The arctic fox is the most northerly of the wild canids (dog family). It ranges from the subarctic regions to the high arctic. Arctic foxes have been spotted only 61 km from the North Pole, making it the most northern-ranging of any land mammal. While a typical arctic fox has a home range of 3 to 25 square km, they have been recorded moving over 1500 km.
Arctic foxes have the warmest pelt of the arctic animals. The temperature has to drop below -50 degrees Celsius before an arctic fox needs to increase its metabolism. Arctic foxes also have an advanced counter-current heat exchange mechanism in their legs. This helps them to avoid heat loss as they warm the blood in the legs that is returning to the heart.
Arctic foxes are known for their spectacular pelts that change seasonally. Their white or sometimes blue-tinged winter coat makes it difficult for their prey to see them, giving them an excellent hunting advantage. Their brown or greyish summer coat allows them to blend in with tundra rocks and plants.
Arctic foxes are monogamous and may mate for life. The pair will remain together to raise the young. The amount of food available will affect the number of offspring born, with an average of 8 pups. However in times of plenty they can have up to 25 young. Arctic foxes use the same dens for generations and have been recorded to make use of dens that are 300 years old.
As opportunistic predators and scavengers, Arctic foxes have a diverse diet that includes small mammals such as lemmings, voles, snowshoe hares and Arctic ground squirrels, the eggs and the young of many bird species, fish, seal carcasses, marine invertebrates and even berries and some vegetation.