Foxes are small to medium-sized, omnivorous mammals belonging to several genera of the family Canidae. They have a flattened skull, upright, triangular ears, a pointed, slightly upturned snout, and a long bushy tail ("brush").
Twelve species belong to the monophyletic "true fox" group of genus Vulpes. Approximately another 25 current or extinct species are always or sometimes called foxes; these foxes are either part of the paraphyletic group of the South American foxes, or of the outlying group, which consists of the bat-eared fox, gray fox, and island fox.[1]
Foxes live on every continent except Antarctica. The most common and widespread species of fox is the red fox (Vulpes vulpes) with about 47 recognized subspecies.[2] The global distribution of foxes, together with their widespread reputation for cunning, has contributed to their prominence in popular culture and folklore in many societies around the world. The hunting of foxes with packs of hounds, long an established pursuit in Europe, especially in the British Isles, was exported by European settlers to various parts of the New World.
The word fox comes from Old English and derives from Proto-Germanic *fuhsaz.[nb 1] This in turn derives from Proto-Indo-European *puḱ- "thick-haired, tail."[nb 2] Male foxes are known as dogs, tods, or reynards; females as vixens; and young as cubs, pups, or kits, though the last term is not to be confused with the kit fox, a distinct species. "Vixen" is one of very few modern English words that retain the Middle English southern dialectal "v" pronunciation instead of "f"; i.e., northern English "fox" versus southern English "vox".[3] A group of foxes is referred to as a skulk, leash, or earth.[4][5]
Foxes are generally smaller than some other members of the family Canidae such as wolves and jackals, while they may be larger than some within the family, such as raccoon dogs. In the largest species, the red fox, males weigh on average between 4.1 and 8.7 kilograms (9 and 19+1⁄4 pounds),[7] while the smallest species, the fennec fox, weighs just 0.7 to 1.6 kg (1+1⁄2 to 3+1⁄2 lb).[8]
Fox features typically include a triangular face, pointed ears, an elongated rostrum, and a bushy tail. They are digitigrade (meaning they walk on their toes). Unlike most members of the family Canidae, foxes have partially retractable claws.[9] Fox vibrissae, or whiskers, are black. The whiskers on the muzzle, known as mystacial vibrissae, average 100–110 millimetres (3+7⁄8–4+3⁄8 inches) long, while the whiskers everywhere else on the head average to be shorter in length. Whiskers (carpal vibrissae) are also on the forelimbs and average 40 mm (1+5⁄8 in) long, pointing downward and backward.[2] Other physical characteristics vary according to habitat and adaptive significance.