Wolverine
The wolverine is the largest land-dwelling member of the weasel family, but stocky enough to look more like a small bear than a weasel. It lives across the boreal forests, alpine meadows and tundra of the Northern Hemisphere, from Alaska and Canada to Scandinavia, Russia, northern Mongolia and the far north of China. Its broad, well-padded paws spread its weight over snow the way snowshoes do, allowing it to chase down prey that would otherwise sink and tire. Wolverines are famous for strength out of proportion to their size. They can drive bigger animals away from a carcass and crack frozen bones with their powerful jaws. Solitary and wide-ranging, a single adult may patrol a home range of several hundred square kilometers, and males often cover more than 1,000. Despite their fearsome reputation, wolverines are shy around people and are rarely seen in the wild.
What is a wolverine? The real animal behind the name
Many people first hear the word wolverine through comics and movies, but the real wolverine is a wild carnivore of the far north, known to scientists as Gulo gulo. It belongs to the mustelid family, the same group as weasels, otters, martens and badgers, and it is the largest member of that family that lives on land. Only the giant otter and the sea otter grow heavier. Its thick body, short legs and rounded head make it look like a small bear, which explains old nicknames such as skunk bear, but it has no close relationship with bears at all. In Europe it has long been called the glutton, a name that comes from the Latin gulo and from the old belief that it ate without limit. In French Canada it is known as the carcajou, a word borrowed from an Indigenous language. A single species lives across North America, Europe and Asia. Most experts split it into two subspecies: the Eurasian or European wolverine and the North American wolverine, which some authors treat as a separate species. Both look and behave almost the same.
How big is a wolverine? Size, weight and appearance
A wolverine is about the size of a medium dog, but much more solid. Its body measures roughly 65 to 105 centimeters from nose to rump, and a bushy tail adds another 13 to 26 centimeters. Males are clearly bigger than females: adult males usually weigh 12 to 18 kilograms, while females weigh around 8 to 12 kilograms. Standing about 30 to 45 centimeters tall at the shoulder, it carries its weight low to the ground, with the back slightly arched and the head held down as it lopes along. The coat is long, dense and dark brown, almost black on the legs. A pale band of tan or golden fur runs along each side, starting at the shoulders and meeting over the rump and the base of the tail, which gives the animal its striped look. Many wolverines also have a light mask across the forehead and patches of white or cream on the throat and chest, and the pattern is different in every individual, so researchers use it to tell animals apart in photos. The ears are small and round, and the eyes are small too. The feet are surprisingly large for the body, which is one of the keys to how it moves over deep snow.
Wolverine claws, jaws and strength
Pound for pound, few animals can match the wolverine. Each foot has five toes armed with long, curved claws that are partly retractable, strong enough for digging through hard snow, tearing into frozen carcasses and climbing trees and rock faces. The jaws are just as important. A special upper molar, turned sideways in the mouth, lets the wolverine shear through frozen meat and crack bones that many predators leave behind in winter. Thanks to this power it often wins standoffs over food with animals several times its weight, and there are observations of wolverines pushing foxes, lynx and even bears away from carcasses, although it usually avoids wolf packs. Its endurance is equally remarkable. Wolverines regularly travel 30 kilometers or more in a day through deep snow and steep terrain. In Glacier National Park in Montana, a radio collared male known as M3 climbed the last 1,500 meters of Mount Cleveland, the highest peak in the park, in about 90 minutes in the middle of winter. Dense, oily fur sheds frost and moisture, which is why people across the Arctic have long used wolverine fur to trim the hoods of their parkas.
Where do wolverines live?
Wolverines live in some of the coldest and most remote places on Earth. According to the IUCN, the species is found in Canada, the United States, Finland, Norway, Sweden, Russia, Mongolia and China. In North America its range covers Alaska and most of northern and western Canada, with small populations in the northern Rocky Mountains and the Cascades of Washington. In Europe it lives in the mountains of Norway and Sweden and in the forests of eastern and northern Finland, and from there the range continues across the whole Russian taiga and tundra to the Pacific. In Asia it reaches the forested mountains of northern Mongolia and the Altai, and in China it survives only in the Greater Khingan Mountains of the northeast and the Altai in the far northwest. Wolverines use boreal forest, alpine meadows, rocky slopes and open tundra, from sea level in the Arctic up to about 2,400 meters in the mountains. What ties these places together is snow: females dig their dens in snow that lasts into spring, and cold keeps food caches fresh. Wolverines once lived in eastern Canada too, but there has been no verified record in Quebec since 1978 or in Labrador since the 1950s.
What do wolverines eat?
