Arctic Fox

The Arctic Fox (Alopex lagopus), also known as the White fox, is a Fox of the order Carnivora. It is a small fox native to cold Arctic regions of the Northern Hemisphere. It is common in all three tundra biomes. Although some authorities have suggested placing it in the genus Vulpes, it has long been considered the sole member of the genus Alopex.

The Arctic fox has evolved to live in the most frigid extremes on the planet. Among its adaptations for cold survival are its deep, thick fur, a system of countercurrent heat exchange in the circulation of paws to retain core temperature, and a good supply of body fat. The fox has a low surface-area-to-volume ratio, as evidenced by its generally rounded body shape, short muzzle and legs, and short, thick ears. Since less of its surface area is exposed to the cold, less heat escapes the body. Its furry paws allow it to walk on ice floors in search of food. It is also able to walk on top of snow and listen for the movements of prey underneath. Its thick fur is the warmest of any mammal.

Arctic foxes tend to be active in early September to early May. The gestation period is 52 days. Litters tend to average 6-7 pups but may be as many as 11. 1 Both the mother and the father help to raise their young. The female leave the family and form their own groups and the males stay with the family.

Foxes tend to form monogamous pairs in the breeding season. Litters of between 4 and 11 kits are born in the early summer. The parents raise the young in a large den. Dens can be complex underground networks, housing many generations of foxes. Young from a previous year's litter may stay with the parents to help rear younger siblings.

The Arctic fox will generally eat any meat it can find, including lemmings, Arctic Hare, reptiles and amphibians, eggs, and carrion. Lemmings are the most common prey. A family of foxes can eat dozens of lemmings each day. During April and May the Arctic fox also preys on ringed seal kits when the young animals are confined to a snow den and are relatively helpless. Fish beneath the ice are also part of their diet. When its normal prey is scarce, the Arctic fox scavenges the leftovers of larger predators, such as polar bears, even though the bears' prey includes the Arctic fox itself.

The length of the head and body is 55 cm (21.7 in) in the male and 53 cm (21 in) in the female. The tail is 31 cm (12.2 in) long in the male and 30 cm (11.8 in) long in the female. It is 25-30 cm (9.9-11.8 in) high at the shoulder, and males weigh 3.8 kg (8.2 lb) while females can weigh 6 to 12 pounds.