The Sierra Nevada red fox is one of the rarest mammals in North America: until recently they hadn’t been spotted in Yosemite National Park for nearly 100 years. They used to be plentiful in the region, but hunting and habitat destruction from logging, livestock grazing, and off-road vehicles have cut their population to fewer than 50 individuals. Climate change is also affecting the foxes’ habitat, forcing them farther up into the mountains. Fewer Sierra Nevada foxes mean that their genetic diversity is limited, which may have grave implications for the species’ survival.
The Yosemite Conservancy is funding a study to determine the occurrence and distribution of rare carnivores in the park. Good news: Biologists have announced that in the past two months there have been two sightings of one (or two) Sierra Nevada foxes in the northern part of Yosemite, caught on remote cameras in the back country. (It’s unclear if the cameras have caught two images of the same Sierra Nevada fox or one image each of different foxes.)
Near the remote cameras, the park’s biologists have set up hair snare stations in an effort to collect hair samples for genetic analysis. A few Sierra Nevada foxes have been seen north of the park, in the Sonora Pass area, over the past few years, and the biologists want to determine if the fox(es) spotted in Yosemite are related genetically to the Sonora Pass foxes. The more the merrier: more foxes = a more diverse gene pool, which may help the Sierra Nevada red fox stage a real comeback.