[1] 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.

Likewise, Portuguese: raposa 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.

[19]: 115–116  The earliest fossil remains of the modern species date back to the mid-Pleistocene,[21] found in association with middens and refuse left by early human settlements.

[23] 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.

Fossils dating from the Wisconsinan are present in 25 sites across Arkansas, California, Colorado, Idaho, Missouri, New Mexico, Ohio,[25] Tennessee, Texas, Virginia, and Wyoming.

The southern (or montane) 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.

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 (north of the Bay Area) than in the south, as the wilderness is more alpine and isolated.

[49]: 36  North American red foxes are generally lightly built, with comparatively long bodies for their mass and have a high degree of sexual dimorphism.

[52] The largest red fox on record in Great Britain was a 1.4 m (4 ft 7 in) long male, that weighed 17.2 kg (38 lb), killed in Aberdeenshire, Scotland, in early 2012.

Their auditory perception is acute, being able to hear black grouse changing roosts at 600 paces, the flight of crows at 0.25–0.5 km (0.16–0.31 mi) and the squeaking of mice at about 100 m (330 ft).

[56] The anal sacs act as fermentation chambers in which aerobic and anaerobic bacteria convert sebum into odorous compounds, including aliphatic acids.

[citation needed] The red fox has been implicated in the extinction or decline of several native Australian species, particularly those of the family Potoroidae, including the desert rat-kangaroo.

[72] Outside the breeding season, most red foxes favour living in the open, in densely vegetated areas, though they may enter burrows to escape bad weather.

[9] Their burrows are often dug on hill or mountain slopes, ravines, bluffs, steep banks of water bodies, ditches, depressions, gutters, in rock clefts and neglected human environments.

[7][10] Secondary prey species include birds (with Passeriformes, Galliformes and waterfowl predominating), leporids, porcupines, raccoons, opossums, reptiles, insects, other invertebrates, flotsam (marine mammals, fish and echinoderms) and carrion.

Other endoparasites include Demodex folliculorum, Notoderes, Otodectes cynotis (which is frequently found in the ear canal), Linguatula serrata (which infects the nasal passages) and ringworms.

[7] The most common nematode species found in red fox guts are Toxocara canis and Uncinaria stenocephala, Capillaria aerophila[103] and Crenosoma vulpis; the latter two infect their lungs and trachea.

He reappeared in 1175 in Pierre Saint Cloud's Le Roman de Renart, and made his debut in England in Geoffrey Chaucer's The Nun's Priest's Tale.

[112] In Arab folklore, the fox is considered a cowardly, weak, deceitful, and cunning animal, said to feign death by filling its abdomen with air to appear bloated, then lies on its side, awaiting the approach of unwitting prey.

[43] The animal's cunning was noted by the authors of the Bible who applied the word "fox" to false prophets (Ezekiel 13:4) and the hypocrisy of Herod Antipas (Luke 13:32).

An Inuit story tells of how Fox, portrayed as a beautiful woman, tricks a hunter into marrying her, only to resume her true form and leave after he offends her.

'An old red, generally so called irrespective of age, as a tribute to his prowess, might lead the dogs all day, and end by losing them as evening fell, after taking them a dead stretch for thirty miles.

[117] North American red foxes, particularly those of northern Alaska, are the most valued for their fur, as they have guard hairs of a silky texture which, after dressing, allow the wearer unrestricted mobility.

Red foxes living in southern Alaska's coastal areas and the Aleutian Islands are an exception, as they have extremely coarse pelts that rarely exceed one-third of the price of their northern Alaskan cousins.

In the second half of the 20th century, a lineage of domesticated silver foxes was developed by Russian geneticist Dmitry Belyayev who, over a 40-year period, bred several generations selecting only those individuals that showed the least fear of humans.

Eventually, Belyayev's team selected only those that showed the most positive response to humans, thus resulting in a population of silver foxes whose behaviour and appearance was significantly changed.

These behavioural changes were accompanied by physical alterations, which included piebald coats, floppy ears in kits and curled tails, similar to the traits that distinguish domestic dogs from grey wolves.

[123] City-dwelling red foxes may have the potential to consistently grow larger than their rural counterparts as a result of abundant scraps and a relative lack of predators.

Doing this regularly can attract urban red foxes to one's home; they can become accustomed to human presence, warming up to their providers by allowing themselves to be approached and in some cases even played with, particularly young kits.

[122] In January 2014 it was reported that "Fleet", a relatively tame urban red fox tracked as part of a wider study by the University of Brighton in partnership with the BBC TV series Winterwatch, had unexpectedly traveled 195 miles in 21 days from his neighbourhood in Hove at the western edge of East Sussex across rural countryside as far as the town of Rye, near the eastern edge of the county.