Red fox
The red fox is the largest of the true foxes and one of the most widely distributed members of the order Carnivora, being present across the entire Northern Hemisphere including most of North America, Europe and Asia, plus parts of North Africa. Its range has increased alongside human expansion, having been introduced to Australia, where it is considered harmful to native small and medium-sized rodents and marsupials. It is listed as of least concern on the IUCN Red List. Because of its impact on native species, it is included on the list of the "world's 100 worst invasive species".
The red fox originated in Eurasia during the Middle Pleistocene at least 400,000 years ago and later colonised North America sometime prior to 130,000 years ago. Among the true foxes, the red fox represents a more progressive form in the direction of carnivory. Apart from its large size, the red fox is distinguished from other fox species by its ability to adapt quickly to new environments. Despite its name, the species often produces individuals with other colourings, including leucistic and melanistic individuals. Forty-five subspecies are currently recognised, which are divided into two categories: the large northern foxes and the small, basal southern grey desert foxes of Asia and North Africa.
Red foxes are usually found in pairs or small groups consisting of families, such as a mated pair and their young, or a male with several females having kinship ties. The young of the mated pair remain with their parents to assist in caring for new kits. The species primarily feeds on small rodents, though it may also target rabbits, squirrels, game birds, reptiles, invertebrates and young ungulates. Fruit and vegetable matter is also eaten sometimes. Although the red fox tends to kill smaller predators, including other fox species, it is vulnerable to attack from larger predators, such as wolves, coyotes, golden jackals, large predatory birds such as golden eagles and Eurasian eagle-owls, and medium- and large-sized felids.
The species has a long history of association with humans, having been extensively hunted as a pest and furbearer for many centuries, as well as being represented in human folklore and mythology. Because of its widespread distribution and large population, the red fox is one of the most important fur-bearing animals harvested for the fur trade. Too small to pose a significant threat to humans, it has extensively benefited from the presence of human habitation, and has successfully colonised many suburban and urban areas. Domestication of the red fox is also underway in Russia, and has resulted in the domesticated silver fox.
Terminology
Males are called tods or dogs, females are called vixens, and young are known as cubs or kits. Although the Arctic fox has a small native population in northern Scandinavia, and while the corsac fox's range extends into European Russia, the red fox is the only fox native to Western Europe, and so is simply called "the fox" in colloquial British English.Etymology
The word "fox" comes from Old English, which derived from Proto-Germanic *fuhsaz. Compare with West Frisian foks, Dutch vos, and German Fuchs. This, in turn, derives from Proto-Indo-European *puḱ- 'thick-haired; tail'. Compare to the Hindi pū̃ch 'tail', Tocharian B päkā 'tail; chowrie', and Lithuanian pūkas 'fur / fluff'. The bushy tail also forms the basis for the fox's Welsh name, llwynog, literally 'bushy', from llwyn 'bush'. Likewise, from rabo 'tail', Lithuanian uodẽgis from uodegà 'tail', and Ojibwe waagosh from waa, which refers to the up and down "bounce" or flickering of an animal or its tail.The scientific term vulpes derives from the Latin word for fox, and gives the adjectives vulpine and vulpecular.
Evolutionary history
The red fox is considered to be a more specialised form of Vulpes than the Afghan, corsac and Bengal fox species, in regards to their overall size and adaptation to carnivory; the skull displays far fewer neotenous traits than in other foxes, and its facial area is more developed. It is, however, not as adapted for a purely carnivorous diet as the Tibetan fox.The sister lineage to the red fox is the Rüppell's fox, but the two species are surprisingly closely related through mitochondrial DNA markers, with Rüppell's fox nested inside the lineages of red foxes. Such a nesting of one species within another is called paraphyly. Several hypotheses have been suggested to explain this, including recent divergence of Rüppell's fox from a red fox lineage, incomplete lineage sorting, or introgression of mtDNA between the two species. Based on fossil record evidence, the last scenario seems most likely, which is further supported by the clear ecological and morphological differences between the two species.
Origins
The species is Eurasian in origin, and may have evolved from either Vulpes alopecoides or the related Chinese V. chikushanensis, both of which lived during the Middle Villafranchian of the Pleistocene Epoch. The earliest fossil specimens of V. vulpes were uncovered in Baranya County, Hungary, dating from 3.4 to 1.8 million years ago. The ancestral red fox was likely more diminutive compared to today's extant foxes, as the earliest red fox fossils have shown a smaller build than living specimens. The earliest fossil remains of the modern species date back to the mid-Pleistocene, found in association with middens and refuse left by early human settlements. This has led to the theory that the red fox was hunted by primitive humans ; the possibility also exists of red foxes scavenging from middens or butchered animal carcasses.Colonisation of North America
Red foxes colonised the North American continent in two waves: before and during the Illinoian glaciation, and during the Wisconsinan glaciation. Gene mapping demonstrates that red foxes in North America have been isolated from their Old World counterparts for over 400,000 years, thus raising the possibility that speciation has occurred, and that the previous binomial name of Vulpes fulva may be valid. In the far north, red fox fossils have been found in Sangamonian Stage deposits near the Fairbanks District, Alaska, and Medicine Hat, Alberta. Fossils dating from the Wisconsinan are present in 25 sites across Arkansas, California, Colorado, Idaho, Missouri, New Mexico, Ohio, Tennessee, Texas, Virginia, and Wyoming. Although they ranged far south during the Wisconsinan, the onset of warm conditions shrank their range toward the north, and they have only recently reclaimed their former North American ranges because of human-induced environmental changes. Genetic testing indicates that two distinct red fox refugia exist in North America, which have been separated since the Wisconsinan. The northern refugium occurs in Alaska and western Canada, and consists of the larger subspecies V. v. alascensis, V. v. abietorum, V. v. regalis, and V. v. rubricosa. The southern refugium occurs in the subalpine parklands and alpine meadows of the west, from the Rocky Mountains to the Cascades and the Sierra Nevada ranges, consisting of the smaller subspecies V. v. cascadensis, V. v. macroura, V. v. necator, and V. v. patwin. The latter clade has been separated from all other red fox populations since at least the last glacial maximum, and may possess unique ecological or physiological adaptations.Although European foxes were introduced to portions of the United States in the 1900s, recent genetic investigation indicates an absence of European fox mitochondrial haplotypes in any North American populations. Additionally, introduced eastern North American red foxes have colonised most of inland California, from Southern California to the San Joaquin Valley, Monterey and north-coastal San Francisco Bay Area. In spite of the red fox's adaptability to city life, they are still found in somewhat greater numbers in the northern portions of California than in the south, as the wilderness is more alpine and isolated. The eastern red foxes appear to have mixed with the Sacramento Valley red fox only in a narrow hybrid zone. In addition, no evidence is seen of interbreeding of eastern American red foxes in California with the montane Sierra Nevada red fox or other populations in the Intermountain West.
Subspecies
The third edition of Mammal Species of the World listed 45 subspecies as valid. In 2010, a distinct 46th subspecies, the Sacramento Valley red fox, which inhabits the grasslands of the Sacramento Valley, was identified through mitochondrial haplotype studies. Castello recognized 30 subspecies of the Old World red fox and nine subspecies of the North American red fox as valid.Substantial gene pool mixing between different subspecies is known; British red foxes have crossbred extensively with red foxes imported from Germany, France, Belgium, Sardinia and possibly Siberia and Scandinavia. However, genetic studies suggest very little differences between red foxes sampled across Europe. Lack of genetic diversity is consistent with the red fox being a highly agile species, with one red fox covering in under a year's time.
Red fox subspecies in Eurasia and North Africa are divided into two categories:
- are large and brightly coloured.
- include the Asian subspecies V. v. griffithi, V. v. pusilla, and V. v. flavescens. These foxes display transitional features between the northern foxes and other, smaller fox species; their skulls possess more primitive, neotenous traits than the northern foxes and they are much smaller; the maximum sizes attained by southern grey desert foxes are invariably less than the average sizes of northern foxes. Their limbs are also longer and their ears larger.
| Subspecies | Trinomial authority | Trinomial authority | Description | Range | Synonyms |
| Scandinavian red fox V. v. vulpes | Linnaeus | 1758 | A large subspecies measuring 70–90 cm in length and weighing 5–10 kg; the maximum length of the skull for males is 163.2 mm. The fur is bright red with a strongly developed whitish and yellow ripple on the lower back. | Scandinavia and the northern and middle districts of the European part of the former Soviet Union, southwards to the forest-steppe and eastwards approximately to the Urals and probably Central and Western Europe | |
| British Columbia red fox V. v. abietorum | Merriam | 1900 | Generally similar to V. v. alascensis, but with a lighter, longer and more slender skull | Southern Yukon, the North-West Territories, northern Alberta, the interior of British Columbia and in the adjoining coastal southeast Alaska. | sitkaensis |
| Northern Alaskan fox V. v. alascensis | Merriam | 1900 | A large, long-tailed, small-eared form with golden-fulvous fur | The Andreafsky Wilderness, Alaska, U.S. | |
| Eastern Transcaucasian fox V. v. alpherakyi | Satunin | 1906 | A small subspecies weighing 4 kg; its maximum skull length is 132–39 mm in males and 121–26 mm in females. The fur is rusty grey or rusty brown, with a brighter rusty stripe along the spine. The coat is short, coarse and sparse. | Geok Tepe, Aralsk, Kazakhstan | |
| Anatolian fox V. v. anatolica | Thomas | 1920 | İzmir, the Aegean Region, Turkey | ||
| Arabian red fox V. v. arabica | Thomas | 1920 | Dhofar and the Hajar Mountains, Oman | ||
| Atlas fox V. v. atlantica | Wagner | 1841 | The Atlas Mountains, Mila Province, Algeria | algeriensis | |
| Labrador fox V. v. bangsi | Merriam | 1900 | Similar to V. v. fulva, but with smaller ears and less pronounced black markings on the ears and legs. | L'Anse au Loup, the Strait of Belle Isle, Labrador, Canada | |
| Barbary fox V. v. barbara | Shaw | 1800 | The Barbary Coast, northwestern Africa | acaab | |
| Anadyr fox V. v. beringiana | Middendorff | 1875 | A large subspecies; it is the most brightly coloured of the Old World red foxes, the fur being saturated bright-reddish and almost lacking the bright ripple along the back and flanks. The coat is fluffy and soft. | The shores of the Bering Strait, northeastern Siberia | anadyrensis beringensis kamtschadensis kamtschatica schantaricus |
| Cascade red fox V. v. cascadensis | Merriam | 1900 | A short-tailed, small-toothed subspecies with yellow rather than fulvous fur; it is the subspecies most likely to produce "cross" colour morphs. | The Cascade Mountains, Skamania County, Washington, U.S. | |
| North Caucasian fox V. v. caucasica | Dinnik | 1914 | A large subspecies; its coat is variable in colour, ranging from reddish to red-grey and nearly grey. The fur is short and coarse. This subspecies could be a hybrid caused by mixing the populations of V. v. stepensis and V. v. karagan. | Near Vladikavkaz, the Caucasus, Russia | |
