Red foxes are the most widely distributed wild carnivores in the world, occurring in North America, Asia, Europe, and North Africa. They are also widespread in Australia, where they were introduced in about 1850 so that fox-hunters would have something to hunt. Their range in North America has expanded since colonial times as their competitors, wolves, were eliminated, but their range has also contracted in areas where they are in competition with coyotes. Red foxes prey on voles, rabbits, hares, and other small mammals, and also eat birds, fruits, and invertebrates even beetles and earthworms. A male female pair typically inhabits a territory, and older, usually female, siblings help care for the younger offspring by bringing them food. Red foxes are among the main carriers and victims of rabies.
Red foxes are found throughout much of the northern hemisphere from the Arctic circle to Central America, the steppes of central Asia, and northern Africa. This species has the widest distribution of any Canidae. Red foxes have also been introduced to Australia and the Falkland Islands.
Red foxes commonly inhabit areas with a high proportion of edge. Fire that creates a mosaic of burned and unburned areas is probably the most beneficial to red foxes. Periodic fire may help to maintain habitat for many prey species of red fox. Many small mammal populations increase rapidly in response to an increase in food availability subsequent to burning [14,19,22]. In Alaska red foxes should benefit during the first 10 to 20 years following fire due to the increase in northern red-backed voles (Clethrionomys rutilus) and meadow voles . Fire often improves hare and rabbit forage quality and quantity for two or more growing seasons . Wagle  reported that fire suppression in grasslands is detrimental to populations of small bird and mammal herbivores due to organic matter accumulation and reduced plant vigor.
Many fruiting shrubs that are important late summer and fall foods of red foxes such as blackberries (Rubus spp.), blueberries, and raspberries, do not fruit the year of burning but produce the most fruit 2 to 4 years after fire pruning [14,19].
Red foxes are the most widely distributed carnivore in the world. They occur throughout most of North America (except in the Great Plains and the extreme Southeast and Southwest), Europe, and Asia, and are found in parts of northern Africa. They have spread throughout much of Australia, where they were introduced in the late 1800's [30,36].
There is some question whether red foxes are native to North America. Churcher  hypothesized that red foxes were native to North America north of latitude 40 degrees North, but were scarce or absent in most of the vast hardwood forests where common gray foxes (Urocyon cinereoargenteus) were abundant. Others believe that the North American red fox originated from the European red fox, which was introduced into the southeastern section of the United States around 1750. It may have interbred with the scarce indigenous population to produce a hybrid population . The distribution of the ten subspecies of red fox is as follows :
V. v. abietorum - Occurs throughout western Canada V. v. alascensis - Occurs in Alaska, and Yukon Territory, and the Northwest Territories V. v. cascadensis - Occurs along the northwest coast of the United States and British Columbia V. v. fulva - Occurs in the eastern United States V. v. harrimani - Occurs on Kodiak Island, Alaska V. v. kenaiensis - Occurs on the Kenai Peninsula, Alaska V. v. macroura - Occurs throughout the Rocky Mountains V. v. necator - Occurs in California and Nevada V. v. regalis - Ranges from north-central Canada south to Nebraska and Missouri V. v. rubricosa - Occurs in southern Quebec and Nova Scotia
Breeding season - Red foxes are monestrous [1,5]. The red fox breeding season generally lasts from December to March [1,5,36]. However, the onset of breeding varies in different parts of red fox range, earlier in the south and later in the north. Breeding in Ontario occurs from late January to late March . Breeding peaks occur from late December to early January in Iowa, late January in Wisconsin, and late January and early February in New York. The earliest recorded breeding dates for red foxes in the United States are early December and the latest are in April .
It is not known whether red foxes in the wild are normally polygamous. However, it is common to see several males near a female during estrus . Estrus last 1 to 6 days. Females may breed at 10 months of age. However, not all females breed their first year. Most males are capable of breeding their first year .
Gestation and litter size - Gestation usually lasts 51 to 53 days. Litters of four to seventeen have been reported, with a mean of five [5,13,36]. Generally only one litter is produced per year.
Development of young - Newborn pups remain at the den for the first month of life. They first open their eyes at 9 days of age. Red fox parents may move the pups from one den to another as many as three times before they are 6 weeks old. Litters are sometimes split with half the litter residing in one den and half in another. Pups are weaned at 8 to 10 weeks. When pups are 10 weeks old they may travel short distances from the den without being accompanied by a parent. At about 12 weeks of age pups begin to explore their parents' home range independently or with a parent .
Dispersal - By mid-September or early October pups begin to disperse. Male red foxes usually disperse before females and move greater distances . Most red foxes disperse from their parents' home range before their first birthday . The mean distance dispersed by males in Iowa and Illinois was 18 miles (29 km) . In Ontario, straight-line dispersal distances as great as 76 miles (122 km) were recorded, but most males dispersed a straight-line distance of about 19 miles (30 km) during the first 15 days after leaving the den. Females dispersed an average of 5 miles (8 km) in Ontario and 10 miles (16 km) in Iowa and Illinois [23,36].
Social organization - The red fox social unit is comprised of pups and either one male and one female or a group of one male and several females . When a group contains several females they are generally kin. In much of North America, social groups are just pairs. Where groups include additional adult females, the largest groups occur in rural-suburban habitat and average more than three females. Only a minority of females in large groups rear pups. Nonbreeding females tend to be socially subordinate to breeding ones, and some act as helpers. Where more than one female breeds within a social group, communal denning and nursing are common .
Life span - Most red foxes in the wild live 3 or 4 years .
Red Fox density is highly variable. In the UK, density varies between one fox per 40 km² in Scotland and 1.17/km² in Wales, but can be as high as 30 foxes per km² in some urban areas where food is superabundant (Harris 1977; Macdonald and Newdick 1982; Harris and Rayner 1986). Social group density is one family per km² in farmland, but may vary between 0.2-5 families per km² in the suburbs and as few as a single family per 10 km² in barren uplands (Macdonald 1981; Lindsay and Macdonald 1986). Fox density in mountainous rural areas of Switzerland is three foxes per km² (Meia 1994). In northern boreal forests and Arctic tundra, they occur at densities of 0.1/km², and in southern Ontario, Canada at 1/km² (Voigt 1987). The average social group density in the Swiss mountains is 0.37 family per km² (Weber et al. 1999).
The pre-breeding British fox population totals an estimated 240,000 (Harris et al. 1995). Mean number of foxes killed per unit area by gamekeepers has increased steadily since the early 1960s in 10/10 regional subdivisions of Britain, but it is not clear to what extent this reflects an increase in fox abundance. Although an increase in fox numbers following successful rabies control by vaccination was widely reported in Europe (e.g., fox bag in Germany has risen from 250,000 in 1982–1983 to 600,000 in 2000–2001), no direct measures of population density have been taken.