Endangered and Threatened Wildlife and Plants; Endangered Species Status for the Sierra Nevada Distinct Population Segment of the Sierra Nevada Red Fox, 41743-41758 [2021-16249]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 86, Number 146 (Tuesday, August 3, 2021)]
[Rules and Regulations]
[Pages 41743-41758]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-16249]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R8-ES-2019-0006; FF09E21000 FXES11110900000 212]
RIN 1018-BC62


Endangered and Threatened Wildlife and Plants; Endangered Species 
Status for the Sierra Nevada Distinct Population Segment of the Sierra 
Nevada Red Fox

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), determine 
endangered species status under the Endangered Species Act of 1973 
(Act), as amended, for the Sierra Nevada Distinct Population Segment 
(DPS) of the Sierra Nevada red fox (Vulpes vulpes necator) (hereafter 
referred to in

[[Page 41744]]

this rule as the Sierra Nevada DPS). The Sierra Nevada red fox is a 
small mammal occurring in California and Oregon, with the Sierra Nevada 
DPS of this broader taxon inhabiting the highest elevations of the 
Sierra Nevada mountain range in California. This rule adds the Sierra 
Nevada DPS of Sierra Nevada red fox to the List of Endangered and 
Threatened Wildlife.

DATES: This rule is effective September 2, 2021.

ADDRESSES: This final rule is available on the internet at https://www.regulations.gov under Docket No. FWS-R8-ES-2019-0006. Comments and 
materials we received, as well as supporting documentation we used in 
preparing this rule, are available for public inspection at https://www.regulations.gov under Docket No. FWS-R8-ES-2019-0006.

FOR FURTHER INFORMATION CONTACT: Michael Fris, Field Supervisor, U.S. 
Fish and Wildlife Service, Sacramento Fish and Wildlife Office, 2800 
Cottage Way, Room W-2605, Sacramento, California 95825; telephone 916-
414-6700. Persons who use a telecommunications device for the deaf 
(TDD) may call the Federal Relay Service at 800-877-8339.

SUPPLEMENTARY INFORMATION:

Executive Summary

    Why we need to publish a rule. Under the Endangered Species Act, a 
species may warrant protection through listing if it is endangered or 
threatened throughout all or a significant portion of its range. 
Listing a species as an endangered or threatened species can only be 
completed by issuing a rule.
    What this document does. This rule will finalize listing the Sierra 
Nevada DPS of the Sierra Nevada red fox (Vulpes necator) (Sierra Nevada 
DPS) as an endangered species under the Endangered Species Act. This 
rule adds the Sierra Nevada DPS to the List of Endangered and 
Threatened Wildlife in title 50 of the Code of Federal Regulations at 
50 CFR 17.11(h).
    The basis for our action. Under the Act, we may determine that a 
species is an endangered or threatened species because of any of 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. We have determined that the Sierra Nevada DPS 
faces the following threats: (1) Deleterious impacts associated with 
small population size, such as inbreeding depression and reduced 
genomic integrity (Factor E); (2) hybridization with nonnative red fox 
(Factor E); and possibly (3) reduced prey availability and competition 
with coyotes resulting from reduced snowpack levels (Factor E). 
Existing regulatory mechanisms and conservation efforts do not address 
the threats to the Sierra Nevada DPS to the extent that listing the DPS 
is not warranted (Factor D).
    Section 4(a)(3) of the Act requires the Secretary of the Interior 
(Secretary) to designate critical habitat concurrent with listing to 
the maximum extent prudent and determinable. In this case, we have 
found that the designation of critical habitat for the Sierra Nevada 
DPS is not prudent.
    Peer review and public comment. During the proposed rule stage, we 
sought the expert opinions of five appropriate specialists regarding 
the species status assessment (SSA) report. We received responses from 
two specialists, which informed our determination. We also considered 
all comments and information received from the public during the 
comment period.

Previous Federal Actions

    On January 8, 2020, we published a proposed rule in the Federal 
Register (85 FR 862) to list the Sierra Nevada DPS as an endangered 
species under the Act (16 U.S.C. 1531 et seq.). Please refer to that 
proposed rule for a detailed description of previous Federal actions 
concerning this DPS, which we refer to as a ``species'' or 
``subspecies'' in this rule, in accordance with the Act's definition of 
``species'' at 16 U.S.C. 1532(16).

Summary of Changes From the Proposed Rule

    In preparing this final rule, we reviewed and fully considered 
comments from the public on the proposed rule. We did not make any 
substantive changes to this final rule after consideration of the 
comments we received. We did update some biological and threats 
information based on comments and some additional information provided, 
as follows: (1) We made several nonsubstantive clarifications and 
corrections (including addition of information related to potential 
snowmobiling impacts) in the Species Information and Summary of 
Biological Status and Threats sections of this rule in order to ensure 
better consistency, clarify some information, and update or add new 
references; (2) we included additional information we received 
regarding observations of Sierra Nevada DPS detections and population 
size across its range; and (3) we added a summary discussion of the 
threat of habituation to humans and human-based food sources in this 
rule, which was based on additional information provided by a 
commenter. However, the information we received during the comment 
period for the proposed rule did not change our previous analysis of 
the magnitude or severity of threats facing the DPS.

Supporting Documents

    A species status assessment (SSA) team prepared an SSA report for 
the Sierra Nevada DPS (Service 2018, entire). The SSA team was composed 
of Service biologists, in consultation with other species experts. The 
SSA report represents a compilation of the best scientific and 
commercial data available concerning the status of the DPS, including 
the impacts of past, present, and future factors (both negative and 
beneficial) affecting the species.
    In accordance with our joint policy on peer review published in the 
Federal Register on July 1, 1994 (59 FR 34270), and our August 22, 
2016, memorandum updating and clarifying the role of peer review of 
listing actions under the Act, we sought peer review of the SSA report. 
The Service sent the SSA report to five independent peer reviewers and 
received two responses. The purpose of peer review is to ensure that 
our listing determinations are based on scientifically sound data, 
assumptions, and analyses. The peer reviewers have expertise in the 
biology, habitat, and threats to the species. The Service also sent the 
SSA report to five agency partners and three Tribes, including 
scientists with expertise in the Sierra Nevada DPS, conservation 
biology, and forest management, for review. We received reviews from 
five partners: The fish and wildlife agencies of California and Nevada, 
the National Park Service, the U.S. Forest Service (USFS), and the U.S. 
Marine Corps.

Final Listing Determination

Background

    A thorough review of the taxonomy, life history, ecology, and 
overall viability of the Sierra Nevada DPS is presented in the SSA 
report (Service 2018; available at https://www.regulations.gov). This 
report summarizes the relevant biological data and a description of 
past, present, and likely future stressors, and presents an analysis of 
the viability of the Sierra Nevada DPS. The SSA report documents

[[Page 41745]]

the results of the comprehensive biological status review, provides an 
evaluation of how potential threats may affect the species' viability 
both currently and into the future, and provides the scientific basis 
that informed our regulatory decision regarding whether this DPS should 
be listed as an endangered or threatened species under the Act, as well 
as the risk analysis on which the determination was based (Service 
2018, entire). The following discussion is a summary of the SSA report.

Species Information

    Red foxes (Vulpes vulpes) are small, slender, doglike carnivores, 
with elongated snouts, pointed ears, and large bushy tails (Aubry 1997, 
p. 55; Perrine 2005, p. 1; Perrine et al. 2010, p. 5). The Sierra 
Nevada red fox is one of 10 North American subspecies of the red fox 
(Hall 1981, p. 938; Perrine et al. 2010, p. 5). Diagnostic features, by 
which red foxes can be distinguished from other small canines, include 
black markings on the backs of their ears, black shins, and white tips 
on their tails (Statham et al. 2012, p. 123).
    Sierra Nevada red foxes average about 4.2 kilograms (kg) (9.3 
pounds (lb)) for males and 3.3 kg (7.3 lb) for females, as compared to 
the general North American red fox average of about 5 kg (11 lb) for 
males and 4.3 kg (9.5 lb) for females (Perrine et al. 2010, p. 5).
    The Sierra Nevada red fox is characterized by what appears to be 
specialized adaptations to cold areas (Sacks et al. 2010, p. 1524). 
These apparent adaptations include a particularly thick and deep winter 
coat (Grinnell et al. 1937, p. 377), longer hind feet (Fuhrmann 1998, 
p. 24), and small toe pads (4 millimeters (mm) (0.2 inch (in)) across 
or less) that are completely covered in winter by dense fur, which may 
facilitate movement over snow (Grinnell et al. 1937, pp. 378, 393; 
Fuhrmann 1998, p. 24; Sacks 2014, p. 30). The Sierra Nevada red fox's 
smaller size may also be an adaptation to facilitate movement over snow 
by lowering weight supported by each footpad (Quinn and Sacks 2014, p. 
17), or it may simply result from the reduced abundance of prey at 
higher elevations (Perrine et al. 2010, p. 5).
    Genetic analyses indicate that red foxes living near Sonora Pass, 
California, as of 2010 are descendants of the Sierra Nevada red fox 
population that was historically resident in the area (Statham et al. 
2012, pp. 126-129). This is the only population known to exist in the 
Sierra Nevada mountain range, and is thus the last known remnant of the 
larger historical population that occurred along the upper elevations 
of the Sierra Nevada mountain range from Tulare to Sierra Counties. The 
only other known Sierra Nevada red fox population in California is 
located near Lassen Peak, in the southern Cascade mountain range, and 
shows clear genetic differences from the Sonora Pass population 
(Statham et al. 2012, pp. 129-130) (see also DPS analysis in our 
October 8, 2015, 12-month finding (80 FR 61011)). The population near 
Lassen Peak is part of another population segment, whose range also 
includes the Cascade Mountains of Oregon. We determined that listing 
the Southern Cascades population segment was not warranted in 2015 (80 
FR 60989).
Range and Habitat
    Based on known detections, as well as what is known regarding high-
quality habitat, we consider the current range of the Sierra Nevada DPS 
to run southeast along the Sierra crest from just south of California 
State Highway 88 to a few miles north of Kings Canyon National Park 
(Figure 1). The range includes the easternmost portion of Yosemite 
National Park (hereafter referred to as ``Yosemite''), in Tuolumne and 
Madera Counties, as well as additional portions of those counties, and 
of Alpine, Mono, Fresno and Inyo Counties (Cleve et al. 2011, entire; 
Sacks et al. 2015, pp. 10, 14; Eyes 2016, p. 2; Hiatt 2017, p. 1; 
Figure 1; Quinn 2018a, attachments; Stermer 2018, p. 1).
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[GRAPHIC] [TIFF OMITTED] TR03AU21.000

BILLING CODE 4333-15-C
    Sierra Nevada DPS sightings have consistently occurred in subalpine 
habitat and high-elevation conifer areas at elevations ranging from 
2,469 to 3,538 meters (m) (8,100 to 11,608 feet (ft)) (Sacks et al. 
2015, pp. 3, 11; Dunkelberger 2020, p. 3). Four detections (out of more 
than 750 scat or hair samples that have been obtained since 2011) have 
occurred at lower elevations (from 6,805 to 7,059 ft (2,074 to 2,152 
m)), but these outliers appear to be from three individuals that were 
in the process of dispersing (Quinn 2020, p. 1). In the Sonora Pass 
area used by the Sierra Nevada DPS, subalpine habitat is characterized 
by a mosaic of high-elevation meadows, rocky areas, scrub vegetation, 
and woodlands (largely mountain hemlock (Tsuga mertensiana), whitebark 
pine (Pinus albicaulus), and lodgepole pine (Pinus contorta)) (Fites-
Kaufman et al. 2007, p. 475; Sacks et al. 2015, p. 11; Quinn 2017, p. 
3). Snow cover is typically heavy, and the growing season lasts only 7 
to 9 weeks (Verner and Purcell 1988, p. 3). Forested areas are 
typically relatively open and patchy (Verner and Purcell 1988, p. 1; 
Lowden 2015, p. 1), and trees may be stunted and bent (krumholtzed) by 
the wind and low temperatures (Verner and Purcell 1988, p. 3; Sacks et 
al. 2015, p. 11).

