ARCTIC FOX } Alopex lagopus
DESCRIPTION: Arctic foxes are well adapted to the cold: They are small and stout compared to other foxes; their short snouts, stubby legs, and little, curled ears help to minimize heat loss. Thick fur combined with a unique circulation system in their paws keep the pads of Arctic foxes' feet warm while maintaining their core temperature. In the winter, these foxes boast a long white coat that sheds to short, dark gray to bluish-brown fur in the summer. They measure three feet from nose to tail and weigh between six and 12 pounds.
HABITAT: Arctic foxes live in Arctic and alpine tundra, in coastal areas, on ice floes, and north of the tree line.
RANGE: The Arctic fox has a circumpolar range and is found in the tundra extending through the northernmost regions of Europe, Asia, North America, Greenland, and Iceland. In North America, the Arctic fox is found from western Alaska east through northern Canada, including portions of the Northwest Territories, Alberta, Manitoba, and Quebec.
MIGRATION: In Alaska, Arctic foxes migrate from their fall breeding grounds and travel to coastal areas, returning in late winter or early spring. Large-scale migrations have been recorded in Canada, Russia, and the Scandinavian peninsula, possibly a result of drastic reductions in available food supply.
BREEDING: Arctic foxes form monogamous pairs during the breeding season. The average gestation period is four to five weeks. Births occur from April through June for the first litter and in July or August for the second litter. Usual litter size is five to eight kits, although as many as 15 have been known. The young are weaned at two to four weeks at which time they emerge from the den. Arctic foxes reach sexual maturity in as few as 10 months.
LIFE CYCLE: Arctic foxes live for three to six years.
FEEDING: Arctic foxes are opportunistic feeders, eating practically any animal alive or dead. They rely on populations of rodents, especially lemmings, voles, and other small mammals. They will also eat birds, insects, eggs, berries, reptiles, and amphibians. During the summer months, Arctic foxes collect a surplus of food and carry it back to their dens to bury and store. Come wintertime when prey is scarce, they will follow polar bears and wolves to scavenge the remains of their kills. Arctic foxes walk on top of the snow and use their acute hearing to listen for small creatures below. If they hear something move, they will jump up and down to break through the snow and reach with their front paws to grab the prey. Foxes living near water take advantage of access to marine animals like fish, seals, seabirds, and marine invertebrates.
THREATS: Arctic foxes are threatened by global warming, competition from the larger, northward-spreading red fox, and hunting and trapping for the fur trade.
POPULATION TREND: The worldwide population of Arctic fox is believed to be several hundred thousand, though only a few populations have been studied. Some populations have suffered sharp declines due to over-hunting, including those in Scandinavia, where insufficient food sources in the 1980s and 1990s reduced fox numbers to an estimated 120 adults. As ice retreats and boreal forests spread northward, fox habitat shrinks, causing serious concern for the long-term survival of the species.