Arctic foxes live in the circumpolar north, throughout the entire Arctic and in sub-Arctic tundra and alpine areas. It is the only land mammal to venture as far north as the polar bear. It is also the only land mammal native to Iceland, having arrived there by crossing the frozen sea at the end of the last ice age.
Everything about the Arctic fox changes from summer to winter. It looks different, behaves differently, and lives differently depending on the season.
During the brief Arctic spring and summer, Arctic foxes move inland to mate and occupy extensive, communal summer dens. Generations of the same family of foxes often return to the same den each year, and like many growing families, they sometimes put on additions to their home. Large Arctic fox dens are impressive underground labyrinths of fox apartments.
Arctic foxes are active and opportunistic predators during the warmer months. They are well camouflaged for the job by their short, brownish-gray summer coats. They hunt, steal, scavenge and eat whatever they can, including fish, crustaceans, birds, bird eggs, and their favorite small mammal (and the main staple of their diet), lemmings. They are in constant food-gathering mode for themselves and their pups. Arctic foxes have also been known to cache food for winter.
When the cold sets in again, Arctic foxes transform into completely different looking animals. Beautiful, pristine balls of white fluff, to be exact. Their stunningly white winter coats will keep them warm through the long, dark, freezing Arctic winter. When warm-weather food supplies grow scarce, Arctic foxes turn solitary and nomadic. They migrate toward shore and even out to sea in search of food. Many foxes survive the winter by following polar bears onto the pack ice and scavenging their kills. One Arctic fox may cover hundreds and even thousands of miles in a single winter, searching for food.
Like polar bears, Arctic foxes are well adapted to extreme cold. Their winter coat is the densest and warmest of any land mammal and covers every part of their bodies, including the soles of their feet. This helps them to retain body heat, as do small ears and a small snout. They use their bushy tails as muffs. During a blizzard, an Arctic fox will curl up in a tight ball, wrap its tail around itself, and be blanketed by snow. The snow acts as an insulator and the fur traps body heat, so even in the coldest temperatures – even as cold as 50 degrees below Fahrenheit! – Arctic foxes are comfortable.
Because Arctic foxes are such effective predators with such voracious appetites during warmer months, they significantly impact the ecosystems in which they live. Highs and lows in Arctic fox populations correspond especially with highs and lows in lemming populations. During colder months, the impact that Arctic foxes have as predators declines significantly. Still, though, if you’re an Arctic fox trailing a polar bear, you don’t go unnoticed.
Arctic foxes are widespread throughout Arctic and sub-Arctic regions, where many different predators roam. Arctic foxes are preyed upon by red foxes, wolves, wolverines, and polar bears. Fox pups may be taken by birds of prey as well, including snowy owls, large hawks, and jaegers. Native people of the Far North also trap Arctic fox for their fur.
Arctic Foxes are monogamous and may mate for life. Mating generally occurs in early spring and females give birth to pups in late May, June, or early July. Inside the family den, females give birth to litters of 6 to 12 pups on average. Large litters compensate for high pup mortality. Both parents feed and care for the pups for their first several weeks of life. By late summer, the parents separate from their pups, leave summer dens, and begin to ready themselves for winter. The pups are on their own then.