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Feeding
    Individuals of the Sierra Nevada DPS are opportunistic predators of 
small mammals such as rodents (Perrine et al. 2010, pp. 24, 30, 32-33; 
Cross 2015, p. 72). Leporids such as snowshoe hare (Lepus americanus) 
and white-tailed jackrabbit (Lepus townsendii) are also an important 
food source for the Sierra Nevada DPS, particularly in winter and early 
spring (Aubry 1983, p. 109; Rich 2014, p. 1; Quinn 2017, pp. 3-4; Sacks 
2017, p. 3).
Life History
    Although information regarding Sierra Nevada DPS reproductive 
biology is limited, it is likely similar in many ways to other North 
American red fox subspecies (Aubry 1997, p. 57). Other subspecies are 
predominantly monogamous, with a gestation period of 51 to 53 days 
(Perrine et al. 2010, p. 14). Based on information from both the Sierra 
Nevada and Southern Cascades populations, Sierra Nevada DPS foxes 
likely mate in mid-February to early March, with births occurring in 
April and early May (Dunkelberger 2020, p. 1; Sacks and Quinn 2020, p. 
3). This is somewhat later than lowland subspecies, possibly as an 
adaptation to the later growth of spring vegetation at higher 
elevations (Quinn and Sacks 2020, p. 3). Members of the Sierra Nevada 
DPS use natural openings in rock piles or crevices in exposed bedrock 
as denning sites (Grinnell et al. 1937, p. 394). Individual foxes from 
the Southern Cascades population in both Oregon and California have 
also recently been found to dig earthen dens (Dunkelberger 2020, p. 2; 
Sacks and Quinn 2020, p. 3), suggesting that Sierra Nevada DPS foxes do 
as well. Dens are used by foxes in the Southern Cascades population 
(and likely in the Sierra Nevada DPS) to raise the young from early 
spring through early fall, and they are often reused from year to year 
(Dunkelberger 2020, pp. 1-3). A 7-year study of the Sierra Nevada DPS 
found litter sizes of 2.3 pups on average (9 litters and 21 pups, not 
counting one purely nonnative litter) (Quinn and Sacks 2018, p. 38). 
This is within the range of two to three pups per litter that appear to 
be typical in the Southern Cascades population (Perrine 2005, p. 152). 
Reproductive output is generally lower in montane foxes than in those 
living at lower elevations, possibly due to comparative scarcity of 
food (Perrine 2005, pp. 152-153; Sacks 2017, p. 2).
Demographics
    In our proposed listing rule (85 FR 862, p. 866), we estimated the 
population size of the Sierra Nevada DPS at 10 to 50 adults. Based on 
comments received, we now revise that estimate to approximately 18 to 
39 individuals, of which 10 to 31 are north of Yosemite (Sacks and 
Quinn 2020, p. 1), about 5 are in or just east of Yosemite (Central 
Sierra Environmental Resource Center (CSERC) et al. 2020, pp. 2-3, 
California Department of Fish and Wildlife (CDFW) 2020, p. 4), and 3 
have been identified south of Yosemite in the general area of Mono 
Creek (CDFW 2020, p. 3). All detections, including new detections 
mentioned in comments to the proposed rule, have been within the 
approximate current range (Figure 1). Population density north of 
Yosemite is estimated at approximately 4 foxes per 100 sq km (square 
kilometers) (about 1 fox per 10 sq mi (square miles)) (Sacks and Quinn 
2020, p. 1).
    The average lifespan, age-specific mortality rates, sex ratios, and 
demographic structure of the Sierra Nevada DPS are not known, and are 
not easily extrapolated from other red fox subspecies because heavy 
hunting and trapping pressure on those other subspecies likely skew the 
results (Perrine et al. 2010, p. 18). However, three individual Sierra 
Nevada red fox within the Southern Cascades population (in the Lassen 
area) lived at least 5.5 years (CDFW 2015, p. 2), and a study of the 
Sierra Nevada DPS (in the Sonora Pass area) found the average annual 
adult survival rate to be about 70 percent, which is relatively high 
for red foxes (Sacks and Quinn 2020, p. 2).

Regulatory and Analytical Framework

Regulatory Framework

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations (50 CFR part 424) set forth the procedures for determining 
whether a species is an ``endangered species'' or a ``threatened 
species.'' The Act defines an endangered species as a species that is 
``in danger of extinction throughout all or a significant portion of 
its range,'' and a threatened species as a species that is ``likely to 
become an endangered species within the foreseeable future throughout 
all or a significant portion of its range.'' The Act requires that we 
determine whether any species is an ``endangered species'' or a 
``threatened species'' because of any of the following 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.
    These factors represent broad categories of natural or human-caused 
actions or conditions that could have an effect on a species' continued 
existence. In evaluating these actions and conditions, we look for 
those that may have a negative effect on individuals of the species, as 
well as other actions or conditions that may ameliorate any negative 
effects or may have positive effects.
    We use the term ``threat'' to refer in general to actions or 
conditions that are known to or are reasonably likely to negatively 
affect individuals of a species. The term ``threat'' includes actions 
or conditions that have a direct impact on individuals (direct 
impacts), as well as those that affect individuals through alteration 
of their habitat or required resources (stressors). The term ``threat'' 
may encompass--either together or separately--the source of the action 
or condition or the action or condition itself.
    However, the mere identification of any threat(s) does not 
necessarily mean that the species meets the statutory definition of an 
``endangered species'' or a ``threatened species.'' In determining 
whether a species meets either definition, we must evaluate all 
identified threats by considering the expected response by the species, 
and the effects of the threats--in light of those actions and 
conditions that will ameliorate the threats--on an individual, 
population, and species level. We evaluate each threat and its expected 
effects on the species, then analyze the cumulative effect of all of 
the threats on the species as a whole. We also consider the cumulative 
effect of the threats in light of those actions and conditions that 
will have positive effects on the species, such as any existing 
regulatory mechanisms or conservation efforts. The Secretary determines 
whether the species meets the definition of an ``endangered species'' 
or a ``threatened species'' only after conducting this cumulative 
analysis and describing the expected effect on the species now and in 
the foreseeable future.

Analytical Framework

    The SSA report documents the results of our comprehensive 
biological status review for the DPS, including an assessment of the 
potential threats to the species. The SSA report does not represent a 
decision by the Service on whether the species should be listed as an 
endangered or threatened species

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under the Act. It does, however, provide the scientific basis that 
informs our regulatory decisions, which involve the further application 
of standards within the Act and its implementing regulations and 
policies. The following is a summary of the key results and conclusions 
from the SSA report; the full SSA report can be found at Docket No. 
FWS-R8-ES-2019-0006 on https://www.regulations.gov and on the Sacramento 
Fish and Wildlife Office's website at https://www.fws.gov/sacramento/.
    To assess the Sierra Nevada DPS's viability, we used the three 
conservation biology principles of resiliency, redundancy, and 
representation (Shaffer and Stein 2000, pp. 306-310). Briefly, 
resiliency supports the ability of the species to withstand 
environmental and demographic stochasticity (for example, wet or dry, 
warm or cold years), redundancy supports the ability of the species to 
withstand catastrophic events (for example, droughts, large pollution 
events), and representation supports the ability of the species to 
adapt over time to long-term changes in the environment (for example, 
climate changes). In general, the more resilient and redundant a 
species is and the more representation it has, the more likely it is to 
sustain populations over time, even under changing environmental 
conditions. Using these principles, we identified the species' 
ecological requirements for survival and reproduction at the 
individual, population, and species levels, and described the 
beneficial and risk factors influencing the species' viability.
    The SSA process can be categorized into three sequential stages. 
During the first stage, we evaluated the individual species' life-
history needs. The next stage involved an assessment of the historical 
and current condition of the species' demographics and habitat 
characteristics, including an explanation of how the species arrived at 
its current condition. The final stage of the SSA involved making 
predictions about the species' responses to positive and negative 
environmental and anthropogenic influences. This process used the best 
available information to characterize viability as the ability of a 
species to sustain populations in the wild over time. We use this 
information to inform our regulatory decision.

