Gray fox

{{Short description|Species of canid}} {{About|the North and Central American animal}} {{Use dmy dates|date=August 2021}} {{Speciesbox | name = Gray fox | fossil_range = Early pliocene - present 3.6 - 0 Ma | image = Gray fox.jpg | image_caption = In southern Nevada. | status = LC | status_system = IUCN3.1 | status_ref = <ref name="iucn status 12 November 2021">{{cite iucn |author=Roemer, G. |author2=Cypher, B. |author3=List, R. |date=2016 |title=''Urocyon cinereoargenteus'' |volume=2016 |article-number=e.T22780A46178068 |doi=10.2305/IUCN.UK.2016-1.RLTS.T22780A46178068.en |access-date=12 November 2021}}</ref> | genus = Urocyon | species = cinereoargenteus | authority = (Schreber, 1775) | range_map = Urocyon cinereoargenteus map.svg | range_map_caption = Gray fox range }}

The '''gray fox''' ('''''Urocyon cinereoargenteus'''''), or '''grey fox''', is an omnivorous mammal of the family Canidae, widespread throughout North America and Central America. This species and its only congener, the diminutive island fox (''Urocyon littoralis'') of the California Channel Islands, are the only living members of the genus ''Urocyon'', which is considered to be genetically sister to all other living canids. Its species name ''cinereoargenteus'' means "ashen silver".

It was once the most common fox in the eastern United States, and though still found there, human advancement and deforestation allowed the red fox to become the predominant fox-like canid. Despite this post-colonial competition, the gray fox has been able to thrive in urban and suburban environments, one of the best examples being southern Florida.<ref>{{cite news |last=Fleshler |first=David |date=2015-11-25 |title=Gray foxes thrive in South Florida – but are rarely seen |url=https://www.sun-sentinel.com/local/fl-urban-foxes-20151125-story.html |access-date=2022-01-02 |newspaper=Sun-Sentinel |place=South Florida}}</ref><ref>{{cite news |title=Wild foxes dwell among us |date=2005-09-23 |newspaper=Sun-Sentinel |place=South Florida |url=https://www.sun-sentinel.com/news/fl-xpm-2005-09-23-0509210175-story.html |access-date=2022-01-02 |language=en}}</ref> The Pacific States and Great Lakes region still have the gray fox as their prevalent fox.<ref>{{cite web |author=Merrill, Andrea |date=2021-02-25 |title=Foxes of the Pacific Northwest |website=Animals of the Pacific Northwest |url=https://animalsofpnw.com/2021/02/24/foxes-of-the-pacific-northwest/ |access-date=2022-01-02 |language=en-US}}</ref><ref>{{cite web |series=Wildlife spotlight |title=Gray Fox |website=Irvine Ranch Conservancy |url=http://www.irconservancy.org/1/post/2020/04/wildlife-spotlight-gray-fox.html |access-date=2022-01-02 |language=en }}{{Dead link|date=April 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref><ref>{{cite web |title=Gray Fox (''Urocyon cinereoargenteus'') |series=Minnesota mammals |website=mnmammals.d.umn.edu |publisher=University of Minnesota |place=Duluth, MN |url=https://mnmammals.d.umn.edu/gray-fox |access-date=2022-01-02}}</ref>

==Etymology== The genus ''Urocyon'' comes from Ancient Greek οὐρά (ourá, "tail") + κύων (kúōn, "dog"). The species epithet ''cinereoargenteus'' is a combination of 'cinereo' (from 'cinereus') meaning ashen, and 'argenteus' (from argentum), meaning 'silver', referencing the color of the tail.

==Description== The gray fox is mainly distinguished from most other canids by its grizzled upper parts, black stripe down its tail and strong neck, ending in a black-tipped tail, while the skull can be easily distinguished from all other North American canids by its widely separated temporal ridges that form a 'U'-shape. Like other canids, the fox's ears and muzzle are angular and pointed. Its claws tend to be lengthier and curved.

There is little sexual dimorphism, save for the females being slightly smaller than males. The gray fox ranges from {{convert|76|to|112.5|cm|in|abbr=on}} in total length. The tail measures {{convert|27.5|to|44.3|cm|in|abbr=on}} of that length and its hind feet measure {{convert|100|to|150|mm|abbr=on}}. The gray fox typically weighs {{convert|3.6|to|7|kg|abbr=on}}, though exceptionally large individuals can weigh as much as {{convert|9|kg|lb|abbr=on}}.<ref name="CWC"/><ref>{{cite book |last=Boitani |first=Luigi |year=1984 |title=Simon & Schuster's Guide to Mammals |publisher=Simon & Schuster / Touchstone Books |isbn=978-0-671-42805-1}}</ref><ref>{{cite web |title=Common gray fox (''Urocyon cinereoargenteus'') |website=nsrl.ttu.edu |url=http://www.nsrl.ttu.edu/tmot1/uroccine.htm |access-date=2013-01-26 |archive-url=https://web.archive.org/web/20090411103337/http://www.nsrl.ttu.edu/tmot1/uroccine.htm |archive-date=11 April 2009}}</ref><ref name="nhpbs.org">{{cite web |title=Gray fox - ''Urocyon cinereoargenteus'' |department=Nature Works |website=nhpbs.org |url=https://nhpbs.org/natureworks/grayfox.htm |access-date=2021-11-13}}</ref> The gray fox is readily distinguished from the red fox by its obvious lack of the "black stockings" that stand out on the red fox. The grey fox has a stripe of black hair that runs along the middle of its tail, and individual guard hairs that are banded with white, gray, and black.<ref name="Fritzell-1982"/> The gray fox displays white on the ears, throat, chest, belly, and hind legs.<ref name="Fritzell-1982"/> Gray foxes also have black around their eyes, on the lips, and on their noses.<ref>{{cite book |last=Castelló |first=José R. |year=2018|title=Canids of the World: Wolves, wild dogs, foxes, jackals, coyotes, and their relatives |location=Princeton, NJ |publisher=Princeton University Press |isbn=978-0-691-18541-5 |pages=264–310 |language=en |url=https://books.google.com/books?id=islgDwAAQBAJ}}</ref> [[File:Urocyon cinereoargenteus grayFox cameo.jpg|thumb|right|Showing black tail stripe, Sierra Nevada]]

In contrast to the species in genus ''Vulpes'', such as the red fox, the gray fox has oval (instead of slit-like) pupils.<ref name=Alderton-1998/>{{rp|style=ama|p=122}} The gray fox also has reddish coloration on parts of its body, including the legs, sides, feet, chest, and back and sides of the head and neck.<ref name="nhpbs.org"/> The stripe on the fox's tail ends in a black tip as well.<ref>{{Cite web |title=Gray fox |website=Wildlife Science Center |language=en-US |url=https://www.wildlifesciencecenter.org/gray-fox |access-date=2021-11-13}}</ref> Its weight can be similar to that of a red fox, but the gray fox appears smaller because its fur is not as long and it has shorter limbs.<ref>{{cite web |title=Gray fox |series=Learning mammal species |publisher=National Center for Wildlife |website=www.ncwildlife.org |url=https://www.ncwildlife.org/Learning/Species/Mammals/Gray-fox |access-date=2021-11-13}}</ref>

The dental formula of ''U. cinereoargenteus'' is {{DentalFormula|upper=3.1.4.2|lower=3.1.4.3}} = 42.<ref name="Fritzell-1982"/>

==Origin and genetics== [[File:Gray fox kit at the Baylands Bill Leikam 12-14-2011.jpg|left|thumb|Kit at the Palo Alto Baylands in California]] The gray fox appeared in North America during the mid-Pliocene (Hemphillian land animal age) epoch {{Mya|3.6|million years}} ago (AEO) with the first fossil evidence found at the lower 111 Ranch site, Graham County, Arizona with contemporary mammals like the giant sloth, the elephant-like ''Cuvieronius'', the large-headed llama, and the early small horses of ''Nannippus'' and ''Equus.''<ref name="r4"/> Faunal remains at two northern California cave sites confirm the presence of the gray fox during the late Pleistocene.<ref>{{cite report |last1=Graham |first1=R.W. |last2=Lundelius |first2=E.L. Jr. |year=2010 |title=New data for North America with a temporal extension for the Blancan, Irvingtonian and early Rancholabrean |series=FAUNMAP II Database |edition=1.0 |url=http://www.ucmp.berkeley.edu/faunmap |access-date=13 December 2015 }}</ref> Genetic analysis has shown that the gray fox migrated into the northeastern United States post-Pleistocene in association with the Medieval Climate Anomaly warming trend.<ref name="r6"/>

Genetic analyses of the fox-like canids confirmed that the gray fox is a distinct genus from the red foxes (''Vulpes'' spp.). The genus ''Urocyon'' is considered to be sister to the other living canid taxa.<ref name="r1"/> Genetically, the gray fox often clusters with two other ancient lineages: The east Asian raccoon dog (''Nyctereutes procyonoides'') and the African bat-eared fox (''Otocyon megalotis'').<ref name="r5"/>

The chromosome number is 66 (diploid) with a fundamental number of 70. The autosomes include 31 pairs of sub-graded subacrocentrics, but one only pair of metacentrics.<ref name="Fritzell"/>

Recent mitochondrial genetic studies suggests divergence of North American eastern and western gray foxes in the Irvingtonian mid-Pleistocene into separate sister taxa.<ref name="Goddard"/> The gray fox's dwarf relative, the island fox, is likely descended from semi-domesticated mainland gray foxes.<ref name="FullerCypher"/> These foxes apparently were transported by humans to the islands and from island to island, and are descended from a minimum of 3–4 matrilineal founders.<ref name="Goddard"/>

==Distribution and habitat== [[File:GrayFoxApr04NFla.jpg|right|thumb|Yawning, northern Florida]] The species occurs throughout most rocky, wooded, brushy regions of the southern half of North America from southern Canada (Manitoba through southeastern Quebec)<ref>{{cite web |title=Gray fox |series=Know our species |publisher=Nature Canada |website=Naturecanada.ca |url=http://www.naturecanada.ca/what-we-do/naturevoice/endangered-species/know-our-species/gray-fox/ |access-date=2019-01-29}}</ref> to the northern part of South America (Venezuela and Colombia), excluding the mountains of northwestern United States.<ref name="msw3"/> The species prefers a mix of wooded and agricultural land in the Midwest, juniper forests as well as ponderosa pine in the west, and deciduous forests in the east.<ref>{{Cite journal |last1=Veals |first1=Amanda M. |last2=Koprowski |first2=John L. |last3=Vercauteren |first3=Kurt C. |last4=Bergman |first4=David L. |last5=Mazzamuto |first5=Maria Vittoria |date=2022-08-30 |title=Gray Fox (Urocyon Cinereoargenteus) Space Use in Southeastern Arizona |url=https://bioone.org/journals/the-southwestern-naturalist/volume-66/issue-2/0038-4909-66.2.166/GRAY-FOX-UROCYON-CINEREOARGENTEUS-SPACE-USE-IN-SOUTHEASTERN-ARIZONA/10.1894/0038-4909-66.2.166.full |journal=The Southwestern Naturalist |volume=66 |issue=2 |page=166 |doi=10.1894/0038-4909-66.2.166 |bibcode=2022SWNat..66..166V |issn=0038-4909|url-access=subscription }}</ref> It is the only canid whose natural range spans both North and South America.<ref>{{cite book |author1=Kurten, B. |author2=Anderson, E. |year=1980 |title=Pleistocene Mammals of North America |publisher=Columbia University |location=New York, NY |isbn= 978-0-231-03733-4}}</ref> In some areas, high population densities exist near brush-covered bluffs.<ref name="Fritzell-1982"/> The species prefers a mix of forest and agricultural land towards the southern part of their range (Belize ).<ref>{{Cite journal |last1=Harmsen |first1=Bart J. |last2=Sanchez |first2=Emma |last3=Figueroa |first3=Omar A. |last4=Gutierrez |first4=Said M. |last5=Doncaster |first5=C. Patrick |last6=Foster |first6=Rebecca J. |date=July 2019 |title=Ecology of a versatile canid in the Neotropics: gray foxes (Urocyon cinereoargenteus) in Belize, Central America |url=http://link.springer.com/10.1007/s13364-018-00413-2 |journal=Mammal Research |language=en |volume=64 |issue=3 |pages=319–332 |doi=10.1007/s13364-018-00413-2 |issn=2199-2401}}</ref> In southeastern Mexico, the species prefers areas with a human presence such as near roads.<ref>{{Cite journal |last1=Gallina |first1=Sonia |last2=López Colunga |first2=Paloma |last3=Valdespino |first3=Carolina |last4=Farías |first4=Verónica |date=2016-06-28 |title=Abundancia relativa de la zorra gris Urocyon cinereoargenteus (Carnívora: Canidae) en la zona centro de Veracruz, México |journal=Revista de Biología Tropical |volume=64 |issue=1 |page=221 |doi=10.15517/rbt.v64i1.18237 |issn=2215-2075|doi-access=free }}</ref>

==Behavior== The gray fox is specifically adapted to climb trees. Its strong, hooked claws allow it to scramble up trees to escape many predators, such as the domestic dog or the coyote,<ref name="Fedriani"/> or to reach tree-bound or arboreal food sources. It can climb branchless, vertical trunks to heights of {{convert|18|m||abbr=}} and jump from branch to branch.<ref>{{cite report |author1=Sillero-Zubiri, Claudio |author2=Hoffman, Michael |author3=MacDonald, David W. |year=2004 |title=Canids: Foxes, Wolves, Jackals, and Dogs: Status survey and conservation action plan |place=Gland, Switzerland / Cambridge, UK |publisher=IUCN |page=95}}</ref> It descends primarily by jumping from branch to branch, or by descending slowly backwards like a domestic cat. The gray fox is primarily nocturnal or crepuscular and makes its den in hollow trees, stumps or appropriated burrows during the day. Such gray fox tree dens may be located {{convert|30|ft||abbr=on|sigfig=1}} above the ground.<ref name=Alderton-1998/>{{rp|style=ama|p=122}} For the most part, they rest on the ground rather than higher up in trees.

Prior to European colonization of North America, the red fox was found primarily in boreal forest and the gray fox in deciduous forest. With the increase in human populations in North America, their habitat selection has adapted: Gray foxes that live near human populations tend to choose areas near hardwood trees, locations used primarily by humans, or roads to utilize as their habitat.

The increase of coyote populations around North America has reduced certain fox populations, so gray foxes choose habitats that will allow escape from coyotes, therefore the foxes's tendency to live nearer to areas where humans are active. The larger predators of the gray fox, like coyotes and bobcats, tend to avoid human-use areas and paved roads. They heavily utilize the edges of forests as a travel corridor, which is used for primary movement from place to place. Their choices do not change based on sex, the season, or the time of day. They also do the majority of their hunting in edges, and use them to escape from predators as well. Gray foxes are thus known as an "edge species."<ref>{{cite journal |last1=Deuel |first1=Nicholas R. |last2=Conner |first2=L. Mike |last3=Miller |first3=Karl V. |last4=Chamberlain |first4=Michael J. |last5=Cherry |first5=Michael J. |last6=Tannenbaum |first6=Larry V. |date=2017-10-17 |title=Habitat selection and diurnal refugia of gray foxes in southwestern Georgia, USA |journal=PLOS ONE |language=en |volume=12 |issue=10 |article-number=e0186402 |doi=10.1371/journal.pone.0186402 |pmid=29040319|pmc=5645120 |bibcode=2017PLoSO..1286402D |issn=1932-6203 |doi-access=free}}</ref>

== Interspecies competition == [[File:Red Fox vs Grey Fox - San Joaquin National Wildlife Refuge.jpg|thumb|right|A red fox (''Vulpes vulpes'') confronting a gray fox, San Joaquin Wildlife Refuge ]] Gray foxes often hunt for the same prey as bobcats and coyotes who occupy the same region. To avoid interspecific competition, the gray fox has developed certain behaviors and habits to increase their survival chances. In regions where gray foxes and coyotes hunt for the same food, the gray fox has been observed to give space to the coyote, staying within its own established range for hunting.<ref name="Farias-2005">{{cite journal |last1=Farias |first1=Veronica |last2=Fuller |first2=Todd K. |last3=Wayne |first3=Robert K. |last4=Sauvajot |first4=Raymond M. |date=2005-06-16 |title=Survival and cause-specific mortality of gray foxes (Urocyon cinereoargenteus) in southern California |journal=Journal of Zoology |volume=266 |issue=3 |pages=249–254 |doi=10.1017/s0952836905006850 |issn=0952-8369}}</ref><ref name="Farías-2012">{{cite journal |last=Farías |first=Verónica |date=2012-06-02 |title=Activity and distribution of gray foxes (''Urocyon Cinereoargenteus'') in southern California |url=https://www.proquest.com/docview/1034899017 |journal=The Southwestern Naturalist |volume=57 |issue=2 |pages=176–181 |doi=10.1894/0038-4909-57.2.176 |bibcode=2012SWNat..57..176F |s2cid=39115546 |id={{ProQuest|1034899017}} |url-access=subscription }}</ref> Gray foxes may also avoid competitors by occupying different habitats from them. In California, gray foxes do this by living in chaparral where their competitors are fewer and the low shrubbery provides them a greater chance to escape from a dangerous encounter.<ref name="Farías-2012"/> It also has been suggested that gray foxes could be more active at night than during the day to avoid larger, diurnal competitors.<ref name="Farías-2012"/>

Still, gray foxes frequently fall victim to bobcats and coyotes. When killed, the carcasses are often unconsumed, suggesting they are victims of intraguild predation.<ref name="Farias-2005"/> These gray foxes are often killed on or near the boundary of their established range, when they begin to interfere with their competitors.<ref name="Farias-2005"/> Gray foxes are known as mesopredators because they are mid-tier predators and their prey consists mostly of smaller mammals, while coyotes are known as de facto apex predators due to the removal of other apex predators, like wolves, in North America.<ref>{{cite journal |last1=Wooster |first1=Eamonn |last2=Wallach |first2=Arian D. |last3=Ramp |first3=Daniel |date=November 2019 |title=The wily and courageous red fox: Behavioural analysis of a mesopredator at resource points shared by an apex predator |journal=Animals |language=en |volume=9 |issue=11 |page=907 |pmid=31683979 |pmc=6912404 |doi=10.3390/ani9110907 |doi-access=free}}</ref><ref>{{cite journal |last1=Jones |first1=Brandon M. |last2=Cove |first2=Michael V. |last3=Lashley|first3=Marcus A. |last4=Jackson |first4=Victoria L. |date=February 2016|title=Do coyotes ''Canis latrans'' influence occupancy of prey in suburban forest fragments? |journal=Current Zoology |volume=62 |issue=1 |pages=1–6 |issn=1674-5507 |pmc=5804128 |pmid=29491884 |doi=10.1093/cz/zov004}}</ref> This explains the gray fox's tendency to change behavior in response to the coyote threat, as they are essentially lower on the food chain.

== Reproduction == The gray fox is assumed to be monogamous, like other foxes. The breeding season of the gray fox varies geographically; in Michigan, the gray fox mates in early March, in Alabama, breeding peaks occur in February. The gestation period lasts approximately 53 days. Litter size ranges from 1–7, with a mean of 3.8 young per female.

[[File:Gray Fox Kits.jpg|thumb|Kits at Zion Canyon]] The sexual maturity of females is around 10 months of age. Kits begin to hunt with their parents at the age of 3 months. By the time that they are 4 months old, the kits will have developed their permanent dentition and can now easily forage on their own. The family group remains together until the autumn, when the young males reach sexual maturity, then they disperse.<ref name="Fritzell"/> In a study of 9 juvenile gray foxes, only the males dispersed, moving up to {{convert|84|km|abbr=on}}. The juvenile females stayed within proximity of the den within {{convert|3|km|abbr=on}} and always returned.<ref>Sheldon (1953){{full citation needed|date=January 2022}}</ref> Adult gray foxes showed no signs of dispersion for either sex.<ref>Follmann (1973){{full citation needed|date=January 2022}}</ref> The gray fox will typically live between six and ten years.<ref>{{cite web |title=Grey fox |website=Foxes worlds |date=6 March 2014 |url=https://www.foxesworlds.com/gray-fox/ }}</ref>

The annual reproductive cycle of males has been described through epididymal smears. They become fertile earlier and remain fertile longer than females.<ref name="Fritzell"/>

Logs, trees, rocks, burrows, or abandoned dwellings serve as suitable den sites. Dens are used at any time during the year but mostly during whelping season. Dens are built in brushy or wooded regions and are better concealed than the dens of the red fox.<ref name="Fritzell-1982"/>

== Diet == {{multiple image | direction = vertical | image1 = greyfox.jpg | width1 = | alt1 = | caption1 = At night | image2 = Adult Male & Female Grey Fox.jpg | width2 = | alt2 = | caption2 = Adult male and female | footer = }}

The gray fox is an omnivorous, solitary hunter. It frequently preys on the eastern cottontail (''Sylvilagus floridanus'') in the eastern U.S., though it will readily catch voles, shrews, and birds. In California, the gray fox primarily eats rodents (such as deer mice, woodrats, and cotton rats),<ref name="animaldiversity.org">{{cite web | url=https://animaldiversity.org/accounts/Urocyon_cinereoargenteus/ | title=Urocyon cinereoargenteus (Gray fox) | website=Animal Diversity Web }}</ref> followed by lagomorphs, e.g. jackrabbit, brush rabbit, etc.<ref name="Fedriani"/> When it is available, gray foxes may also feed on carrion.<ref name="animaldiversity.org"/> In some parts of the Western United States (such as in the Zion National Park in Utah), the gray fox is primarily insectivorous and herbivorous.<ref name=Alderton-1998/>{{rp|style=ama|p=124}} Fruit is an important component of the diet of the gray fox, and they seek whatever fruits are readily available, generally eating more vegetable matter than does the red fox (''Vulpes vulpes'').<ref name="CWC"/> Generally, there is an increase in fruits and invertebrates (such as grasshoppers, beetles, butterflies, and moths)<ref name="animaldiversity.org"/> within the gray fox's diet in the transition from winter to spring. As nuts, grains, and fruits become more numerous, they are cached by foxes. Typically, they attempt to cover the area with their scent either through their scent glands or urine. This marking serves the dual purpose of allowing them to find the food again later and preventing other animals from taking it.<ref name="Vu">{{cite web |last=Vu |first=Long |title=''Urocyon cinereoargenteus'' (gray fox) |website=Animal Diversity Web |language=en |url=https://animaldiversity.org/accounts/Urocyon_cinereoargenteus/ |access-date=2021-11-11}}</ref>

== Ecosystem role == Since woodrats, cotton rats, and mice make up a large part of the gray fox's diet, they serve as important regulators of small rodent populations.

In addition to their beneficial predation on rodents, gray foxes are also less welcome hosts to some external and internal parasites, which include fleas, lice, nematodes, and tapeworms.<ref name="Vu"/> In the United States, the most common parasite of the gray fox is a flea (''Pulex simulans''); however, several previously undocumented parasitic arthropods were found in populations in central Mexico, and a warming climate may encourage them to migrate north.<ref>{{cite journal |last1=Hernández-Camacho |first1=Norma |last2=Pineda-López |first2=Raúl Francisco |last3=de Jesús Guerrero-Carrillo |first3=María |last4=Cantó-Alarcón |first4=Germinal Jorge |last5=Jones |first5=Robert Wallace |last6=Moreno-Pérez |first6=Marco Antonio|last7=Mosqueda-Gualito |first7=Juan Joel |last8=Zamora-Ledesma |first8=Salvador |last9=Camacho-Macías |first9=Brenda |display-authors=6 |date=2016-08-01 |title=Gray fox (''Urocyon cinereoargenteus'') parasite diversity in central Mexico |journal=International Journal for Parasitology: Parasites and Wildlife |language=en |volume=5 |issue=2 |pages=207–210 |doi=10.1016/j.ijppaw.2016.06.003 |pmid=27408801 |pmc=4930337 |bibcode=2016IJPPW...5..207H |issn=2213-2244}}</ref>

== Hunting == Gray foxes are hunted in the U.S. The intensity of the hunting has correlated with the value of their pelts. Between the 1970–1971 and 1975–1976 hunting seasons, the price of gray fox pelts greatly increased and the number of individuals hunted jumped over six-fold from 26,109 to 163,458.<ref name="Fritzell"/> It has been recently reported that over 500,000 gray foxes are killed every year for their fur.<ref>{{cite web |title=Animal Fact Sheet: Gray Fox|url=https://www.desertmuseum.org/kids/oz/long-fact-sheets/Gray%20Fox.php |website=Desert Museum |access-date=30 October 2022}}</ref>

== Subspecies == thumb|''U. c. fraterculus''<br />Tikal, Guatemala  There are 16 subspecies recognized for the gray fox.<ref name="Fritzell" /> * ''Urocyon cinereoargenteus borealis'' (New England) * ''Urocyon cinereoargenteus californicus'' (southern California) * ''Urocyon cinereoargenteus cinereoargenteus'' (eastern United States) * ''Urocyon cinereoargenteus costaricensis'' (Costa Rica) * ''Urocyon cinereoargenteus floridanus'' (Gulf states) * ''Urocyon cinereoargenteus fraterculus'' (Yucatán) * ''Urocyon cinereoargenteus furvus'' (Panama) * ''Urocyon cinereoargenteus guatemalae'' (southernmost Mexico south to Nicaragua) * ''Urocyon cinereoargenteus madrensis'' (southern Sonora, south-west Chihuahua, and north-west Durango) * ''Urocyon cinereoargenteus nigrirostris'' (south-west Mexico) * ''Urocyon cinereoargenteus ocythous'' (Central Plains states) * ''Urocyon cinereoargenteus orinomus'' (southern Mexico, Isthmus of Tehuantepec) * ''Urocyon cinereoargenteus peninsularis'' (Baja California) * ''Urocyon cinereoargenteus scottii'' (south-western United States and northern Mexico) * ''Urocyon cinereoargenteus townsendi'' (northern California and Oregon) * ''Urocyon cinereoargenteus venezuelae'' (Colombia and Venezuela)

