VALLEJO, Calif., Dec. 03, 2010 — After an absence of more than two decades, it appears that the Sierra Nevada red fox has returned to northern California.
In August 2010 a female Sierra Nevada red fox was discovered in the Humboldt-Toiyabe National Forest. In the fall, two additional red foxes were photographed in the Stanislaus National Forest, within two to four miles of the original. This find implies the continued persistence of a genetically-unique population of Sierra Nevada red fox in the southern Sierra Nevada, rather than a single individual.
Adam Rich, a wildlife biologist for the Stanislaus National Forest, worked with a team of high school volunteers to collect scat at the two new photo locations. Canid geneticists of the Interagency Sierra Nevada Red Fox Working Group, Drs. Ben Sacks and Mark Statham of UC Davis, analyzed DNA from the scat to identify a male Sierra Nevada red fox, potentially related to the original female photographed. “Scat” is feces (droppings) that may contain the animal’s DNA so scientists can get specimens without harming (or even capturing) the animal.
This red fox subspecies or geographically–distinct race is one of the rarest, most elusive and least-known mammals in California and the United States. Once widespread throughout California’s mountains, the Sierra Nevada red fox has become very rare in recent decades, with only a single known population of fewer than 20 individuals in the Lassen region. The U.S. Forest Service, the California Department of Fish and Game, the National Park Service, and researchers at both UC Davis and Cal Poly San Luis Obispo are working together to expand the survey effort to gain a better understanding of the distribution, population size, habitat relationships, and threats to this population of Sierra Nevada red fox, along with the Lassen population. These surveys are a simple and cost effective way to manage and monitor rare wildlife.
The Sierra Nevada red fox is a rare but essential part of the Sierra and Cascade mountain ecosystems in California. As a small carnivore preying on mice, squirrels, and hares, its food habits contribute to ecological balance. Due to its scarcity, the Sierra Nevada red fox was state-listed as threatened in 1980, and is a U.S. Forest Service sensitive species.
California has several different species of foxes (red, gray, island, and kit) that can readily be distinguished in the field by coat color as well as the geographical area and habitat where they live. Red foxes have a characteristic reddish to reddish-yellow coloration with black legs and a white tail tip. The back side of their ears is always black, easily visible as the animal moves away. Also known as “mountain red fox,” the Sierra Nevada red fox exists in alpine habitat high in the Sierra Nevada and Cascade mountain ranges. They are rarely seen below 5,000 feet in elevation, and are usually found above 7,000 feet. Biologists know little about the specific habitat needs of this elusive animal, though it seems to favor broken subalpine forestland with scattered meadows, and alpine habitat above the tree line.
It is a little-known fact that red foxes can exhibit other color phases, including black, silver, and “cross” (like the red and black individual photographed on the Humboldt-Toiyabe NF). The white tip of the tail is the main distinguishing mark of the red fox. In contrast, gray fox, with their black-tipped tails, are widely distributed in California, though they favor brush-covered areas and oak woodlands. People sometimes confuse the reddish side coloration of gray foxes with red foxes, so observers should pay special attention to the tail-tip coloration and the elevation and habitat type to differentiate a red from gray fox.
For more information on this rare subspecies, please see: