, 12). One
occurrence (Tehachapi Pass) has been extirpated as a result of road
construction, and five new occurrences (Monroe Canyon, Tollhouse
Canyon, Indian Creek, an unnamed canyon south of Indian Creek, and
Silver Creek) have been found.
Current Status
The Tehachapi slender salamander has been listed as threatened by
the State of California since June 1971 (CDFG 2009, p. 7). The species
has a global heritage ranking of G2, meaning that the species is
classified by NatureServe as globally imperiled (NatureServe 2009, p.
1; Hansen 2009, p. 2). The Tehachapi slender salamander is considered
sensitive by BLM (2006, p. 2) and the U.S. Forest Service (2005, p.
78).
Summary of Information Pertaining to the Five Factors
Section 4 of the Act (16 U.S.C. 1533) and implementing regulations
at 50 CFR part 424 set forth procedures for adding species to the
Federal List of Endangered and Threatened Wildlife. An ``endangered
species'' is any species in danger of extinction throughout all or a
significant portion of its range. A ``threatened species'' is any
species which is likely to become an endangered species within the
foreseeable future throughout all or a significant portion of its
range. Under section 4(a)(1) of the ESA, a species may be determined to
be endangered or threatened based on any of the following five factors:
(A) The present or threatened destruction, modification, or
curtailment of its habitat or range;
(B) Overutilization for commercial, recreational, scientific, or
educational purposes;
(C) Disease or predation;
(D) The inadequacy of existing regulatory mechanisms; or
(E) Other natural or manmade factors affecting its continued
existence.
In considering what factors might constitute threats, we must look
beyond the exposure of the species to the factor to determine whether
the species responds to the factor in a way that causes actual impacts
to the species. If there is exposure and the species responds
negatively, the factor may be a threat and we then attempt to determine
how significant a threat it is. If the threat is significant, it may
drive or contribute to the risk of extinction of the species such that
the species warrants listing as endangered or threatened as those terms
are defined by the Act.
In making our 12-month finding, we considered and evaluated all
scientific and commercial information in our files, including
information received during the public comment period that ended June
22, 2009.
Factor A: The Present or Threatened Destruction, Modification, or
Curtailment of the Species' Habitat or Range
Under Factor A, we consider whether the Tehachapi slender
salamander is threatened by the present or threatened destruction,
modification, or curtailment of its habitat or range by growth and
development of human communities, road construction, mining, domestic
livestock grazing, and flood control projects (Nichols 2006, p. 6). We
will evaluate each of these threats for both the Caliente Canyon
population and Tehachapi Mountains population of the Tehachapi slender
salamander.
Like other plethodontids, Tehachapi slender salamanders require
moisture to maintain the permeability of their skin for gas exchange
for respiration (Feder 1983, p. 295). This physiological requirement
limits the time during which they are active at the soil's surface to
relatively brief, rainy periods between the late fall and early spring
(Hansen 2009, p. 2; Hansen and Wake 2005, p. 694). These salamanders
forage and breed during periods of surface activity (Feder 1983, p.
296). During the remainder of the year, they retreat into talus or
rocky substrates, or deep under fallen logs or leaf litter, which
provide refuge from the climatic extremes of the Tehachapi and Sierra
Nevada Mountains (Hansen 2009, p. 2).
Given its physiology and life history, this species may be
negatively affected by disturbances that remove or reduce surface and
soil moisture, relative humidity, or suitable rocky and leafy
substrates. Disturbances that reportedly impact Tehachapi slender
salamanders through habitat removal and degradation include residential
and commercial development, livestock grazing, road construction,
mining, and flood control projects (Hansen and Wake 2005, p. 693;
Hansen and Stafford 1994, pp. 254-255; Jennings 1996, pp. 928-929).
Construction associated with residential and commercial development,
new roads, and mines can remove habitat and can also cause erosion that
washes away the substrates of talus, woody debris, and leaf litter that
the Tehachapi slender salamander uses as refugia. The removal and
degradation of habitat can also cause habitat fragmentation, which
would require individuals to travel longer distances between suitable
habitat patches during brief periods of suitable climate to find mates.
In addition, these activities, along with flood control
[[Page 62906]]
projects, may alter the hydrology of the mesic environment upon which
the species depends (Jennings 1996, pp. 928-929; Hansen and Wake 2005,
p. 693; CNDDB 2007). Our evaluation of the extent and magnitude of
potential effects caused by these activities is based on existing and
expected land uses within the species' range.
Caliente Canyon Population
The main land use within the range of the Caliente Canyon
population of the Tehachapi slender salamander is livestock grazing
(mainly cattle). Seventeen of the 18 confirmed occurrences of the
Caliente Canyon population of the Tehachapi slender salamander are on
lands used primarily for livestock grazing. The remaining occurrence is
on a 34-ac (13.8-ha) parcel with a private residence located at the
base of a north-facing slope. In terms of land ownership, 15
occurrences are on private land, and 3 occurrences are on BLM land.
In 2008, Hansen conducted a habitat assessment of the 14
occurrences in Caliente Canyon (Hansen 2009, pp. 1-30) (Figure 1),
which was prior to the discovery of the other 4 occurrences that make
up the Caliente Canyon population. In his 2009 report, Hansen (pp. 11-
12) noted moderate but localized impacts at 4 of the 14 occurrences in
Caliente Canyon from one or more of the following: Cattle grazing,
disturbance associated with a residence on a private parcel, or erosion
from a nearby road (Hansen in litt. 2010a, pp. 1-3). The other 10
occurrences show minor to low levels of disturbance from cattle grazing
(Hansen in litt. 2010a, pp. 1-5; Hansen 2009, p. 11). Hansen did point
out that there was plenty of suitable habitat in good to fair condition
at all 14 occurrences that would adequately function for the species
(Hansen in litt. 2010a, pp. 3-7; Hansen 2010 pers. comm.), and that
overall, the habitat in the canyon had remained relatively stable since
his first visit in 1979 (Hansen 2009, p. 3).
Livestock grazing could potentially impact Tehachapi slender
salamander habitat through trampling and erosion. The degree of cattle-
related degradation is directly related to the concentration of cattle
in a given area (Hansen in litt. 2010a, p. 3). Heavy trampling,
particularly during moist conditions, could crush Tehachapi slender
salamander burrows and individual salamanders during their surface
activity, and could degrade habitat by displacing and removing talus,
logs, and rocks that serve as critical components of cover and habitat
for the species (Hansen 2010, 2008b, pers. comm.; Kuritsubo 2010 pers.
comm.). Habitat cover consisting of talus, leaf litter, and woody
debris can be displaced by cattle and further removed by wind and water
erosion, potentially making the area less hospitable for the species to
burrow and retain moisture for skin respiration. However, impacts from
cattle within the range of the Caliente Canyon population of the
Tehachapi slender salamander are typically localized, and are generally
low to moderate in degree (Hansen in litt. 2010a, pp. 1-7). In
addition, Tehachapi slender salamander occurrences in Caliente Canyon
have persisted for decades in areas grazed by cattle (Hansen 2009, pp.
3, 11). The same is likely true for the four newly discovered
occurrences of the Caliente Canyon population.
Although livestock grazing (mainly cattle) occurs throughout
Caliente Canyon, Hansen (2009) found a moderate and localized level of
habitat degradation from livestock grazing in the vicinity of only 3 of
the 14 occurrences in the canyon, but also noted that sufficient
habitat in good-to-fair condition remained in these three areas to
support the species. One of the three occurrences that show a moderate
level of habitat degradation is on BLM land that has been designated as
a BLM grazing allotment. BLM manages the allotment in Caliente Canyon
for 74 animal unit months (AUMs) (i.e., 6 cows graze throughout the
allotment year-round or 74 cows graze in the allotment for 1 month per
year) on 470 ac (190 ha) within the Canyon (Kuritsubo in litt. 2009b,
p. 1). Although the other occurrence in Caliente Canyon on BLM land is
also within the grazing allotment, it is considered to be in good
condition (Hansen 2009, p. 11). The third occurrence affected by
grazing is on private land (Hansen 2009, p. 11). The limited impact of
cattle grazing on Tehachapi slender salamander habitat in Caliente
Canyon and elsewhere may be because they are free ranging. Cattle tend
to graze the grass to a certain height and move on, unless their
movement is restricted to a corral or a fenced area. According to
Hansen (in litt. 2010a, p. 3; 2010 pers. comm.), cattle throughout the
range of the species are free ranging, thus trampling and removal of
vegetation to the point of exposing bare ground to such an extent that
it reduces, fragments, or otherwise makes the habitat unsuitable for
the Tehachapi slender salamander is not evident for any of the
occurrences throughout the Caliente Canyon population's range.
The fourth occurrence in Caliente Canyon (of the four with visible
disturbance) is located on private land near a residence. The area
immediately surrounding the point where the species had originally been
found showed moderate to high localized disturbance; however, Hansen
(in litt. 2010a, pp. 1-7; Hansen 2009, p. 11) indicated that sufficient
undisturbed habitat remained in the area to support the species.
All of the confirmed occurrences in Caliente Canyon are adjacent to
a two-lane, paved road. The impacts of roads on the Tehachapi slender
salamander are varied. Road construction, such as construction of State
Highway 58 (the section between the unincorporated communities of Keene
and Monolith was constructed during the 1960s), Interstate Highway 5
(the section between Lebec and Fort Tejon was completed in 1964), and
Caliente Creek Road (date of construction unknown), likely removed
Tehachapi slender salamander habitat and likely caused some habitat
fragmentation (Cismowski in litt. 2010, p. 1; Hansen and Wake 2005, p.
693; Hansen 2009b pers. comm.). Further, road run-off from
precipitation may contribute to erosion of the talus, leaf litter, and
small rocks that comprise salamander habitat. Hansen noted that erosion
was occurring, possibly from run-off from the roads, in the vicinity of
2 of the 14 occurrences in Caliente Canyon (Hansen 2009, p. 11).
Erosion at one of the two occurrences is associated with the main paved
road through the canyon, while the other is from a narrow, unpaved road
(see below). The impact of erosion in the vicinity of these two
occurrences was moderate and localized, with sufficient remaining
habitat nearby to continue to support the species (Hansen in litt.
2010a, p. 3). We are not aware of any new roads planned for
construction within the range of this population.
Mining has occurred in the Caliente Creek region of Kern County
since the late 1800s (SRK Consulting 2002, p. 6). The Zenda Gold Mine
project is located on private land about 1 mi (1.6 km) from one of the
occurrences of the Tehachapi slender salamander in Caliente Canyon
(Hansen 2009, p. 11). Kern County issued a conditional use permit in
1990 to Equinox, the mine owner at the time, but the permit has since
expired and has not been renewed (Kuritsubo 2009b pers. comm.).
Although the Zenda Gold Mine is located on private land and is
sufficiently distant not to be a threat to any occurrences, Equinox's
mining claim also extends onto BLM land in the vicinity of one or more
occurrences. Mining companies often hold claims for lands that they may
not own that extend beyond what they are currently mining (Kuritsubo
2009c pers. comm.). For example, these areas may be included to
[[Page 62907]]
provide access to the actual mine site. Although Equinox's claim
extends onto BLM land, they have not conducted any activity on the
claim (Falcon in litt. 2010, p. 1; SRK 2002, pp. 6-7). Although the
claim is still in effect,the county permit for the mine has expired,
and there are no mine plans filed with BLM or Kern County under the
State Mining and Reclamation Action of 1975 (SMARA) (Falcon in litt.
2010, p. 1; Kuritsubo 2009a pers. comm.). Based on the best information
available to us, there are no active mines within the range of this
population.
One of the two occurrences where erosion has occurred is downslope
from Last Chance Canyon Road, a narrow, unpaved road leading to the
Zenda gold mine. Hansen (2009, p.11) notes in his 2009 report that
construction of this unpaved road eliminated some Tehachapi slender
salamander habitat and is causing erosion of the remaining habitat in
this area. Regardless of how much the Last Chance Canyon Road is
traveled, its mere presence may degrade Tehachapi slender salamander
habitat through erosion from wind and runoff from seasonal
precipitation. Even so, Hansen (in litt. 2010a, p. 1) describes the
impacts to the habitat in the general vicinity of the occurrence as
moderate and localized, but also noted that sufficient habitat in good-
to-fair condition remained to support the species. There are no new
mining roads planned within the range of the Caliente Canyon
population.
The habitat at the four new occurences of the Caliente Canyon
population has not been surveyed, and therefore the habitat assessment
below is based on topographic maps, aerial photos, and survey photo
records of each location (Sweet 2011, pp. 2-5 and 8-10). The habitat at
the Tollgate Canyon occurrence appears to be in good condition, and
although grazing likely occurs in the general area, there are no signs
of disturbance from grazing. An unpaved road is near the occurrence,
but there are many acres of contiguous salamander habitat surrounding
the occurrence. There are no paved roads, buildings, mines, or other
forms of activity in the area. The habitat at the unnamed canyon south
of Indian Creek occurrence appears to be in good condition. This
occurrence is on BLM land that is not part of a grazing allotment, and
there are no signs of disturbance from grazing. There are no paved or
unpaved roads, buildings, mines, or other forms of activity in the
area. The habitat at the Indian Creek location appears to be in fair to
good condition because grazing is more readily apparent near this
occurrence than the two above occurrences. There is also an unpaved
road in the vicinity of the occurrence. However, there are no paved
roads, buildings, mines, or other forms of activity in the area. The
habitat at the Silver Creek occurrence appears to be in fair to good
condition because grazing occurs in the area. There is also a building
and an unpaved road near this occurrence, but there are many acres of
contiguous salamander habitat surrounding the occurrence.
In summary, grazing occurs on much of the private land and the BLM
lands that are part of allotments in the range of the Caliente Canyon
population of the Tehachapi slender salamander. Of the 14 occurrences
in Caliente Canyon, 4 have experienced a moderate level of localized
habitat disturbance. Of these four, one occurrence is moderately
affected by cattle grazing; one on BLM land is moderately affected by
cattle grazing and erosion from an adjacent paved road; one is
moderately affected by grazing and erosion from an adjacent narrow,
unpaved mine road; and one is moderately affected by a residence.
Habitat with little or no disturbance is present in the same areas as
these four occurrences. The other 10 occurrences show a minor-to-low
level of disturbance from cattle grazing (Hansen in litt. 2010a, pp. 1-
4; Hansen 2009, p. 11). The only activity in the areas where the 4 new
occurrences are located is cattle grazing, with the exception of a
single building near one of the occurrences. One of the newly
discovered occurrences appears to be in good condition, with little
sign of grazing. Another, which is on BLM land that is not part of an
allotment, appears to be in good condition. We classify the other two
occurrences as being in fair to good condition because there are signs
of cattle grazing in their immediate vicinity. There are no flood
control projects occurring or planned within areas of known Tehachapi
slender salamander occurrences in Caliente Canyon.
Based on the best information we have, there are no planned or
proposed land use changes within the range of the Caliente Canyon
population of the Tehachapi slender salamander. BLM's land use
management plans are updated every 15 to 20 years. Although the BLM
land containing three confirmed occurrences may be disposed of (meaning
relinquished or sold) based on the current plan, we have no information
to indicate that the land will be sold or developed, or that the
current grazing practices will change within the next 15 to 20 years
(Kuritsubo in litt. 2008, p. 1; Kuritsubo 2009b pers. comm.). No new
residential or commercial development projects planned on parcels with
occupied Tehachapi slender salamander habitat are expected in the
foreseeable future (Kern County in litt. 2009, p. 9). No permit
requests have been submitted to Kern County to restart mining activity
in the foreseeable future. Therefore, the Caliente Canyon population of
the Tehachapi slender salamander and its habitat are not threatened
with destruction or curtailment now and are not likely to be threatened
with destruction or curtailment in the future.
Tehachapi Mountains Population
For the reasons discussed above (see ``Potential Suitable Habitat''
section), we define the range of the Tehachapi Mountains population as
consisting of five occupied canyon segments totaling 10.2 linear mi
(16.4 km), which includes six known occurrences. Four of the canyon
segments (five of the occurrences) are on the privately owned Tejon
Ranch, and one is on Fort Tejon SHP. The main land uses that are
presently occurring within the range of the Tehachapi Mountains
population of the Tehachapi slender salamander are ranching, farming,
and recreation (Hansen 2009, p. 12; ICF Jones and Stokes 2009, p. 1-4).
Currently, specific land uses on the 270,365-ac (109,413-ha) Tejon
Ranch include: farming and irrigation systems; livestock grazing and
range management activities; film production (which may involve
temporary construction and use of explosives); repair, maintenance, and
use of roads; maintenance and construction of utilities; and fence
construction and maintenance (Dudek 2008, pp. 2-5 through 2-8). There
is an existing 2-in (5-cm) water pipeline that overlaps with one
confirmed occurrence near Pastoria Creek (Miller in litt. 2010b, p. 2).
Because this pipeline is already in place, and it does not carry any
dangerous substance, we do not find the presence of this pipeline to
threaten the Tehachapi slender salamander or its habitat. The closest
farming and irrigation activities are approximately 1,000 ft (305 m)
from the occupied portion of any canyon, and are, therefore, far enough
away not to negatively affect slopes known to be occupied by Tehachapi
slender salamanders (Miller in litt. 2010b, p. 4).
Possible impacts from cattle grazing are as discussed for the
Caliente Canyon population of the Tehachapi slender salamander. There
are approximately 14,500 head of cattle (Dudek 2008, p. 2-5) grazing on
255,000 ac (103,195 ha) (Miller in litt. 2010b, p. 5) of Tejon Ranch.
Cattle grazing on Tejon Ranch are managed by seasonal rotation,
[[Page 62908]]
following the availability of green pasture (Miller in litt. 2010a, p.
1). While Tejon Ranch's livestock managers continually assess the
availability of feed, cattle are allowed to ``drift'' through gates to
different pastures where feed is available (Miller in litt. 2010a, p.
1). This approach provides for active management of free-range cattle
grazing and avoids depletion of vegetation and significant damage of
the habitat.
In his 2000 Tehachapi slender salamander survey, Hansen documented
that grazing, and to a limited extent logging, were evident in occupied
Tehachapi slender salamander habitat (Hansen 2009, p. 12).
Specifically, Hansen noted that grazing and logging activities were
evident along Bear Trap Canyon in the area known to be occupied (Hansen
2009, p. 5). From 1989 through 1994, Tejon Ranch had a short-term
timber harvesting operation targeting hardwoods for fuel on 367 ac
(148.5 ha) in an area that includes Bear Trap Canyon (Vance in litt.
2009a, pp. 2, 8). To the best of our knowledge, no commercial logging
activities are currently in operation and none are proposed on Tejon
Ranch (Brauer in litt. 2009, p.1; Vance in litt. 2009a, p. 1). Hansen
reported that the habitat at all of the then known four occurrences on
Tejon Ranch was in good condition, despite the presence of grazing
(Hansen 2009, p. 12). The fifth, and most recently discovered
occurrence in Monroe Canyon, is reported to be in habitat of good
condition, with no evidence of disturbance by cattle (Miller in litt.
2010b, p. 4).
Wild turkeys (Meleagris gallopavo) and pigs (Sus scrofa) were
introduced on Tejon Ranch in 1989 and 1990, respectively (Miller in
litt. 2010b, p. 5; Dudek 2008, p. 3-4). There are approximately 1,200
turkeys and 5,000 pigs with free range on 255,000 ac (103,195 ha) on
Tejon Ranch (Miller in litt. 2010b, pp. 4-5). Similar to livestock
grazing, wild pigs and turkeys could degrade and fragment Tehachapi
slender salamander habitat by removing talus and leaf litter, thus
damaging the soil cover while foraging (Dudek 2008, pp. 5-26, 6-6).
Pigs are known to be particularly destructive because of their rooting
and tilling behavior (Hansen 2009, p. 4; Dudek 2008, p. 3-4). Although
turkeys and pigs overlap with the Tehachapi population of the Tehachapi
slender salamander and have the potential to destroy habitat through
scraping and rooting, we have no information to indicate that the
Tehachapi slender salamander is being threatened by these nonnative
species; and no damage from turkeys or pigs has been reported in
occupied habitat. In fact, Tehachapi slender salamander habitat on the
ranch is reported to be in good habitat condition (Miller in litt.
2010b, p. 5; Hansen in litt. 2010a, p. 3).
Activities involving ground disturbance associated with
construction include film production; repair, maintenance, and use of
roads; maintenance and construction of utilities; and fence
construction and maintenance. All of these activities could result in
the removal of habitat cover (talus, leaf litter, and vegetation),
digging, and removal of soil. Such actions may result in habitat
degradation, fragmentation, and the injury or mortality of the
Tehachapi slender salamander. All of these activities occur on a
sporadic and limited basis. We have no evidence that they occur in
areas of known Tehachapi slender salamander occurrences.
Overall, current ranch-wide activities on Tejon Ranch have not
removed or destroyed the Tehachapi slender salamander's habitat within
the range of the Tehachapi Mountain population. Cattle ranching has
been practiced since the late 1800s (Tejon Ranch 2011, p. 1), and the
presence of cattle has not modified the habitat in any noticeable
manner (Hansen 2009, p. 12). Fuel management (vegetation thinning and
clearing) does not appear to have any visible effect on habitat. Wild
turkeys and pigs cause localized habitat degradation, but apparently no
degradation has been documented in this area. Finally, with the
exception of one existing water pipeline, farming, irrigation, road
repair and construction activities do not occur within occupied
habitat.
Tejon Ranch plans to construct a residential and commercial
development on their property called Tejon Mountain Village (TMV). The
TMV development envelope consists of 7,860 ac (3,181 ha), within which
a development footprint of up to 5,533 ac (2,239 ha) is proposed
(Letterly in litt 2010, p. 1). Although Tejon Ranch does not plan to
exceed the 5,533-ac (2,239-ha) footprint, the exact location for
construction could be anywhere within the 7,860-ac (3,181-ha)
development envelope.
The TMV development would include a total of 3,624 dwelling units,
464,920 square feet (43,192 square meters) of commercial development,
two golf courses, an equestrian center, up to 750 hotel rooms, and up
to 350,000 square feet (32,516 square meters) of support uses (e.g.,
hotel lobby support services, food and beverage service, golf
clubhouses, equestrian facilities, private recreation facilities)
(Dudek 2008, p. 2-11) that would be constructed over approximately 30
years. The TMV development envelope has been designed to completely
avoid all occupied habitat (i.e., occupied canyon segments that make up
the range of the species) and all known occurrences of the Tehachapi
slender salamander. Potentially, the closest development to occupied
habitat (i.e., the distance to the boundary of the development
envelope) is about 0.5 mi (0.8 km) at Monroe Canyon; all other occupied
habitat is a minimum 1 mi (1.6 ha) from any potential development.
Therefore, because the species is confined to the identified canyon
segments based on the biology of the species, and those canyon segments
are outside of the proposed development envelope, we do not expect that
construction of the TMV project will result in the loss of any occupied
habitat.
The proposed TMV development is expected to reduce the area grazed
on the ranch by approximately 2 percent (5,000 ac (2,023 ha) of the
255,000 ac (103,195 ha)), leaving approximately 250,000 ac (101,171.4
ha) available to cattle (Miller in litt. 2010b, p. 5). The number of
cattle grazing on the ranch would be commensurate with the reduction in
area available for grazing, and the reduction in available feed (Miller
in litt. 2010b, p. 5). As a result, we do not anticipate grazing
impacts to increase as a result of the proposed TMV development.
Tejon Ranch has submitted a habitat conservation plan (HCP) to the
Service, in support of an application for an incidental take permit
(ITP), that addresses 27 species, including the Tehachapi slender
salamander, that potentially may be affected by the TMV project and
current ranch-wide uses, such as grazing, proposed to be covered under
the ITP. The HCP covers approximately 141,886 ac (57,419 ha) of the
270,365-ac (109,413-ha) ranch (Dudek 2008, p. 1-1). In addition to an
HCP, a draft Environmental Impact Statement (EIS) on the HCP/ITP has
been circulated for public comment in accordance with the National
Environmental Policy Act (NEPA). A Final Environmental Impact Report
(EIR) that focuses on the TMV project was certified by Kern County in
2009 to comply with the California Environmental Quality Act (CEQA).
Dudek, the consultants preparing the HCP for Tejon Ranch, developed
a habitat suitability model to estimate impacts to each of the species
addressed in the plan. Based on the model, Dudek estimates up to 3,797
ac (1,537 ha) of suitable habitat for the Tehachapi slender salamander
may exist within the
[[Page 62909]]
141,886-ac (57,419-ha) HCP boundary (Dudek 2008, p. 5-14; ICF Jones and
Stokes 2008, p. 3.1-15). However, both Tejon Ranch and Dudek point out
that the habitat suitability model is constrained by broad assumptions
and limited information on the species' habitat characteristics; thus,
the model likely overestimates the presence of suitable habitat (Dudek
2008, pp. 5-14 and D-31). We concur with Dudek's assessment of the
model, and also believe it greatly overestimates the amount of suitable
habitat; therefore, the model should be considered a worst-case
approach for determining the amount of potentially affected habitat.
As we discussed in the ``Potential Suitable Habitat'' section
above, the species' habitat requirements are highly specific, and the
Dudek model overgeneralizes suitable habitat. For example, we
understand that the species is mostly found on north-facing slopes;
however, the model includes east-facing (90 degree) and west-facing
(270 degree) slopes (Dudek 2008, p. D-31). Further, information was not
available for the model to account for the presence of talus or leaf
litter that the species uses for refuge. The model also assumes uniform
distribution of habitat, whereas in reality, the species and its
habitat are patchily distributed in the landscape. As a result,
suitable habitat identified in the model includes areas with unsuitable
and inhospitable substrates for the species, and thus the model
overgeneralizes and overestimates the amount of Tehachapi slender
salamander habitat. For these reasons, we have based our analysis
mainly on threats to the known occupied canyons. However, we also
recognize the possibility that other suitable habitat exists beyond
these canyons and that some of these areas could potentially be
occupied, and, therefore, we have also considered the results of the
Dudek suitability model as a worst-case approach to assessing the
impacts of the TMV project.
Although the TMV development envelope avoids all habitat segments
we consider to be occupied and all known occurrences within the
Tehachapi Mountains population (i.e., the discrete range of this
portion of the species), the habitat suitability model for the
Tehachapi slender salamander estimates that 108 ac (44 ha) (16 percent)
of the 760 ac (308 ha) of potentially suitable habitat within the
proposed TMV development envelope would be removed (ICF Jones and
Stokes 2008, p. 4.1-31). The EIR for the proposed TMV project states
that short-term and long-term impacts from construction, which would
result in the loss of 16 percent of potentially suitable habitat in the
project area without the proposed mitigation measures sited in the EIR
(ICF Jones and Stokes 2009, pp. 4.4-102 and 4.4-156), could be
significant to the Tehachapi slender salamander. However, we believe
the EIR's conclusion overstates potential impacts to the Tehachapi
slender salamander.. Our reasons are based on the following:
(1) The EIR for the proposed TMV project uses data from the Dudek
habitat suitability model for the Tehachapi slender salamander to
estimate potential impacts to the species, which as previously
discussed, overestimates the amount of suitable habitat for the species
on the ranch and likewise, overestimates the number of acres of
suitable habitat potentially removed as a result of the project;
(2) the EIR analysis of impacts is based on the estimated number of
acres of potentially suitable habitat within the boundaries of the
proposed TMV development envelope, but the loss of 108 ac (44 ha)
actually represents only 2.8 percent of the potentially suitable
habitat within the HCP boundary on the ranch;
(3) we have no indication that the 108 ac (44 ha) is occupied by
the species; and
(4) the development envelope does not overlap with occupied habitat
or known occurrences of the species.
Although known occupied habitat will not be lost as a result of the
proposed development, development will result in the fragmentation of
potential modeled habitat in some canyons, and development will occur
between some canyons. Although no salamanders were found in the canyons
within the development envelope during surveys, (Dudek 2008, p. 6-5),
if in fact these canyons are actually occupied (based on a worst-case
scenario considering best available information currently identifies
this area as unoccupied), salamander movement up- and down-canyon could
be restricted in some areas. However, we do not believe salamanders are
capable of moving from canyon to canyon because of the dry and rugged
terrain that occurs between canyons. Therefore, we do not believe that
the proposed development will result in any further isolation of
occupied habitat and the effects of fragmentation would be limited to
the loss of potential suitable habitat in some of the canyons that
occur within the development envelope and would only constitute an
impact to the species if those canyons were occupied.
A component of the TMV proposed project includes fuel management
(vegetation thinning and clearing) to reduce threats of fire outbreaks
and damage. Outside of the development areas, fuel management on
141,886 ac (57,419 ha) of the 270,365-ac (109,413-ha) ranch will
consist primarily of cattle grazing, which is used to maintain
vegetation at a certain height rather than denude areas to bare ground
or involve the removal of shrubs, branches, or trees. In addition to
the existing grazing program, fuel management activities in open space
areas will include maintenance of the existing fuel break network
(e.g., dirt/gravel roads), coordination with State or local agencies
for mowing or other fire protection measures along fire prone areas
(e.g., highways), and irrigation or vegetation clearing/mowing within
120 ft (36.6 m) surrounding existing structures (e.g., hunting cabins
and ranch structures). Within the TMV development envelope, fuel
management zones in open space may extend 200 ft (61 m) from new
structures and fuel management will be limited to thinning and
nonirrigation treatment.
Fuel management may remove some vegetation cover that maintains
soil moisture in the mesic microenvironments that provide suitable
habitat for the Tehachapi slender salamander; however, it is not
expected to affect any of the known occupied habitat or occurrences.
Tejon Ranch proposes to develop a fuel management plan, as described in
the HCP and Ranch-wide Land Use Agreement, which, if the HCP is
approved, will be subject to Service review and approval to ensure
consistency with the conservation measures described in the HCP (Dudek
2008, pp. 2-5, 2-6; Agreement 2008, pp. 4, 20). Even without the fuel
management plan, fuel management activities are not expected to
threaten the existence of the Tehachapi slender salamander now or in
the foreseeable future because no occupied habitat is within 200 ft (61
m) of the TMV development.
If the TMV project is realized, new roads would be constructed to
gain access to residential, commercial, and recreational areas.
However, no new roads are planned near occupied habitat or known
occurrences (ICF Jones and Stokes 2009, Figure 3-14). The TMV project
does propose to implement road improvements, including an existing
ranch road in Bear Trap Canyon, which is one of the canyons occupied by
the salamander. This road may approach the very west end of occupied
habitat in the canyon, but it is located entirely on the flat, dry
terrain below the occupied
[[Page 62910]]
north-facing slope and veers entirely out of the canyon at that point.
Any improvements to the existing road are expected to be limited
because the road will be used only as an Emergency Access Road (ICF
Jones and Stokes 2009, Figures 4.4-8 and 3-14; Marshall in litt. 2009,
p. 1), and any potential impact to the salamander would be at the very
west end of occupied habitat. This information is also consistent with
the proposed development envelope being situated away from known
Tehachapi slender salamander occurrences. Although new roads or road
improvements will not affect occupied habitat, they may cross
potentially suitable habitat (modeled habitat) and may result in
additional fragmentation of potentially suitable habitat.
Although there will be no direct impacts to the known range of the
Tehachapi Mountains population (which is based on six occurrences and
consists of five canyon segments totaling approximately 10.2 linear mi
(16.4 km) of known occupied habitat) from the proposed development of
the TMV project, the EIR lists the following potential indirect effects
from construction as significant: Construction dust; increased human
activity from construction workers; construction-related noise,
vibration, and lighting; vehicle collisions, chemical releases, and
hydrological modifications (ICF Jones and Stokes 2009, p. 4.4-156); and
increased foot traffic and trail usage.
Given that this species is primarily nocturnal and spends most of
the year up to 3 ft (0.9 m) underground (i.e., during dry conditions),
and given that impacts from construction dust would be limited to
above-ground surfaces, it is unlikely to have a negative effect on the
fossorial habitat of the species. Impacts from increased human
activity, noise, vibrations, lighting, and vehicle collisions are not
likely to have an effect on the species' population because they would
be primarily limited to the development envelope (Hansen 2010 pers.
comm.), which is at a minimum 0.5 mi (0.8 km) removed from any occupied
Tehachapi slender salamander habitat and about 0.7 mi (1.1 km) from any
known occurrence.
It is possible that chemical releases from a construction activity
could affect habitat, depending on the location and time of year (e.g.,
during the rainy season a release could be washed over a larger area,
compared to a release in the dry season); however, chemical releases
associated with construction are expected to be restricted to the
development envelope and therefore, away from areas of occupied
habitat. Even if under unusual circumstances, a chemical release was to
move past the development envelope, the closest area to occupied
habitat is about 0.5 mi (0.8 km), and we do not believe that any
construction-related chemical release would be of sufficient quantity
to extend that far.
Stormwater runoff resulting from residential and commercial
development can increase water flows due to an increase in impervious
surfaces and degrade water quality. Although new roads would be limited
to the development envelope, and therefore at a sufficient distance
from known occurrences as to not have direct effects on individual
salamanders, we do not have information to accurately estimate the
frequency and intensity of impacts from runoff that could potentially
affect Tehachapi slender salamanders. According to the EIR,
hydrological modifications from the TMV development involving
stormwater runoff, siltation, and erosion are expected to be only minor
(e.g., less than 5 percent) (ICF Jones and Stokes 2009, p. 4.8-32;
Letterly in litt. 2011, p. 1).
Stormwater runoff from residential and commercial communities can
degrade water quality. However, water quality is not expected to
experience a noticeable change from existing levels of potential
pollutants, including phosphorous, nitrates, ammonia, copper, lead, and
zinc (ICF Jones and Stokes 2009, p. 4.8-26; Letterly in litt. 2011, p.
1). Therefore, degradation of water quality from stormwater runoff is
not expected to have a measurable impact on the Tehachapi slender
salamander and its habitat.
In addition to the indirect effects identified in the TMV EIR,
potential indirect effects to the Tehachapi slender salamander from
increased human presence on TMV include edge effects, changes in
microclimate, and increased predation. Terrestrial salamanders are
impacted by edge effects. Microclimate conditions within forest edges
of habitat often exhibit higher air and soil temperatures, lower soil
moisture, and lower humidity compared to interior forested areas
(Moseley et al. 2009, p. 426). Due to the physiological nature of
terrestrial salamanders, they are sensitive to these types of
microclimate alterations, particularly to temperature and moisture
changes (Moseley et al. 2009, p. 426). Generally, more salamanders are
observed with increasing distance from some edge types, which is
attributed to reduced moisture and microhabitat quality (Moseley et al.
2009, p. 426). However, edge effects from the proposed TMV development
are expected to be at a sufficient distance from known occurrences as
to not substantially impact the species. In addition, the Tehachapi
slender salamander's semifossorial behavior further limits the negative
impacts from edge effects, as the salamanders emerge to the surface
during the rainy season.
Increased human residential, commercial, and recreational use of
the area will likely increase the number of potential predators (i.e.,
dogs, cats, crows, and raccoons) in developed areas. Domestic cats are
known to kill amphibians although the proportion of amphibians killed
by cats compared to other species is very small (Woods et al. 2003, p.
1). Coyotes (Canis latrans) also occur in Kern County (see Ralls and
White 1995, Cypher and Spencer 1998, Nature Alley 2010) and the Tejon
Ranch (ICF Jones and Stokes 2009, p. 4.4-432), and the abundance of
cats and raccoons has been found to be much lower where coyotes occur
(Crooks and Soul[eacute] 1999, p. 563). Crooks and Soul[eacute] (1999,
p. 565) also found that a large number of owners restrict their cats'
outdoor activity when coyotes were present. In addition, the
salamander's exposure to predation is very limited due to its short
activity period above ground, thus we do not believe that the increased
presence of predators would rise to the level of threatening the
Tehachapi slender salamander now or in the foreseeable future.
Foot traffic, increased use of trails, and creation of new trails
would also likely increase in the vicinity of residential development.
Increased use of existing trails can result in erosion and new trails
can eliminate habitat and cause erosion. The Tehachapi slender
salamander habitat that would most likely be affected would be in
Monroe Canyon, which is the closest to the development envelope
(minimum of 0.5 mi (0.8 km)). However, foot traffic in this area and
any area of potential suitable habitat would most likely be along
existing dirt roads and the flatter terrain below or above the steep,
talus-covered slopes occupied by the species.
The fifth occupied canyon (one occurrence) of the Tehachapi
Mountains population of the Tehachapi slender salamander is Johnson
Canyon on Fort Tejon SHP on the west side of the Interstate Highway 5,
adjacent to a service road near the entrance to the Park (Hansen 2009,
p. 28; CDPR 1989, p. 175). The habitat at this occurrence on Fort Tejon
SHP shows minimal, if any, impacts. Fort Tejon SHP provides for passive
recreational activities including hiking, picnicking, camping, wildlife
viewing, and educational
[[Page 62911]]
programs; no livestock grazing is allowed. A narrow, paved road lies at
the base of the occupied slope but does not cross any habitat, and
there are no plans to widen or change this road. As such, we do not
believe that impacts from the road (if any) threaten the existence of
the species in the area. No future land use changes on Fort Tejon SHP
are planned that would affect the Tehachapi slender salamander (Bylin
in litt. 2009, p. 1).
In summary, based on the best scientific and commercial information
available, we conclude that current ranch-wide activities do not pose a
threat to the Tehachapi Mountains population of the Tehachapi slender
salamander and its habitat, nor do we anticipate such activities will
pose a threat in the future. We also conclude that the proposed TMV
development will avoid known occurrences of the species and all
occupied habitat (i.e., occupied canyon segments that make up the range
of the species) on Tejon Ranch (see ``Tehachapi Mountains Population''
section under Factor A) and is not likely to cause any significant
indirect impacts to the Tehachapi Mountains slender salamander or its
habitat now or in the future.
Summary of Factor A
Livestock grazing occurs throughout the species' range (with the
exception of Fort Tejon SHP), and depending on the intensity, grazing
has the potential to degrade Tehachapi slender salamander habitat
through trampling, soil scraping, and compaction, which can cause
surface soil erosion and desiccation. However, habitat degradation in
the range of the salamander is notable at only a few occurrences in
Caliente Canyon. Road construction can destroy Tehachapi slender
salamander habitat, but no new road construction is planned for either
Caliente Canyon or the other occupied canyons that make up the Caliente
Canyon population, and roads planned for the TMV project avoid occupied
habitat. Erosion from existing roads through Caliente Canyon may be
having a localized effect in a few areas in the occupied portion of the
canyon, but the overall impact on the range of the Caliente Canyon
population is at most minimal. There has been no mining activity within
the Caliente Canyon area for almost 20 years, and there are no plans
for mining to start again in the foreseeable future.
The one new residential and commercial development planned within
the range of the species is proposed on Tejon Ranch. Tejon Ranch's
proposed TMV development would remove 108 ac (44 ha) of potentially
suitable habitat based on a habitat suitability model. However, the 108
ac (44 ha) are not known to be occupied by the species, and TMV is
designed to avoid all occupied habitat and all known occurrences on
Tejon Ranch. Indirect effects from development (e.g., construction-
associated impacts (lighting, noise, vibrations), increased human
presence, predators, soil erosion, runoff, and edge effects) are not
expected to rise to a point that would threaten the Tehachapi Mountains
population of the species. We are also not aware of any existing or
planned flood control projects within the range of the species. For
these reasons, we conclude that cattle grazing, roads, mining, flood
control projects, and commercial and residential development do not
constitute a substantial threat to the Tehachapi slender salamander
throughout its range now and are not likely to pose a substantial
threat in the future. Therefore, we conclude that the Tehachapi slender
salamander is not threatened or endangered throughout all of its range
by the present or threatened destruction, modification, or curtailment
of its habitat or range.
Factor B: Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
We do not have any information that overutilization for commercial,
recreational, scientific, or educational purposes is a threat to the
Tehachapi slender salamander. Therefore, we have no information to
suggest that the Tehachapi slender salamander is threatened or
endangered throughout all of its range now, or within the future, by
overutilization for commercial, recreational, scientific, or
educational purposes.
Factor C: Disease or Predation
Little is known about predators of the Tehachapi slender
salamander. The only known predator of the species is the ring-necked
snake; although turkeys and pigs, present on Tejon Ranch, are known to
consume amphibians. However, we have no evidence that turkeys and pigs
are threatening Tehachapi slender salamanders on Tejon Ranch, and there
is no evidence that they are affecting the salamanders' habitat;
therefore, we do not consider them a threat to the species.
Potential indirect effects from residential and commercial
development within or near Tehachapi slender salamander habitat could
include an increase in human and introduced predator presence. This
could potentially be the case for the Tehachapi Mountains population of
the Tehachapi slender salamander, as indirect, long-term potential
effects from the TMV project would include an increase in human and
introduced predator presence on the Tejon Ranch. For example, there may
be an increase in passive outdoor recreation by adults and children,
and their pets (e.g., cats). The increase in human presence may also
increase the population of native amphibian predators, including
raccoons (Procyon lotor) and various species of corvids (such as crows
and jays). However, coyotes may also be more abundant near development,
and as discussed previously, the abundance of cats and raccoons has
been found to be much lower where coyotes occur (Crooks and
Soul[eacute] 1999, p. 563). The species' nocturnal and subfossorial
behavior may also reduce potential impacts from predation by corvids.
There are no reports of the Tehachapi slender salamander being
infected with any disease. However, related species have been found to
suffer from Chytridiomycosis, a skin infection. Chytridiomycosis is
described as an epidermal infection of amphibians caused by the chytrid
fungus (Batrachochytrium dendrobatidis). Chytridiomycosis has been
implicated in mass mortalities, population declines, and extinctions of
some amphibian species, but species appear to vary in their
susceptibility to the disease (Blaustein et al. 2005, p. 1460; Ouellet
et al. 2005, p. 1431). The chytrid fungus requires moisture for
survival, and is most likely transmitted to amphibians by contact with
infected water or other amphibians (Johnson and Speare 2003, p. 922).
Chytridiomycosis was thought to be restricted to species using aquatic
habitat and surface water; however, Cummer et al. (2005, p. 248)
reported the first case of the chytrid fungus infecting a strictly
terrestrial salamander. The infected Jemez Mountains salamander
(Plethodon neomexicanus), a completely terrestrial species endemic to
the Jemez Mountains of New Mexico, suggests that the chytrid fungus can
survive in terrestrial habitats (Cummer et al. 2005, p. 248). The
authors note the origin of the pathogen is unknown, but hypothesize the
Jemez Mountains salamander may have been directly or indirectly
infected by a sympatric aquatic amphibian carrying the pathogen (Cummer
et al. 2005, p. 248). Further, these findings suggest that more
amphibians are at risk of contracting the chytrid fungus than was
previously believed.
Indirect effects from livestock activities may include the risk of
aquatic disease transmission, such as chytrid,
[[Page 62912]]
from earthen stock ponds that create areas of standing surface water.
Earthen stock tanks are often utilized by tiger salamanders (Ambystoma
tigrinum) (Davidson et al. 2003, pp. 601-607), western toads (Bufo
boreas), Pacific treefrogs (Hyla regilla), and introduced bullfrogs
(Rana catesbeiana), which are known to be vectors for disease (i.e.,
they can carry and spread disease). It is possible that these species
use adjacent upland areas and may transmit disease to the Tehachapi
slender salamander in areas where they co-occur (Hansen in litt. 2011,
p. 1). However, we do not have enough information to draw conclusions
on the extent or role western toads, Pacific tree frogs, and bullfrogs
may play in disease transmission. Although some small-scale habitat
modification is possible, livestock are managed to maintain a grassy
habitat under the tree canopies, and the connection between earthen
stock tanks for livestock and aquatic disease transmission is unclear.
Therefore, we conclude that disease transmission from livestock is not
a current threat to the salamander, nor do we believe it will be in the
future.
A recent study from the University of California, Berkeley, has
shown that the chytrid fungus has infected the California slender
salamander, Oregon slender salamander (Batrachoseps wrighti), Gabilan
Mountains slender salamander (B. gavilanensis), and relictual slender
salamander (B. relictus), all related species sharing the same genus as
the Tehachapi slender salamander (Weinstein in litt. 2008b, p. 1).
Weinstein's study confirms that Chytridiomycosis causes California
slender salamander mortality in the lab; however, individuals may fair
better in the field because the population has remained stable, despite
the presence of the pathogen in the wild population for a minimum of 35
years (Weinstein in litt. 2008a, p. 1; Weinstein 2009, p. 1). Results
showed that infected salamanders maintained in a dry environment in the
lab were able to recover, whereas salamanders in a wet lab environment
had high mortality rates (Weinstein, In press, p. 2). These findings
not only confirm that the chytrid fungus can infect terrestrial species
in the subgenus Batrachoseps, but also the possibility that salamanders
may recover from the disease in dry environments.
We do not know whether the Tehachapi slender salamander has been,
or will be, exposed to the chytrid fungus or that exposure would lead
to transmission throughout its range. The likelihood of the Tehachapi
slender salamander contracting the pathogen is lower than if it were
closely associated with aquatic environments because this species is
not associated with bodies of water, occurs in a characteristically dry
environment, has limited chances of coming into contact with other
amphibians due to its brief above-ground activity during intermittent
periods during the year, and has limited dispersal abilities. To the
best of our knowledge, no studies have been done to detect the pathogen
in the Tehachapi slender salamander, or in the yellow-blotched
salamander (also referred to as the yellow-blotched ensatina (Ensatina
eschscholtzii croceator)) that co-occurs with both populations of the
Tehachapi slender salamander (Jockusch in litt. 2009d, pp. 1-2; Germano
2006, pp. 123-125; Hansen and Wake 2005, p. 694).
The black-bellied slender salamander, which is a close relative of
the Tehachapi slender salamander and co-occurs with the Tehachapi
Mountains population, is vulnerable to the chytrid fungus (Jockusch in
litt. 2009d, p. 1). Some of the black-bellied slender salamanders
collected in San Luis Obispo County in the 1990s exhibited symptoms of
Chytridiomycosis (Jockusch in litt. 2009d, pp. 1-2). Weinstein later
confirmed that those specimens indeed carried Batrachochytrium
dendrobatidis (Jockusch in litt. 2009d, p. 1). However, the infected
black-bellied slender salamanders were collected in San Luis Obispo
County, which is 110 mi (177 km) from the closest confirmed occurrence
of the Tehachapi Mountains population of the Tehachapi slender
salamander in Kern County. It is unlikely that infected black-bellied
slender salamanders in San Luis Obispo County could infect individuals
in Kern County due to the distance and the species' limited dispersal
abilities. We do not have any evidence of infected black-bellied
slender salamanders in Kern County that co-occur with the Tehachapi
slender salamander.
Summary of Factor C
We have no evidence that predation is an impact to the Tehachapi
slender salamander. Although there is potential for an increase in
human and introduced predator presence within the vicinity of occupied
salamander habitat that could result in indirect impacts to the
salamander, we anticipate that the presence of coyotes and the species'
nocturnal and subfossorial behavior will likely reduce potential
impacts. We do not have any information to indicate that the chytrid
fungus is present in either the Caliente Canyon or the Tehachapi
Mountains population of the Tehachapi slender salamander or in co-
occurring populations of other species that may carry this fungus. The
chytrid fungus is known to have infected a closely related species, the
black-bellied slender salamander. However, the infected black-bellied
slender salamanders were 110 mi (177 km) from the closest confirmed
occurrence of the Tehachapi slender salamander within the Tehachapi
Mountains population. Although we do have information that the disease
has infected other terrestrial and aquatic salamanders, we do not have
any evidence that the disease is present in either the Tehachapi
Mountains population or the Caliente Canyon population of the Tehachapi
slender salamander, nor is there evidence that this or any other
disease currently places this species at risk of extinction. In
addition, we do not have any information in our files to suggest that
this, or any other disease, will become a threat to either population
of the Tehachapi slender salamander in the future. Therefore, we
conclude that the Tehachapi slender salamander is not threatened or
endangered throughout all of its range now, or in the future, by
disease or predation.
Factor D: Inadequacy of Existing Regulatory Mechanisms
In determining whether the inadequacy of existing regulatory
mechanisms constitutes a threat to the Tehachapi slender salamander, we
focused our analysis on existing Federal and State laws and regulations
that apply to the species and its habitats, and that could potentially
address any possible significant threats identified under the other
Factors. If a threat is minor, listing may not be warranted even if
existing regulatory mechanisms provide little or no protection to
counter the threat. Regulatory mechanisms may preclude the need for
listing if such mechanisms are judged to adequately address the
threat(s) to the species such that listing is not warranted.
Conversely, threats on the landscape are exacerbated when not addressed
by existing regulatory mechanisms, or when the existing mechanisms are
inadequate (or not adequately implemented or enforced).
Federal Protections
National Environmental Policy Act
The National Environmental Policy Act of 1969 (42 U.S.C. 4321 et
seq.), as amended (NEPA), requires that all activities undertaken,
authorized, or funded by Federal agencies be analyzed for potential
impacts to the human environment prior to implementation. Under NEPA,
all Federal agencies are
[[Page 62913]]
required to formally document and publicly disclose the environmental
impacts of their actions and management decisions. Documentation for
NEPA is provided in an environmental impact statement, an environmental
assessment, or a categorical exclusion, and may be subject to
administrative or judicial appeal. NEPA does not require that adverse
impacts be mitigated. NEPA is required for projects with a Federal
nexus (i.e., projects that require a Federal permit, receive Federal
funding, or are implemented by a Federal agency). Actions with no
Federal nexus are not required to comply with this law. For actions
with a Federal nexus, NEPA would apply regardless of the location of
the action within the range of the species. Our review finds that there
are no significant threats to the species on lands with a Federal nexus
for any of the four other Factors.
Clean Air Act
The Clean Air Act of 1970 (42 U.S.C. 7401 et seq.) directs 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 U.S. 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. 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. EPA's 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 EPA's finding or how effective they would
be in addressing climate change. Therefore, the Clean Air Act and its
existing implementing regulations do not currently address climate
change effects on wildlife, plants, and ecosystems. However, our status
review did not reveal information that indicates that climate change is
a significant threat to the Tehachapi slender salamander now or within
the foreseeable future (see Factor E).
Federal Land Policy and Management Act
As noted earlier, three occurrences of the Caliente Canyon
population of Tehachapi slender salamander are on BLM land, while there
are no occurrences of the Tehachapi Mountains population on Federal
land. Although strongly oriented toward multiple use, the Federal Land
Policy and Management Act of 1976, which is BLM's organic act, requires
that public lands be managed in a manner that will protect the quality
of scientific, scenic, historical, ecological, environmental, air and
atmospheric, water resource, and archeological values; that, where
appropriate, will preserve and protect certain public lands in their
natural condition; that will provide food and habitat for fish and
wildlife and domestic animals; and that will provide for outdoor
recreation, human occupancy and use. Typically, land management plans
are renewed every 15 to 20 years (Kuritsubo in litt. 2010a, p. 1). This
law does not require specific protection for the Tehachapi slender
salamander against potential threats that may occur on BLM land, such
as impacts from grazing. One of the three occurrences on BLM land shows
some moderate, localized habitat degradation from cattle trampling, as
discussed under Factor A. However, our status review did not reveal
information that indicates that livestock grazing is a significant
threat to the Tehachapi slender salamander throughout its range (see
Factor A).
Sensitive Species Designation by the Bureau of Land Management
As noted earlier, the Tehachapi slender salamander is classified by
BLM as a sensitive species. As stated in BLM's Manual, Section 6840,
BLM Sensitive Species are managed to promote their conservation and to
minimize the likelihood and need for listing under the Act (Kuritsubo
in litt. 2009a, p. 1). BLM's Bakersfield, California Field Office
implements BLM's National and State policy directives (California BLM
Manual supplement 6840.2) by evaluating projects for potential
Tehachapi slender salamander habitat prior to implementing or
authorizing activities that may affect the species (Kuritsubo in litt.
2009a, pp. 1-2). If potential habitat is present, then BLM designs the
project or places stipulations on the authorization such that impacts
to salamander habitat are avoided and/or minimized (Kuritsubo in litt.
2007, p. 1). BLM has screened and surveyed for Tehachapi slender
salamander habitat for several projects on their lands that fall within
the range of the species as part of NEPA compliance.
Two of the three Tehachapi slender salamander occurrences located
on BLM land are within an existing grazing allotment (Kuritsubo in
litt. 2010b, p. 1); the third location on BLM land is in an area that
is not leased for grazing (BLM 2011, p. 1). BLM is required by Federal
grazing regulations (43 CFR 4100) to periodically (approximately every
5 to 10 years) evaluate all grazing allotments. If grazing is
determined to have adverse impacts to Tehachapi slender salamander
habitat, BLM regulations require that BLM take action to modify the
grazing management to ensure that the negative impact is addressed
(Kuritsubo 2009b, pers. comm.). As described in Factor A, we did not
find that cattle grazing and trampling are significant threats to the
Caliente Canyon population of the Tehachapi slender salamander or its
habitat. BLM's land use management plan for this area is in the process
of being updated, and is still in draft. All alternatives in the draft
plan include measures to provide habitat for sensitive species,
including the Tehachapi slender salamander (Kuritsubo in litt. 2010a,
p. 1). There are no plans for the allotment to change within the next
15 to 20 years (Kuritsubo in litt. 2010a, p. 1; Kuritsubo in litt.
2009b, p. 1; Kuritsubo 2009b, 2010, pers. comm.).
BLM's organic act and designation of the Tehachapi slender
salamander as a sensitive species provide some protection for the
species where it occurs on BLM land. However, the benefits to the
species are limited because BLM land within the range of the salamander
is limited to the Caliente Canyon population and makes up only a small
portion (3 of 24 occupied occurrences, or 12.5 percent) of the species'
entire range.
State Protections in California
California Endangered Species Act
The Tehachapi slender salamander is listed as threatened under CESA
(CDFG 2009, p. 7). CESA provides protections for the Tehachapi slender
salamander both through the prohibition against take of State-listed
species without authorization (i.e., 2081 incidental take permit) and
the requirement that any
[[Page 62914]]
take authorized under the statute must be fully mitigated (14 CCR Sec.
783.4). Under CESA, private landowners who wish to implement projects
that would result in take of State-listed species must obtain a 2081
permit. Similar to section 10(a)(1)(B) of the Federal Endangered
Species Act, 2081 permit applicants must develop an HCP that explains
how the impacts of taking Tehachapi slender salamanders would be fully
mitigated. HCPs developed to support a 2081 permit request would
include conservation measures, often in the form of habitat
conservation, to address the loss of Tehachapi slender salamanders. In
our experience working with the CDFG in reviewing HCPs on private land
in support of incidental take permit applications under CESA and the
Federal Endangered Species Act, such plans require measures to avoid,
minimize, or mitigate the impacts of the taking, including mortality
resulting from habitat removal.
CESA offers protections for the Tehachapi slender salamander on
private and State-owned land, comprising the majority of lands that are
known to be occupied by the species (i.e., 21 of the 24 occupied
occurrences or 87.5 percent). CESA does not necessarily constrain
activities on the small portion (12.5 percent) of occupied Tehachapi
slender salamander habitat on Federal lands within the Caliente Canyon
population. However, as noted above, regulations are in place that
provide some protection to Tehachapi slender salamander habitat on BLM
land.
California Environmental Quality Act
Another State law that may address threats to the Tehachapi slender
salamander is the California Environmental Quality Act (CEQA). CEQA
requires review of any project that is undertaken, funded, or permitted
by the State or a local governmental agency. If significant effects are
identified, the lead agency has the option of requiring mitigation
through changes in the project or to decide that overriding
considerations make mitigation infeasible (CEQA section 21002). In the
latter case, projects may be approved that cause significant
environmental impacts, including impacts to listed species and their
habitat. Protection of listed species through CEQA is, therefore,
dependent upon the discretion of the lead agency involved.
Tejon Ranch's proposed TMV project has undergone CEQA review. The
TMV Final Environmental Impact Report (EIR) found that construction
activities could result in significant impacts to the Tehachapi
Mountain population of the Tehachapi slender salamander without the
implementation of specific species and habitat avoidance and mitigation
measures (ICF Jones and Stokes 2009, pp. 4.4-102, 4.4-156) (see
discussion under Factor A). However, based on our own analysis
(described in Factor A) we do not concur with the EIR's conclusions
regarding significant impacts to the species, and find that the project
design avoids direct impacts, and any indirect impacts that may occur
would not likely rise to a level that would threaten the species.
CEQA applies to the entire range of the species. As of the date of
this finding, we are not aware of any other projects proposed or
planned within the range of the Caliente Canyon population that would
require CEQA analysis.
Summary of Factor D
Twenty of the known occupied occurrences of the Tehachapi slender
salamander occur on privately owned land, three occur on BLM land and
one occurs on State land. Almost all of the private land and two of the
three areas on BLM lands (the third area is not part of a BLM
allotment) are primarily used for grazing. We did not find that grazing
poses a significant threat to the Tehachapi slender salamander or its
habitat and thus do not consider existing regulatory mechanisms,
including CEQA, CESA, NEPA, FLPMA, and BLM's classification of the
Tehachapi slender salamander as a sensitive species, inadequate to
address the impacts of grazing on the species and its habitat. If such
threats were to emerge in the future due to a change in grazing
intensity, then CEQA and CESA would apply on private land and require
authorization for take of Tehachapi slender salamander. Additionally,
NEPA, FLPMA, and BLM regulations and policies would apply on Federal
land and require that potential impacts from grazing or any other
development be identified and measures implemented to avoid or minimize
such impacts.
The TMV project within Tejon Ranch is the one planned residential
and commercial development proposed within the vicinity of known
occurrences (5 out of 24 occupied occurrences or approximately 20.8
percent) in the foreseeable future (Kern County in litt. 2009, pp. 1-
9). The TMV project has been designed to avoid all known occurrences
and occupied habitat of the Tehachapi slender salamander and to
minimize any indirect effects on the species and its habitat.
In summary, we conclude that the threats to the Tehachapi slender
salamander and its habitat on Federal, State, and private lands from
grazing and other existing uses, and on private lands from proposed
development are low. Existing Federal regulatory mechanisms provide
protection for the species on the small portion of Tehachapi slender
salamander habitat on BLM lands, and existing State laws provide
protection on State and private lands from these threats. We did not
find the current limitations of implementing the Clean Air Act to be a
significant threat to the Tehachapi slender salamander. We did not find
any threats to the Tehachapi slender salamander associated with Factors
B or C that would warrant protection through a regulatory mechanism.
Climate change and stochastic events pose potentially minor threats to
the species (see Factor E); however, the current limitations of
regulatory mechanisms addressing these potential threats do not pose a
significant threat to the species now or in the foreseeable future.
Therefore, we conclude that the species is not threatened now or in the
future throughout its range by the inadequacy of existing regulatory
mechanisms.
Factor E: Other Natural or Manmade Factors Affecting the Continued
Existence of the Species
Under Factor E, we consider whether climate change and stochastic
events threaten the Tehachapi slender salamander. Stochastic events are
rare, chance events such as epidemics; prolonged drought; and large,
severe wildfires.
Climate Change
The term ``climate'' refers to an area's long-term average weather
patterns, or more specifically as the mean and variation of surface
variables such as temperature, precipitation, and wind, whereas
``climate change'' refers to any change in climate over time, whether
due to natural variability or human activity (Intergovernmental Panel
on Climate Change (IPCC) 2007, pp. 6, 871). Although changes in climate
occur continuously over geological time, changes are now occurring at
an accelerated rate. For example, at continental, regional, and ocean-
basin scales, recent observed changes in long-term trends include: a
substantial increase in precipitation in eastern parts of North America
and South America, northern Europe, and northern and central Asia;
declines in precipitation in the Mediterranean, southern Africa, and
parts of southern Asia; and an increase in intense tropical cyclone
activity in
[[Page 62915]]
the North Atlantic since about 1970 (IPCC 2007, p. 30). Examples of
observed changes in the physical environment include an increase in
global average sea level and declines in mountain glaciers and average
snow cover in both the northern and southern hemispheres (IPCC 2007, p.
30).
The IPCC used Atmosphere-Ocean General Circulation Models and
various greenhouse gas emissions scenarios to make projections of
climate change globally and for broad regions through the 21st century
(Meehl et al. 2007, p. 753; Randall et al. 2007, pp. 596-599).
Highlights of these projections include: (1) It is virtually certain
there will be warmer and more frequent hot days and nights over most of
the earth's land areas; (2) it is very likely there will be increased
frequency of warm spells and heat waves over most land areas, and the
frequency of heavy precipitation events will increase over most areas;
and (3) it is likely that increases will occur in the incidence of
extreme high sea level (excludes tsunamis), intense tropical cyclone
activity, and the area affected by droughts in various regions of the
world (Solomon et al. 2007, p. 8). More recent analyses using a
different global model and comparing other emissions scenarios resulted
in similar projections of global temperature change (Prinn et al. 2011,
pp. 527, 529).
As is the case with all models, there is uncertainty associated
with projections due to assumptions used, data available, and features
of the models. Despite this, however, under all models and emissions
scenarios the overall surface air temperature trajectory is one of
increased warming in comparison to current conditions (Meehl et al.
2007, p. 762; Prinn et al. 2011, p. 527). Climate models and associated
assumptions, data, and analytical techniques continue to be refined,
and thus projections are refined as more information becomes available
(e.g., Rahmstorf 2010 entire). For instance, observed actual emissions
of greenhouses gases, which are a key influence on climate change, are
tracking at the mid- to higher levels of the various scenarios used for
making projections, and some expected changes in conditions (e.g.,
melting of Arctic sea ice) are occurring more rapidly than initially
projected (Raupach et al. 2007, Figure 1, p. 10289; Comiso et al. 2008,
p. 1; Pielke et al. 2008, entire; LeQuere et al. 2009, Figure 1a, p. 2;
Manning et al. 2010, Figure 1, p. 377; Polyak et al. 2010, p. 1797). In
short, the best scientific and commercial data available indicates that
increases in average global surface air temperature and several other
changes are occurring and likely will continue for many decades and in
some cases for centuries (e.g. Solomon et al. 2007, pp. 822-829; Church
2010, p. 411).
Changes in climate can have a variety of direct and indirect
impacts on species, and can exacerbate the effects of other threats.
For instance, climate-associated environmental changes to the
landscape, such as decreased stream flows, increased water
temperatures, reduced snowpacks, and increased fire frequency, or other
changes occurring individually or in combination, may affect species
and their habitats. The vulnerability of a species to climate change
impacts is a function of the species' sensitivity to those changes, its
exposure to those changes, and its adaptive capacity (IPCC 2007, p.
883). As described above, in evaluating the status of a species the
Service uses the best scientific and commercial data available, and
this includes consideration of direct and indirect effects of climate
change. As is the case with all other stressors we assess, if the
status of a species is expected to be affected that does not
necessarily mean it is a threatened or endangered species as defined
under the Act.
We recognize that temperatures in southern California where the
Tehachapi slender salamander occurs are likely to increase, which could
potentially negatively affect the Tehachapi slender salamander. As
discussed in the ``Biology and Natural History'' section, the Tehachapi
slender salamander's surface activity, during which the species forages
and likely finds mates, is limited to periods with high surface
moisture and above freezing temperatures. Increased average surface
temperatures could cause soils used by Tehachapi slender salamanders to
become drier earlier in the year or for longer periods, which may
further limit the amount of time they can remain at the surface. If the
period when surface moisture is sufficient for activity becomes too
short, then the habitat may no longer be suitable for the species.
It is especially difficult with currently available models to make
meaningful predictions of climate change for specific, local areas such
as the small portion of California where the Tehachapi slender
salamander occurs (Parmesan and Matthews 2005, p. 354). However, a
climate change stress report for the Tehachapi Mountains (TNC 2009)
projects varying levels of drought stress by the end of the 21st
Century. The following examples demonstrate possible changes in
precipitation and temperature from averaging 15 global climate models
(TNC 2009, no page numbers):
(1) The two most likely possibilities of precipitation change are a
40 percent projection that the area will see little (-1 to +1 in (-2.5
to 2.5 cm)) change in precipitation, and a 53 percent projection that
the area will receive between 1 and 5 in (2.5 and 12.7 cm)) less
precipitation.
(2) The two most likely possibilities of temperature change are a
53 percent projection that the temperature of the area will increase by
greater than 10 degrees Fahrenheit (5.6 degrees Celcius), and a 27
percent projection that the temperature of the area will increase by 8
to 10 degrees Fahrenheit (4.4 to 5.6 degrees Celsuis).
On the other hand, Kelly and Goulden (2008, p. 11824) predict that
the amount and duration of precipitation may increase for California
(in general), and, if this occurs, surface moisture could be maintained
despite the warmer temperatures that are predicted. In addition,
warming may reduce the degree and duration of extreme cold at higher
elevations. Under these conditions, the duration of surface activity
for the Tehachapi slender salamander may remain the same.
Climate change can affect plants and animals in a number of ways,
including changes in distribution, population size, behavior, and even
changes in physiological and physical characteristics (Parmesan and
Mathews 2005, p. 373). A number of published studies predict that
temperature and precipitation trends may change in the near future, and
some describe how biotic communities may respond to such changes
(Parmesan and Mathews 2005, pp. 333-374; IPCC 2007a, pp. 1-21; IPCC
2007b, pp. 1-22; Kelly and Goulden 2008, pp. 11823-11826; Miller et al.
2008, pp. 1-17; Loarie et al. 2008, pp. 1-10; Jetz et al. 2007, pp.
1211-1216). During a 30-year study in Southern California's Santa Rosa
Mountains, Kelly and Goulden (2008, pp. 11823-11824) observed a
geographic shift in plant distributions to higher elevations that was
uniform across elevation gradients and that corresponded with an
observed increase in surface temperatures and variability in
precipitation over the same timeframe. Similarly, a study in
California's Cascade and Sierra Nevada Ranges found that plant species
tended to move towards higher elevations in response to increasing
temperatures regardless of the presence of suitable habitat to the
north or south (Loarie et al. 2008, p. 3).
Based on the research on plant communities in montane habitats by
Kelly and Goulden (2008, pp. 11823-11824) and Loarie et al. (2008, p.
3),
[[Page 62916]]
populations of Tehachapi slender salamanders may respond to climate
change by attempting to shift to higher elevations to follow the
shifting vegetation patterns. However, we cannot predict the
consequences of any potential shift because there is likely a complex
suite of indirect effects for any shift in distribution. For example,
the mesic microclimates that define suitable Tehachapi slender
salamander habitat are dependent on a combination of vegetation cover
(providing shade), slope, and aspect (affecting the amount of sun
exposure on a hillside). The more a hillside is exposed to sun, the
more it experiences heat and evapotranspiration (and thus,
desiccation). For example, steeper north-facing slopes experience less
time in the sun than gradual south-facing slopes. In addition, the
upper slopes of north-facing hillsides are exposed to sun for longer
periods than north-facing canyon bottoms.
Populations of Tehachapi slender salamanders may be limited to
shifting their range up-canyon to north-facing slopes at higher
elevations. The ability of a population to shift up-canyon would depend
on the availability of contiguous (or closely spaced) habitat patches
that would provide a movement corridor. We do not expect that the
species would be able to shift to different canyons at higher altitudes
because of the limited dispersal ability of individuals and the
presence of rugged and unsuitable habitat that occurs between most
canyons. Also, shifting farther up the slopes that are currently
occupied could be limited because the upper reaches of a hillside would
be more exposed to sunlight, and thus to increased evapotranspiration
and dry surface cover, which are considered unsuitable for Tehachapi
slender salamander.
It is possible that some of the Tehachapi slender salamander's
range could be reduced (i.e., suitable habitat that is contiguous with
the known occurrences could disappear from the lower elevations or from
more mesic habitat patches), especially if both temperature increases
and precipitation declines. Depending on the degree of temperature rise
and precipitation decline, some loss of habitat and reduction in range
is likely; however, potential loss of habitat or a range reduction
could be compensated for in those areas where up-canyon shifts in
distribution are possible.
Overall, the limited range of the Tehachapi slender salamander
makes it vulnerable to potential climate change impacts such as habitat
alteration (Jetz et al. 2007, pp. 1211-1216; Parmesan and Mathews 2005,
p. 373) or fragmentation. Habitat fragmentation resulting from warmer,
drier conditions could make it difficult for Tehachapi slender
salamanders to travel between habitat patches. If temperatures
potentially increase and precipitation decreases in the forseeable
future (as discussed above), one can expect changes in vegetation such
as a shift in vegetation to higher elevations or a reduction of
suitable habitat and possibly a reduction in the range of the species.
Vegetation changes within the range of the Tehachapi slender salamander
will likely be most prevalent in more open, montane habitat that is not
representative of the vegetation on the lower, most heavily shaded
portions of north-facing slopes where the salamander occurs (TNC 2009,
p. 4). Thus, these lower, north-facing slopes may not be altered or
fragmented to the degree that the open, montane habitat could be,
resulting in the salamander's habitat (i.e., the current known
occurrences and the contiguous suitable habitat that makes up the range
of the species) remaining relatively stable and acting as refugia for
the salamander.
In summary, available climate models predict average temperatures
in the Tehachapi Mountains are likely to increase in the future,
although there is less certainty as to whether precipitation will
remain the same or decrease. However, there is a great deal of
uncertainty as to how these changes may affect the Tehachapi slender
salamander. How the Tehachapi slender salamander may react to these
changes will be the result of a complex array of factors including the
degree of temperature increase, the decline in precipitation, if any;
the degree to which the specific habitat requirements of the salamander
(such as the timing and duration of soil moisture, and under- and
overstory composition) will be affected; changes and shifts in plant
diversity and abundance; and the ability and opportunity of salamander
populations to shift over time.
It is possible that the range of some populations may be reduced,
while others are able to shift up-canyon to higher slopes. It may also
be that the vegetation on the cooler, lower portions of the north-
facing slopes occupied by the salamander may not be subject to the same
changes predicted for more open, warmer, and drier slopes. Because of
these uncertainties, any prediction about the potential impact of
climate change on the Tehachapi slender salamander will be highly
speculative. However, with those uncertainties in mind, we believe
that, although some loss of habitat in the more exposed portions of the
canyons currently occupied by the salamander will occur because of
climate change, habitat will remain in the lower, most-shaded portions
to support the salamander and in some cases the salamander may be able
to shift within the canyon in response to climate change.
In addition to the uncertainties discussed above, habitat loss due
to potential future human encroachment could exacerbate the potential
effects of climate change by both reducing the availability of suitable
habitat the species can move to and increasing the distance between
habitat patches (Jetz et al. 2007, pp. 1211-1216; Parmesan and Mathews
2005, p. 373). As described under Factor A above and based on the best
information currently available, TMV is the one development with County
approval near Tehachapi slender salamander occurrences, and this
project is not expected to impact the salamander's occurrences nor the
adjacent contiguous suitable habitat that makes up the range of the
Tehachapi Mountains population of the species. We do not anticipate
significant impacts to the species across its range as a result of
cumulative effects from human encroachment and climate change due to a
combination of the ecology of the species (e.g., its ability to retreat
to underground refugia, minimal surface time during the moist periods
of the year, generation time) and because the TMV development is
designed to avoid all known occurrences and occupied habitat (see
``Climate Change'' discussion above under Factor E, ``Tehachapi
Mountains Population'' discussion under Factor A, and the Biology and
Natural History section).
Stochastic Events
Under Factor E, we also consider whether three risks, represented
by demographic, genetic, and environmental stochastic events, are
substantive enough to threaten the continued existence of the Tehachapi
slender salamander.
In basic terms, demographic stochasticity is defined by chance
changes in the population growth rate for the species (Gilpin and
Soul[eacute] 1986, p. 27). Population growth rates are influenced by
individual birth and death rates (Gilpin and Soul[eacute] 1986, p. 27),
immigration and emigration rates, as well as changes in population sex
ratios. Natural variation in the survival and reproductive success of
individuals and chance disequilibrium of sex ratios may act in concert
to contribute to demographic stochasticity (Gilpin and Soul[eacute]
1986, p. 27).
[[Page 62917]]
Genetic stochasticity is caused by changes in gene frequencies due
to genetic drift, and diminished genetic diversity, and effects due to
inbreeding (i.e., inbreeding depression) (Lande 1995, p. 786).
Inbreeding can have individual or population-level consequences either
by increasing the phenotypic expression (the outward appearance, or
observable structure, function, or behavior of a living organism) of
recessive, deleterious alleles or by reducing the overall fitness of
individuals in the population (Shaffer 1981, p. 131).
Environmental stochasticity is defined as the susceptibility of
small, isolated populations of wildlife species to natural levels of
environmental variability and related ``catastrophic'' events (e.g.,
disease epidemics, prolonged drought, wildfire) (Young 1994, pp. 410-
412; Mangel and Tier 1994, p. 612; Dunham et al. 1999, p. 9). Each risk
will be analyzed specifically for the Tehachapi slender salamander.
As a whole, the Tehachapi slender salamander is considered a
naturally rare species, due to its restricted and endemic geographic
distribution and specific habitat requirements and is likely vulnerable
to the threat of genetic stochasticity. The two populations of the
Tehachapi slender salamander have relatively small geographic ranges
and limited dispersal abilities, and we do believe that any contact
between the two populations is unlikely because of the distance and
type of terrain between them. This conclusion is supported by the
substantial genetic differences between the two populations (Jockusch
in litt. 2009e, p. 1).
As with all species of Batrachoseps, Tehachapi slender salamanders
are sedentary and individuals travel no more than about 10 ft (3 m)
(Hansen in litt. 2009b, p. 1). For example, a study reported that the
California slender salamander stayed within a 5-ft (1.5-m) area over 2
years of observations (Yanev 1980, p. 533). Analyses of the fossil
record of currently threatened species suggest that species with these
characteristics are at a higher risk of extinction than are mobile,
widely distributed species (Jablonksi 1986, pp. 129-133; Manne et al.
1999, p. 260; Dynesius and Jansson 2000, p. 9116; Payne and Finnegan
2007, pp. 10506-10511). However, other than the one occurrence near the
Tehachapi Pass (see Figure 2), and the area along the Tejon Pass (i.e.,
the Interstate Highway 5 corridor), there is no evidence that the
species distribution has significantly changed over the past 200 years
(Hansen in litt. 2011, p. 1). The four occurrences of Tehachapi slender
salamander discovered in 2009 are all located within the general range
of the Caliente Canyon population; though distributed over a a wider
area than previously thought (Sweet in litt. 2011, p. 1). Occupied
habitat in Caliente Canyon is more patchily distributed than in any of
the other occupied canyons, with a few gaps between habitat of more
than a mile. These gaps are beyond the limited dispersal ability of
individuals, and movement up and down canyon across large gaps may only
occur under extreme circumstances (such as a major flood).
Habitat in the other occupied canyons is more contiguous, and
movement up and down canyon is likely to occur. The average distance
between occupied canyons for both the Caliente Canyon and Tehachapi
Mountains populations is about 4 mi (6.4 m), indicating that genetic
exchange between canyons is unlikely. However, although the species may
be vulnerable to genetic stochasticity, we have no evidence of a
genetic bottleneck or inbreeding depression. We do not have information
to indicate that these have occurred.
The vulnerability of the species to demographic stochasticity may
be indicated by skewed sex ratios or a small or reduced number of
offspring. However, there are no data that would indicate such a threat
to the species exists.
Stochastic (chance) events such as epidemics, severe drought, or
large, severe fires can threaten the persistence of species with
restricted ranges because a single event can occur within all or a
large portion of their range. Species that are relatively sedentary are
probably less able than mobile animals to recolonize parts of their
range where they have been extirpated. The Tehachapi slender
salamander's characteristics of being rare, patchily distributed, and
sedentary could further increase the species' risks of extinction from
stochastic events (Hansen and Wake 2005, p. 694). In the absence of
information identifying threats to the species and linking those
threats to the rarity of the species, the Service does not consider
rarity alone to be a threat. However, we need to consider potential
threats (e.g., fire, drought) that might be exacerbated by rarity, as
discussed below.
Epidemics and large, severe fires are two kinds of stochastic
events that could negatively affect populations of the Tehachapi
slender salamander. The only lethal disease we are aware of that could
behave as an epidemic in populations of this salamander is
chytridiomycosis (see Factor C), but we have no information of this
species contracting the disease or whether it would be lethal in wild
populations of the Tehachapi slender salamander (see Factor C).
Further, we do not know of any other salamander species, or other
amphibians, that co-occurs with either population that has been
affected by the fungus in Kern County that could pass along the
infection through physical contact.
The State of California has experienced cycles of drought for many
years. For example, between 1928 and 1987 the U.S. Geological Survey
(USGS) reported five severe droughts across California, including the
longest drought in the State's history from 1929 to 1934 (USGS 2004, p.
2). The Tehachapi slender salamander has persisted through these
periods of severe drought. During periods of severe drought, Tehachapi
slender salamanders likely remain in a state of aestivation below
ground. Plethodontids are known for their low metabolism and ability to
survive long periods without feeding (Feder 1983, pp. 304-305).
Therefore, based on their metabolism and demonstrated ability to
persist during periods of severe drought in the past, we do not believe
that severe drought will threaten the species in the foreseeable
future.
The Tehachapi slender salamander could be at some risk from large,
severe wildfires in the foreseeable future. Studies suggest that
forests in California will experience longer fire seasons and more
frequent, extensive, and severe fires by the end of this century
(Lenihan et al. 2003, p. A-13; Miller et al. 2008, pp. 1-15). An
increase in fire frequency and extent will likely lead to an increase
in fire impacts, including soil erosion, sediment runoff, and habitat
fragmentation (Miller et al. 2008, p. 13). Therefore, fire could have a
negative impact on the species in the future if the frequency and
intensity of forest fires increases as predicted.
The impacts of forest fires on the Tehachapi slender salamander are
not well understood. Fire outbreaks would likely occur during the dry
season when salamanders are aestivating below ground where they are
afforded some level of protection. However, the vegetation canopy that
helps retain surface moisture and the leaf litter and downed logs that
are important components of the salamander's habitat would be affected.
