Federal Register / Vol. 86, No. 146 / Tuesday, August 3, 2021 / Rules and Regulations 41743 

failure (M.C. Smith 1968, pp. 308–309; 

Finley 1969, all; Steele and Koprowski 

2001, p. 67). Placement of these 

middens tends to be on gentler, nonsoutherly-facing slopes in healthier, 

older forested areas with higher canopy 

closure, basal area, and number of large 

live trees (Finley 1969, p. 237; 

Zugmeyer and Koprowski 2009, p. 179; 

Hatten 2014, p. 111). This type of 

placement allows specific moisture 

levels to be maintained within the 

midden, thereby creating prime storage 

conditions for cones and other food 

items, such as mushrooms, acorns, and 

bones (Finley 1969, p. 237; Brown 1984, 

pp. 66–67; USFWS 1993, pp. 5–7; 

Zugmeyer and Koprowski 2009, p. 179). 

They also seem to prefer areas with 

snags, piles and tangles of downed 

timber, and a higher volume of logs that 

provide cover and safe travel routes, 

especially in winter, when open travel 

across snow exposes them to increased 

predation, as the species does not 

hibernate. Wood et al. (2007, p. 2362) 

determined that midden site selection 

occurs not only at the microclimate 

level (where conditions are appropriate 

for cone storage), but also on a larger 

scale that encompasses other features 

found on the landscape, usually in areas 

with a high number of healthy trees and 

correspondingly high seedfall. There 

appears to be no differentiation in 

selection of midden sites based on sex 

(Alanen et al. 2009, pp. 204–205). 

Within their territory, Mount Graham 

red squirrels build nests in hollow trees, 

in hollow snags, in hollow logs, outside 

trees in nests of grass or foliose lichens 

(called dreys or bolus nests), or in holes 

in the ground (C.C. Smith 1968, p. 58; 

Leonard and Koprowski 2009, p. 132). 

Nests may be built in natural hollows or 

abandoned cavities made by other 

animals, such as woodpeckers, and 

enlarged by squirrels (USFWS 1993, p. 

11). Nest site selection by Mount 

graham red squirrels is strongly 

influenced by stand composition, 

particularly density of corkbark fir, 

mature (large) trees, and decaying logs 

(Merrick et al. 2007, p. 1961). The 

availability of larger snags and cavitycontaining trees, especially aspen, is of 

particular importance for this 

population, as they provide preferred 

nesting locations (Merrick et al. 2007, p. 

1961). 

Critical Habitat 

Current Critical Habitat Designation 

On January 5, 1990, we published a 

final rule (55 FR 425) designating 

critical habitat for the Mount Graham 

red squirrel as mature spruce-fir forest 

in: 

1. Hawk Peak-Mount Graham Area. 

The area above the 10,000-ft (3,048-m) 

contour surrounding Hawk Peak and 

Plain View Peak, plus the area above the 

9,800-ft (2,987-m) contour that is south 

of lines extending from the highest 

point of Plain View Peak eastward at 90° 

(from true north) and southwestward at 

225° (from true north). 

2. Heliograph Peak Area. The area on 

the north-facing slope of Heliograph 

Peak that is above the 9,200-ft (2,804-m) 

contour surrounding Heliograph Peak 

and that is between a line extending at 

15° (from true north) from a point 160 

ft (49 m) due south of the horizontal 

control station on Heliograph Peak and 

a line extending northwestward at 300° 

(from true north) from that same point. 

3. Webb Peak Area. The area on the 

east facing slope of Webb Peak that is 

above the 9,700-ft (2,957-m) contour 

surrounding Webb Peak and that is east 

of a line extending due north and south 

through a point 160 ft (49 m) due west 

of the horizontal control station on 

Webb Peak. 

12-Month Determination 

Pursuant to the provisions of the Act 

regarding revision of critical habitat and 

petitions for revision, we now publish 

notice of how we intend to proceed with 

the requested revision. As described 

below under How the Service Intends to 

Proceed, we intend to assess potential 

revisions to the subspecies’ critical 

habitat after a species status assessment 

(SSA) and a revision of the Mount 

Graham red squirrel’s recovery plan are 

complete. 

How the Service Intends To Proceed 

Section 4(b)(3)(D)(ii) of the Act states 

that if we find that a petition presents 

substantial information indicating that a 

revision to critical habitat may be 

warranted, then within 12 months of 

receiving the petition we are to indicate 

how we intend to proceed with the 

requested revision and promptly 

publish a notice of our intention in the 

Federal Register. We intend that any 

revisions to critical habitat for the 

Mount Graham red squirrel be as 

accurate and comprehensive as possible. 