Summary of Biological Status and Threats

    The summary below of our analyses represents an evaluation of the 
biological status of the DPS, based upon our assessment of the effects 
anticipated from each of the identified threats. We also consider the 
cumulative impact of all effects anticipated from the identified 
threats, and how that cumulative impact may affect the Sierra Nevada 
DPS's continued existence currently and in the future. We used the best 
available scientific and commercial information, and the expert 
opinions of the analysis team members. The threats identified as having 
the greatest potential to act upon the DPS include: (1) Deleterious 
impacts associated with small population size, such as inbreeding 
depression and increased effects of deleterious stochastic events 
(Factor E); (2) over-hybridization with nonnative red fox (Factor E); 
and possibly (3) competition with coyotes (Factor E) resulting from 
reduced snowpack levels. We also evaluated the existing regulatory 
mechanisms (Factor D) and implementation of conservation efforts.
    The environmental characteristics that are most important for 
Sierra Nevada DPS population resiliency include cold subalpine habitat 
with low primary productivity, high snowpack, and rodent and leporid 
prey (Service 2018, pp. 14-20). Additional demographic characteristics 
contributing to the species' redundancy and representation include (1) 
Either a single large or multiple populations, which would help insure 
that large portions of the DPS remain even after a catastrophic loss 
over a large area; (2) a population(s) situated to include habitat 
variations occurring from northern to southern portions of the range 
(rather than clustering in one general area); and (3) representative 
genetic diversity to avoid genetic swamping and loss of the species' 
adaptive native genes, which could result from continuing and overbroad 
levels of interbreeding with nonnative red fox subspecies.
    The best available scientific and commercial information at this 
time indicates that the Sierra Nevada DPS population size needs to be 
larger to help ensure its viability into the future. The minimum 
population size necessary for the Sierra Nevada DPS to maintain 
viability is unknown, but that number has been estimated at about 150 
individuals for the Santa Catalina Island fox (Urocyon littoralis 
catalinae) (Kohlmann et al. 2005, p. 77), which has a small range 
compared to suitable habitat available for the Sierra Nevada DPS. 
Lacking better data, we use this number as an example of what the 
minimum viable population size for the Sierra Nevada DPS could be. The 
current estimated population size of 18 to 39 individuals is well below 
that number, meaning that the population is likely vulnerable to 
stochastic disturbance (in addition to other threats discussed below).
    When considering redundancy, there is currently only one small, 
isolated population of Sierra Nevada DPS known within the Sierra Nevada 
mountain range. In general, given the low number of foxes currently 
known within this DPS and the limited range they inhabit, the DPS 
appears to have a low ability to withstand catastrophic events should 
they occur. Additionally, there do not appear to be any other 
populations within the range of this DPS to serve as a source to 
recover from a catastrophic loss of individuals.
    When considering the breadth of genetic and environmental diversity 
within and among populations (representation), the Sierra Nevada DPS 
historically occurred throughout the high elevations of the Sierra 
Nevada. The current, small population has been experiencing genetic 
challenges, including inbreeding depression, as well as hybridization 
with non-Sierra Nevada red fox individuals, which can potentially lower 
survivorship or reproductive success by interfering with adaptive 
native genes or gene complexes (Allendorf et al. 2001, p. 617; Frankham 
et al. 2002, pp. 386-388). Having broad genetic and environmental 
diversity would help the DPS withstand environmental changes. However, 
at this time, the Sierra Nevada DPS does not have this broad diversity.

Summary of Existing Regulatory Measures and Voluntary Conservation 
Efforts

    Since 1998, the USFS have identified the Sierra Nevada DPS as a 
sensitive species where it occurs on National Forest lands. The current 
range of the DPS includes portions of the Stanislaus, El Dorado, 
Humboldt-Toiyabe, Inyo, and Sierra National Forests. Sensitive species 
receive special consideration during land use planning and activity 
implementation to ensure species viability and to preclude population 
declines (USFS 2005, section 2670.22). The USFS included Sierra Nevada 
red fox-specific protection measures in the Sierra Nevada Forest Plan 
Amendment (SNFPA) Standards and Guidelines given the extensive overlap 
of suitable and in some cases occupied habitat for the Sierra Nevada 
red fox with USFS lands. These specific protection measures require the 
USFS to conduct and analyze potential impacts of activities within 8 km 
(5 mi) of a verified Sierra Nevada red fox individual sighting (USFS 
2004, p. 54). The protection measures also limit the time of year that 
certain activities may occur to avoid adverse impacts to Sierra

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Nevada red fox breeding efforts, and require 2 years of evaluations 
following activities near sightings that are not associated with a den 
site (USFS 2004, p. 54).
    The National Park Service management policies prohibit hunting, 
trapping, and snowmobiling in Yosemite and manage natural resources to 
``preserve fundamental physical and biological processes, as well as 
individual species, features, and plant and animal communities'' (NPS 
2006, p. 26). Land management plans for Yosemite and Sequoia National 
Parks (the latter of which is not known to currently harbor Sierra 
Nevada DPS foxes but are within the DPS's historical range) do not 
contain specific measures to protect the Sierra Nevada DPS individuals 
or habitat. However, areas not developed specifically for recreation 
and camping are managed toward natural processes and species 
composition, and the best available scientific and commercial 
information indicates that the National Park Service would maintain the 
DPS's habitat.
    The Department of Defense recently completed an Integrated Natural 
Resources Management Plan (INRMP) for the U.S. Marine Corps Mountain 
Warfare Training Center (MWTC), which is a facility and training area 
that falls within the Sierra Nevada DPS's range, including overlap with 
some known sightings. The INRMP includes provisions prohibiting 
disturbance within 100.6 m (330 ft) of Sierra Nevada red fox den sites 
from March 1 to June 30 (MWTC 2018, p. 4-37). The INRMP also 
establishes food storage and trash clean-up provisions to prevent 
habituation (MWTC 2018, p. 4-38). A table in the INRMP incorrectly 
identifies the dates during which disturbance of den sites must be 
avoided as January 1 to June 30 (MWTC 2018, p. 3-26), but the MWTC's 
2020 Annual Operating Plan supports the March 1 to June 30 dates (MWTC 
2019, p. 24).
    On October 2, 1980, the State of California listed the Sierra 
Nevada red fox as a threatened species. The designation prohibits 
possession, purchase, or ``take'' of threatened or endangered species 
without an incidental take permit, issued by the CDFW. Additionally, 
red foxes in general are protected by the State from hunting and 
trapping (14 C.C.R. 460).
    A conservation effort currently is underway by the Sierra Nevada 
Red Fox Working Group. This working group was formed in 2015 by 
representatives of Federal and State wildlife agencies, State 
universities, and nongovernmental conservation organizations (Sierra 
Nevada Red Fox Working Group 2015, p. 1; 2016, p. 1). In addition to 
continued monitoring of the Sierra Nevada red fox across its range, 
including the Sierra Nevada DPS, the working group is currently 
developing a conservation strategy, which will include a genetics 
management plan. While the Sierra Nevada DPS population remains low, 
careful monitoring and genetics management will be key in identifying 
and responding appropriately to any downward trends in population 
numbers.

Risk Factors Affecting the Sierra Nevada DPS of Sierra Nevada Red Fox

    Our SSA considered a variety of environmental and demographic 
characteristics important to the viability of the Sierra Nevada DPS, 
taking into consideration both current and potential future conditions 
that may impact the DPS. The environmental characteristics we 
considered were: (1) Extent of subalpine habitat, (2) deep winter snow 
cover, (3) and rodent and leporid (rabbit and hare) populations. 
Subalpine habitat is important because its lower primary productivity 
and short growing season leave it unable to support as many prey 
animals as typically occur at lower elevations (Verner and Purcell 
1988, p. 2). This makes subalpine habitat more ``marginal'' for 
supporting mid-sized carnivores, such as coyotes and foxes. Red foxes 
tend to avoid competition with coyotes by relocating to marginal 
habitats that coyotes find less attractive (Cross 2015, p. 38). Several 
studies have found this tendency can result in elevational 
stratification, with red foxes relegated to the poorer habitat at 
higher elevations (Perrine 2005, p. 84).
    The smaller size and furred feet of Sierra Nevada DPS foxes also 
improve their chances relative to coyotes at catching leporids running 
over deep snow (Grinnell et al. 1937, pp. 395-396; Perrine 2005, p. 
81), and let them travel over snow more easily to reach productive 
hunting areas (Grinnell et al. 1937, p. 393; Fuhrmann 1998, p. 24; 
Perrine 2005, p. 81). Mule deer carrion (Odocoileus hemionus) is an 
important non-winter food source for both red foxes and coyotes at high 
elevations in and around Lassen Volcanic National Park, but deer in 
Lassen typically descend to lower elevations in winter, avoiding heavy 
snow (Perrine 2005, p. 30). Mule deer are also present in the range of 
the Sierra Nevada DPS, but a camera survey found none in the area 
during winter months (Sacks et al. 2015, p. 24). The low productivity 
and heavy snows of the Sierra Nevada DPS's high-elevation range 
therefore appear to discourage coyotes from occupying the area in 
winter to the same extent as at lower elevations, thereby leaving 
Sierra Nevada DPS foxes to occupy the area with less direct competition 
from coyotes (Sacks 2017, p. 2).
    The remaining environmental characteristic, rodent and leporid 
population levels, is important to consider separately because prey 
population numbers can change for reasons unrelated to primary 
productivity or snowpack depth.
    The demographic characteristics we considered important to the 
viability of the Sierra Nevada DPS include: (1) Genomic integrity 
(extent of hybridization or inbreeding depression), (2) population 
size, and (3) number of populations.
    Risk factors affecting the environmental characteristics that the 
DPS relies on include changing climate-related conditions, such as 
primary production levels and snowpack, which can affect coyote 
presence (and thus competition with Sierra Nevada DPS individuals) in 
high-elevation areas; prey availability; and potential impacts of 
habituation to humans and human-provided food sources. Risk factors 
affecting the demographic characteristics include deleterious impacts 
associated with small population size, including inbreeding depression 
(as a consequence of population reduction and a lack of other 
populations) and reduced genomic integrity, and levels of hybridization 
with nonnative red foxes. Our evaluation of the best available 
scientific and commercial information indicates the Sierra Nevada DPS's 
resiliency is not significantly adversely affected by impacts 
specifically associated with its habitat. We presented several 
potential causal connections between habitat conditions and their 
importance to the Sierra Nevada DPS, as well as scenarios related to 
possible future trajectories of the risk factors that could affect 
those habitat conditions. As we analyzed these potentialities, we 
determined that the relative importance of potential causal connections 
was lower than presented in some scenarios, and that the most likely 
scenario of future conditions would exhibit a lower overall risk to the 
DPS's habitat. As such, we conclude that there are not any current or 
future significant habitat-based threats. The best available scientific 
and commercial information suggests that threats to the subspecies 
directly (as opposed to habitat) are of greatest concern. Below is a 
summary of the factors influencing the species viability, provided in 
detail in the SSA report (Service 2018) and

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available on the internet at www.regulations.gov, Docket No. FWS-R8-ES-
2019-0006.
Subalpine Habitat Suitability, Snowpack Levels, and Coyote Presence
    Over the past 75 years, average annual temperatures in the Sierra 
National Forest (which overlaps the southwestern portion of the Sierra 
Nevada DPS's range) have increased by about 1.0 to 1.5 [deg]C (Meyer et 
al. 2013, p. 2). In the Lake Tahoe region (northern Sierra Nevada 
mountain range in California), the average number of days per year for 
which the average temperature was below-freezing has decreased from 79 
in 1910 to about 51 in 2010 (Kadir et al. 2013, p. 102). These 
increased average temperatures coupled with periodic drought conditions 
can result in changed habitat conditions in subalpine habitat. For 
example, direct measurements of primary productivity in a subalpine 
meadow in Yosemite have shown that mesic (medium wet) and hydric (wet) 
meadows both tend to increase productivity in response to warmer, drier 
conditions (Moore et al. 2013, p. 417). Xeric (dry) meadows tend to 
increase productivity due to warmth, but decrease due to drier 
conditions (Moore et al. 2013, p. 417). A comparison of tree biomass 
and age in subalpine forests now and about 75 years ago also points to 
increased productivity over time (Kadir et al. 2013, p. 152). 
Specifically, small trees with comparatively more branches increased by 
62 percent, while larger trees decreased by 21 percent, resulting in 
younger, denser stands (Kadir et al. 2013, p. 152). This overall 
increase in biomass occurred consistently across the subalpine regions 
of the Sierra Nevada mountain range and across tree species. The 
primary cause was an increase in the length of the growing season 
(Kadir et al. 2013, p. 152).
    A study of coyotes and montane red foxes in the Lassen area of 
California found that coyotes moved out of high elevation areas during 
the winter, possibly due to deep snow (Perrine 2005, p. 74). Red foxes 
also moved to somewhat lower elevations in winter, but tended to remain 
at higher elevations than coyotes (average 1,878 m (6,161 ft) versus 
average 1,690 m (5,545 ft) for coyotes) (Perrine 2005, p. 96). Studies 
in Alberta and Maine have also documented elevational separation of 
coyotes and red foxes (Perrine 2005, p. 84). A study of coyotes in 
Sonora Pass, however, where Sierra Nevada DPS foxes occur, found that 
coyotes outnumber DPS foxes during the summer in the high elevation 
areas most used by Sierra Nevada DPS foxes, and also found several 
coyotes that were occupying the high-elevation areas year-round (Quinn 
and Sacks 2014, p. 12; Quinn 2017, pp. 6-7). Areas unoccupied by 
coyotes may serve as refugia for red foxes (Perrine 2005, p. 84), so 
the coyotes occupying high elevation areas near Sonora Pass during the 
winter may be negatively impacting Sierra Nevada DPS foxes by 
restricting them from hunting areas or den sites, by the threat of 
direct predation on adult foxes or cubs, and by generally reducing the 
carrying capacity of the area available for the foxes (Quinn and Sacks 
2018, p. 18). The extent of the impact is of course unclear, but given 
the current small estimated size of the Sierra Nevada DPS population, 
any death or reproductive failure resulting largely from coyote 
presence could affect the overall viability of the DPS as a whole.
    In the central portion of the Sierra Nevada mountain range, average 
recent April 1 snowpack levels in Yosemite (which overlaps a portion of 
the known Sierra Nevada DPS sightings) have been just above 60 cm (23.6 
in) (Curtis et al. 2014, p. 9). To date, all Sierra Nevada DPS 
individuals sighted within the park have been in the areas of highest 
snowpack (Eyes 2016, p. 2).
    While snowpack conditions vary by year and location, the best 
available scientific and commercial information suggests that the areas 
where the Sierra Nevada DPS occurs have been maintaining high snowpack 
during winter and spring most years (see section 4.1 of the SSA report 
(Service 2018, pp. 22-23)). Therefore, the current condition of the 
snowpack depth appears adequate for the DPS's needs, except during 
drought years such as occurred in California and other western states 
from 2012 to 2017 (Kim and Lauder 2017, pp 2-45).
Prey Availability
    Rodent population numbers in subalpine areas have likely increased 
due to an increase in primary productivity (Service 2018, pp. 21, 24). 
Despite several factors that may limit their availability (e.g., 
increased presence of coyotes), the general landscape appears adequate 
for rodents.
    Adequate leporid population numbers may be of concern given that 
both white-tailed jackrabbits and snowshoe hares are considered species 
of special concern across the Sierra Nevada by CDFW (CDFW 2017, p. 51), 
a designation meaning they are potentially vulnerable to extirpation in 
California (CDFW 2017, p. 10). Regardless of rangewide leporid 
abundance, the best available scientific and commercial information 
does not indicate that leporid abundance is inadequate in the vicinity 
of the majority of known Sierra Nevada DPS sighting locations (i.e., 
Sonora Pass area); leporids appear currently to be relatively common 
and present all year in the Sonora Pass area (Rich 2014, p. 1).
Habituation
    Based on new information received, habituation of Sierra Nevada DPS 
foxes to humans and human food sources may expose Sierra Nevada DPS fox 
individuals to harm or injury, such as from dog attacks, dog diseases, 
and vehicle collisions (Dunkelberger 2020, p. 2). Sierra Nevada red 
foxes in the Southern Cascades population have been exhibiting begging 
behavior at the Lassen Peak parking lot (Perrine 2005, p. 150). A 
female from that population was killed by a dog in 2002 after having 
previously exhibited begging behavior (Perrine 2005, p. 135). The death 
occurred less than 175 m (600 ft) from a ski chalet.
    Other indicators of habituation have also been noted in the range 
of the Sierra Nevada DPS. The Humboldt-Toiyabe National Forest has 
several photographs of Sierra Nevada DPS foxes closely approaching 
hikers and snowmobilers, presumably in hopes of obtaining food 
(Dunkelberger 2020, p. 2). Hikers within the DPS's range have also 
posted photographs on social media showing themselves feeding Sierra 
Nevada DPS foxes. Although we have no reports of Sierra Nevada DPS 
foxes approaching soldiers at the MWTC, trash has occasionally been 
left after training exercises, and tracks from Sierra Nevada red foxes, 
as well as fox scat containing food wrappers have been found in these 
debris areas (Dunkelberger 2020, p. 2). The recently completed INRMP 
commits the MWTC to implement measures that prevent habituation of 
foxes, including an education program for military personnel on these 
measures (MWTC 2018, p. 3-67). As a result of these actions, we do not 
expect habituation on MWTC lands to significantly affect the population 
of the DPS. We have no information indicating loss of Sierra Nevada DPS 
foxes due to habituation. Overall, the best available information 
suggests that habituation of individual foxes may occur, but is 
expected to be restricted to a few individuals over time.
Deleterious Effects Associated With Small Populations
    Sierra Nevada DPS population numbers are currently low (18 to 39 
individuals spread across the Sonora Pass, northern Yosemite, and Mono

[[Page 41751]]

Creek areas) (Sacks and Quinn 2020, p. 1; CSERC et al. 2020, pp. 2-3, 
CDFW 2020, pp. 3-4) and appear to have been low for many years. 
Sightings fell considerably in the mid-1900s, for instance, as compared 
to trapping data reported by Grinnell et al. (1937, p. 389) (Schempf 
and White 1977, p. 44). The low numbers make this DPS more susceptible 
to deleterious stochastic events such as major fires or diseases. Loss 
of a few individuals due to stochastic events would mean the loss of a 
relatively large proportion of the small Sierra Nevada DPS population.
    Additionally, the Sierra Nevada DPS's low population numbers make 
it vulnerable to inbreeding depression. Inbreeding depression is caused 
by the chance loss of beneficial gene variants (alleles) in small 
populations, leaving deleterious alleles as the only remaining variants 
of a given gene (Soul[eacute] 1980, pp. 157-158). It can result in 
lowered reproductive ability, congenital defects, and lowered disease 
resistance (Soul[eacute] 1980, pp. 157-158; Gilpin 1987, p. 132; 
O'Brien 2003, pp. 62-63). To avoid inbreeding depression, a population 
typically requires an ``effective'' population size of at least 100 
reproducing adults (Frankham et al. 2014, p. 58). The ``effective 
size'' of a population is generally smaller than the actual size, and 
refers to the number of breeding individuals that would be necessary to 
produce the level of genetic diversity observed in the population if 
the members of the population interbred in a manner that was ideal for 
maximizing genetic diversity (Lande and Barrowclough 1987, pp. 88-89). 
So for instance, a population in which few individuals bred, and in 
which they chose mates from among their geographical neighbors, would 
have a smaller effective size than a population in which almost all 
adults bred and chose mates from among the entire population.
    The Sierra Nevada DPS's actual population size of 18 to 39 
individuals is already well below 100, but (based on samples taken from 
2015 to 2017) its effective population size was only 6.1 prior to the 
immigration into the population of two nonnative males in 2012 (CDFW 
2020, p. 3). Thus, the same level of genetic diversity could have been 
produced by only about six breeding individuals in an ``ideal'' 
population in which breeding practices maximized diversity. This means 
the Sierra Nevada DPS had likely been suffering from inbreeding 
depression prior to the arrival of two Great Basin foxes in 2012 (Sacks 
et al. 2015, pp. 3, 10, 29-30) (see Genomic Integrity, below). 
Additional support for this conclusion is provided by preliminary 
results of a study that estimated the inbreeding coefficient of a 
Sierra Nevada DPS fox that was born prior to the arrival of the Great 
Basin immigrants (Sacks and Quinn 2020, p. 2). The inbreeding 
coefficient was found to be above 0.4, which is at the high end of the 
range found in Isle Royal wolves, a population with demonstrated severe 
inbreeding depression (Sacks and Quinn 2020, p. 2).
    These data indicate that lowered reproductive success from 
inbreeding depression may be primarily responsible for the complete 
lack of pup production documented in the Sonora Pass area from 2011 
through 2017 by mated pairs of pure Sierra Nevada DPS foxes (Quinn et 
al. 2019, p. 571). It is thus likely to have constituted a limiting 
factor on population size in recent years (Sacks and Quinn 2020, p. 3). 
And while recent interbreeding with foxes from the Great Basin appears 
to have increased reproductive success, we have no information 
regarding the extent of other potential effects that are typically 
associated with inbreeding depression, such as congenital defects and 
lowered disease resistance, nor whether these potential effects may 
also have been alleviated. The population also remains small at 
present, and thus potentially susceptible to renewed impacts from 
inbreeding depression (Quinn et al. 2019, p. 573), or from deleterious 
chance events such as drought or fire. If inbreeding depression does 
return, the impacts would likely be worse due to the addition of new 
alleles from the Great Basin into the population (Quinn et al. 2019, p. 
573).
Genomic Integrity
    Prior to spring of 2013, no reproduction between native individuals 
of the Sierra Nevada DPS and nonnative immigrant red fox was known to 
have occurred (Sacks et al. 2015, p. 9; Sacks 2017, p. 4). However, two 
nonnative male red foxes with a mixture of Great Basin montane (V. v. 
macroura) and fur-farm ancestry arrived at the Sonora Pass area in 2012 
(Sacks et al. 2015, pp. 3, 10, 29-30). By 2014, they had produced a 
total of 11 hybrid pups (Sacks et al. 2015, pp. 29-30), and by 2017, 
the hybrids had interbred and produced 13 additional pups (Quinn et al. 
2019, p. 571). These 24 pups, all with a mixture of Sierra Nevada DPS 
and Great Basin montane fox ancestry, are the only pups known to have 
been produced in the population since 2011 (Quinn et al. 2019, p. 571; 
Sacks and Quinn 2020, p. 2). A third nonnative male was sighted (once) 
in 2014, and a fourth in 2017 (Sacks and Quinn 2020, p. 2), although we 
have no information to indicate whether either of these produced young.
    While the hybrid pups assist in helping the Sierra Nevada DPS 
experience less inbreeding depression (as discussed above), there 
remains the possibility that so many immigrants might enter the 
population and produce young that the unique heritable characteristics 
of the Sierra Nevada DPS are lost (Sacks et al. 2015, pp. 17-18; Quinn 
et al. 2019, p. 573). This loss of genes representative of the 
diversity of the DPS would initially mean a loss of representation 
(i.e., a diminished ability to adapt to long-term changes due to the 
lost genes). If such genetic replacement continued to the point where 
the DPS as a whole was facing replacement by nonnative foxes, then that 
would represent a loss of resiliency (i.e., the inability of remaining 
members of the DPS in the population to recover from stochastic 
events). For instance, if the last remaining individuals considered 
members of the DPS were of an older generation because their pups were 
all too hybridized to qualify as Sierra Nevada DPS, then any stochastic 
event that eliminated the last of the older DPS individuals would also 
eliminate the DPS as a whole, despite the continuing existence of non-
DPS foxes in the area.
    The current demographic circumstances of the DPS as a single, small 
population is also likely to result in low representation, because 
unique adaptations and genetic variations that DPS members in other 
portions of the historical range may once have had are likely to be 
lost now that the DPS no longer includes those areas. The historical 
range (as sketched by Grinnell et al. (1937, p. 382)) stretched for 
roughly 460 km (285 mi) from the northern to the southern Sierra Nevada 
mountains. The estimated current range, at only about 188 km (117 mi) 
long, and about half as wide, only covers portions of the central 
Sierras. Examples of differing ecological characteristics across the 
historical range include a north to south pattern of decreasing annual 
precipitation, increasing temperatures for a given elevation, and 
increasing maximum elevations (Fites-Kaufman et al. 2007, p. 458). 
Vegetation differences also follow this gradient, with whitebark pine 
more dominant in the north, but limber pine (Pinus flexilis) becoming 
more prominent in the central Sierras and foxtail pine (Pinus 
balfouriana) in the south (Fites-Kaufman et al. 2007, 475).
Cumulative or Synergistic Effects
    As discussed above, both rodent population numbers and the 
incidence

