Red foxes are the biggest of the fox species. Their length can be from 45 to 90 cm, with an extra 30 to 55 cm for the tail, with a weight of 3 to 14 kg. Males are slightly bigger than females. Their fur color range is from pale yellowish red to a deep reddish brown for the upper parts, and white or ashy on the underside. The legs are usually black on the lower parts and the tail often is tipped with black or white, and has tail glands. Their eyes are yellow in adulthood. The nose is black or dark brown.
Red foxes live in many different habitat around the world including forests, grasslands, deserts and mountains, having the greatest geographic range of all members of the Carnivora family. They can adapt well to human habitats such as farms and suburban areas, even quite large communities. Its resourcefulness has given it a legendary reputation as an intelligent and cunning animal. They are distributed across all of the Northern Hemisphere but do not live in Iceland, some parts of Siberia, the Arctic islands, or in extreme deserts. In addition, there is an introduced population in Australia, where red foxes are considered harmful to native mammals and bird populations.
Red foxes live in family groups sharing a joint territory. Adults have a home range that varies in size according to the quality of the environment. In rich areas they may measure 5 to 12 square kilometers, being larger in poorer areas, from 20 to 50 square kilometers. Occupants of a range are an adult male, and one or two females with their young. Families and individuals live in dens made of earth and often have emergency burrows within the home range. Often the same den is used over several generations.
Red foxes are omnivores and eat a highly varied diet. They feed mostly on small rodents such as voles, mice, hamsters, ground squirrels, gerbils, woodchucks, deer mice and pocket gophers. They also eat birds, rabbits, porcupines, hares, raccoons, opossums, insects and small reptiles.
Mating is from January to March. The female builds one or more dens following mating. The spare dens can be used if the original one is disturbed. Gestation is about two months and then 1 to 10 kits are born. The male supplies the female with food while she looks after the kits. At about a month old the kits begin to play outside the den. The mother feeds them regurgitated food and later brings them live prey which they "play" with before eating, which helps develop skills for hunting. At about 7 months old the kits leave the mother.
Globally, there appear to be no major threats to Red fox at present. Locally, these foxes may suffer from habitat degradation, loss, and fragmentation, and overhunting.
Its worldwide population is difficult to estimate, due to its widespread distribution. According to IUCN, as of 1995, the total pre-breeding British fox population was approx. 240,000 individuals. The population in Germany was estimated at about 600,000 in 2000–2001. The ICUN classifies the red fox as "Least Concern", with a stable population trend.
Red foxes help control the populations of their prey, such as rabbits and rodents. They may also disperse seeds due to eating fruit.
Red foxes usually do not make good pets. Well-meaning people adopt supposedly abandoned kits during the spring period. Actual orphans are rare; those adopted have probably strayed from the site of their den. Generally friendly toward people when very young, captive Red foxes develop a fear of humans, except for their handlers, from 10 weeks of age.