| European fox V. v. crucigera | Bechstein | 1789 | A medium-sized subspecies; its yellowish-fulvous or reddish-brown pelt lacks the whitish shading on the upper back. The tail is not grey, as in most other red fox subspecies. It is primarily distinguished from V. v. vulpes by its slightly smaller size, distinctly smaller teeth and widely spaced premolars. Red foxes present in Great Britain are usually ascribed to this subspecies, though many populations there display a great degree of tooth compaction not present in continental European red fox populations. | All of Europe except Scandinavia, the Iberian Peninsula and some islands of the Mediterranean Sea; introduced to Australia and North America | alba cinera diluta europaeus hellenica hypomelas lutea melanogaster meridionalis nigra stepensis |
| Trans-Baikal fox V. v. daurica | Ognev | 1931 | A large subspecies; the colour along its spine is light, dull yellowish-reddish with a strongly developed white ripple and greyish longitudinal stripes on the anterior side of the limbs. The coat is coarse but fluffy. | Kharangoi, 45 km west of Troizkosavsk, Siberia | ussuriensis |
| Newfoundland fox V. v. deletrix | Bangs | 1898 | A very pale-coloured form; its light, straw-yellow fur deepens to golden yellow or buff-fulvous in some places. The tail lacks the usual black basal spot. The hind feet and claws are very large. | St. George's Bay, Newfoundland, Canada | |
| Ussuri fox V. v. dolichocrania | Ognev | 1926 | Sidemi, southern Ussuri, southeastern Siberia | ognevi | |
| V. v. dorsalis | J. E. Gray | 1838 | |||
| Turkmenian fox V. v. flavescens | J. E. Gray | 1838 | A small subspecies with an infantile-looking skull and an overall grey-coloured coat; its body length is 49–57.5 cm and it weighs 2.2–3.2 kg. | Northern Iran | cinerascens splendens |
| American red fox V. v. fulva | Desmarest | 1820 | This is a smaller subspecies than V. v. vulpes, with a smaller, sharper face, a shorter tail, a lighter pelt more profusely mixed with whitish and darker limbs. | Eastern Canada and the eastern U.S. | pennsylvanicus |
| Afghan red fox V. v. griffithi | Blyth | 1854 | Slightly smaller than V. v. montana; it has a more extensively hoary and silvered pelt. | Kandahar, Afghanistan | flavescens |
| Kodiak fox V. v. harrimani | Merriam | 1900 | This large subspecies has an enormous tail and coarse, wolf-like fur on the tail and lower back. The hairs on the neck and shoulders are greatly elongated and form a ruff. | Kodiak Island, Alaska, U.S. | |
| South Chinese fox V. v. hoole | R. Swinhoe | 1870 | Near Amoy, Fukien, southern China | aurantioluteus lineiventer | |
| Sardinian fox V. v. ichnusae | Miller | 1907 | A small subspecies with proportionately small ears. | Sarrabus, Sardinia, Italy; may have been introduced to the English Midlands | |
| Cyprus fox V. v. indutus | Miller | 1907 | Cyprus | ||
| Yakutsk fox V. v. jakutensis | Ognev | 1923 | This subspecies is large, but smaller than V. v. beringiana. The back, neck and shoulders are brownish-rusty, while the flanks are bright ocherous reddish-yellow. | The taiga south of Yakutsk, eastern Siberia | sibiricus |
| Japanese fox V. v. japonica | Ognev | 1923 | Japan, except for Hokkaido | ||
| Karaganka fox V. v. karagan | Erxleben | 1777 | A smaller subspecies than V. v. vulpes; its fur is short, coarse and of a light sandy-yellow or yellowish-grey colour. | The Kirghiz Steppes, Khirgizia, Russia | ferganensis melanotus pamirensis tarimensis |
| Kenai Peninsula fox V. v. kenaiensis | Merriam | 1900 | One of the largest North American subspecies; it has softer fur than V. v. harrimani. | The Kenai Peninsula, Alaska, U.S. | |
| Transcaucasian montane fox V. v. kurdistanica | Satunin | 1906 | A form intermediate in size between V. v. alpheryaki and V. v. caucasica; its fur is pale yellow or light grey, sometimes brownish-reddish and is fluffier and denser than that of the other two Caucasian red fox subspecies. | Northeastern Turkey | alticola |