[[Page 41752]]

of droughts affecting snowpack levels have been affected by climate 
change in ways that have likely increased coyote numbers in the DPS's 
range. It is possible that a gradual increase in coyote numbers during 
the mid 1900's was one of the factors causing the DPS's numbers to 
drop. Whatever the cause, this drop in population size eventually led 
to inbreeding depression, which would have tended to lower the 
population size even more. The recent instances of hybridization with 
immigrant males from the Great Basin appears to have helped alleviate 
the most obvious reproductive impacts of inbreeding depression, but (as 
discussed above) risks from inbreeding depression and deleterious 
chance events remain so long as the population remains small.

Current Condition Summary

    We considered several risk factors involving both environmental and 
demographic characteristics affecting the Sierra Nevada DPS. The 
available information does not show that any environmental risk factors 
are currently threatening the DPS's viability. Increased primary 
productivity in high elevation areas due to climate change may have 
increased coyote numbers in the fox's range, but we lack evidence of 
the extent of increase or of resulting impacts. Important prey species 
remain generally available, and we lack evidence of population-level 
impacts resulting from habituation.
    Several demographic risk factors do appear to constitute current 
threats to the viability of the Sierra Nevada DPS. The DPS currently 
consists of a single known population of fewer than 50 individuals. 
This small size leaves the DPS susceptible to serious impacts from 
relatively common stochastic changes in the environment, such as 
drought or wildfire. The resiliency and redundancy of the DPS--its 
ability to survive and quickly rebound from both common stochastic 
changes and more serious catastrophes--is thus low. Since this one 
small population is the last representative of a DPS that was once much 
larger, the representation of the DPS is also threatened by the 
population's small size and susceptibility to extirpation.
    The small size of the population has also led to inbreeding 
depression in the recent past, which in turn likely contributed to 
further contractions in size due to lowered reproductive success. 
Population size appears to have begun increasing again since the 
arrival and interbreeding of two nonnative male foxes in 2011, but it 
is too early to determine if previous impacts from inbreeding 
depression have been ameliorated. Additionally, renewed inbreeding 
depression remains a possibility so long as the population size remains 
low. Thus, inbreeding depression also constitutes an apparent threat to 
the resiliency, redundancy, and representation of the DPS.
    Finally, the DPS is currently at risk of genetic swamping due to 
ongoing interbreeding with nonnative immigrant foxes. The extent of 
this risk cannot be precisely determined because it depends on 
currently unknown factors, such as the extent to which ongoing 
immigration and interbreeding will continue into the future.

Critical Habitat

    Section 4(a)(3) of the Act, as amended, and implementing 
regulations (50 CFR 424.12), require that, to the maximum extent 
prudent and determinable, the Secretary shall designate critical 
habitat at the time a species is determined to be an endangered or 
threatened species. In the proposed rule (85 FR 862, January 8, 2020), 
we determined that designation of critical habitat was not prudent 
because the present or threatened destruction, modification, or 
curtailment of habitat or range is not a threat to the Sierra Nevada 
DPS, and habitat does not appear to be a limiting factor for the 
species.

Summary of Comments and Recommendations

    In the proposed rule published on January 8, 2020 (85 FR 862), we 
requested that all interested parties submit written comments on the 
proposal by March 9, 2020. We also contacted appropriate Federal and 
State agencies, scientific experts and organizations, and other 
interested parties and invited them to comment on the proposal. 
Newspaper notices inviting general public comment were published in the 
Fresno Bee. We did not receive any requests for a public hearing. All 
substantive information received during the comment period has either 
been incorporated directly into this final determination or addressed 
below. We did not receive comments from Tribes.

Peer Reviewer Comments

    In accordance with our joint policy on peer review published on 
July 1, 1994 (59 FR 34270), and our August 22, 2016, memorandum 
updating and clarifying the role of peer review of listing actions 
under the Act, we sought peer review of the SSA report. We sent the SSA 
report to five independent peer reviewers and received two responses. 
The purpose of peer review is to ensure that our listing determinations 
are based on scientifically sound data, assumptions, and analyses. The 
peer reviewers have scientific expertise that included familiarity with 
the Sierra Nevada DPS and its habitat, biological needs, and threats.
    We incorporated the peer reviewers' comments into the final SSA 
report (Service 2018, entire). The changes consisted of adjustments and 
additions regarding average litter size; certainty regarding the 
genetic basis of local adaptations; the importance of coyotes, 
leporids, and snowmobiles; the extent to which snowpack level may 
affect coyote presence; and the extent to which ongoing hybridization 
may constitute a potential benefit or threat. The peer reviewers' 
comments did not change our determination that this DPS meets the 
definition of an endangered species under the Act.

