Facts About Foxes: Meet the Endangered Sierra Nevada Red Fox

High in California’s Sierra Nevada, the elevation lends itself to cold and snowy seasons. A unique subspecies of montane red fox lives here. The Sierra Nevada red fox is specially adapted to this environment but fewer than 40 individuals may be left on the landscape.

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USFS

Defenders of Wildlife is working to increase protections for the Sierra Nevada red fox so the species has a fighting chance of recovery. Read on to get to know this incredible fox, including its unique adaptations, why it’s endangered and what we’re doing to defend it.

What types of foxes live in North America?

There are six species of fox found in North America. Red foxes (Vulpes vulpes) and gray foxes (Urocyon cinereoargenteus) are the most common.  

The Sierra Nevada red fox (Vulpes vulpes necator) is one of 10 subspecies of red foxes in North America. It’s one of three mountain-dwelling subspecies, the other two are the Rocky Mountain and Cascade foxes.  

How are Sierra Nevada red foxes different from other red fox species?

Sierra Nevada red foxes have reddish to black fur, similar to other red foxes. On their back, though, some Sierra Nevada red foxes have a distinctive intermediate “cross-fur” pattern, with blonde and darker hairs crisscrossing.

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USFWS

The biggest distinction is the Sierra Nevada red fox’s specialized adaptations for cold and snow. They have well-furred paws as part of their winter coat, longer hind legs and are slightly smaller. Each of these adaptations is thought to help this fox hunt in the snow!

What do foxes eat?

Foxes are omnivores, eating both meat and plants. Most foxes eat small animals — with many species specializing in a few specific prey items — along with berries, seeds and nuts. Sierra Nevada red foxes primarily eat rodents, snowshoe hares and white-tailed jackrabbits. They also will eat caches of whitebark pinenuts when the trees release large number of nuts every few years.

Where do these foxes live?

Both the Sierra Nevada and the Cascades subspecies of red fox historically ranged from Mt. Hood in the Oregon Cascades, through the Southern Cascades to Mt. Shasta and Mt. Lassen in northern California, and down the spine of the Sierra Nevada to the area of Sequoia-Kings Canyon National Parks. Hunting, poisoning and predator eradication programs in the 1800s through the 1900s caused a decline so extreme that the Sierra Nevada subspecies was believed to be largely or entirely extirpated from California. Then, in 2010, the fox was rediscovered by a remote camera trap near Sonora Pass.  

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Barry Klein

While still relatively rare and low in numbers, Sierra Nevada red foxes are now found along the Sierra Crest from just south of Lake Tahoe southward through Yosemite and Sequoia-Kings Canyon National Parks. In addition, their range overlaps with substantial tracts of Forest Service land — including designated wilderness areas — a Marine Corps mountain warfare training center and a snowmobile area.  

In 2021, when the U.S. Fish and Wildlife Service listed the Sierra Nevada red fox under the Endangered Species Act, there was an estimated 18 to 39 individuals known to exist in the Sierra Nevada distinct population segment (the portion of the Sierra Nevada subspecies south of Mt. Lassen).

What threatens Sierra Nevada red foxes today?

When listing the Sierra Nevada red fox distinct population segment, FWS identified three primary threats:

1. Small population size: There is a high chance of inbreeding and less genetic diversity with smaller populations. Inbreeding and lack of genetic diversity can lead to a higher susceptibility to diseases and other catastrophic events.
2. Hybridization with non-native red foxes: Lowland red foxes were introduced from the Midwest in the late 1800s for fur-farming. These non-native subspecies do not have the specialized characteristics native Sierra Nevada red foxes possess. Adaptations are less pronounced in hybrid kits.
3. Reduced snowpack levels due to climate change: Sierra Nevada red foxes are specialized for snowy areas, so other carnivores – like coyotes – may outperform or prey upon the fox in areas with now less snowy conditions due to the impacts of the changing climate.

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U.S. Department of Agriculture

How to help these cute foxes

Defenders is currently fighting for much needed critical habitat designation for these foxes. These important habitat protections would help reduce additional habitat stressors and risks of additional habitat modification in the long term. They would also protect connectivity between native red fox populations, helping increase population size.

You can help Sierra Nevada red foxes too by sharing this story with your friends, family and followers. When exploring areas where endangered wildlife lives, be mindful of and do not disturb scientific monitoring equipment including camera traps. If you think you’ve come across equipment that has been damaged or moved, make a note or take a photo of the item and location and report it to a local ranger. Additionally, never feed wildlife and pick up all trash when hiking in the High Sierra, especially along the Pacific Crest Trail. Feeding and trash deposition make foxes accustomed to humans, which ultimately can place them in danger.

Finally, if you are able, support organizations like Defenders that are speaking up for wildlife and trying to protect endangered species and their habitats.