Vulpes vulpes, the red fox, is one of the most widely distributed of all wild canids.  It occurs naturally over much of the northern hemisphere, ranging throughout most of North America, Europe and Asia.  It is also found in areas of northern Africa.  Additionally, it has now spread across much of the Australian continent since its introduction by man in the 1800s.  Red foxes are extremely adaptable, and inhabit a very wide variety of habitats.  The only type of environment that they generally avoid is desert.  The red fox is the largest member of the genus Vulpes, with males from northern regions attaining weights of 30 lb (14 kg).  However, a weight of less than 20 lb (9 kg) is average for the species.  Colouration in the red fox, as its name implies, is basically of a rufous hue, though the coat is somewhat variable depending on the region.  Very dark coloured (melanistic) red foxes are known from areas of northern Europe, and there have been occasional accounts of black red foxes in England.  Albinistic individuals have also been recorded.  The diet of the red fox consists primarily of rodents, birds, insects, and other small animals, as well as a rather large amount of plant material, particularly fruits and berries.  Red foxes are typically born in litters of less than 6.  Both parents cooperate in caring for the young.  In the wild, a red fox's life expectancy is about 3 years, but in captivity they have lived for as long as 12.