As discussed in the Climate Change section above, there is also a great
deal of uncertainty about future climate change within the range of the
species and in turn, over the future of fire. However, the Tehachapi
slender salamander has persisted in Caliente Canyon (and surrounding
[[Page 62918]]
occupied canyon areas) and the Tehachapi Mountains, which are prone to
forest fires, for thousands of years. Therefore, we conclude that
forest fires are a concern, but do not rise to the level of a
significant threat to the Caliente Canyon and Tehachapi Mountains
populations of the Tehachapi slender salamander.
Summary of Factor E
Because of the rarity and limited dispersal ability of the species,
genetic stochasticity is a concern. However, we do not have any
evidence of genetic bottlenecks or inbreeding depression to indicate
that genetic stochasticity is a significant threat. Nor do we have any
information to indicate that demographic stochasticity or a disease
outbreak is likely to be a significant threat in the future.
Environmental stochasticity, particularly wildfire, is a concern;
however, we do not believe that this rises to a level that threatens
the persistence of the species over the long-term.
Changes in climate can have a variety of direct and indirect
impacts on species such as the Tehachapi slender salamander, and can
exacerbate the effects of other threats. However, there is a great deal
of uncertainty as to how climate change may affect the Tehachapi
slender salamander, and any prediction about the potential impact of
climate change on the Tehachapi slender salamander will be highly
speculative. However, with those uncertainties in mind, we believe
that, although some loss of habitat in the more exposed portions of the
canyons currently occupied by the salamander will occur because of
climate change, habitat will remain in the lower, most-shaded portions
to support the salamander and in some cases the salamander may be able
to shift within the canyons in response to climate change.
A species may also be affected by more than one threat in
combination. Within the preceding review of the five listing factors,
we have identified several threats that could have interrelated impacts
on the Tehachapi slender salamander. For example, potential suitable
habitat may be lost or altered as a result of a combination of
development (Factor A) and effects of climate change (Factor E).
Likewise, predation (Factor C) in combination with a stochastic event
(Factor E), such as a forest fire could result in a major loss of
individuals in one or more populations. However, as we discuss above,
regardless of its source, we do not believe that the threats discussed
above, either individually or in combination, are of sufficient
imminence, intensity or magnitude to affect the status of the Tehachapi
slender salamander.
We conclude that the best available information concerning Factor E
indicates that the Tehachapi slender salamander is not threatened
individually or cumulatively by the effects of climate change or
demographic, genetic, or environmental stochasticity. Therefore, we
conclude that the Tehachapi slender salamander is not threatened or
endangered throughout all of its range now or in the future by other
natural or manmade factors.
Finding
We have assessed the best scientific and commercial information
available regarding threats faced by the Tehachapi slender salamander.
We have reviewed the petition, scientific literature, information
available in our files, and all information submitted to us following
our 90-day petition finding (74 FR 18336; April 22, 2009). We also
consulted with recognized Tehachapi slender salamander experts, Federal
land managers, and local governments, and arranged for a recognized
Tehachapi slender salamander expert to assess potential threats to the
habitat and range of the species relative to current and planned land
uses and occurrences of the species.
Potential threats include development, road construction, mining,
domestic livestock grazing, introduced species, and flood control
projects. Based on the best available information, we find that the
evidence supports a finding that listing the Tehachapi slender
salamander is not warranted.
While only two Tehachapi slender salamander populations are known,
information in our files does not indicate whether these populations
are in decline, stable, or increasing; however, the Caliente Canyon
population is now known to be made up of five populations, rather than
the previously known single population (Sweet in litt. p. 1). The best
available information indicates that this species is naturally rare.
While rare species may face threats from normal population fluctuations
due to predation, disease, changing food supply, and stochastic
(random) events, our evaluation of the best available information
indicates that these potential threats do not threaten the continued
existence of the Tehachapi slender salamander.
The range of the salamander within the Caliente Canyon area is
primarily on land used for grazing, an activity for which data shows
only minor to moderate signs of degradation from livestock use. Some
localized habitat at 3 of the 18 occurrences (approximately 16.7
percent) show signs of moderate impact from cattle trampling; however,
habitat in good to fair condition that would support the species
remains at the 3 occurrences. There are no proposed projects associated
with residential or commercial development, road construction, or
mining anywhere near known occurrences within Caliente Canyon.
The primary land use within the range of the Tehachapi Mountains
population is also livestock grazing, and we do not have any
information that indicates that use by cattle has resulted in
significant habitat degradation of any of the five canyons known to be
occupied by this population. Tejon Ranch is planning a large-scale
residential and commercial development project, TMV. However, the TMV
development envelope is designed to avoid known salamander occurrences
and all occupied habitat within the species range for the Tehachapi
Mountains population. In a worst-case scenario, 2.8 percent of the
potentially suitable habitat for the species on the Tejon Ranch will be
lost to development. Indirect impacts from the TMV project are expected
to be restricted to the immediate vicinity of development well away
from all occupied habitat and known occurrences of the species.
Therefore, we believe that the development is not a significant threat
to the species.
We do not have any indication that flood control projects occur or
are planned to occur within either the Caliente Canyon or Tehachapi
Mountains area.
The impact of climate change is a concern for the species, and
although there is uncertainty, we believe that some loss of habitat in
the more exposed portions of the canyons that are currently occupied by
the salamander will occur because of climate change. However, we also
believe that habitat will remain in the lower, most-shaded portions of
canyons to support the salamander and in some cases the salamander may
be able to shift within the canyon in response to climate change.
Because of the rarity and limited dispersal ability of the species,
genetic stochasticity is also a concern. However, we do not have any
evidence of genetic bottlenecks or inbreeding depression to indicate
that genetic stochasticity is a significant threat.
There are regulatory mechanisms in place, such as CESA, CEQA, and
BLM's special status designation for the
[[Page 62919]]
species, that provide adequate protections from threats for both
populations of the species.
In summary, the main activity in the range of the Tehachapi slender
salamander at the present time is cattle grazing, which is likely to
remain the only activity within the range of the Caliente Canyon
population. We have determined that the impacts of grazing are limited
to a few areas in Caliente Canyon, and sufficient habitat to support
the species remains in these areas; few impacts from grazing have been
observed in the canyons known to be occupied by the Tehachapi Mountains
population. Therefore, we have determined that cattle grazing is not a
significant impact to the species now or in the foreseeable future.
Second, we have determined the proposed residential and commercial
development on Tejon Ranch will not have a significant impact on the
species because the footprint of the development has been designed to
avoid all known occurrences of the salamander and does not overlap with
any habitat that is likely occupied. Third, we have determined that
indirect impacts from the proposed development will not be significant
because they are not likely to extend far enough from the proposed
development footprint to affect known occurences or occupied habitat
and because the salamander is above ground for only a few months of the
year and remains under talus and fallen logs when it is at the surface.
Fourth, although climate change is a concern, we have determined that
the impacts of climate change will not be significant because there is
some uncertainty as to how the climate in the area where the species
occurs will change and that sufficient habitat will remain to support
the species. Finally, we have determined that the cumulative impacts of
all of the five factors on the species will not be significant because,
based on the best available information, the interrelated current and
anticipated impacts of development, road construction, mining, domestic
livestock grazing, introduced species, flood control projects, climate
change, and stochastic events do not threaten the Tehachapi slender
salamander. Considering all of the identified impacts in combination,
sufficient habitat will remain to support the species.
Therefore, on the basis of the best scientific and commercial
information available, we find that the species is not at risk of
extinction across its range now or in the foreseeable future and as a
result find that listing the species range-wide as threatened or
endangered under the Act is not warranted at this time.
Distinct Vertebrate Population Segments
After assessing whether the species is threatened or endangered
throughout its range, we next consider whether a Distinct Vertebrate
Population Segment (DPS) or whether any significant portion of the
Tehachapi slender salamander's range is in danger of extinction or
likely to become so within the foreseeable future.
Distinct Population Segment
As previously noted, we have determined that there are two separate
populations of the Tehachapi slender salamander. Under section 4(a)(1)
of the Act, we must evaluate five threat factors to determine whether a
species should be listed as endangered or threatened. Section 3(16) of
the Act defines ``species'' to include ``any subspecies of fish or
wildlife or plants, and any distinct population segment (DPS) of any
species of vertebrate fish or wildlife which interbreeds when mature''
(16 U.S.C. 1532(16)). To interpret and implement the DPS portion of the
definition of a species under the Act and Congressional guidance, the
Service and the National Marine Fisheries Service published an
interagency Policy Regarding the Recognition of Distinct Vertebrate
Population Segments under the Act (DPS Policy) on February 7, 1996 (61
FR 4722). The DPS Policy allows for more refined application of the Act
that better reflects the conservation needs of the taxon being
considered and avoids the inclusion of entities that may not warrant
protection under the Act.
Under our DPS Policy, we consider three elements in a decision
regarding the status of a possible DPS as endangered or threatened
under the Act. We apply them similarly for additions to the List of
Threatened and Endangered Wildlife and Plants (List), reclassification,
and removal from the List. They are: (1) discreteness of the population
segment in relation to the remainder of the taxon; (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 (whether the population segment is, when treated
as if it were a species, endangered or threatened).
Analysis for Discreteness
Under the DPS policy, a population segment of a vertebrate taxon is
considered to be discrete if it meets 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.
(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 note that the
standard set forth in the DPS policy is that a DPS be ``markedly
separated'' from other populations--thus, while absolute separation is
not required, there must be sufficient separation such that ``large
numbers'' of individuals are not migrating between populations.
Markedly Separated From Other Populations of the Taxon
The Caliente Canyon and Tehachapi Mountains populations of the
Tehachapi slender salamander both meet the discreteness element of the
DPS policy. The general region where the Tehachapi slender salamander
occurs consists of semi-arid terrain containing localized areas of
mesic habitat favorable to salamanders (Hansen in litt. 2009a, p. 13).
The Caliente Canyon group of occurrences is isolated from the Tehachapi
Mountains occurrences by a minimum of 13 mi (21 km) of rugged terrain,
much of which is dry, unsuitable habitat (Hansen in litt. 2009a, p.
11). There is no evidence of movement between the Caliente Canyon and
Tehachapi Mountains populations due to the sedentary nature of the
species, and the distance and rugged terrain between them (Hansen in
litt. 2009a, p. 11). In addition, genetic studies show that the
Caliente Canyon and Tehachapi Mountains populations have been isolated
from each other for over a million years (Hansen in litt. 2009a, p. 11;
Hansen 2009b pers. comm.; Jockusch 1996, p. 91; Jockusch in litt.
2009f, p. 2).
Further, we have no evidence of breeding and gene flow between the
Caliente Canyon population and the Tehachapi Mountains population.
Genetic exchange between these populations is prevented by the distance
and lack of suitable movement corridors between them (Hansen 2009a,
pers. comm.). Hansen suggests that interbreeding of Tehachapi slender
salamanders between occupied canyons within the two populations rarely
occurs due to a number of factors, including: patchy distribution of
Tehachapi slender salamanders, distance between occupied habitat, lack
of suitable habitat corridors between occupied canyons, and the
sedentary
[[Page 62920]]
characteristics of the salamanders (Hansen 2009b pers. comm.).
In addition to the distance and the physical and genetic isolation
between the two populations, there are reported differences in
morphology (appearance) and habitat between the Caliente Canyon
population and the population found in the Tehachapi Mountains
(Jockusch and Wake 2002, p. 383; Hansen and Wake 2005, p. 694). As
stated in the DPS policy, ``Quantitative measures of genetic or
morphological discontinuity may provide evidence of this separation.''
For example, Tehachapi slender salamanders in Caliente Canyon tend to
have more noticeable brick-red/copper coloration, and tend to be larger
with proportionately larger tails than salamanders living in the
Tehachapi Mountains (Hansen 2009b pers. comm.; Hansen in litt. 2009d,
p. 1). Tehachapi slender salamanders in the Caliente Canyon area occur
at much lower elevations (1,804 ft (550 m)) than those in the Tehachapi
Mountains (3,100 ft (945 m)) (Hansen 2009, p. 1; Sweet in litt. 2011,
p. 1). Tehachapi slender salamanders in Caliente Canyon are more often
found under rocks and talus. On the other hand, salamanders in the
Tehachapi Mountains are more often found under leaves, woody debris,
and talus (Hansen and Wake 2005, p. 694). Based on the physical
separation of the two populations and the evidence that they do not
interbreed, including differences in genetics and morphology, we find
that the Caliente Canyon and Tehachapi Mountains populations are
discrete.
International Border Issues
A population segment of a vertebrate species may be considered
discrete if it is delimited by international governmental boundaries
across 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. Given that the
range of the species as a whole lies entirely within the United States
borders, international border issues do not apply in this situation.
In summary, available information on the Tehachapi slender
salamander indicates that the Caliente Canyon population and Tehachapi
Mountains population are markedly separated from one another by
distance, gene flow, and to a lesser degree, morphology and habitat use
and, therefore, meet the criteria for being discrete. If a population
segment is considered discrete pursuant to one or more of the
conditions described in our DPS policy, its biological and ecological
significance will be considered in light of Congressional guidance.
Analysis of Significance
If a population segment is considered discrete under one or more of
the conditions described in our 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
does provide four possible reasons why a discrete population may be
significant. 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 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 criteria to
be considered significant. Furthermore, the list of criteria is not
exhaustive; other criteria may be used as appropriate.
Ecological Setting
The Caliente Canyon and Tehachapi Mountains populations are 13 mi
(21 km) apart, and we would not generally expect that ecological
differences would occur in that short distance, and the habitat of the
two populations is similar. However, as discussed previously, the range
of the Caliente Canyon population is as much as 1,300 ft (396 m) lower
in elevation than that of the Tehachapi Mountains population. This
elevational difference exposes the two populations to different
climatic conditions. For example, the lower Caliente Canyon populations
experience higher temperatures for a longer period of time than any of
the Tehachapi Mountains populations, and snowfall occurs less often and
remains on the ground for shorter periods of time at the lower
elevations. These differences are likely to result in differences in
the length and timing of surface activity between the two populations.
There are also minor differences in either the material available on
the surface or the surface material selected by the two populations,
with the Caliente Canyon population most often found under rocks and
talus, while the Tehachapi Mountains population is more often found
under leaves, woody debris, and talus (Hansen and Wake 2005, p. 694).
Although differences exist in the ecological setting of the two
populations, we do not find these differences to be great enough to be
considered unusual or unique for the taxon.
Gap in the Range
Because the species consists of only two, discrete populations that
constitute 47 percent and 53 percent, respectively, of the species
known range, the loss of either the Caliente Canyon population to the
north or the Tehachapi Mountains population to the south would create a
substantial gap in the range of the species.
Whether the Population Represents the Only Surviving Natural Occurrence
of the Taxon
Both populations of the Tehachapi slender salamander are in
entirely natural settings, and there are no populations that have been
introduced outside the range of the species and there are no captive
populations. Consequently, this factor is not applicable to our
determination regarding significance.
Marked Differences in Genetic Characteristics
As discussed previously, a high level of divergence (greater than 5
percent) in mtDNA exists between the Caliente Canyon and Tehachapi
Mountains populations (Jockusch in litt. 2009e, p. 1; Jockusch in litt.
2009f, pp. 1-2). However, mtDNA represents only five females of the two
populations (Jockusch in litt. 2009e, p. 1). Jockusch's (in litt.
2009d, p. 1) preliminary findings on nuclear DNA (based on only two
individuals), which represents both sexes, found less divergence than
with mtDNA. Although this research indicates that there may be genetic
differences between the two populations, because of the small
[[Page 62921]]
sample size, the available information is too inconclusive and limited
for us to find that the two populations are markedly genetically
different from each other.
Conclusion of Distinct Population Segment Review
We find that, because there are only two populations of the
species, the loss of either would result in a significant gap in the
overall range of the species. However, we do not find that either
population represents the only surviving natural occurrence or that
either population is markedly genetically different. Therefore, because
each population meets one of the considerations for significance in our
DPS policy, we find that both the Caliente Canyon and Tehachapi
Mountains populations are significant under the policy.
The Caliente Canyon and the Tehachapi Mountains populations of the
Tehachapi slender salamander are both discrete and significant. The two
populations have been physically separated by distance and barriers
such as dry, unsuitable habitat for over a million years, and there is
no evidence of gene flow between the two. The two populations are each
significant because loss of either one would result in a substantial
gap in the range of the species. For these reasons, we find that the
Caliente Canyon population and the Tehachapi Mountains population each
constitute a distinct population segment of the Tehachapi slender
salamander.
Summary of Information Pertaining to the Five Factors
Section 4 of the Act (16 U.S.C. 1533) and implementing regulations
at 50 CFR part 424 set forth procedures for adding species to the
Federal List of Endangered and Threatened Wildlife. An ``endangered
species'' is any species in danger of extinction throughout all or a
significant portion of its range. A ``threatened species'' is any
species which is likely to become an endangered species within the
foreseeable future throughout all or a significant portion of its
range. In making this finding, we summarize below information regarding
the status and threats to the two DPS's of the Tehachapi slender
salamander in relation to the five factors in section 4(a)(1) of the
Act. A species may be determined to be an endangered or threatened
species due to one or more of the five factors described in section
4(a)(1) of the Act. In making our 12-month finding, we considered and
evaluated all scientific and commercial information in our files,
including information received during the public comment period that
ended June 22, 2009.
Factor A: The Present or Threatened Destruction, Modification, or
Curtailment of the Species' Habitat or Range
Because the Factor A analysis for the entire range of the species
specifically discussed these threats for the Caliente Canyon
population, the same analysis applies for the Caliente Canyon DPS.
Likewise, the analysis of threats under Factor A for the Tehachapi
Mountains population, equally applies to the Tehachapi Mountains DPS.
The threats are briefly summarized below for each DPS. Please refer to
the Factor A analysis for the entire range of the species for details.
Summary of Factor A of the Caliente Canyon DPS
Overall, 4 out of 18 occurrences showed relatively localized signs
of moderate disturbance from cattle grazing, residential use, or
erosion from a nearby road. Disturbance specifically associated with
cattle trampling was seen at 3 out of 18 occurrences (approximately
16.7 percent). However, sufficient habitat in good-to-fair condition to
support the species remains at all 4 locations, while all of the
habitat at the other 14 occurrences is in good to fair condition. No
new road construction is planned within the range of the Caliente
Canyon population; however, erosion associated with an existing road in
Caliente Canyon is affecting habitat in a few localized areas. Mining
activity within the Caliente Canyon area is not occurring, and there
are no confirmed plans for mining to start again in the foreseeable
future. In addition, there are no plans for new residential or
commercial development within the Caliente Canyon DPS of the species.
We are also not aware of any flood control projects within the range of
the DPS or any planned flood control projects. For these reasons, we
conclude that cattle grazing, roads, mining, flood control projects,
and commercial and residential development do not constitute a
substantial threat to the Caliente Canyon DPS of the Tehachapi slender
salamander. Therefore, we conclude that this DPS is not threatened or
endangered throughout all of its range within the future by the present
or threatened destruction, modification, or curtailment of its habitat
or range.
Summary of Factor A of the Tehachapi Mountains DPS
Four of the five canyons (five of the six known occurrences)
occupied by the Tehachapi Mountains DPS are found on Tejon Ranch.
Current land use on Tejon Ranch in the area where occupied canyons and
potential habitat for the Tehachapi slender salamander are located
includes cattle grazing, farming, and recreation. We know that cattle
grazing and rooting from pigs and turkeys can affect the habitat of
Tehachapi slender salamander through trampling and erosion. However,
habitat at all known occurrences on Tejon Ranch is in good condition,
despite the presence of cattle, turkeys, and pigs (Hansen in litt.
2010a, p. 3; Miller in litt. 2010b, p. 4). Therefore, we have no
evidence that indicates that cattle grazing or rooting from pigs and
turkeys are threats to the Tehachapi Mountains DPS on Tejon Ranch.
None of the four occupied canyons fall within the 7,860-ac (3,181-
ha) proposed TMV development envelope, and all occupied habitat and
occurrences are will be at least 0.5 mi (0.8 km) away from any
development. Although Tejon Ranch's planned TMV project may remove 108
ac (44 ha) of potentially suitable habitat, the TMV project is designed
to avoid all occupied habitat and all known occurrences of the
Tehachapi slender salamander within the project development area and
footprint. Because the TMV development is designed to avoid direct
impacts to the DPS, and indirect effects from the development
(including increased presence of humans, pets, and predators) are not
considered to be a significant threat to the species, the proposed
residential and commercial development is not considered a threat to
the Tehachapi Mountains DPS.
There are no known flood control projects or mining projects
occurring or planned to occur within the range of this DPS. In
addition, there are no known threats of habitat removal or degradation
for the species on Fort Tejon SHP. Therefore, we conclude that this DPS
is not threatened or endangered throughout all of its range within the
future by the present or threatened destruction, modification, or
curtailment of its habitat or range.
Factor B: Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
We are not aware of any information that indicates overutilization
for commercial, recreational, scientific, or educational purposes is a
threat to the Caliente Canyon DPS or the Tehachapi
[[Page 62922]]
Mountains DPS of the Tehachapi slender salamander. Therefore, we
conclude that neither DPS is threatened or endangered throughout all of
its range within the future by overutilization for commercial,
recreational, scientific, or educational purposes.
Factor C: Disease or Predation
As discussed under Factor C for the species as a whole, we do not
know whether the Tehachapi slender salamander has been, or will be,
exposed to a deadly pathogen, such as the chytrid fungus. However,
related terrestrial species of salamanders have been found to suffer
from Chytridiomycosis, including the California and black-bellied
slender salamanders. As previously discussed, Weinstein's study showed
that Chytridiomycosis causes mortality of a fully terrestrial
salamander species in a moist lab environment; however, individuals
were able to recover in a dry lab environment. Her study suggests that
individuals of terrestrial slender salamander species may fair better
in the field (Weinstein in litt. 2008a, p. 1; Weinstein 2009, p. 1).
We do not have any information to indicate that the chytrid fungus
is present in the Caliente Canyon DPS of the Tehachapi slender
salamander or any other species with which it co-occurs. The black-
bellied slender salamander, which has been infected by chytrid in San
Luis Obispo County (110 mi or 177 km away), only co-occurs with the
Tehachapi Mountain DPS of the Tehachapi slender salamander. Other
amphibian species that could co-occur with the Tehachapi slender
salamander that have been known to carry chytrid include the Pacific
tree frog, western toad, and bullfrog; however, the disease has not
been detected in these species in the range of the Tehachapi slender
salamander in Kern County. Based on the limited information available,
it appears that the Tehachapi Mountains DPS runs a slightly higher risk
of contracting chytrid from a co-occurring species than the Caliente
Canyon DPS. However, based on our current understanding of the
transmission and the ability of fully terrestrial slender salamander
species to recover from the effects of chytrid, we do not believe that
this risk rises to the level of threatening the continued existence of
either DPS.
As discussed in Factor C for the species as a whole, potential
indirect effects from residential or commercial development within or
near Tehachapi slender salamander habitat could include an increase in
human and predator presence. This could potentially be the case for the
Tehachapi Mountains DPS of the Tehachapi slender salamander, as
indirect, long-term potential effects from the TMV project would
include an increase in human and predator presence at Tejon Ranch. An
increased presence of humans, domestic animals, and predators will be
primarily concentrated within the TMV development envelope, although it
is possible for predators to disperse to areas of occupied Tehachapi
slender salamander habitat. We do not have any evidence to indicate
that these indirect effects will rise to a level that would threaten
the existence of the Tehachapi slender salamander.
We do not have any evidence that predation threatens the
persistence of either the Caliente Canyon or Tehachapi Mountains DPS.
Pigs and turkeys are present within the Tehachapi Mountains DPS and are
known to prey on amphibians; however, currently available information
does not indicate that they are affecting Tehachapi slender
salamanders. Therefore, we conclude that the Caliente Canyon and
Tehachapi Mountains DPSs of the Tehachapi slender salamander are not
threatened or endangered throughout all of their range within the
future by disease or predation.
Factor D: Inadequacy of Existing Regulatory Mechanisms
To the extent that we identify possibly significant threats in the
other Factors, we consider under this factor whether those threats are
adequately addressed by existing regulatory mechanisms. Thus, if a
threat is minor, listing may not be warranted even if existing
regulatory mechanisms provide little or no protection to counter the
threat. Please refer to the Factor D discussion in the species section
for a description of the relevant regulatory mechanisms that may
provide some protections for one or both DPSs.
Federal Protections
NEPA is required for projects within the Caliente Canyon and
Tehachapi Mountains DPSs if there is a Federal nexus (i.e., projects
that require a Federal permit, receive Federal funding, or are
implemented by a Federal agency). Although NEPA requires analysis and
disclosure of impacts to the human environment, including biological
resources such as the Tehachapi slender salamander, it stops short of
requiring that protection measures be implemented.
EPA policies to implement the Clean Air Act in addressing climate
change caused by greenhouse gas emissions are still evolving. Our
status review did not reveal substantial information that indicates
that climate change poses a significant threat to the Tehachapi slender
salamander throughout its range including both the Caliente Canyon and
Tehachapi Mountains DPSs (see Factor E).
BLM's organic act and designation of the Tehachapi slender
salamander as a sensitive species provide some protection for the
species where it occurs on BLM land. Although we find that BLM's
policies protect Tehachapi slender salamander habitat, the benefits to
the species are limited because only a small portion of the Tehachapi
slender salamander's range within the Caliente Canyon DPS occurs on BLM
land (approximately 16.7 percent), and there is no BLM land within the
range of the Tehachapi Mountains DPS.
State Protections
CESA provides protection to the species on privately owned and
State-owned land (i.e., 21 of the 24 occupied occurrences or 87.5
percent), but not necessarily on the small portion (12.5 percent) of
occupied habitat on Federal lands within the Caliente Canyon
population.
CEQA applies to both the Caliente Canyon and Tehachapi Mountains
DPSs; however, as of the date of this finding, there are no projects
proposed or planned within the range of the Caliente Canyon DPS that
would require CEQA. The EIR associated with Tejon Ranch's proposed TMV
project addresses occurrences of the Tehachapi slender salamander
within the Tehachapi Mountains DPS. The Final EIR serves to confirm a
project design that avoids all known occurrences and occupied habitat
of the Tehachapi slender salamander on Tejon Ranch.
There are no other development projects proposed within the
Tehachapi Mountains DPS; therefore, threats of habitat removal and
degradation from commercial and residential development (see Factor A)
do not rise to a level that would threaten the DPS at this time or
within the future.
Summary of Factor D
As discussed in Factors A, B, C, and E, we did not find a specific
factor that threatens the continued survival of the Tehachapi slender
salamander within the Caliente Canyon or the Tehachapi Mountains DPSs.
Therefore, we find that neither DPS is threatened by the inadequacy of
existing regulatory mechanisms throughout its range now, or within the
future.
[[Page 62923]]
Factor E: Other Natural or Manmade Factors Affecting the Continued
Existence of the Species
As discussed in the analysis of threats under Factor E for the
Tehachapi slender salamander across its entire range, the petitioner
stated the Tehachapi slender salamander is threatened by climate change
caused by anthropogenic emissions of greenhouse gases, and by
stochastic events due to its small, narrowly distributed populations
(Nichols 2006, p. 8).
Climate Change
The possible effects to the populations within the Caliente Canyon
and Tehachapi Mountains areas, as discussed in Factor E for the
species, are identical for each DPS. Please refer to the Factor E
discussion for the species for further details. Based on a review of
available information, we believe that some loss of habitat in the more
open, exposed parts of occupied canyons will occur as a result of
climate change. However, we also believe that habitat will remain in
the lower, most-shaded portions of canyons to support the salamander
and in some cases the salamander may be able to shift within the canyon
in response to climate change. Therefore, we find that neither the
Caliente Canyon nor Tehachapi Mountains DPS of the Tehachapi slender
salamander is threatened by climate change throughout its range, now or
within the future.
Stochastic Events
Under this factor we explore whether three risks, represented by
demographic, genetic, and environmental stochastic events, are
substantive to threaten the continued existence of the Tehachapi
slender salamander within the Caliente Canyon and the Tehachapi
Mountains DPSs. Because of the rarity and limited dispersal ability of
the species, genetic stochasticity is a concern. However, we do not
have any evidence of genetic bottlenecks or inbreeding depression to
indicate that genetic stochasticity is a significant threat. Nor do we
have any information to indicate that demographic stochasticity or a
disease outbreak is likely to be a significant threat in the
foreseeable future. Environmental stochasticity (particularly wildfire)
is a concern; however, we do not believe that this rises to a level
that threatens the persistence of the species over the long-term.
A species may also be affected by more than one threat in
combination. Within the preceding review of the five listing factors,
we have identified several threats that could have interrelated impacts
on the Tehachapi slender salamander. For example, potential suitable
habitat may be lost or altered as a result of a combination of
development (Factor A) and effects of climate change (Factor E).
Likewise, predation (Factor C) in combination with a stochastic event
(Factor E), such as a forest fire could result in a major loss of
individuals in one or more populations. However, as we discuss above,
regardless of its source, we do not believe that the threats discussed
above, either individually or in combination, are of sufficient
imminence, intensity or magnitude to affect the status of either the
Caliente Canyon or Tehachapi Mountains DPS of the Tehachapi slender
salamander.
Therefore, we conclude that neither the Caliente Canyon nor the
Tehachapi Mountains DPS is threatened or endangered throughout its
range within the future by other natural or manmade factors.
Finding for Distinct Population Segments
As previously mentioned for the finding for the species as a whole,
we have carefully assessed the best scientific and commercial
information available regarding threats faced by the Caliente Canyon
DPS and the Tehachapi Mountains DPS of the Tehachapi slender
salamander. We have reviewed the petition, scientific literature,
information available in our files, and all information submitted to us
following our 90-day petition finding (74 FR 18336; April 22, 2009). We
also consulted with recognized Tehachapi slender salamander experts,
Federal land managers, and local government, and arranged for a
recognized Tehachapi slender salamander expert to assess potential
threats to the habitat and range of the species relative to current and
planned land uses and species occurrences.
Potential threats include development, road construction, mining,
domestic livestock grazing, introduced species, and flood control
projects. Based on the best available information, we find that there
is little evidence to support a finding that listing either DPS is
warranted based on these identified threats.
While the available information suggests that the number of
individuals in each DPS appears to be few and that they are narrowly
distributed, we do not have any trend data to indicate that the number
of individuals within each DPS is in decline, stable, or increasing.
The range of the Caliente Canyon DPS is primarily on land used for
grazing and showed generally low signs of degradation from livestock
trampling and erosion, with only 3 of 18 occurrences exhibiting
moderate degradation in some portions of their habitat. There are no
proposed projects associated with residential or commercial development
or mining anywhere near known occurrences within Caliente Canyon.
The primary land use within the range of the Tehachapi Mountains
DPS is also livestock grazing, but we do not have any information that
indicates that grazing has resulted in significant habitat degradation.
Tejon Ranch is planning a large-scale residential and commercial
development project, TMV. The TMV development envelope avoids all known
occurrences and adjacent contiguous habitat, and occurs at a sufficient
distance from the species' dispersal range. Because the DPS' confirmed
occurrences are discretely distributed and isolated, the proposed
development is not expected to affect movement patterns or breeding.
The approved EIR estimates that 108 ac (44 ha) of potentially suitable
habitat within the TMV development envelope would be lost due to
construction. The loss of 108 ac (44 ha) is likely an overestimation of
the amount of suitable habitat that exists, due to the constraints of
modeling projections, but even using this 108 ac (44 ha) value as a
worst-case assumption, only 2.8 percent of the potentially suitable
habitat on the Tejon Ranch would be lost to development.