| Wasatch Mountains fox V. v. macroura | Baird | 1852 | This fox is similar to V. v. fulvus, but with a much longer tail, larger hind feet and more extensive blackening of the limbs. | Named for the Wasatch Mountains near the Great Salt Lake, Utah, found in the Rocky Mountains from Colorado and Utah, western Wyoming and Montana through Idaho north to southern Alberta | |
| Hill fox V. v. montana | Pearson | 1836 | This subspecies is distinguished from V. v. vulpes by its smaller size, proportionately smaller skull and teeth and coarser fur. The hairs on the sole of the feet are copiously mixed with softer, woolly hairs. | The Himalayas and northern Indian subcontinent | alopex himalaicus ladacensis nepalensis waddelli |
| Sierra Nevada red fox or High Sierra fox V. v. necator | Merriam | 1900 | Externally similar to V. v. fulvus; it has a short tail, but cranially it is more like V. v. macroura | The High Sierra, California | |
| Nile fox V. v. niloticus | E. Geoffroy Saint-Hilaire | 1803 | A small subspecies; it measures 76.7–105.3 cm in body length, 30.2–40.1 cm in tail length and weighs 1.8–3.8 kg. It is ruddy to grey-brown above and darker on the back of the neck. The flanks are greyer and tinged with buff. It is larger than V. v. arabica and V. v. palaestina. | Egypt and Sudan | aegyptiacus anubis vulpecula |
| Turkestan fox V. v. ochroxantha | Ognev | 1926 | Aksai, Semirechye, eastern Russian Turkestan, Kirgizia | ||
| Palestinian fox V. v. palaestina | Thomas | 1920 | Ramleh, near Jaffa, Israel | ||
| Korean fox V. v. peculiosa | Kishida | 1924 | Northeastern China, Southeastern Russia, and Korea | kiyomassai | |
| White-footed fox V. v. pusilla | Blyth | 1854 | Slightly smaller than V. v. griffithii; it closely resembles the Bengal fox in size, but is distinguished by its longer tail and hind feet. | The Salt Range, Punjab, Pakistan | leucopus persicus |
| Northern plains fox V. v. regalis | Merriam | 1900 | The largest North American red fox subspecies; it has very large and broad ears and a very long tail. It is a golden-yellow colour with pure black feet. | The Elk River, Sherburne County, Minnesota, US | |
| Nova Scotia fox V. v. rubricosa | Bangs | 1898 | A large-sized subspecies with a large, broad tail and larger teeth and rostrum than V. v. fulvus; it is the deepest-coloured subspecies. | Digby County, Nova Scotia, Canada | bangsi deletrix rubricos vafra |
| Ezo red fox V. v. schrencki | Kishida | 1924 | Sakhalin, Russia and Hokkaido, Japan | ||
| Iberian fox V. v. silacea | Miller | 1907 | Though equal in size to V. v. vulpes, it has smaller teeth and more widely spaced premolars. The fur is dull buff without any yellowish or reddish tints. The hindquarters are frosted with white and the tail is clear grey in colour. | The Iberian Peninsula | |
| Kurile Islands fox V. v. splendidissima | Kishida | 1924 | The northern and central Kurile Islands, Russia | ||
| Steppe red fox V. v. stepensis | Brauner | 1914 | This subspecies is slightly smaller and more lightly coloured than V. v. crucigera, with shorter, coarser fur. Specimens from the Crimean Mountains have brighter, fluffier and denser fur. | The steppes near Kherson, Ukraine | krymeamontana crymensis |
| Tobolsk fox V. v. tobolica | Ognev | 1926 | This large subspecies has yellowish-rusty or dirty-reddish fur with a well-developed cross and often a black area on the belly. The coat is long and fluffy. | Obdorsk, Tobolsk, Russia | |
| North Chinese fox V. v. tschiliensis | Matschie | 1907 | Slightly larger than V. v. hoole, but unlike other Chinese red foxes, it closely approaches V. v. vulpes in size. | Beijing and Hebei province, China | huli |