The California Department of Fish and Wildlife (CDFW) has reached a significant goal in conservation science by gaining the ability to study more closely the behavioral patterns of the Sierra Nevada red fox (Vulpes vulpes necator) in the southern Sierra Nevada. The Department’s capacity to closely track the fox’s movements is a critical step toward understanding and protecting one of California’s rarest and most elusive native carnivores.
Due to their rarity, Sierra Nevada red foxes in California are protected as a Threatened Species under the California Endangered Species Act. The population in the Sierra Nevada has additional federal protection, considered an Endangered Species under the federal Endangered Species Act.
The January capture, which occurred near Mammoth Lakes and was conducted by biologists from the CDFW Bishop Field Office, marks the first time the Department has captured, fitted with a GPS-tracking collar and released a Sierra Nevada red fox in the Sierra Nevada.
The foxes in the Sierra Nevada are isolated from their relatives in the Cascade Range, and the movements and behavior of this collared fox will offer scientists a rare opportunity to better understand the ecology and conservation needs of this remote group.
The Sierra Nevada population is estimated to be fewer than 50 individuals. The species is typically extremely wary of humans and inhabits barren, rugged terrain at high elevations. Cautious behavior, remote habitat and low-density populations make them extremely difficult to find and capture, making this a noteworthy event.
“This represents the culmination of 10 years of remote camera and scat surveys to determine the range of the fox in the southern Sierra, and three years of intensive trapping efforts,” said CDFW Environmental Scientist Julia Lawson. “Everyone on the team was thrilled to see our hard work pay off. Our goal is to use what we learn from this collared animal to work toward recovering the population in the long term.”
Location data from the GPS collar and biological samples obtained during the capture of this animal are important management and research tools to help increase CDFW’s understanding of the species, directly support its protection and aid in increasing the efficiency of future capture and survey efforts.
In 2018, a team of scientists led by CDFW Wildlife Biologist Jennifer Carlson attached GPS satellite collars to several Sierra Nevada red foxes in the Lassen Peak region of northern California. That effort helped biologists subsequently locate several dens, leading to a much better understanding of the patterns of reproduction, movement and habitat use in this little-studied species.
Although red foxes are common and widespread throughout North America and Eurasia, the Sierra Nevada red fox is a distinct lineage found only in the high elevation regions of California and Oregon. According to historical accounts, these alpine red foxes have always been exceedingly rare and elusive.
The factors causing the population decline of Sierra Nevada red fox are not fully known, but unregulated hunting and trapping in the early 20th century likely played a major role, and low genetic diversity has continued to weaken the subspecies over time. The population in California’s Sierra Nevada was thought to have disappeared, until an automatic trail camera detected one near Sonora Pass in 2010. Since then, researchers have documented Sierra Nevada red foxes as far south as Cottonwood Pass, west of Lone Pine.
Conservation of the rare Sierra Nevada red fox reflects California’s commitment to biodiversity and the 30x30 Initiative, which seeks to conserve 30% of lands and coastal waters by 2030. Protecting rare species and their habitats strengthens ecosystems, ensuring healthy wildlife populations that support sustainable outdoor activities like hunting, fishing, and wildlife viewing. Science-driven efforts, such as GPS tracking and habitat conservation, help maintain balanced ecosystems where game species and other wildlife can thrive, for the benefit of all Californians.
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