The Arctic fox has the warmest pelt of any animal found in the Arctic. It can endure temperatures as low as -50 °C before its metabolism increases to provide warmth.
Physiology
The Arctic fox is about the size of a large domestic cat. It is part of the canid family,
meaning it is related to other foxes, wolves and dogs, and it is the smallest wild canid
found in Canada. It usually measures between 75 to 115 centimetres in length, and its bushy
tail makes up between 30 and 35 percent of its total length. The Arctic fox has a brown
or grey coat with a lighter belly in the summer, and it turns into a thick, white one during
the winter season. The white coat makes it very hard for the fox's prey to see it in the
snow before it's too late. Some have a grey to dark grey-blue coat in the winter. The Arctic
fox is the only canid that changes the colour of its coat in the summer.
In addition to its thick coat, the Arctic fox is able to stay warm in the winter because
it has short legs, a short muzzle and small rounded ears. These characteristics all reduce
the amount of surface area it has for heat loss. Also, its feet are covered in fur, similar
to the fur on a hare's foot.
The Arctic fox is both a carnivore and scavenger, eating lemmings, eggs and the young of
different species of bird. In the winter, it scavenges the bodies of already-dead animals,
normally left behind by timber wolves or polar bears. The Arctic fox may also dig ringed
seal pups out of their lairs and eat them. To find prey during the winter, the Arctic fox
uses its hearing and sense of smell to detect animals travelling in tunnels underneath the
snow.
The foxes begin to form mating pairs in March or April. A female's, or vixen's, pregnancy
normally lasts 51 to 57 days, and the pair remains together throughout pregnancy and the
raising of its young. The fox nurses its pups, or whelps, in dens that can be up to 300
years old, with as many as 100 entrances. The litters are born between late May and early
June, with an average litter size of 11 whelps. This is the largest litter recorded for
any wild mammal in the world.
Range
The Arctic fox lives in the circumpolar Arctic, which goes from the northern tip of Ellesmere
Island to the southern tip of James Bay in Canada. They are normally found where seals and
polar bears are present in and on ice floes. Each Arctic fox has its own home range, varying
in size from three to 25 square kilometres. They are, however, very mobile and can travel
large distances over both land and sea ice. Over 2,000 kilometres of individual fox movement
has been recorded.
Hunters, diseases, and native traplines also cause the reduction of an Arctic fox population.