World of the Wolf - Urocyon cinereoargenteus

Urocyon cinereoargenteus - Grey fox
Range: United States, Mexico and Central America
Size: 7 - 15 lb (3 - 7 kg)

The grey fox (Urocyon cinereoargenteus) occurs throughout much of the United States, Mexico and Central America. It is a forest species, and is not usually found in regions devoid of trees. Although grey is its predominant coat colour, it also bears patches of silver and yellowish red, especially on the legs. One of the most common and widespread of North American foxes, it is highly adaptable and can often be found living in and around cities and towns.

One of the unique characteristics of the Grey fox is that it has the ability to climb trees, hence its alternative name of "tree climbing fox". To climb a tree, the grey fox uses the long claws on its hind feet to gain a foothold on the trunk, while using its forefeet to grab upward. Descent is performed by shimmying down backwards. Their dens, which are always well hidden, may even be constructed several meters high into trees. This semi-arboreal habit, along with a number of other primitive features, has led to Urocyon's classification as one of the most primitive of living canid species.

The diet of the grey fox is essentially the same as that of other fox species: rodents, rabbits, birds, occasional reptiles, insects, and various plant material. In some of the more arid, western parts of their range, their diet tends to be made up more of insects and plants than those living in the east.

The pups have very dark coats at birth. They become independent by about 4 months of age, although they tend to occupy the territory of their parents for some time afterward.

The grey fox is of a prolific nature, and its numbers do not appear to be in decline. It is even in the process of recolonizing areas of its former range, especially southern Canada. However, a large quantity (approx. 500,000) are still being trapped for their fur each year, especially in the United States. Although this does not seem to be adversely affecting the grey fox's population, it is a factor which deserves careful attention.

A close relative of U. cinereoargenteus is the island grey fox (Urocyon littoralis). It lives only on several of southern California's Channel Islands. It is descended from grey foxes which likely became isolated in Pleistocene times, when some of the islands were a part of the mainland. Additionally, the fox was apparently introduced to some of the other Channel islands in both pre-Columbian and more recent times by humans. Because of its highly restricted range, the island grey fox is vulnerable. The islands which it inhabits are now heavily protected by the National Park service and US Navy.