Sierra Nevada red fox

Like other montane foxes, Sierra Nevada red foxes are somewhat smaller and lighter in weight than lowland North American red foxes. Their fur may be red, cross, or silver phase with the red phase having the greyish-blonde coloration characteristic of montane foxes.{{cite web |author=John Perrine |display-authors=etal |title=Sierra Nevada Red Fox (Vulpes vulpes necator): A Conservation Assessment |year=2010 |publisher=United States Department of Agriculture |url=http://nrm.dfg.ca.gov/FileHandler.ashx?DocumentVersionID=41941 |access-date=2015-12-16 }} All three phases occur in the Oregon Cascade and Sonora Pass populations, but only red phase individuals have been found in the Lassen population. Their foot pads are fur-covered, a common adaptation to travel over snow. Sierra Nevada red foxes are relatively long-lived compared to other red foxes, typically living five to six years. Non-invasively monitored females have either not bred or bred a minority of years.

File:Sierra Nevada red fox in Yosemite 2014-12-13.jpg

Sierra Nevada red foxes are one of three fox subspecies in the montane clade of North America, occurring in the Cascade Mountains south of the Columbia River and California's Sierra Nevada range.{{cite journal|last=Sacks |first=Benjamin |title=North American montane red foxes: expansion, fragmentation, and the origin of the Sacramento Valley red fox |journal=Conservation Genetics |volume=11 |issue=4 |date=June 2010 |pages=1523–1539 |doi=10.1007/s10592-010-0053-4 |s2cid=7164254 |url=https://www.vgl.ucdavis.edu/cdcg/documents/Sacksetal2010-ConsGen_001.pdf |access-date=2015-12-05|doi-access=free |bibcode=2010ConG...11.1523S }}{{cite journal|last=Wells |first=Gail |year=2011 |title=Tracing the fox family tree: the North American red fox has a diverse ancestry forged during successive ice ages |publisher=Science Findings |issue=132 |pages=5 |url=http://www.fs.fed.us/pnw/sciencef/scifi132.pdf |access-date=2015-12-05}} Joseph Grinnell identified separated montane fox populations in the Oregon Cascades, Mount Shasta, Lassen Peak, and Sierra Nevada in 1937.{{cite book |title=Fur-bearing mammals of California |author=J. Grinnell |author2=J. Dixon |author3=J. Linsdale |year=1937 |publisher=University of California Press |location=Berkeley, California |isbn=978-0-7812-5041-2 }} Study then lapsed for approximately 60 to 75 years, depending on location. Rediscovery of the Lassen population began in 1993 followed by detection of a Sierra Nevada population at Sonora Pass in 2010{{cite news |title=Fox spit helped Forest Service confirm rare find |publisher=University of California, Davis |date=2010-09-03 |url=http://news.ucdavis.edu/search/printable_news.lasso?id=9596&table=news |access-date=2011-04-30 }}{{cite news |title='Extinct' fox rediscovered in California |work=WildlifeExtra.com |date=September 2010 |url=http://www.wildlifeextra.com/go/news/sierra-nevada-fox.html#cr |access-date=2015-01-29 }}{{cite journal|author=Mark J. Statham |author2=Adam C. Rich |author3=Sherri K. Lisius |author4=Benjamin N. Sacks |title=Discovery of a remnant population of Sierra Nevada red fox (Vulpes vulpes necator) |journal=Northwest Science |volume=86 |issue=2 |year=2012 |pages=122–132 |doi=10.3955/046.086.0204 |bibcode=2012NWSci..86..122S |s2cid=32876374 |url=https://www.vgl.ucdavis.edu/cdcg/documents/Stathametal2012-SNRFdiscovery.pdf |access-date=2015-12-16}} and rediscovery of the Oregon Cascades population began in 2011.{{cite news |title=Threatened California fox species found in Oregon |author=Carolyn Jones |work=San Francisco Chronicle |date=2012-06-20 |url=http://www.sfgate.com/science/article/Threatened-California-fox-species-found-in-Oregon-3646317.php |access-date=2015-12-05 }} The Lassen and Sonora Pass populations are isolated from each other and it is unknown if a population remains at Mount Shasta.