==Parasites== Parasites of gray fox include trematode ''Metorchis conjunctus''.<ref>{{cite journal |author1=Mills, J.H. |author2=Hirth, R.S. |year=1968 |title=Lesions caused by the hepatic trematode, ''Metorchis conjunctus'', Cobbold, 1860: A comparative study in carnivora |journal=Journal of Small Animal Practice |volume=9 |issue=1 |pages=1–6 |doi=10.1111/j.1748-5827.1968.tb04678.x |pmid=5688935}}</ref> Other common parasites that were collected on gray foxes in Texas were a variety of tapeworms (''Mesocestoides litteratus'', ''Taenia pisiformis'', ''Taenia serialis'') and roundworms (''Ancylostoma caninum'', ''Ancylostoma braziliense'', ''Haemonchus similis'', ''Spirocerca lupi'', ''Physaloptera rara'', ''Eucoleus aerophilus''). ''T. pisiformis'' was the most common parasite species and was associated with frequent impacts on health.<ref>{{cite journal|last1=Buechner|first1=Helmut Karl|title=Helminth Parasites of the Gray Fox|journal=Journal of Mammalogy|volume=25|issue=2|year=1944|pages=185–188|doi=10.2307/1375019|jstor=1375019 }}</ref>

==See also== * Cozumel fox, a recently/nearly extinct grey fox formerly found on Mexico's Cozumel Island * South American gray fox, also known as the gray zorro, but only distantly related * ''Urocyon progressus'', the extinct ancestor of the gray fox

== References == {{Reflist|25em|refs=

<ref name=Alderton-1998> {{cite book |last=Alderton |first=David |year=1998 |title=Foxes, Wolves, Lions, and Wild Dogs of the World |place=London, UK |publisher=Blandford |isbn=0-8160-5715-X |pages=122, 124 }} </ref>

<ref name="msw3">{{MSW3 Carnivora| page = 582| id = 14000841}}</ref>

<ref name="CWC"> {{cite web | title=''Urocyon cinereoargenteus'' | website=Animal Diversity Web | publisher=University of Michigan | url=http://animaldiversity.ummz.umich.edu/site/accounts/information/Urocyon_cinereoargenteus.html | access-date=2007-08-19 }} </ref>

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<ref name="Goddard"> {{cite journal |author1=Goddard, Natalie S. |author2=Statham, Mark J. |author3=Sacks, Benjamin N. |date=19 August 2015 |title=Mitochondrial analysis of the most basal canid reveals deep divergence between eastern and western North American gray foxes (''Urocyon'' spp.) and ancient roots in Pleistocene California |journal=PLOS ONE |volume=10 |issue=8 |article-number=e0136329 |doi=10.1371/journal.pone.0136329 |doi-access=free |pmid=26288066 |pmc=4546004 |bibcode=2015PLoSO..1036329G }} </ref>

}}

== External links == {{Commons category|Urocyon cinereoargenteus}} {{Wikispecies|Urocyon cinereoargenteus|Gray fox}} * {{cite web |url=http://www.digimorph.org/specimens/Urocyon_cinereoargenteus/female/ |title=Skull morphology ''U. cinereoargenteus'' |website=digimorph.org}} * {{cite AV media |url=https://www.youtube.com/watch?v=IQfWKPZKJ6E |medium=video |title=Gray fox filmed in Colorado}} * {{cite AV media |url=https://www.youtube.com/watch?v=70I8ZYdxqYQ |medium=video |title=Gray fox filmed in Austin, Texas}}

Category:Carnivorans of North America Category:South American foxes gray fox Category:Mammals of the United States Category:Mammals of Canada Category:Carnivorans of Central America Category:Mammals of Colombia Category:Mammals of Mexico Category:Mammals of Venezuela Category:Fauna of northern South America Category:Fauna of the Sierra Nevada (United States) Category:Least concern biota of North America  gray fox Category:Symbols of Delaware Category:Fauna of California Category:Taxa named by Johann Christian Daniel von Schreber Category:Necrophages