Indirect effects from development--including increased human
presence, runoff and erosion, and predators--are not expected to pose a
significant threat to the Tehachapi Mountains DPS. Depending on the
nature of the potential impact, the source of the impact is either far
enough removed from any known occurrence or occupied habitat so as not
to constitute a threat, or there is some other factor, such as the
species' nocturnal and subfossorial behavior, that greatly reduces the
potential threat. Therefore, impacts from development are not expected
to threaten the Tehachapi Mountains DPS. We do not have any indication
that flood control projects occur or are planned to occur within either
the Caliente Canyon or Tehachapi Mountains DPSs.
The impact of climate change is a concern for the species, and
while there is uncertainty, we believe that some loss of occupied
habitat will occur because of climate change in the more exposed
portions of the canyons salamander. However, we also believe that
habitat will remain in the lower, most-shaded portions of canyons to
support the salamander, and in some cases the
[[Page 62924]]
salamander may be able to shift within the canyon in response to
climate change. Because of the rarity and limited dispersal ability of
the species, genetic stochasticity is also a concern. However, we do
not have any evidence of genetic bottlenecks or inbreeding depression
to indicate that genetic stochasticity is a significant threat.
There are regulatory mechanisms in place, such as CESA, CEQA, and
BLM's special status designation for the species, that provide adequate
protections for both DPSs of the species given the types and minor
degree of potential threats faced by the species. Therefore, we find
that listing the Caliente Canyon DPS or the Tehachapi Mountains DPS as
threatened or endangered under the Act is not warranted at this time.
And finally, we determined that both of the DPSs are not affected
cumulatively by all of the five factors. Therefore, based on our
conclusions for each of the five factors singly and cumulatively, we
find that there are no threats of sufficient imminence, intensity, or
magnitude to cause a substantial decrease in distribution, or loss of
viability of either DPS throughout their range. Therefore, we do not
find that either DPS is in danger of extinction (endangered), or likely
to become endangered or threatened throughout their range within the
foreseeable future. Consequently, listing the Caliente Canyon DPS or
the Tehachapi Mountains DPS as threatened or endangered under the Act
is not warranted at this time.
Significant Portion of the Range Analysis
The Act defines ``endangered species'' as any species which is ``in
danger of extinction throughout all or a significant portion of its
range,'' and ``threatened species'' as any species which is ``likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range.'' The definition of
``species'' is also relevant to this discussion. The Act defines the
term ``species'' as follows: ``The term `species' includes any
subspecies of fish or wildlife or plants, and any distinct population
segment [DPS] of any species of vertebrate fish or wildlife which
interbreeds when mature.'' The phrase ``significant portion of its
range'' (SPR) is not defined by the statute, and we have never
addressed in our regulations: (1) The consequences of a determination
that a species is either endangered or likely to become so throughout a
significant portion of its range, but not throughout all of its range;
or (2) what qualifies a portion of a range as ``significant.''
Two recent district court decisions have addressed whether the SPR
language allows the Service to list or protect less than all members of
a defined ``species'': Defenders of Wildlife v. Salazar, 729 F. Supp.
2d 1207 (D. Mont. 2010), concerning the Service's delisting of the
Northern Rocky Mountain gray wolf (74 FR 15123, Apr. 12, 2009); and
WildEarth Guardians v. Salazar, 2010 U.S. Dist. LEXIS 105253 (D. Ariz.
Sept. 30, 2010), concerning the Service's 2008 finding on a petition to
list the Gunnison's prairie dog (73 FR 6660, Feb. 5, 2008). The Service
had asserted in both of these determinations that it had authority, in
effect, to protect only some members of a ``species,'' as defined by
the Act (i.e., species, subspecies, or DPS), under the Act. Both courts
ruled that the determinations were arbitrary and capricious on the
grounds that this approach violated the plain and unambiguous language
of the Act. The courts concluded that reading the SPR language to allow
protecting only a portion of a species' range is inconsistent with the
Act's definition of ``species.'' The courts concluded that once a
determination is made that a species (i.e., species, subspecies, or
DPS) meets the definition of ``endangered species'' or ``threatened
species,'' it must be placed on the list in its entirety and the Act's
protections applied consistently to all members of that species
(subject to modification of protections through special rules under
sections 4(d) and 10(j) of the Act).
Consistent with that interpretation, and for the purposes of this
finding, we interpret the phrase ``significant portion of its range''
in the Act's definitions of ``endangered species'' and ``threatened
species'' to provide an independent basis for listing; thus there are
two situations (or factual bases) under which a species would qualify
for listing: a species may be endangered or threatened throughout all
of its range; or a species may be endangered or threatened in only a
significant portion of its range. If a species is in danger of
extinction throughout an SPR, it, the species, is an ``endangered
species.'' The same analysis applies to ``threatened species.''
Therefore, the consequence of finding that a species is endangered or
threatened in only a significant portion of its range is that the
entire species shall be listed as endangered or threatened,
respectively, and the Act's protections shall be applied across the
species' entire range.
We conclude, for the purposes of this finding, that interpreting
the SPR phrase as providing an independent basis for listing is the
best interpretation of the Act because it is consistent with the
purposes and the plain meaning of the key definitions of the Act; it
does not conflict with established past agency practice (i.e., prior to
the 2007 Solicitor's Opinion), as no consistent, long-term agency
practice has been established; and it is consistent with the judicial
opinions that have most closely examined this issue. Having concluded
that the phrase ``significant portion of its range'' provides an
independent basis for listing and protecting the entire species, we
next turn to the meaning of ``significant'' to determine the threshold
for when such an independent basis for listing exists.
Although there are potentially many ways to determine whether a
portion of a species' range is ``significant,'' we conclude, for the
purposes of this finding, that the significance of the portion of the
range should be determined based on its biological contribution to the
conservation of the species. For this reason, we describe the threshold
for ``significant'' in terms of an increase in the risk of extinction
for the species. We conclude that a biologically based definition of
``significant'' best conforms to the purposes of the Act, is consistent
with judicial interpretations, and best ensures species' conservation.
Thus, for the purposes of this finding, a portion of the range of a
species is ``significant'' if its contribution to the viability of the
species is so important that, without that portion, the species would
be in danger of extinction.
We evaluate biological significance based on the principles of
conservation biology using the concepts of redundancy, resiliency, and
representation. Resiliency describes the characteristics of a species
that allow it to recover from periodic disturbance. Redundancy (having
multiple populations distributed across the landscape) may be needed to
provide a margin of safety for the species to withstand catastrophic
events. Representation (the range of variation found in a species)
ensures that the species' adaptive capabilities are conserved.
Redundancy, resiliency, and representation are not independent of each
other, and some characteristic of a species or area may contribute to
all three. For example, distribution across a wide variety of habitats
is an indicator of representation, but it may also indicate a broad
geographic distribution contributing to redundancy (decreasing the
chance that any one event affects the entire species), and the
likelihood that some habitat types are less susceptible to certain
threats, contributing to
[[Page 62925]]
resiliency (the ability of the species to recover from disturbance).
None of these concepts is intended to be mutually exclusive, and a
portion of a species' range may be determined to be ``significant'' due
to its contributions under any one of these concepts.
For the purposes of this finding, we determine if a portion's
biological contribution is so important that the portion qualifies as
``significant'' by asking whether, without that portion, the
representation, redundancy, or resiliency of the species would be so
impaired that the species would have an increased vulnerability to
threats to the point that the overall species would be in danger of
extinction (i.e., would be ``endangered''). Conversely, we would not
consider the portion of the range at issue to be ``significant'' if
there is sufficient resiliency, redundancy, and representation
elsewhere in the species' range that the species would not be in danger
of extinction throughout its range if the population in that portion of
the range in question became extirpated (extinct locally).
We recognize that this definition of ``significant'' establishes a
threshold that is relatively high. On the one hand, given that the
consequences of finding a species to be endangered or threatened in an
SPR would be listing the species throughout its entire range, it is
important to use a threshold for ``significant'' that is robust. It
would not be meaningful or appropriate to establish a very low
threshold whereby a portion of the range can be considered
``significant'' even if only a negligible increase in extinction risk
would result from its loss. Because nearly any portion of a species'
range can be said to contribute some increment to a species' viability,
use of such a low threshold would require us to impose restrictions and
expend conservation resources disproportionately to conservation
benefit: Listing would be rangewide, even if only a portion of the
range of minor conservation importance to the species is imperiled. On
the other hand, it would be inappropriate to establish a threshold for
``significant'' that is too high. This would be the case if the
standard were, for example, that a portion of the range can be
considered ``significant'' only if threats in that portion result in
the entire species' being currently endangered or threatened. Such a
high bar would not give the SPR phrase independent meaning, as the
Ninth Circuit held in Defenders of Wildlife v. Norton, 258 F.3d 1136
(9th Cir. 2001).
The definition of ``significant'' used in this finding carefully
balances these concerns. By setting a relatively high threshold, we
minimize the degree to which restrictions will be imposed or resources
expended that do not contribute substantially to species conservation.
But we have not set the threshold so high that the phrase ``in a
significant portion of its range'' loses independent meaning.
Specifically, we have not set the threshold as high as it was under the
interpretation presented by the Service in the Defenders litigation.
Under that interpretation, the portion of the range would have to be so
important that current imperilment there would mean that the species
would be currently imperiled everywhere. Under the definition of
``significant'' used in this finding, the portion of the range need not
rise to such an exceptionally high level of biological significance.
(We recognize that if the species is imperiled in a portion that rises
to that level of biological significance, then we should conclude that
the species is in fact imperiled throughout all of its range, and that
we would not need to rely on the SPR language for such a listing.)
Rather, under this interpretation we ask whether the species would be
endangered everywhere without that portion, i.e., if that portion were
completely extirpated. In other words, the portion of the range need
not be so important that even being in danger of extinction in that
portion would be sufficient to cause the remainder of the range to be
endangered; rather, the complete extirpation (in a hypothetical future)
of the species in that portion would be required to cause the remainder
of the range to be endangered.
The range of a species can theoretically be divided into portions
in an infinite number of ways. However, there is no purpose to
analyzing portions of the range that have no reasonable potential to be
significant and threatened or endangered. 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. Depending
on the biology of the species, its range, and the threats it faces, it
might be more efficient for us to address the significance question
first or the status question first. Thus, if we determine that a
portion of the range is not ``significant,'' we do not need to
determine whether the species is endangered or threatened there; if we
determine that the species is not endangered or threatened in a portion
of its range, we do not need to determine if that portion is
``significant.'' In practice, a key part of the portion status 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 clearly would not meet the biologically based
definition of ``significant,'' such portions will not warrant further
consideration.
Tehachapi Slender Salamander
The Caliente Canyon and the Tehachapi Mountains DPSs together
constitute the entirety of the range of the Tehachapi slender
salamander. The distinct and geographically separate areas occupied,
respectively, by the Caliente Canyon DPS and the Tehachapi Mountains
DPS, constitute the two significant portions of the range of the
Tehachapi slender salamander. Significant threats to either DPS would
constitute a significant threat to the Tehachapi slender salamander in
a significant portion of its range. We have previously determined,
however, that neither DPS is threatened or endangered across its range.
Therefore, we conclude that the Tehachapi slender salamander is not in
danger of extinction or likely to become endangered in the foreseeable
future, in a significant portion of its range.
We acknowledge that the Ninth Circuit Court of Appeals decision in
Defenders of Wildlife v. Norton, 258 F.3d 1136 (2001) can be
interpreted to require that in determining whether a species is
threatened or endangered throughout a significant portion of its range,
the Service should consider whether lost historical range (as opposed
to current range) constitutes a significant portion of the range of the
species at issue. While this is not our interpretation of the statute,
we conclude that there are no such areas for the Tehachapi slender
salamander, the Caliente Canyon DPS, or the Tehachapi Mountains DPS. As
we discussed in detail in our assessment of threats to each species,
there is no evidence of meaningful range contraction for the species;
in fact, the range of the Caliente Canyon DPS and therefore, the
species is now known to be larger than previously believed. Therefore,
we do not believe the species is threatened or endangered in a
significant portion of its range due to lost historical habitat.
We next evaluate whether there are any significant portions of the
ranges of either the Caliente Canyon DPS or the
[[Page 62926]]
Tehachapi Mountains DPS where the species is in danger of extinction or
is likely to become endangered in the foreseeable future.
Caliente Canyon DPS
The Caliente Canyon DPS consists of sections of five canyons,
totaling about 9 linear mi (14.5 km). To determine whether the Caliente
Canyon DPS is threatened in a significant portion of its range, we
first addressed whether any portions of the range of the DPS warrant
further consideration. Our analysis indicates that the conservation
status of the Caliente Canyon DPS is essentially the same throughout
its range; there is no area within the range of the DPS where potential
threats to this species are significantly concentrated or are
substantially greater than in other portions of the range. And, as we
explained in detail in our analysis of the status of the species, none
of the threats faced by the species, alone or in combination, are
sufficient to place it in danger of extinction now (endangered) or in
the foreseeable future (threatened). The main potential threat to the
Caliente Canyon DPS is livestock grazing, which occurs throughout most
of the range of this DPS; however, the impacts of grazing to the
species are minor and are not concentrated in any geographic portion of
the range of the DPS. For these reasons, we find that there are no
portions of the Caliente Canyon DPS's range that warrant further
consideration as significant portions of the range.
Tehachapi Mountains DPS
To determine whether the Tehachapi Mountains DPS is threatened in a
significant portion of its range, we also first addressed whether any
portions of the range of the DPS warrant further consideration. Our
analysis indicates that the conservation status of the Tehachapi
Mountains DPS is essentially the same throughout its range; there is no
area within the range of the DPS where potential threats to this
species are significantly concentrated or are substantially greater
than in other portions of the range. And, as we explained in detail in
our analysis of the status of the species, none of the threats faced by
the species, alone or in combination, are sufficient to place it in
danger of extinction now (endangered) or in the foreseeable future
(threatened).
A large development project (Tejon Ranch TMV project) is planned
within the general vicinity of half of the occurrences of the Tehachapi
Mountains DPS. However, the TMV development envelope is configured to
avoid all known occurrences and occupied habitat of the species within
this DPS. The TMV project, if implemented, will likely affect 108 ac
(44 ha) out of the estimated 3,797 ac (1,537 ha) (or less than three
percent) of habitat that may be suitable for the Tehachapi Mountains
DPS on Tejon Ranch. We do not have evidence that the 108 ac (44 ha) of
potentially suitable habitat likely to be affected by the TMV project
is significant to the survival and recovery of the DPS. The five
occupied canyons that make up the Tehachapi Mountains DPS are widely
distributed across the DPS's range. We found no evidence that
individuals of this DPS are concentrated in any geographic portion of
the range that would increase the vulnerability of this DPS to a
particular threat. For these reasons, we find that there are no
portions of the Tehachapi Mountains DPS's range that warrant further
consideration as significant portions of the range.
We do not find that the Caliente Canyon DPS or the Tehachapi
Mountains DPS is in danger of extinction now, nor do we find that
either DPS is likely to become endangered within the foreseeable future
throughout all or a significant portion of its range. Therefore,
listing the Caliente Canyon DPS or the Tehachapi Mountains DPS as
threatened or endangered under the Act is not warranted at this time.
We request that you submit any new information concerning the
status of, or threats to, these species to our Ventura Fish and
Wildlife 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 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 Ventura Fish and
Wildlife Office (see ADDRESSES section).
Author
The primary authors of this notice are the staff of the Ventura
Fish and Wildlife Office (see ADDRESSES).
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.).
Dated: September 23, 2011.
Rowan Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2011-25522 Filed 10-7-11; 8:45 am]
BILLING CODE 4310-55-P