Genetic studies beginning in 2010 have also shown the Sacramento Valley red fox (Vulpes vulpes patwin) is a distinct subspecies more closely related to the Sierra Nevada red fox than introduced lowland red foxes present in the rest of California.{{cite report|url=http://www.vgl.ucdavis.edu/cdcg/documents/30May2010_FinalReport_ForDistribution_000.pdf|title=The Native Sacramento Valley red fox. Report to the California Department of Fish and Game|date=2010-05-30|pages=49|access-date=2012-07-07|vauthors=Sacks BN, Wittmer HU, Statham MJ}} A relatively restricted and narrow hybrid zone between Sacramento Valley red and non-native foxes has been stable for several decades, despite the 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 habits and highly specific mate selection.{{cite journal|author=Benjamin N. Sacks|author2=Marcelle Moore|author3=Mark J. Statham|author4=Heiko U. Wittmer|year=2011|title=A restricted hybrid zone between native and introduced red fox (Vulpes vulpes) populations suggests reproductive barriers and competitive exclusion|url=https://www.vgl.ucdavis.edu/cdcg/documents/Sacksetal2011_000.pdf|journal=Molecular Ecology|volume=20|issue=2|pages=326–341|doi=10.1111/j.1365-294X.2010.04943.x|pmid=21143330|bibcode=2011MolEc..20..326S |access-date=2015-12-05|s2cid=2995171}} A similar genetic boundary may exist between Sierra Nevada red foxes and both the Sacramento Valley red fox and the introduced lowland foxes.

File:Sierra Nevada Red Fox imported from iNaturalist photo 289085807 on 6 December 2024.jpg Sierra Nevada red fox]]

The extent of the Sierra Nevada red fox populations is an area of active research. In Oregon, ongoing studies at Mount Hood{{cite web |title=Wolverine Tracking Project 2014-5 Season Report |publisher=Cascadia Wild |date=2015 |url=http://www.cascadiawild.org/uploads/8/2/5/8/8258980/wolverine_tracking_project_2014-5_report.pdf |access-date=2015-12-05}} and Central Oregon{{cite web |title=Final Progress Report: Forest Carnivore Research in the Northern Cascades of Oregon |publisher=Oregon Department of Fish and Wildlife |date=2014 |url=http://www.dfw.state.or.us/resources/hunting/small_game/docs/forest_carnivore_project_report_hiller.pdf }}{{cite web |title=Citizen Science Fall 2015 Annual Report |publisher=Friends of the Central Cascades Wilderness |date=2015-10-17 |url=http://centralcascades.org/wp-content/uploads/2014/12/FCCW-Citizen-Science-2014-15-Annual-Report.pdf |access-date=2015-12-05}} were prompted by observations in 2012 and 2013. Recent genetic evidence also suggests range expansion into western Oregon since the 1940s.{{cite journal|last=Statham |first=Mark |title=The origin of recently established red fox populations in the United States: translocations or natural range expansions? |journal=Journal of Mammalogy |volume=93 |issue=1 |date=February 2012 |pages=52–65 |doi=10.1644/11-MAMM-A-033.1 |url=http://www.mammalsociety.org/articles/origin-recently-established-red-fox-populations-united-states-translocations-or-natural-ran |format=PDF |access-date=2016-02-03|doi-access=free }} In California, detections occurred in northern Yosemite National Park the winter of 2014–15,{{cite web |title=Fox photographed with remote motion-sensitive camera |date=2015-01-28 |publisher=National Park Service |url=http://www.nps.gov/yose/parknews/rare-sierra-nevada-red-fox-spotted-in-yosemite-national-park.htm |access-date=2015-01-29 }}{{cite news |title=Rare Sierra Nevada Red Fox Caught On Camera In Yosemite National Park |work=The Huffington Post |date=2015-01-29 |url=http://www.huffingtonpost.com/2015/01/28/sierra-nevada-red-fox-yosemite_n_6567680.html }} the Stanislaus National Forest in late 2015,{{cite web |title=CSERC cameras detect rare fox at new location in the Stanislaus Forest!!! |date=2015-10-30 |publisher=Central Sierra Environmental Resource Center |url=http://www.cserc.org/news/cserc-cameras-detect-rare-fox-new-location-the-stanislaus-forest/ |access-date=2015-12-16 }} and in Lassen Volcanic National Park in 2018.{{citation |url= http://amp.sacbee.com/latest-news/article204035134.html |title= They've tried for years to catch a Sierra Nevada red fox. Now scientists have caught two |work=The Sacramento Bee |date=March 18, 2018}} The first two areas are near Sonora Pass, but it has not been confirmed the individuals are part of the Sonora Pass population.

Elevations occupied by the Sierra Nevada red fox are also an area of current research. Oregon detections have occurred between 4900 and 6500 feet, though observations of Cascade red fox in Washington suggest lower elevations may be accessed during dispersal. John Perrine's study on Lassen Peak, using 144 baited motion-sensitive cameras from 1997 to 2002, found no foxes below 4520 feet.{{cite journal |title=Genetic evidence for the persistence of the critically endangered Sierra Nevada red fox in California |author=John D. Perrine |author2=John P. Pollinger |author3=Benjamin N. Sacks |author4=Reginald H. Barrett |author5=Robert K. Wayne |year=2007 |pages=1083–1095 |journal=Conservation Genetics |url=http://www.sierraforestlegacy.org/Resources/Conservation/SierraNevadaWildlife/SierraNevadaRedFox/RF-Perrine07.pdf |access-date=2011-04-21 |doi=10.1007/s10592-006-9265-z |volume=8|issue=5 |bibcode=2007ConG....8.1083P |s2cid=20629983 }} Historically, Grinnell's 1937 survey found occurrence from 4500 to 11,500 feet in California.{{rp|381}} The fox was initially described in 1906 as occurring above 6000 feet in the high Sierra.{{cite book |title=California Mammals |author=Frank Stephens |page=[https://archive.org/details/californiamammal00step/page/n230 218] |url=https://archive.org/details/californiamammal00step |quote=high sierra fox. |access-date=2015-12-16 |publisher=West Coast Publishing Co. |year=1906 }}{{rp|281}}

A 2005 study of the then remnant population surviving on Mount Lassen found that the foxes are nocturnal hunters whose diet is predominantly mammals, especially rodents and mule deer, supplemented by birds, insects and pinemat manzanita berries as seasonally available. Lagomorphs (hares, rabbits and pikas) were virtually absent from the foxes' diet.

File:Redfox - Flickr - USDAgov.jpg

Documented trapping of the Sierra Nevada red fox may have begun when Moses Schallenberger of the Stephens–Townsend–Murphy Party spent the winter of 1844–45 at Donner Pass, taking an average of one red fox every two days.{{cite book |title=Moses Schallenberger at Truckey's Lake, 1844-1845 |author=Moses Schallenberger |editor=Charles H. Todd |publisher=19th Century Publications |location=Winters, California |year=2007 }} Red fox fur was sought after by trappers during the early part of the 20th century because it was softer than that of California’s gray fox (Urocyon cinereoargenteus).{{cite web |title=Sierra Nevada red fox (Vulpes vulpes necator) |publisher=Sierra Forest Legacy |url=http://www.sierraforestlegacy.org/FC_SierraNevadaWildlifeRisk/SierraNevadaRedFox.php |access-date=2011-04-30 }} The State of California banned trapping of Sierra Nevada red foxes in 1974 and listed the subspecies as threatened in 1980.{{Cite thesis |title=Ecology of Red Fox (Vulpes vulpes) in the Lassen Peak Region of California, USA |author=John Perrine |publisher=University of California, Berkeley |date=Fall 2005 |url=http://www.sierraforestlegacy.org/Resources/Conservation/SierraNevadaWildlife/SierraNevadaRedFox/RF-Perrine05.pdf |access-date=2011-04-30 }}

The fox's Sierra Nevada Distinct Population Segment is estimated at 29 adults near Sonora Pass in California. The Southern Cascades Distinct Population Segment consists of an estimated 42 adults near Lassen Volcanic National Park and an unknown number of individuals in five areas of Oregon.{{cite web |title=12-Month Finding on a Petition To List Sierra Nevada Red Fox as an Endangered or Threatened Species |date=8 October 2015 |publisher=U.S. Fish and Wildlife Service |url=https://www.federalregister.gov/articles/2015/10/08/2015-25289/endangered-and-threatened-wildlife-and-plants-12-month-finding-on-a-petition-to-list-sierra-nevada |access-date=2015-12-05}} No other populations are known. Interbreeding with non-native red foxes and recruitment success are primary conservation concerns.{{cite web |title=Mesocarnivores of Northern California: Biology, Management, & Survey Techniques |date=1997-08-12 |pages=55–61 |publisher=The Wildlife Society, Northern California Chapter |url=http://www.fs.fed.us/psw/publications/4251/harris.pdf |access-date=2015-12-16}}{{cite web |title=Ben Sacks Lecture on Sacramento Valley and Sierra Nevada Red Fox |publisher=California Department of Fish and Wildlife |year=2014 |url=https://www.youtube.com/watch?v=Q1aKfLl5YZI |access-date=2015-12-16 }}

The fox is a data gap species in Oregon{{cite web |title=Oregon 2015 Conservation Plan|publisher=Oregon Department of Fish and Wildlife |url=http://www.dfw.state.or.us/conservationstrategy/public_comment.asp |access-date=2015-12-05}} and designated an Oregon sensitive species by the U.S. Forest Service.{{cite web |title=Region 6 Forest Service Special Status Species Lists 7/21/2015 |publisher=Interagency Special Status / Sensitive Species Program (ISSSSP) |url=http://www.fs.fed.us/r6/sfpnw/issssp/documents3/2670-1950-final-sss-list-enc1-20150713.xlsx |access-date=2015-12-05}} Listing of the Southern Cascades Distinct Population Segment was found to be not warranted. The Sierra Nevada Distinct Population Segment was listed under the Endangered Species Act in 2021.{{Cite news|agency=Associated Press|date=2021-08-02|title=Sierra Nevada red fox to be listed as federally endangered|url=https://news3lv.com/news/local/sierra-nevada-red-fox-to-be-listed-as-federally-endangered|access-date=2021-08-03|work=KSNV}}

The three subspecies in the montane clade separated after the Wisconsin glaciation, 15 to 20,000 years ago,{{cite journal |title=Phyleogeography of the North American red fox: vicariance in Pleistocene forest refugia |author=Keith B. Aubry |author2=Mark J. Statham |author3=Benjamin N. Sacks |author4=John D. Perrine |author5=Samantha M. Wisely |journal=Molecular Ecology |year=2009 |volume=18 |issue=12 |pages=2668–2686 |doi=10.1111/j.1365-294X.2009.04222.x |url=https://www.vgl.ucdavis.edu/cdcg/documents/Aubry_2009_red_fox_phylogeography.pdf |access-date=2015-12-16 |pmid=19457180|bibcode=2009MolEc..18.2668A |s2cid=11518843 }} with the Columbia River perhaps dividing the Cascade and Sierra Nevada red foxes. However, prior to 2010, montane red foxes in Oregon were presumed to be the Cascade red fox. Earlier literature therefore indicates incorrect ranges for the Cascade and Sierra Nevada red fox.

{{Reflist}}

{{Commons category|Vulpes vulpes necator|Sierra Nevada red fox}}

• [https://www.youtube.com/watch?v=Q1aKfLl5YZI Ben Sacks Lecture on Sacramento Valley and Sierra Nevada Red Fox, 2014]
• [https://www.wildlife.ca.gov/Conservation/Mammals/Sierra-Nevada-Red-Fox Report Sierra Nevada red fox sightings to the California Department of Fish and Game]

{{Taxonbar|from=Q7511533}}

Category:Vulpes

Category:Endemic mammals of the United States

Category:Fauna of the Sierra Nevada (United States)

Category:Carnivorans of North America

Category:Fauna of California

Category:Fauna of the Western United States

Category:ESA endangered species