FWS Focus

Overview

Characteristics
Overview

The Sierra Nevada red fox is smaller than most other fox species, has fuzzy paws and is covered by a thick fur coat - all adaptations to help it survive the heavy winter snows and challenging alpine conditions where it lives. Despite its name, Sierra Nevada red foxes can be either mostly red, mostly black or a grayish brown cross phase. 

The Sierra Nevada Distinct Population Segment was listed as endangered in 2021. Only about 18 to 39 individuals remain in the wild today. This small population continues to be vulnerable to losses from unpredictable events like wildfire and drought, competition with coyotes, decreases in prey numbers and widespread hybridization with non-native foxes. Sightings of the Sierra Nevada population have been limited to federal lands in Alpine, Fresno, Inyo, Madera, Mono and Tuolumne counties.

The Southern Cascades Distinct Population Segment includes several populations, located at various points along the lower Cascades from Lassen National Park in California, to near the Columbia River on Oregon's northern border. The Southern Cascades Distinct Population Segment was not listed in 2021, as it is not expected to see substantial population decline across its range.

The Sierra Nevada red fox is threatened by unpredictable events like wildfire and drought, competition with coyotes, decreases in prey numbers and widespread hybridization with non-native foxes.

Scientific Name

Vulpes vulpes necator
Common Name
Sierra Nevada red fox
FWS Category
Mammals
Kingdom

Location in Taxonomic Tree

Identification Numbers

TSN:

Characteristics

Characteristic category

Behavior

Characteristics
Behavior

Sierra Nevada red fox are most active at dusk and at night when many rodents are most active. 

Characteristic category

Habitat

Characteristics
Habitat

The fox primarily lives in mountain areas above 9,000 feet in elevation; however, they have been documented as low as 6,000 feet.

Forest

A dense growth of trees and underbrush covering a large tract.

Mountain

A landmass that projects conspicuously above its surroundings and is higher than a hill.

Characteristic category

Food

Characteristics
Food

Sierra Nevada red fox appear to be opportunistic predators and foragers, with a diet primarily composed of small rodents. Their favorite foods are hares and gophers, but they also eat manzanita berries and deer carrion, particularly in winter and spring. 

Characteristic category

Physical Characteristics

Characteristics
Size & Shape

The Sierra Nevada red fox is smaller than most other fox species, has fuzzy paws, and is covered by a thick fur coat - all adaptations to help it survive the heavy winter snows and challenging alpine conditions.

Color & Pattern

Despite its name, Sierra Nevada red foxes can be either mostly red, mostly black or a grayish brown cross phase. 

Weight

Weight: 9.3 pounds (4.2 kilograms) for males; 7.3 pounds (3.3 kilograms) for females

Characteristic category

Life Cycle

Characteristics
Life Span

The life span is unknown, but individual, wild foxes have been seen for up to 7 years. 

Reproduction

Little information is available on the reproduction of the Sierra Nevada red fox. However, it’s likely similar to the North American red fox subspecies. Other North American subspecies are predominately monogamous and mate over several weeks in the late winter and early spring. The gestation period for red fox is 51 to 53 days, with birth occurring from March through May in sheltered dens, which are usually made from natural openings in rock piles at the base of cliffs and slopes.

Geography

Characteristics
Range

Historically, the fox ranged from the Oregon-Washington border to the southern end of the Sierra Nevada. Today, the Sierra Nevada red fox consists of two distinct population segments that live in California’s Sierra Nevada, known as the Sierra Nevada Distinct Population Segment, and the southern Cascade Range of California and Oregon, known as the Southern Cascades Distinct Population Segment, in areas above 9,000 feet in elevation. 

The Sierra Nevada Distinct Population Segment sightings have been limited to federal lands in Alpine, Fresno, Inyo, Madera, Mono and Tuolumne counties. The Southern Cascades Distinct Population Segment includes several populations, located at various points along the lower Cascades from Lassen National Park in California to near the Columbia River on Oregon's northern border. 

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Timeline

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