Arctic fox

Arctic foxes eat lemmings, which are small furry animals.

They also eat birds, eggs and berries. Sometimes they follow polar bears and eat their leftovers.

In summer, Arctic foxes mostly hunt lemmings and other small rodents, and they catch birds and take eggs. In winter, when food is hard to find, they hunt birds like ptarmigan, eat fish and carrion, and even follow polar bears to eat what is left of their meals.

Arctic foxes plan ahead. In summer, when there is plenty of food, they carry extra back to their dens and hide it under stones to eat later.

Britannica describes an opportunistic diet: in summer mainly rodents such as lemmings, plus birds; in winter birds such as ptarmigan, grouse and puffins, rodents and even reindeer, often as carrion. Arctic foxes frequently follow polar bears to scavenge the remains of their kills. Animal Diversity Web adds fish, eggs, insects, fruit and even dung.

Inland, lemmings dominate the diet, and fox breeding tracks lemming abundance: litter size varies with lemming availability. In summer, surplus prey is carried back to the den and cached under stones, a buffer for leaner times.

Arctic fox families live in a den with many doors.

Some dens are very, very old. Many fox families have used the same den, one after another.

An Arctic fox family lives in a den dug into a low mound on the tundra or among rocks below a cliff. A den can have 4 to 8 entrances and lots of tunnels. Some dens are so good that fox families have used them for hundreds of years.

Dens are spaced out, often at least 1.6 kilometers apart. Arctic foxes must watch out for bigger hunters like polar bears, wolves and wolverines, and in some places red foxes push them out of the best land.

Family groups use dens built in low tundra mounds or rock piles at the base of cliffs, typically at least 1.6 kilometers apart. The tunnel systems, with 4 to 8 entrances over about 30 square meters, can be used for centuries, which makes good den sites a long-term resource for a population.

Arctic foxes are prey for polar bears, wolves and wolverines, and the larger red fox competes with and displaces them where the two meet. Researchers of the COAT program in northern Norway link the red fox's spread into the low Arctic to warmer winters and to more carrion, such as reindeer, left in the landscape. Arctic foxes are both hunters and scavengers, and following polar bears is one way they survive the Arctic winter.

There are lots of Arctic foxes in the far north.

But in some places they are rare. People are helping them by watching over their dens.

Worldwide, Arctic foxes are listed as Least Concern. In the past, many were trapped for their fur, but fur hunting has fallen a great deal since the end of the 1900s.

In some places, though, Arctic foxes are rare, like northern Scandinavia, where there are not many left. There, scientists and wildlife workers protect den areas, watch the fox families closely and study how red foxes and warmer winters affect them.

The IUCN Red List lists the Arctic fox as Least Concern globally (2014) and in Europe (2023), but notes a severely fragmented European population. Commercial trapping once put heavy pressure on the species; Britannica notes this has fallen sharply with the decline of the fur industry since the late 20th century, though hunting remains common among some Arctic communities.

The main concerns now are regional: small, isolated Fennoscandian populations, competition with northward-spreading red foxes, and changes in lemming cycles, on which Arctic fox breeding depends. In northern Norway, the COAT program checks known dens every year with automatic cameras; in Sweden and Finland, EU LIFE projects that combined winter feeding, protection around dens and other actions halted the decline, and the population more than doubled where the work was most intensive.