Therefore, completing the SSA and a 

revised recovery plan will inform any 

future revisions to critical habitat for the 

red squirrel. Once the SSA and revised 

recovery plan are complete, a 

rulemaking process will be initiated if 

revisions to the subspecies’ critical 

habitat are determined to be 

appropriate. 

The currently designated critical 

habitat, as well as areas that support the 

subspecies but are outside of the current 

critical habitat designation, will 

continue to be subject to conservation 

actions implemented under section 

7(a)(1) of the Act. Actions affecting the 

Mount Graham red squirrel or its 

designated critical habitat are subject to 

the regulatory protections afforded by 

section 7(a)(2) of the Act, which 

requires Federal agencies, including the 

Service, to ensure that actions they 

fund, authorize, or carry out are not 

likely to jeopardize the continued 

existence of any listed species or result 

in the destruction or adverse 

modification of critical habitat. 

References Cited 

A complete list of references cited in 

this rulemaking is available on the 

internet at http://www.regulations.gov 

and upon request from the Arizona 

Ecological Services Field Office (see FOR

FURTHER INFORMATION CONTACT). 

Author 

The primary authors of this document 

are the staff members of the Arizona 

Ecological Services Field Office, U.S. 

Fish and Wildlife Service. 

Authority 

The authority for this action is the 

Endangered Species Act of 1973, as 

amended (16 U.S.C. 1531 et seq.). 

Martha Williams, 

Principal Deputy Director, Exercising the 

Delegated Authority of the Director, U.S. Fish 

and Wildlife Service. 

[FR Doc. 2021–16247 Filed 8–2–21; 8:45 am] 

BILLING CODE 4333–15–P 

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. 

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 


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41744 Federal Register / Vol. 86, No. 146 / Tuesday, August 3, 2021 / Rules and Regulations 

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 http://

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 http://

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 http://

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 


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Federal Register / Vol. 86, No. 146 / Tuesday, August 3, 2021 / Rules and Regulations 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). 

BILLING CODE 4333–15–P 


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41746 Federal Register / Vol. 86, No. 146 / Tuesday, August 3, 2021 / Rules and Regulations 

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). 


jbell on DSKJLSW7X2PROD with RULESER03AU21.000</GPH>

Tuo!lumne 

Cmnly 

~ 

eaum,-

Fresno 

Coonly 

Oregcm ldillll)D 

1~~-1 

+ 

Om.nly 

-

Figure I-Approximate current range of the Sierra Nevada DPS of Sierra Nevada red 

fox. The range follows the Sierra crest (the north-to-south ridgeline of the Sierra Nevada 

mountain range), and includes known sighting locations and nearby high-quality habitat 

(Cleve et al. 2011, entire; Eyes 2016, attachments; Hiatt 2017, attachment; Quinn 2018a, 

attachments; Quinn 2018a, attachments; Stermer 2018, p. 1). 
Federal Register / Vol. 86, No. 146 / Tuesday, August 3, 2021 / Rules and Regulations 41747 

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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41748 Federal Register / Vol. 86, No. 146 / Tuesday, August 3, 2021 / Rules and Regulations 

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 http://

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 highelevation 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 climaterelated 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 humanprovided 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 

°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 yearround (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 HumboldtToiyabe 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 


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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 (Soule ́ 1980, pp. 

157–158). It can result in lowered 

reproductive ability, congenital defects, 

and lowered disease resistance (Soule ́

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 (FitesKaufman 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 (FitesKaufman et al. 2007, 475). 

Cumulative or Synergistic Effects 

As discussed above, both rodent 

population numbers and the incidence 


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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 


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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 and recover. 

(9) Comment: One county board of 

supervisors noted the large degree of 

variation that exists in our initial 

estimate of 10 to 50 adult Sierra Nevada 

DPS foxes in the population, and also 

noted the possibility of other 

undiscovered populations. The board 

stated that knowledge of population 

numbers is insufficiently precise to 

support listing. 

Our Response: We have revised 

population estimates in this final rule to 

an estimate of 18 to 39 individuals 

based on additional information that has 

been made available through the public 

comment process (Sacks and Quinn 

2020, p. 1; CSERC et al. 2020, pp. 2–3; 

CDFW 2020, pp. 3–4; See 

Demographics, above). This estimate 

includes the results of camera trapping 

and scat searches throughout the DPS’s 

range. Additionally, as discussed under 

Deleterious Effects Associated With 

Small Populations, the Sierra Nevada 

DPS appears to have been subject to 

inbreeding effects in the recent past, 

which is consistent with known 

information on small population size 

effects (Quinn et al. 2019, pp. 559–560, 

571; Sacks and Quinn 2020, p. 2). 

Therefore, the best available scientific 

and commercial information indicates 

that fewer than 50 individuals currently 

remain in the DPS. While the exact 


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number remains unknown, and is also 

subject to change with new births and 

deaths, it is well below population 

levels that would provide resiliency, 

redundancy, and representation to the 

population. We discuss this issue in 

greater depth above, under Deleterious 

Effects Associated With Small 

Populations. 

(10) Comment: One county board of 

supervisors indicated concern that 

listing would interfere with activities 

such as hiking and snowmobiling. They 

asked for an analysis of potential 

economic impacts prior to listing, and 

requested an opportunity to review any 

economic analyses conducted. 

Our Response: As described below in 

Determination, the Act requires us to 

determine whether a species is 

endangered or threatened ‘‘solely on the 

basis of the best scientific and 

commercial data available’’ (16 U.S.C. 

1533(b)(1)(A); 50 CFR 424.11(b)). We are 

not allowed to consider economic 

impacts in our determination on 

whether to list a species under the Act. 

However, at this time we have no 

information to indicate that public 

hiking or snowmobile use in accordance 

with applicable regulations is impacting 

the Sierra Nevada DPS. 

Public Comments 

(11) Comment: One commenter noted 

that snowmobiles would be allowed in 

two near-natural roadless areas (Pacific 

Valley and Eagle) in the Stanislaus 

National Forest within the Sierra 

Nevada DPS’s range if a proposed 

change to the Forest Plan is approved. 

The commenter indicated that 

compaction of snow by snowmobiles 

could increase ease of access to a given 

area for coyotes, which do not move 

over uncompacted snow as efficiently as 

Sierra Nevada DPS foxes. The 

commenters also stated that snow 

compaction may impact subnivean 

(under-snow) rodent populations by 

lowering the temperature and 

decreasing the oxygen content in the 

compacted area. The commenter stated 

that this is one of the few types of 

potential impacts to the Sierra Nevada 

DPS that government institutions have 

the power to prevent. 

Our Response: The potential change 

to existing snowmobile restrictions in 

the areas mentioned is part of the best 

available scientific and commercial 

information we must consider for our 

listing determination (16 U.S.C. 

1533(b)(1)(A)). The best available 

information does not suggest that 

snowmobiling and its potential to 

compact snow is a risk factor to the 

DPS, although we note that the resulting 

impacts associated with the proposal 

depend on several variables, including 

the likelihood that the proposed 

changes would be adopted, the number 

of snowmobiles allowed and Sierra 

Nevada DPS foxes in the two areas, and 

the extent of resulting snow 

compactions. This, at this time, the best 

available information does not suggest 

that this proposed regulatory change 

constitutes a threat to the population. 

However, because we are listing the 

Sierra Nevada DPS as an endangered 

species based on other information (see 

Risk Factors Affecting the Sierra Nevada 

DPS of Sierra Nevada Red Fox, above), 

we anticipate consulting with the USFS 

under section 7 of the Act to minimize 

effects should that agency change 

snowmobile regulations, thus insuring 

the continued existence of the species is 

not jeopardized (as required by the Act 

under 16 U.S.C. 1636(a)(2)). 

(12) Comment: One commenter stated 

that poachers take more Sierra Nevada 

DPS foxes than recorded, and also 

indicated that Wildlife Services 

personnel (wildlife pest and predator 

removers from the Animal and Plant 

Health Inspection Service) impact the 

species. Another commenter stated that 

indiscriminate use of m–44 cyanide 

anti-predator devices threatens the 

Sierra Nevada DPS. No further 

information was provided by either 

commenter regarding these statements. 

Our Response: Our review of the best 

available scientific and commercial 

information does not indicate these 

sources are a threat to the DPS. If the 

commenters, or other interested parties, 

have additional information that might 

indicate otherwise, we would appreciate 

receiving it. 

(13) Comment: One commenter asked 

us to work with other agencies to 

recover the Sierra Nevada DPS and 

restore its role in the ecosystem. The 

commenter also suggested we seek 

additional information regarding why 

the Sierra Nevada DPS appears to have 

such low population numbers. 

Our Response: We are working with 

State and Federal agencies, academics, 

environmental groups, and other 

interested parties as part of the Sierra 

Nevada Red Fox Working Group to 

develop a conservation strategy and 

recovery plan. We also will consult with 

Federal agencies under section 7 of the 

Act to avoid actions that jeopardize the 

species, and will work with non-Federal 

agencies and individuals who wish to 

initiate recovery actions or habitat 

management plans in accordance with 

section 10 of the Act. 