Food can be hard to find in the frozen north, and wolverines have adapted to eat almost anything available. Carrion is the backbone of their diet in winter, when the carcasses of moose, caribou, reindeer, deer and mountain goats killed by wolves, avalanches or harsh weather provide critical calories. A wolverine can smell a carcass buried under deep snow and dig straight down to it. When the chance comes, it also hunts for itself. Small prey such as lemmings, voles, ground squirrels, snowshoe hares, marmots and birds make up much of the summer menu, along with eggs, insect larvae and berries. Deep snow works in its favor during winter hunts, because it slows down large hoofed animals while the wolverine stays on the surface thanks to its broad paws. In Scandinavia and Finland it regularly kills reindeer, especially calves, and sheep grazing free in the mountains, which is the main source of conflict with people. Wolverines are dedicated cachers. They tear carcasses into pieces and hide the surplus under snow, in rock crevices or in bogs, then come back to it weeks or even months later, a habit that helps females feed their kits in late winter.
How wolverines live: territory, dens and kits
Wolverines are solitary and spend most of their lives alone. They are active by day and by night, alternating a few hours of travel with a few hours of rest, and they do not hibernate. Their territories are enormous for an animal of their size. A female may use a few hundred square kilometers, while a male's territory often covers more than 1,000 and overlaps those of two or three females. Wolverines mark these areas with urine and a strong musky scent from glands near the tail, which is why they are sometimes called skunk bears. Mating takes place in summer, but the fertilized egg does not attach to the womb until late autumn or winter, a pause known as delayed implantation. Kits are born between February and April inside dens that the female digs deep into snowdrifts, often among boulders or fallen trees. Most litters have two or three kits, born with white fur. They grow fast on milk and cached meat, leave the den in spring and are largely independent by their first autumn, at five or six months. Many young wolverines then travel hundreds of kilometers to find a territory of their own. Despite their reputation, wolverines are shy around people and usually vanish long before anyone gets close.
Wolverine tracks in the snow
Because wolverines are so rarely seen, most people only know they are around from their tracks, and researchers in Scandinavia and Finland count the population largely by following trails in fresh snow. A wolverine track is big for the size of the animal. The front print is about 11 to 14 centimeters (4.3 to 5.5 inches) long and almost as wide, and the hind print is a little smaller. Each foot has five toes arranged in a curve, usually with claw marks in front of them, and the toes spread wide on soft snow, giving the print a broad, rounded look. The innermost toe is small and sometimes does not show, so a single print can be confused with a wolf or a large dog track. The pattern of the trail helps. Wolverines usually move in a steady lope that leaves groups of three or four prints close together, repeated every meter or so, or pairs of prints side by side when they bound through deep snow. A wolf, by contrast, shows only four toes and walks or trots in a straight line of single prints. Following a wolverine trail can also lead to dug up caches, scent marks on stumps and, in late winter, the snow den of a female with kits.
Wolverine vs wolf: predators and rivals
Stories often claim that a wolverine can beat a wolf, but in real life the relationship is mostly one sided. Wolves are the main natural predator of adult wolverines in North America, and a pack that catches one away from trees or rocks can kill it. A single wolverine may hold its ground over a carcass against one wolf, yet it usually avoids packs. At the same time, wolverines depend on wolves. Much of the carrion they eat in winter comes from moose, caribou and reindeer killed by wolf packs, and wolverines often follow wolf trails to scavenge what is left. Where wolves disappeared, wolverines lost an important source of food. Other wolverines are a danger too, especially for kits, which are sometimes killed by adults that are not their parents. Bears and other large carnivores may take kits or young animals, and starvation kills many wolverines in hard winters. For adults, though, the biggest cause of death in many areas is people, through legal trapping and hunting, illegal killing near reindeer herds and traffic on roads. With few natural enemies and a slow breeding rate, small changes in human pressure can make a big difference to a local population.
Are wolverines endangered?
Wolverines are not endangered worldwide. The IUCN lists the species as Least Concern in an assessment made in 2015 and published in 2016, but it also notes that the global population is decreasing and that the assessment needs updating. There is no reliable worldwide count. Russia and Canada hold most of the wolverines on Earth, while smaller populations are counted closely in Europe: the latest Scandinavian estimate, for the winter of 2024 and 2025, gives about 1,040 to 1,120 wolverines, roughly 675 to 730 of them in Sweden and 350 to 400 in Norway, and Finland had an estimated 350 to 500 in early 2024. The situation is much worse in some places. In the lower 48 United States only a few hundred wolverines survive, and in November 2023 they were listed as threatened under the Endangered Species Act. In China, surveys suggest only about 300 remain. The main long term threat is climate change, because shorter winters and thinner snowpack reduce the places where females can dig dens. Trapping, illegal killing in reindeer and sheep areas, roads, and growing human activity in the mountains add to the pressure. Wolverines breed slowly, so lost animals are not replaced quickly.
Where it is found
The Wolverine can be found in places such as:
