The Modern English "fox" is derived from Old English with the same spelling, the Old English word itself comes from the Proto-Germanic word "*fukh", compare German "Fuchs", Gothic "fauho", Old Norse "foa" and Dutch "vos", which corresponds to the Proto-Indo-European word "*puk" meaning "tail" (compare Sanskrit "puccha" meaning "tail" as well). The bushy tail is also the source of words for "fox" in Welsh ("llwynog", from "llwyn" meaning "bush").
Most foxes live 2 to 3 years but can survive for up to 10 years, or even longer, in captivity. Foxes are generally smaller than other members of the family Canidae such as wolves, jackals, and domestic dogs. Fox-like features typically include an acute muzzle (a "fox face") and bushy tail. Other physical characteristics vary according to their habitat. For example, the Desert Fox has large ears and short fur, whereas the Arctic Fox has small ears and thick, insulating fur. Another example is the Red Fox which has a typical auburn pelt ending normally with white marking.
Unlike many canids, foxes are usually not pack animals. Typically, they are solitary, opportunistic feeders that hunt live prey (especially rodents). Using a pouncing technique practiced from an early age, they are usually able to kill their prey quickly. Foxes also gather a wide variety of other foods ranging from grasshoppers to fruit and berries.
Foxes are normally extremely wary of humans and are not kept as pets (with the exception of the Fennec); however, the Silver Fox was successfully domesticated in Russia after a 45 year selective breeding program. This selective breeding also resulted in physical traits appearing that are frequently seen in domestic cats, dogs, and other animals: pigmentation changes, floppy ears, and curly tails.
Foxes do not come together in chorus like wolves or coyotes. Fox families, however, keep in contact with a wide array of different sounds. These sounds grade into one another and span five octaves; each fox has its own characteristically individual voice. Fox noises can be divided, with a few exceptions, into two different groups: contact sounds and interaction sounds. The former is used by foxes communicating over long distances, the latter in close quarters.
The best-known vulpine noise is a sort of barking that spans three to five syllables. "Conversations" made up of these noises often occur between widely spaced foxes. As their distance decreases, the sound becomes quieter. A cub is greeted with the quietest version of this sound.
This monosyllabic sound is made by an adult to warn kits of danger. From far away it sounds like a sharp bark, but at closer range it resembles a muffled cough, like a football rattle or a stick along a picket fence.
This is a stuttering, throaty noise made at aggressive encounters. It is most frequently heard in the courting season, or when kits are at play.
This is a long, drawn-out, monosyllabic, and rather eerie wail most commonly made during the breeding season; it is widely thought that it is made by a vixen in heat summoning dog-foxes. Contrary to common belief, however, it is also made by the males, evidently serving some other purpose as well. This noise fits into neither the contact nor the interaction group.
Foxes are readily found in cities and cultivated areas and (depending upon species) seem to adapt reasonably well to human presence.
Red foxes have been introduced into Australia and some other countries for hunting. Australia lacks similar carnivores, and introduced foxes prey on native wildlife, some to the point of extinction. A similar introduction occurred in the 16-1700's in America, where European Reds (Vulpes vulpes) were brought to the colonies for fox hunting, where they decimated the American red fox (Vulpes veloxi) population through more aggressive hunting and breeding. Interbreeding with American Reds, European Red's traits eventually pervaded the genepool, leaving European and American foxes now virtually identical.
Other fox species do not adapt as well as the European red fox, and are endangered in their native environments. Key among these are the Crab-Eating fox and the African Bat-Eared fox. Other foxes such as fennecs, are not endangered, but will be if humans encroach further into their habitat.
Foxes can also be helpful for agricultural purposes. They have been successfully employed to control pests on fruit farms, where they leave the fruit intact.
Historians believe foxes have been imported into non-native environments long before the colonial era. The first example of the introduction of the fox into a new habitat by humans seems to be Neolithic Cyprus. Stone carvings representing foxes have been found in the early settlement of Göbekli Tepe in eastern Turkey.