Regarding reasons for the current 

small size of the population, new 

information submitted by commenters, 

based on research supported in part by 

us, shows that the population was likely 

inbred prior to the arrival of immigrants 

from the Great Basin (see Deleterious 

Effects Associated With Small 

Populations, above). Inbreeding 

depression may therefore be the primary 

reason the population has been so small 

recently. It remains unclear, however, 

when and why the population became 

so low that inbreeding depression 

became an issue. 

(14) Comment: One commenter stated 

that the Sierra Nevada DPS is threatened 

by logging and farming of livestock and 

fish. The commenter also stated that 

Sierra Nevada DPS numbers had 

diminished to as low as 10 to 15 in the 

1990s, and that no action was taken at 

that time. 

Our Response: In our 12-month 

finding published on October 8, 2015 

(80 FR 60990), we investigated logging, 

livestock grazing, and fish stocking as 

potential threats to Sierra Nevada red 

fox in both the Sierra Nevada and 

Southern Cascades DPSs. The best 

available scientific and commercial 

information indicates that these 

activities have more potential for 

negative impacts to the Southern 

Cascades DPS, as foxes in the Sierra 

Nevada DPS typically occur at 

elevations above those used for grazing 

or logging. Additionally, as discussed in 

our 12-month finding (80 FR 60990), 

fish stocking might affect foxes in the 

Southern Cascades DPS because the 

stocked fish can potentially transmit a 

parasite deadly to canines that eat them; 

the parasite has not been found within 

the range of the Sierra Nevada DPS. 

The best available information does 

not include the population size of the 

Sierra Nevada DPS in the 1990s. This 

population was rediscovered by 

scientists in 2010 (Statham et al. 2012, 

p. 122), and a rough population estimate 

(of 14 to 50 adults) was not available 

until 2015 (Sacks et al. 2015, p. 14). 

(15) Comment: One commenter 

mentioned that according to an Oregon 

Department of Fish and Wildlife website 

(i.e., https://www.oregoncon

servationstrategy.org/strategy-species/ 

sierra-nevada-red-fox/), fires are a 

potential threat to the species, while 

actions that promote recruitment and 

maintenance of high-elevation conifer 

forests are beneficial. The commenter 

also mentioned that radio-collaring 

foxes to learn more about them would 

be beneficial. 

Our Response: The Oregon website 

information is specific to the Southern 

Cascades DPS, as opposed to the Sierra 

Nevada DPS that is addressed in this 

rule. We agree that available 

information on the Southern Cascades 

DPS may be helpful to consider when 


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we develop a recovery plan. For 

example, we agree that radio-collaring 

can provide important information, and 

at least one fox in the Sierra Nevada 

DPS has been radio-collared since 

publication of our proposed listing rule 

(Stock and Eyes 2017, p. 21). We will 

take this and other information into 

consideration when we coordinate with 

partners and species experts, including 

the Sierra Nevada Working Group, to 

develop a conservation strategy for the 

entire subspecies and a recovery plan 

for the Sierra Nevada DPS. 

(16) Comment: One commenter 

indicated concern regarding the impact 

of listing the Sierra Nevada DPS on 

Federal timber sales conducted for fire 

management. 

Our Response: We do not expect 

listing the Sierra Nevada red fox to have 

a significant impact on Federal timber 

sales conducted for fire management 

because most such sales are outside the 

range of the DPS. Most of that range is 

designated wilderness, where logging is 

not permitted. Most is also in alpine and 

subalpine habitats, where the scattered 

tree stands, thin soils, and small 

amounts of litter accumulation produce 

a relatively low fire risk (Fites-Kaufman 

et al. 2007, p. 475). In contrast, most 

Federal and state fuels reduction efforts 

are conducted at lower elevations closer 

to urban areas (van Wagtendonk et al. 

2018, p. 271). Finally, any fuel 

reduction projects that do occur in the 

range of the DPS are likely to take place 

during summer months, after most of 

the snow has melted, and are thus less 

likely to impact springtime denning and 

pup raising. For any timber sales within 

the range of the Sierra Nevada DPS, we 

will coordinate with the Federal action 

agency through section 7 consultations 

to ensure projects minimize effects to 

the species while meeting fuels 

reduction goals. 

(17) Comment: One commenter stated 

that existing regulatory mechanisms, 

including hunting and trapping 

restrictions and USFS sensitive species 

status, are adequate to protect the Sierra 

Nevada DPS. 

