Sierra Nevada red fox
|Sierra Nevada red fox|
|High Sierra Red Fox Discovered in Sierras August, 2010|
|Subspecies:||V. v. necator|
|Vulpes vulpes necator
The Sierra Nevada red fox (Vulpes vulpes necator), also known as the High Sierra fox is a subspecies of red fox and one of the most endangered mammals in North America. Until recently, only a few dozen were known to exist in a remnant population near Lassen Volcanic National Park. Recent webcam discoveries of two additional surviving remnant populations near Sonora Pass in 2010 and on Mount Hood, Oregon in 2012 raise hopes for the species' survival. The State of California banned trapping of the Sierra Nevada red fox in 1980, after annual pelt takes had dwindled to 2 per year by the 1970s. It is considered to be critically endangered by the California Department of Fish and Game. On April 26, 2011, the Center for Biological Diversity petitioned the federal government to protect the High Sierra fox under the Endangered Species Act. One serious threat to the Sierra Nevada red fox would be interbreeding with non-native red foxes which have been introduced into California's (Central Valley, San Francisco Bay Area and southern California) from America's eastern and midwestern populations. With only about 50 animals remaining, the U.S. Fish and Wildlife Service announced on Dec. 30, 2011 that it is beginning a full status review, in response to the petition.
The Sierra Nevada red fox is distinguished from members of the introduced lowland population of red foxes by its slightly smaller size and darker colored fur, and by its limited geographical range above 4,500 feet. Red fox fur was sought after by trappers during the early part of last century because it was softer than California’s grey fox.
Red foxes (Vulpes vulpes) are distributed worldwide and in virtually all habitats, however there are three subalpine subspecies whose range is restricted to alpine and subalpine meadows and montane boreal forests, of which the Sierra Nevada red fox is one of the latter. In 1906 naturalist Frank Stephens described the High Sierra fox as occurring only above 6,000 feet in the Sierra Nevada and was initially described at 9,500 feet in Whitney Meadows, Mt. Whitney. Its historical distribution was Oregon's Cascades north to the Columbia River and south to California's southern Sierra Nevada Mountains. Grinnell stated that the Sierra Nevada red fox was "“restricted to the highest timbered peaks and ridges of the main Sierra Nevada,” not occurring below 4500 feet, and considered the Lassen Peak region to be a major population center. Perrine's study of Mt. Lassen using 144 baited motion-sensitive cameras from 1997-2002 found no foxes below 4520 feet as well. The Lassen foxes all had the same Mitochondrial DNA (mtDNA) haplotype, which was the most common haplotype among historic V. v. necator specimens and was rare in the exotic fox populations from California’s lowlands.
The High Sierra foxes current range has been extended by recent webcam discoveries. In August, 2010, a handful were discovered fortuitously by motion sensitive cameras near Sonora Pass set up to detect rare Fisher (Martes pennanti) and Marten (Martes americana). These Sierra Nevada red foxes were photographed in the central Sierra Nevada, more than 200 miles away from Lassen Peak, and genetic analysis of saliva from bites on a bait bag was compared to museum specimens from prior to 1926, confirming their identity. They had not been seen in the Sonora Pass area since 1925. In March 2011 a ski slope groomer on Mount Hood snapped a shot with his flip phone which spurred scientists to set up webcams in Oregon. These subsequently confirmed fox populations not only on Mount Hood, but also 200+ miles south at Crater Lake in June 2012.
Although the California Central Valley red fox population had been considered non-native, genetic studies beginning in 2010 have shown that in the northern section, i.e. the Sacramento River valley, the foxes are genetically different from the introduced red fox populations to the south and in the Bay Area and should be regarded as native. There are historical accounts of these foxes living in arid valley grassland conditions quite distinct from the montane Sierra Nevada population since the 1880s. Also, these native lowland California red fox are larger than the Sierra Nevada red fox. The genetic evidence indicates that this new Sacramento Valley red fox is a distinct subspecies (Vulpes vulpes patwin) and that they are more closely related to the native montane fox than the introduced red fox in the rest of the state. A relatively restricted and narrow hybrid zone between the lowland native and non-native foxes has been stable for several decades, despite five-fold expansion of non-native red fox populations throughout the rest of lowland and coastal California. This may be due to the foxes monogamous mating system and highly specific mate selection.
A 2005 study of the then remnant population surviving on Mt. Lassen found that the foxes are nocturnal hunters whose diet was predominantly mammals, especially rodents and mule deer (Odocoileus hemionus), supplemented by birds, insects and Pinemat manzanita (Arctostaphylos nevadensis) berries as seasonally available. Lagomorphs (hares, rabbits, pikas) were virtually absent from the foxes diet.
Upon reaching Truckey's Lake (now Donner Lake) on November 14, 1844, the Stephens-Townsend-Murphy Party, the first wagon train to cross the Sierra Nevada, left six of their eleven wagons because of difficulties getting the wagons over what would become Donner Pass. Eighteen year old Moses Schallenberger spent the winter there watching over the wagons, surviving the impassably deep snows only by trapping High Sierra foxes for food. He lived on fox which he trapped on average of one every two days, until he was rescued by Canadian-American Dennis Martin at the end of February, 1845, who showed him how to construct proper snowshoes.
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- Matt Weiser (2011-04-27). "Protections sought for Sierra Nevada red fox". The Modesto Bee. Retrieved 2011-11-28.
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- Frank Stephens (1906). California Mammals. West Coast Publishing Co. p. 218. Retrieved 2011-04-28.
- J. Grinnell, J. Dixon, J. Linsdale (1930). Fur-bearing mammals of California. Berkeley, California: University of California Press. ISBN 978-0-7812-5041-2.
- John Dixon Perrine III (Fall 2005). Ecology of Red Fox (Vulpes vulpes) in the Lassen Peak Region of California, USA (Thesis). University of California, Berkeley. Retrieved 2011-04-30.
- John D. Perrine, John P. Pollinger, Benjamin N. Sacks, Reginald H. Barrett, Robert K. Wayne (2007). "Genetic evidence for the persistence of the critically endangered Sierra Nevada red fox in California". Conservation Genetics: 1083–1095. Retrieved 2011-04-21.
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- John D. Perrine, John P. Pollinger, Benjamin N. Sacks, Reginald H. Barrett, Robert K. Wayne (2007). "Genetic evidence for the persistence of the critically endangered Sierra Nevada red fox in California". Conservation Genetics: 1083–1095. doi:10.1007/s10592-006-9265-z.
- Sacks BN, Wittmer HU, Statham MJ (2010-05-30). The Native Sacramento Valley red fox. Report to the California Department of Fish and Game. (Report). pp. 49. http://www.vgl.ucdavis.edu/cdcg/documents/30May2010_FinalReport_ForDistribution_000.pdf. Retrieved 2012-07-07.
- Benjamin N. Sacks, Mark J. Statham, John D. Perrine, Samantha M. Wisely, Keith B. Aubry (2010). "North American montane red foxes: expansion, fragmentation, and the origin of the Sacramento Valley red fox". Conservation Genetics: 523–1539. doi:10.1007/s10592-010-0053-4.
- Benjamin N. Sacks, Marcelle Moore, Mark J. Statham, Heiko U. Wittmer (2011). "A restricted hybrid zone between native and introduced red fox (Vulpes vulpes) populations suggests reproductive barriers and competitive exclusion". Molecular Ecology: 326–341. doi:10.1111/j.1365-294X.2010.04943.x.
- Moses Schallenberger (2007). Charles H. Todd, ed. Moses Schallenberger at Truckey's Lake, 1844-1845. Winters, California: 19th Century Publications.