Red fox conservation

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Conservation biology of endangered mountain and Sacramento Valley red foxes

We are involved in a variety of collaborative projects aimed at conserving native western red fox populations. Most recently, our efforts have centered on estimating the size and of and threats to the Washington Cascade red fox (work led by graduate student researcher, J. Akins) and the 2 known remaining Sierra Nevada red fox populations (including 1 recently re-discovered north of Yosemite). These mountain red fox populations appear to be evolutionarily specialized to the vanishing subalpine zone of western US mountains and have declined significantly in the last several decades potentially to tens of individuals, suggesting they are in very real danger of extinction. A priority for our group is to understand the proximate and potential climate-based causes of their decline to best inform conservation efforts. At present, we are utilizing noninvasive methods of study, but telemetry ultimately will be needed to address the most pressing questions related to fitness, habitats, and threats.

An overview of these findings can be found in a recent USDA Forest Service Science Findings Bulleting featuring Keith Aubry's work on Washington Cascade red foxes and in several peer-reviewed publications,including

Statham, M. J., Rich, A. C., Lisius, S. K., Sacks, B. N. In Review. Discovery of a remnant population of Sierra Nevada red fox (Vulpes vulpes necator).

Statham, M. J., Sacks, B. N., Aubry, K. A., Perrine, J. D., Wisely, S.M. In Press. The origin of recently established red fox populations in the contiguous United States: Translocations or natural range expansions? (JBI-10-0037). Journal of Mammalogy

Sacks, B. N., M. J, Statham, J. D. Perrine, S.M. Wisely, Aubry, K. A. 2010. North American montane red foxes: expansion, fragmentation, and the origin of the Sacramento Valley red fox. Conservation Genetics 11:1523-1539.

Aubry, K. A., M. J, Statham, B. N. Sacks, J. D. Perrine, and S.M. Wisely. 2009. Phylogeography of the North American red fox: vicariance in Pleistocene forest refugia. Molecular Ecology 18: 2668–2686.

We also study the habitat requirements, population status, and ecology of the endemic Sacramento Valley red fox. We recently used phylogenetic approaches and a large sample of historical museum and recent red fox samples to confirm that this anomalous, lowland ecotype was indeed a native and natural population. Status of this newly named subspecies (V. vulpes patwin) is uncertain and genetic integrity is threatened by introgression from nonnative red foxes.

Sacks, B. N., Moore M., Statham, M. J., Wittmer H. U. 2011. A restricted hybrid zone between native and introduced red fox (Vulpes vulpes) populations suggests reproductive barriers and competitive exclusion. Molecular Ecology 20:326-341.

Sacks, B. N., Wittmer H. U. and Statham, M. J. 2010. The Native Sacramento Valley red fox. Report to the California Department of Fish and Game, May 30, 2010, 49 pp

Perrine, J. D., J. P. Pollinger, B. N. Sacks, R. H. Barrett, and R. K. Wayne. 2007. Genetic evidence for the persistence of the critically endangered Sierra Nevada red fox in California. Conservation Genetics 8: 1083-1095.

Research to date (Sept 2011) has been funded principally by the California Department of Fish and Game, US Forest Service, US Fish and Wildlife Service, Washington Department of Fish and Wildlife, Oregon Zoo Foundation, Norcross Wildlife Foundation, Mazamas, and UC Davis, including the Center for Population Biology and the Veterinary Genetics Laboratory; a significant amount of unpaid time has been contributed by UC Davis and CSU, Sacramento researchers, students, and interns.

Other collaboratoring agencies: National Park Service, Bureau of Land Management, Cal Poly San Luis Obsipo, USMC, and reference samples have been provided by several museums

•Smithsonian Natural History Museum

•University of Puget Sound Museum

•Museum of Vertebrate Zoology, Berkeley

•University of Washington, Burke Museum

•University of Puget Sound Museum

•Oregon State University Museum

•San Diego Natural History Museum

Our reseach involves use of DNA-based, remote-camera, telemetry, den search, and snowtracking surveys for individual identification and enumeration in areas of known presence and surveys to discover additional populations.

(Left) Sacramento Valley red fox (Vulpes vulpes patwin)

(Right) Sacramento Valley red foxes being measured, sampled for parasites, blood, and DNA, and fitted with VHF telemetry collars (people, left to right: B Sacks, M Gabriel)

(Above) Sacramento Valley red foxes being released after radio-collaring (people, left to right: A. Gonzales (CDFG), B Sacks)

(Above) M Statham holds Sacramento Vallery red fox pup, SV9, before release after taking measurements and biological samples

(left) Lassen area Sierra Nevada red fox, by MW Gabriel; (right) Sierra Nevada red fox, north of Yosemite, by J Akins

(left 2) J Akins, (right) W Deacy, snowtracking Sierra Nevada red foxes, north of Yosemite, April 2011

(Left) Sierra Nevada red fox tracks at ~10,000 ft, Feb 2011, A Rich, USFS; (Right) Sierra Nevada red fox, cross morph, north of Yosemite, A Rich, USFS