Our Response: The Sierra Nevada DPS 

faces several threats that existing 

regulatory mechanisms are unlikely to 

adequately address, including 

inbreeding depression, loss of genetic 

distinctiveness through hybridization, 

impacts of deleterious events to small 

populations, and competition with 

coyotes. Existing regulatory mechanisms 

include: 

• Identification of the Sierra Nevada 

red fox (including the Sierra Nevada 

DPS) as a sensitive species by the USFS; 

• Inclusion of Sierra Nevada red fox 

protection measures in the Standards 

and Guidelines for the Sierra Nevada 

Forest Plan Amendment; 

• Prohibition of hunting and trapping 

in Yosemite; 

• Management of Yosemite and other 

national parks to ‘‘preserve fundamental 

physical and biological processes, as 

well as individual species, features, and 

plant and animal communities’’ (NPS 

2006, p. 26); 

• Completion of an INRMP for the 

MWTC, with provisions to minimize 

disturbance or habituation of Sierra 

Nevada DPS foxes; 

• Listing of the Sierra Nevada red fox 

as a threatened species under the 

California Endangered Species Act, 

which prohibits ‘‘take’’ of protected 

species; and 

• Protection of red foxes throughout 

California from hunting and trapping 

(14 C.C.R. 460). 

Many of these protections have been 

in place for decades throughout 

California, but the Sierra Nevada DPS 

has nevertheless experienced low 

population numbers, currently 

estimated at 18 to 39 individuals (see 

Demographics, above). 

Determination of Sierra Nevada DPS 

Status 

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 meets 

the definition of ‘‘endangered species’’ 

or ‘‘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 a 

species meets the definition of 

‘‘endangered species’’ or ‘‘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. 

Status Throughout All of Its Range 

The Sierra Nevada DPS faces the 

following threats: Deleterious impacts 

associated with small population size 

(including inbreeding depression and 

increased susceptibility to deleterious 

stochastic events) (Factor E), genetic 

swamping due to over-hybridization 

with nonnative red fox (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. 

After evaluating these threats to the 

species and assessing the cumulative 

effect of the threats under the section 

4(a)(1) factors, and consideration of 

comments and new information 

received (including updated population 

estimate information), we continue to 

determine that the Sierra Nevada DPS of 

the Sierra Nevada red fox is presently in 

danger of extinction throughout its 

range, and that endangered status is 

therefore appropriate. The threats 

discussed above, particularly threats 

associated with small population size, 

leave the DPS in danger of extinction 

throughout all of its range at the present 

time rather than likely to become 

endangered in the foreseeable future. 

The DPS thus meets the definition of an 

endangered species rather than a 

threatened species. 

The DPS is likely to face additional 

potential threats in the future. Climate 

projections indicate a continuing loss of 

snowpack depth (Curtis et al. 2014, p. 

9) and of the general subalpine habitat 

to which the Sierra Nevada DPS has 

adapted (Lenihan et al. 2008, pp. S 219, 

S 221). This will likely lead to increased 

numbers of coyotes in high-elevation 

areas, and to increased competition 

between coyotes and Sierra Nevada DPS 

foxes. White-tailed jackrabbit 

populations, an important food source, 

appear to be declining (Simes et al. 

2015. p. 506), and, if the trend 

continues, the resiliency of the Sierra 

Nevada DPS is likely to suffer. Numbers 

of both white-tailed jackrabbit and 

snowshoe hare also tend to fluctuate 

(Simes et al. 2015, pp. 493, 505), which 

would tend to exacerbate the negative 

effects of deleterious chance events if 

those events coincide with periods of 

prey scarcity. As discussed above, 

recent interbreeding with immigrants 

from the Great Basin has helped 

alleviate low pup production that had 

resulted from inbreeding depression. 

However, the population remains small 

so renewed inbreeding depression 

remains a threat, as does the increased 

susceptibility of small populations to 

deleterious stochastic events. 

Our analysis of the DPS’s current and 

future environmental and demographic 

conditions, as well as consideration of 

existing regulatory mechanisms and 

continued coordination with partners 

on conservation efforts (as discussed 

under Available Conservation Measures, 

below), show that the factors used to 

determine the resiliency, representation, 


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and redundancy for the Sierra Nevada 

DPS will likely continue to decline. 

Thus, after assessing the best available 

scientific and commercial information, 

we determine that the Sierra Nevada 

DPS of the Sierra Nevada red fox is in 

danger of extinction throughout all of its 

range. 

Status Throughout a Significant Portion 

of Its Range 

Under the Act and our implementing 

regulations, a species may warrant 

listing if it is in danger of extinction or 

likely to become so in the foreseeable 

future throughout all or a significant 

portion of its range. We have 

determined that the Sierra Nevada DPS 

of Sierra Nevada red fox is in danger of 

extinction throughout all of its range, 

and accordingly, did not undertake an 

analysis of any significant portions of its 

range. Because we have determined that 

this DPS warrants listing as endangered 

throughout all of its range, our 

determination is consistent with the 

decision in Center for Biological 

Diversity v. Everson, 2020 WL 437289 

(D.D.C. Jan. 28, 2020), in which the 

court vacated the aspect of the Final 

Policy on Interpretation of the Phrase 

‘‘Significant Portion of Its Range’’ in the 

Endangered Species Act’s Definitions of 

‘‘Endangered Species’’ and ‘‘Threatened 

Species’’ (79 FR 37578; July 1, 2014) 

that provided the Services do not 

undertake an analysis of significant 

portions of a species’ range if the 

species warrants listing as threatened 

throughout all of its range. 

Determination of Status 

Our review of the best available 

scientific and commercial information 

indicates that the Sierra Nevada DPS of 

Sierra Nevada red fox meets the 

definition of an endangered species. 

Therefore, we are listing this DPS as an 

endangered species in accordance with 

sections 3(6) and 4(a)(1) of the Act. 

Available Conservation Measures 

Conservation measures provided to 

species listed as endangered or 

threatened species under the Act 

include recognition, recovery actions, 

requirements for Federal protection, and 

prohibitions against certain practices. 

Recognition through listing results in 

public awareness, and conservation by 

Federal, State, Tribal, and local 

agencies, private organizations, and 

individuals. The Act encourages 

cooperation with the States and other 

countries and calls for recovery actions 

to be carried out for listed species. The 

protection required by Federal agencies 

and the prohibitions against certain 

activities are discussed, in part, below. 

The primary purpose of the Act is the 

conservation of endangered and 

threatened species and the ecosystems 

upon which they depend. The ultimate 

goal of such conservation efforts is the 

recovery of these listed species, so that 

they no longer need the protective 

measures of the Act. Section 4(f) of the 

Act calls for the Service to develop and 

implement recovery plans for the 

conservation of endangered and 

threatened species. The recovery 

planning process involves the 

identification of actions that are 

necessary to halt or reverse the species’ 

decline by addressing the threats to its 

survival and recovery. The goal of this 

process is to restore listed species to a 

point where they are secure, selfsustaining, and functioning components 

of their ecosystems. 

Recovery planning consists of 

preparing draft and final recovery plans, 

beginning with the development of a 

recovery outline and making it available 

to the public within 30 days of a final 

listing determination. The recovery 

outline guides the immediate 

implementation of urgent recovery 

actions and describes the process to be 

used to develop a recovery plan. 

Revisions of the plan may be done to 

address continuing or new threats to the 

species, as new substantive information 

becomes available. The recovery plan 

also identifies recovery criteria for 

review when a species may be ready for 

reclassification from endangered to 

threatened (‘‘downlisting’’) or removal 

from protected status (‘‘delisting’’), and 

methods for monitoring recovery 

progress. Recovery plans also establish 

a framework for agencies to coordinate 

their recovery efforts and provide 

estimates of the cost of implementing 

recovery tasks. Recovery teams 

(composed of species experts, Federal 

and State agencies, nongovernmental 

organizations, and stakeholders) are 

often established to develop recovery 

plans. When completed, the recovery 

outline, draft recovery plan, and the 

final recovery plan will be available on 

our website (http://www.fws.gov/ 

endangered), or from our Sacramento 

Fish and Wildlife Office (see FOR

FURTHER INFORMATION CONTACT). 

Implementation of recovery actions 

generally requires the participation of a 

broad range of partners, including other 

Federal agencies, States, Tribes, 

nongovernmental organizations, 

businesses, and private landowners. 

Examples of recovery actions include 

habitat restoration (e.g., restoration of 

native vegetation), research, captive 

propagation and reintroduction, and 

outreach and education. The recovery of 

many listed species cannot be 

accomplished solely on Federal lands 

because their range may occur primarily 

or solely on non-Federal lands. To 

achieve recovery of these species 

requires cooperative conservation efforts 

on private, State, and tribal lands. 

Following publication of this final 

rule, funding for recovery actions will 

be available from a variety of sources, 

including Federal budgets, State 

programs, and cost-share grants for nonFederal landowners, the academic 

community, and nongovernmental 

organizations. In addition, pursuant to 

section 6 of the Act, the State of 

California (and Nevada if surveys 

indicate the species occurs there) will 

be eligible for Federal funds to 

implement management actions that 

promote the protection or recovery of 

the DPS. Information on our grant 

programs that are available to aid 

species recovery can be found at: http:// 

www.fws.gov/grants. 

Please let us know if you are 

interested in participating in recovery 

efforts for the Sierra Nevada DPS of 

Sierra Nevada red fox. Additionally, we 

invite you to submit any new 

information on this species whenever it 

becomes available and any information 

you may have for recovery planning 

purposes (see FOR FURTHER INFORMATION

CONTACT). 

Section 7(a) of the Act requires 

Federal agencies to evaluate their 

actions with respect to any species that 

is listed as an endangered or threatened 

species and with respect to its critical 

habitat, if any is designated. Regulations 

implementing this interagency 

cooperation provision of the Act are 

codified at 50 CFR part 402. Section 

7(a)(2) of the Act requires Federal 

agencies to ensure that activities they 

authorize, fund, or carry out are not 

likely to jeopardize the continued 

existence of any endangered or 

threatened species or destroy or 

adversely modify its critical habitat. If a 

Federal action may affect a listed 

species or its critical habitat, the 

responsible Federal agency must enter 

into consultation with the Service. 

Federal agency actions within the 

species’ habitat that may require 

consultation as described in the 

preceding paragraph include: Issuance 

of section 404 Clean Water Act (33 

U.S.C. 1251 et seq.) permits by the U.S. 

Army Corps of Engineers; construction 

and maintenance of roads or highways 

by the Federal Highway Administration; 

and management actions or activities 

taken by the NPS, USFS, or Department 

of Defense that occur in the high 

elevation habitat of the DPS and that 

may affect individual DPS foxes. 


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Federal Register / Vol. 86, No. 146 / Tuesday, August 3, 2021 / Rules and Regulations 41757 

The Act and its implementing 

regulations set forth a series of general 

prohibitions and exceptions that apply 

to endangered wildlife. The prohibitions 

of section 9(a)(1) of the Act, codified at 

50 CFR 17.21, make it illegal for any 

person subject to the jurisdiction of the 

United States to take (which includes 

harass, harm, pursue, hunt, shoot, 

wound, kill, trap, capture, or collect; or 

to attempt any of these) endangered 

wildlife within the United States or on 

the high seas. In addition, it is unlawful 

to import; export; deliver, receive, carry, 

transport, or ship in interstate or foreign 

commerce in the course of commercial 

activity; or sell or offer for sale in 

interstate or foreign commerce any 

species listed as an endangered species. 

It is also illegal to possess, sell, deliver, 

carry, transport, or ship any such 

wildlife that has been taken illegally. 

Certain exceptions apply to employees 

of the Service, the National Marine 

Fisheries Service, other Federal land 

management agencies, and State 

conservation agencies. 

We may issue permits to carry out 

otherwise prohibited activities 

involving endangered wildlife under 

certain circumstances. Regulations 

governing permits are codified at 50 

CFR 17.22. With regard to endangered 

wildlife, a permit may be issued for the 

following purposes: For scientific 

purposes, to enhance the propagation or 

survival of the species, and for 

incidental take in connection with 

otherwise lawful activities. There are 

also certain statutory exemptions from 

the prohibitions, which are found in 

sections 9 and 10 of the Act. 

It is our policy, as published in the 

Federal Register on July 1, 1994 (59 FR 

34272), to identify to the maximum 

extent practicable at the time a species 

is listed, those activities that would or 

would not constitute a violation of 

section 9 of the Act. The intent of this 

policy is to increase public awareness of 

the effect of a final listing on proposed 

and ongoing activities within the range 

of a listed species. Based on the best 

available information, the following 

actions are unlikely to result in a 

violation of section 9, if these activities 

are carried out in accordance with 

existing regulations and permit 

requirements; this list is not 

comprehensive: 

(1) Normal agricultural and 

silvicultural practices, including 

pesticide use; 

(2) Vehicular travel within the range; 

and 

(3) Hiking and backpacking. 

Based on the best available 

information, the following activities 

may potentially result in a violation of 

section 9 of the Act if they are not 

authorized in accordance with 

applicable law; this list is not 

comprehensive: 

Activities that the Service believes 

could potentially harm the Sierra 

Nevada DPS individuals and result in 

‘‘take’’ include, but are not limited to: 

(1) Unauthorized pursuit, capture, or 

injury of members of the species; 

(2) Unauthorized destruction or 

modification of den sites; 

(3) Unauthorized feeding of members 

of the species, or unauthorized food 

disposal within the species’ range, in a 

manner likely to cause habituation; 

(4) Rodenticide applications within 

the species’ range in violation of label 

restrictions; 

(5) Activities that, due to negligence 

or intent, cause wildfire within the 

species’ range; and 

(6) Unauthorized importation into the 

species’ range of nonnative foxes or 

coyotes. 

Questions regarding whether specific 

activities would constitute a violation of 

section 9 of the Act should be directed 

to the Sacramento Fish and Wildlife 

Office (see FOR FURTHER INFORMATION

CONTACT). 

Required Determinations 

National Environmental Policy Act (42 

U.S.C. 4321 et seq.) 

We have determined that 

environmental assessments and 

environmental impact statements, as 

defined under the authority of the 

National Environmental Policy Act, 

need not be prepared in connection 

with listing a species as an endangered 

or threatened species under the 

Endangered Species Act. We published 

a notice outlining our reasons for this 

determination in the Federal Register 

on October 25, 1983 (48 FR 49244). 

Government-to-Government 

Relationship With Tribes 

In accordance with the President’s 

memorandum of April 29, 1994 

(Government-to-Government Relations 

with Native American Tribal 

Governments; 59 FR 22951), Executive 

Order 13175 (Consultation and 

Coordination With Indian Tribal 

Governments), and the Department of 

the Interior’s manual at 512 DM 2, we 

readily acknowledge our responsibility 

to communicate meaningfully with 

recognized Federal Tribes on a 

government-to-government basis. In 

accordance with Secretarial Order 3206 

of June 5, 1997 (American Indian Tribal 

Rights, Federal-Tribal Trust 

Responsibilities, and the Endangered 

Species Act), we readily acknowledge 

our responsibilities to work directly 

with Tribes in developing programs for 

healthy ecosystems, to acknowledge that 

Tribal lands are not subject to the same 

controls as Federal public lands, to 

remain sensitive to Indian culture, and 

to make information available to Tribes. 

In development of the SSA, the 

proposed and final listing rules, and 

recent efforts in developing a 

conservation strategy for the species, we 

coordinated with Tribes by sending 

them notification letters. The Tribes we 

coordinated with were those with lands 

in the general area of the DPS (noting 

that no Tribal lands actually occur 

within the range of the DPS). We did not 

receive comments from Tribes. We will 

continue to consult on a government-togovernment basis with Tribes as 

necessary. 

References Cited 

A complete list of references cited in 

this rulemaking is available on the 

internet at http://www.regulations.gov 

and upon request from the Sacramento 

Fish and Wildlife Office (see FOR

FURTHER INFORMATION CONTACT). 

Authors 

The primary authors of this final rule 

are the staff members of the Fish and 

Wildlife Service’s Species Assessment 

Team, and the Sacramento and Reno 

Fish and Wildlife Offices. 

List of Subjects in 50 CFR Part 17 

Endangered and threatened species, 

Exports, Imports, Reporting and 

recordkeeping requirements, 

Transportation. 

Regulation Promulgation 

Accordingly, we amend part 17, 

subchapter B of chapter I, title 50 of the 

Code of Federal Regulations, as set forth 

below: 

PART 17—ENDANGERED AND 

THREATENED WILDLIFE AND PLANTS 

■ 1. The authority citation for part 17 

continues to read as follows: 

Authority: 16 U.S.C. 1361–1407; 1531– 

1544; 4201–4245, unless otherwise noted. 

■ 2. Amend § 17.11 in paragraph (h) by 

adding an entry for ‘‘Fox, Sierra Nevada 

red [Sierra Nevada DPS]’’ to the List of 

Endangered and Threatened Wildlife in 

alphabetical order under Mammals to 

read as set forth below: 

§ 17.11 Endangered and threatened 

wildlife. 

* * * * * 

(h) * * * 


jbell on DSKJLSW7X2PROD with RULES
41758 Federal Register / Vol. 86, No. 146 / Tuesday, August 3, 2021 / Rules and Regulations 

Common name Scientific name Where listed Status Listing citations and applicable rules 

Mammals 

*******

Fox, Sierra Nevada red 

[Sierra Nevada DPS].

Vulpes vulpes necator .... U.S.A. (CA)—Sierra Nevada.E 86 FR [Insert Federal Register page where the 

document begins], 8/3/2021. 

*******

* * * * * 

Martha Williams, 

Principal Deputy Director Exercising the 

Delegated Authority of the Director, U.S. Fish 

and Wildlife Service. 

[FR Doc. 2021–16249 Filed 8–2–21; 8:45 am] 

BILLING CODE 4333–15–P 


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