Federal Agency Comments

    (1) Comment: The USFS requested that we work closely with the 
Sierra Nevada Red Fox Conservation Advisory Team, an informal recovery 
planning organization with representative members from numerous State 
and Federal agencies, universities, and environmental organizations. 
They noted that the Conservation Advisory Team is currently drafting a 
Conservation Strategy for the Sierra Nevada red fox subspecies, and 
asked us to update our Sierra Nevada red fox SSA report with new 
information from the Conservation Strategy.
    Our Response: We participate as members of the Sierra Nevada Red 
Fox Conservation Advisory Team and will continue to work closely with 
them. We consider the SSA report a living document, and will update it 
as substantive new information becomes available and as funding 
permits. We will consider all such information as we proceed with 
recovery-related actions for the species.
    (2) Comment: The USFS stated that our range map and habitat 
description do not reflect recent data made available by the Sierra 
Nevada Red Fox Working Group, and that the lower elevational limit for 
detections is 2,469 m (8,100 ft) rather than 2,743 m (9,000 ft). They 
also noted that the range map should show a higher resolution, and it 
should show elevation, spatial references, and landmarks.
    Our Response: We recognize that the range map included in our 
proposed listing rule is not at a high resolution nor as finely 
detailed as the commenter would prefer, rather it is just intended to 
give the public an understanding of where the DPS generally occurs. 
Species

[[Page 41753]]

ranges are not hard and fast boundaries beyond which individuals cannot 
go, so range maps are our best attempt to capture where the species is 
likely to occur, based on available information. For the Sierra Nevada 
DPS, our range map was based both on detections known at this time and 
on Sierra Nevada DPS preferred habitat features identified by Cleve et 
al. (2011, entire). Our range map was not based on elevational contour 
lines; however, we note that the range map includes several areas below 
2,469 m (8,100 ft), and so comports with the commenters point about 
Sierra Nevada red fox detections.
    We have confirmed that all but three Sierra Nevada DPS detections 
are within the mapped range. The three foxes not within the mapped 
range were found within one fifth of a mile of State Highway 395 (Quinn 
in litt. 2020, unpublished data), and presumably reflect use of that 
highway as a dispersal corridor. Two of the three were scat detections 
(both from the same individual) near the highway in the town of Lee 
Vining, and the third was a road-killed individual on State Highway 395 
just south of the junction with State Highway 108 (Quinn in litt. 2020, 
p. 1). These three detections were at elevations ranging from 2,074 to 
2,152 m (6,805 to 7,059 ft) (Quinn in litt. 2020, unpublished data). A 
fourth detection below 2,469 m (8,100 ft) (specifically at 2,311 m 
(7,581 ft)) occurred in the valley of the West Walker River, just south 
of the MWTC and within the mapped range (Quinn in litt. 2020, 
unpublished data). All other detections were above 2,469 m (8,100 ft).
    More detailed GIS mapping information is available from the 
Sacramento Fish and Wildlife Office on request. The range map is also 
available on the internet at https://ecos.fws.gov/ecp.
    (3) Comment: The USFS noted that recent detections of Sierra Nevada 
DPS foxes near Dunderberg Peak and Virginia Lakes change the extent of 
the gap in detections mentioned in the proposed rule from 77.2 km (48 
mi) to 19.3 km (12 mi).
    Our Response: The detections are north of the gap, but we have 
removed discussion of the gap in order to avoid possible confusion 
regarding the estimated range (which does not have gaps) versus the 
location of Sierra Nevada DPS detections.

Comments From States

    (4) Comment: The CDFW provided information on the Lassen population 
of Sierra Nevada red foxes, noting in particular that the population is 
highly inbred and so cannot be used for translocations to help solve 
genetic issues in the Sierra Nevada DPS until it recovers.
    Our Response: Our listing analysis did not extend to the status of 
the Lassen population (see the 12-month finding (October 8, 2015, 80 FR 
60990) regarding the range of the Southern Cascades DPS), but we will 
incorporate this information (and all other pertinent information 
received) into our recovery plan for the Sierra Nevada DPS.

Comments From Local Governments

    (5) Comment: Two county boards of supervisors requested that, if 
the Sierra Nevada red fox is listed as endangered, we seek interagency 
coordination and public review prior to completing a recovery plan. One 
county board was concerned that a recovery plan would not allow 
important fuels reduction or forest health projects to proceed.
    Our Response: While we explain further below that recovery plans 
are not intended, nor do they have the regulatory force, to disallow 
projects, we first note that fuels reduction or forest health actions 
typically take place below the elevational range of the Sierra Nevada 
DPS.
    Recovery plans delineate reasonable actions that are determined 
necessary for the recovery and protection of listed species. Recovery 
plans do not obligate other parties to undertake (or refrain from 
undertaking) specific actions, and are not regulatory documents. When 
developing recovery plans, our process includes seeking public comment 
prior to finalizing them. We also coordinate with stakeholders and 
interested parties during the recovery planning process. We also 
participate in the Sierra Nevada Red Fox Working Group (discussed under 
Summary of Existing Regulatory Measures and Voluntary Conservation 
Efforts, above), which is an interagency organization.
    (6) Comment: One county board of supervisors noted that snowmobile 
impacts in the Bridgeport Winter Recreation Area may be minimal due to 
lack of trail grooming, minimum snow depth requirements, date 
restrictions on use, and permit requirements for snowmobile users. 
These points were also raised by the USFS.
    Our Response: We acknowledge the information provided indicates 
snowmobiling in the BWRA is unlikely to have population-level impacts 
on Sierra Nevada DPS foxes. We will consider any additional information 
that may come to light when writing the recovery plan for the species, 
and as otherwise necessary in consultation with Federal agencies.
    (7) Comment: Two county boards of supervisors requested input into 
any restrictions on snowmobile operations that might result if the 
species is listed as endangered.
    Our Response: The USFS will work with us in accordance with Act 
requirements (16 U.S.C. 1536(a)(2)) to ensure that their policies do 
not jeopardize the species. Any changes to current land management 
practices will involve public comment as required by applicable 
environmental laws.
    (8) Comment: A county board of supervisors stated that there is not 
enough information regarding Sierra Nevada DPS viability to know 
whether listing would help the species thrive.
    Our Response: The Act requires our listing determination to be 
based solely on whether the best scientific and commercial information 
indicates the species meets the definitions of an endangered or 
threatened species (see Determination section, below) (16 U.S.C. 
1533(b)(1)(A); 50 CFR 424.11(b)). The purpose of listing is to provide 
the regulatory protections needed to prevent further decline on a 
trajectory toward extinction. Although the listing itself is not 
intended to ``help the species thrive,'' subsequent components of the 
Act (e.g., recovery plans) may provide the necessary mechanisms for the 
species to thrive an