Rare foxes spotted in Oregon may help California population
BEND — Biologists are hoping a rare subspecies of foxes spotted in Oregon can help boost their number in California.
Biologists captured and radio-collared two of the Sierra Nevada red foxes found in Oregon, The Bulletin reported. There are believed to be fewer than 50 of the foxes in Northern California.
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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. Red fox fur was sought after by trappers during the early part of last century because it was softer than California’s grey fox. Sierra Nevada populations have been reduced by grazing in meadows, which reduces prey populations, and by trapping, logging, and recreational disturbances. Human activities of any significant degree in areas of core habitat will certainly put pressure on this highly endangered species. Given the low numbers of the Sierra Nevada red fox and the increase of non-native red fox population, particularly in the Central Valley of California, competition from this non-native species is increasingly a concern for the Sierra Nevada subspecies.
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Sierra Nevada red fox (Vulpes vulpes necator)
Update September 2010...new siting of Sierra Nevada red fox living in Sonora Pass area! See story, below...
Threats
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. Red fox fur was sought after by trappers during the early part of last century because it was softer than California’s grey fox. Sierra Nevada populations have been reduced by grazing in meadows, which reduces prey populations, and by trapping, logging, and recreational disturbances. Human activities of any significant degree in areas of core habitat will certainly put pressure on this highly endangered species. Given the low numbers of the Sierra Nevada red fox and the increase of non-native red fox population, particularly in the Central Valley of California, competition from this non-native species is increasingly a concern for the Sierra Nevada subspecies.Habitat
The range of the Sierra Nevada red fox is limited to the conifer forests and rugged alpine landscape of the Sierra Nevada and Cascade ranges between 4,000 feet and 12,000 feet. Preferred habitat for the Sierra Nevada red fox appears to be red fir and lodgepole pine forests in the subalpine zone and alpine fell-fields of the Sierra Nevada. Open areas are used for hunting, forested habitats for cover and reproduction. Edges are utilized extensively for tracking and stalking prey. The red fox hunts in forest openings, meadows, and barren rocky areas associated with its high elevation habitats. Found mostly above 6,000 feet in the summer months, Sierra Nevada populations were historically found in a variety of habitats, including alpine dwarf-shrub, wet meadow, subalpine conifer, lodgepole pine, red fir, aspen, montane chaparral, montane riparian, mixed conifer, and ponderosa pine. Jeffrey pine, eastside pine, and montane hardwood-conifer also are used. This species is known to inhabit vegetation types similar to those used by the marten and wolverine. The range of the Red fox is from the northern California Cascades eastward to the northern Sierra Nevada and then south along the Sierran crest to Tulare County.
Conservation
The current range and distribution of Sierra Nevada red fox is unknown. Because of this and the scientific certainty of its hazardously low numbers, greater research is needed to ascertain the full extent of the red foxes range. Recent research conducted in the vicinity of Lassen Peak, has begun the process of understanding exactly how rare the native Sierra Nevada red fox is. This research conducted in the late 1990’s estimated that only 10-15 individuals were likely present in the Lassen Peak area--a number certainly low enough to cause concern over the possibility of localized extinction and highly endangered status throughout its historic range. Other historical evidence related to the Sierra Nevada red fox has led scientists to believe that it likely never occurred in large numbers. From 1940 to 1959, 135 pelts were taken by trappers and that number shrunk down to 2 pelts a year by the 1970’s. It is possible that red fox numbers were declining before these statistics were collected but in either case the Sierra Nevada red fox has certainly been in serious trouble for a very long time. The State of California banned red fox trapping in 1974.
Status
Until this summer (2010), the only known current population has been in the vicinity of Lassen Peak in Lassen Volcanic National Park, and also within Lassen National Forest. Periodic sightings have been reported by inexperienced observers throughout the rest of the Sierra Nevada but have not been documented by experts. In August, Forest Service biologists retrieved photographs from a bait station trail camera near Sonora Pass. DNA retrieved from saliva found on the tooth punctures in the bait bag was then analyzed by canid researchers Ben Sacks and Mark Statham at the UC Davis Veterinary Genetics Laboratory. Sacks and his colleagues confirmed that the DNA was from the rare Sierra Nevada red fox.
The Sierra Nevada red fox is genetically very distinct from red fox populations in coastal lowlands, the San Joaquin Valley and Southern California. These red foxes are derived from introduced foxes from the eastern United States (and Alaska). The Sacramento Valley subspecies is a genetically distinct native species, however.
The Sierra Nevada red fox is so uncommon that the California Fish and Game Commission declared it threatened in 1980 and it is considered critically endangered by the California Department of Fish and Game. The U.S. Forest Service, Pacific Southwest Research Station lists the Sierra Nevada red fox as a sensitive species.
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