Arctic Fox
The arctic fox, Vulpes lagopus, also called the snow fox, polar fox or white fox, is a small fox built for the coldest places on Earth. It lives all around the Arctic, on the tundra and sea ice of Canada, Alaska, Greenland, Iceland, Scandinavia and Russia. Its deep, layered winter fur, short legs, small rounded ears, short muzzle and furry feet keep heat in, and it can stay warm without burning extra energy until temperatures drop to around −40 °C. Most arctic foxes are pure white in winter and turn brown and gray in summer, while the blue morph stays dark blue gray all year. Lemmings and voles are its main prey, and the rise and fall of lemming numbers controls how many pups foxes raise. Coastal foxes eat seabirds, eggs and fish, and in winter many follow polar bears onto the sea ice to feed on the remains of seals. Pairs raise large litters in dens that can be used for centuries. Arctic foxes travel enormous distances: one young fox walked 3,506 km from Svalbard to Canada in 76 days. The species is common worldwide, but in Scandinavia it is critically endangered.
What is an arctic fox? Snow fox, polar fox and white fox
The arctic fox is a small member of the dog family that lives around the North Pole, and it goes by many names. In English it is often called the snow fox, the polar fox or the white fox, names that all describe its famous winter coat, and in Iceland, where it is the only native land mammal, people call it the Icelandic fox or melrakki. Its scientific name is Vulpes lagopus. Vulpes is Latin for fox, and lagopus comes from Greek words meaning hare foot, because the soles of its feet are covered in thick fur, like a hare's. For many years it was placed in its own genus, Alopex, but genetic studies showed that it is a true fox, closely related to the red fox and especially to the swift fox and kit fox of North America. It is one of the few land animals that live their whole lives on the Arctic tundra and sea ice, and it is found farther north than almost any other land mammal, reaching the northern tip of Greenland. Arctic foxes are also part of the culture of the far north. They have long been trapped for their fur by Inuit, Sami and other Arctic peoples, and in Finnish legend the northern lights are called revontulet, or fox fires, after a fox whose tail brushed sparks from the snow.
How big is an arctic fox?
The arctic fox is a small fox, about the size of a large house cat, and noticeably smaller than the red fox. Its head and body measure about 46 to 68 cm, and its bushy tail adds about 30 cm more. It stands only about 25 to 30 cm at the shoulder, because its legs are short, which helps it lose less heat. Most adults weigh 2.5 to 5 kg, and males are slightly larger and heavier than females. Weight changes a lot through the year: in autumn arctic foxes build up thick fat reserves, which can add up to half of their body weight, and they slowly use them up during the long winter when food is scarce. In its thick winter fur an arctic fox looks round and much bigger than it really is; in summer, once it sheds that coat, it looks surprisingly thin and leggy. Everything about its shape is designed to save heat. Its ears are short and rounded instead of long and pointed, its muzzle is short, and its body is compact, so there is less surface for warmth to escape. This is the opposite of its relative the fennec of the Sahara, which has huge ears to get rid of heat. Arctic foxes are also tough and agile, able to trot for hours across the tundra and to leap onto prey under the snow.
Arctic fox colors: white, blue and the summer coat
Arctic foxes come in two color forms, called morphs, and both change with the seasons. The white morph is the famous one. In winter it is pure white, or creamy white, which hides it perfectly on snow and ice. In spring it sheds that thick coat and grows a much thinner summer coat that is brown or grayish brown on the back and head and pale gray or cream underneath, a mix that blends with rocks, soil and tundra plants. This is why an arctic fox in summer looks like a completely different animal and is often mistaken for a small red fox. The blue morph stays dark all year: chocolate brown or charcoal in summer and a smoky blue gray in winter. Blue foxes are rare in most of the Arctic, where white foxes hunt on snow covered tundra, but they are common on coasts and islands with less snow, such as Iceland, where they are the majority in the Westfjords, coastal Greenland, the Pribilof Islands of Alaska and the Commander Islands of Russia. The color change is set off by day length, not temperature. The blue fox was also bred on fur farms, especially in Norway and Finland, where farmed blue foxes are much larger than wild ones. A single litter can include both white and blue pups.
How does the arctic fox survive the cold?
The arctic fox has one of the warmest coats of any mammal. In winter its fur is very deep and has two layers: a dense, woolly underfur that traps air and long guard hairs that shed snow and wind. With this coat it can rest in the open without having to burn extra energy to stay warm until the air drops to around −40 °C, and it can survive temperatures of −50 °C and lower. Its compact body, short legs, short muzzle and small rounded ears reduce the surface that loses heat. The soles of its feet are covered in thick fur, which insulates them from the ice and helps it walk on snow, and its legs use a heat exchange system in the blood vessels that keeps the paws just above freezing while saving the body's warmth. When a blizzard hits, the fox curls into a tight ball, tucks its nose and feet into its long tail and lets the snow cover it, or digs a shelter in a snowbank. Fat stored in autumn keeps it going when food is hard to find, and in the coldest months it can lower its activity to save energy, although it never hibernates. In summer it faces the opposite problem, so it sheds its thick coat and pants to cool down on warm days.
Where do arctic foxes live?
The arctic fox lives all around the top of the world. The IUCN lists it as a native resident of Canada, the United States (Alaska), Greenland, Iceland, Norway, including Svalbard and Jan Mayen, Sweden, Finland and Russia, and as an introduced species on the Aleutian Islands of Alaska. Most live on the open tundra north of the tree line, from the Arctic coasts of Alaska, Canada and Siberia to the high Arctic islands, and in Scandinavia they live on the treeless mountain plateaus called fells. In Iceland it is the only native land mammal, and it probably arrived over the sea ice at the end of the last ice age. Arctic foxes also spend a lot of time on the frozen sea, especially in winter, hunting along the ice edge and following polar bears. They are some of the greatest travelers among land mammals. In 2018 a young female tracked by the Norwegian Polar Institute left Svalbard in March, crossed the sea ice to Greenland and reached Ellesmere Island in Canada 76 days later, after covering 3,506 km, once moving 155 km in a single day. The number of foxes in any area rises and falls sharply from year to year, following the cycles of lemmings, which boom and crash every three to five years in many places.
What do arctic foxes eat?
Arctic foxes eat almost anything they can find, and what they eat depends on where they live. Inland, on the tundra of Scandinavia, Siberia and North America, they are lemming foxes: lemmings and voles are their main food, and in a good lemming year a family of foxes can eat dozens a day. They find them by listening and smelling under the snow, then pounce high and dive nose first to break through the crust. When lemmings crash, inland foxes raise few or no pups. Coastal foxes, like most of those in Iceland, Svalbard, Greenland and the Bering Sea islands, live mainly on the sea and the cliffs. They catch seabirds and their chicks, steal eggs from colonies of geese, ducks and auks, pick up fish, mussels and invertebrates on the shore and eat the carcasses of seals, whales and walruses washed up on the beach. In winter many go out on the sea ice to follow polar bears and eat what is left of their seal kills, and they also catch young ringed seals in their snow dens. They eat berries in late summer too. In the short summer, when food is plentiful, arctic foxes store the extra in caches; one study found a fox den with hundreds of goose eggs buried around it, kept for months in the cold ground.
How arctic foxes live: dens, pups and family life
Arctic foxes usually live in pairs that stay together for the breeding season and often for several years, and sometimes a young female from the year before stays to help raise the new litter. They raise their pups in large underground dens dug into sandy ridges, eskers and mounds, where the soil is not frozen. Good den sites are scarce on the tundra, so the same dens are used again and again by generation after generation; some in Canada and Scandinavia have dozens of entrances and are thought to be hundreds of years old, and their droppings fertilize the soil so the den mounds turn bright green in summer. Mating takes place in late winter and early spring. After a pregnancy of about 52 days, the vixen gives birth in May or June to the largest litters of any wild dog: usually 5 to 8 pups, but in lemming peak years more than 15, and litters of up to around 20 have been recorded. The pups are born dark and blind, come out of the den at about three to four weeks old, and both parents bring them food. By late summer the young foxes start to roam, and most leave in autumn. Arctic foxes communicate with barks, yelps and screams, and they mark their territory with urine and scent.
Arctic fox vs red fox
The arctic fox and the red fox are close relatives, but they are easy to tell apart. The red fox is bigger, often twice as heavy, with longer legs, a longer muzzle, larger pointed ears and an orange red coat with a white tipped tail. The arctic fox is smaller and rounder, with short legs, a short muzzle and small rounded ears, and its coat is white or blue gray in winter and brown in summer. Their lives meet where the forest ends and the tundra begins, and the meeting is bad news for the arctic fox. Red foxes take over the best den sites, chase arctic foxes away and sometimes kill them and their pups. As the Arctic warms and people build roads, towns and dumps that provide extra food, red foxes are moving farther north, into Scandinavia's fells, northern Russia and the Canadian Arctic, and arctic foxes retreat. In Norway and Sweden, red foxes are culled in key arctic fox areas as part of recovery programs. The arctic fox does have one advantage: it copes far better with extreme cold and scarce food, which is why it still rules the high Arctic islands and the open sea ice, where red foxes cannot survive.
Is the arctic fox endangered?
Not globally. The IUCN rates the arctic fox as Least Concern, in an assessment from June 2014 that describes its world population as stable and estimates it at several hundred thousand animals, most of them in Russia, Canada, Alaska and Greenland. Some populations, however, are in serious trouble. In Scandinavia, fur hunting in the early twentieth century crashed the arctic fox, and even after full protection between 1928 and 1940 it did not recover; around the year 2000 only about 40 to 60 adults were left in Norway, Sweden and Finland, and the European population is listed as Critically Endangered. Captive breeding in Norway, supplementary feeding stations and red fox culling have brought it back: the 2025 count found 97 litters, 56 in Sweden, 38 in Norway and 3 in Finland, and an estimated 526 adults, down from 582 the year before. Finland saw its first successful breeding since 1996 in 2022. On Mednyi Island, in Russia's Commander Islands, a unique subspecies crashed from about 1,000 to around 100 after an outbreak of ear mites in the 1970s, and is listed in Russia's Red Book. The biggest long term threats are climate change, which shrinks the tundra and brings in red foxes, and collapsing lemming cycles.
Where it is found
The Arctic Fox can be found in places such as:
