A wolverine looks like a small bear, but it belongs to the weasel family, and it is the largest land-living member of that family. Otters, ferrets and honey badgers are its cousins; wolverines live in a ring around the north of the world, including Scandinavia, Russia, Alaska and northern Canada. In North America, they live mostly in Alaska and Canada, and they need large areas with few people; they are scarce and secretive, and wolverines have been studied less than many other meat-eating animals. Its scientific name, Gulo gulo, comes from the Latin word for glutton; wolverines are sometimes called skunk bears because they look like small bears and give off a strong-smelling musk. A wolverine's fur is dark brown, with a lighter yellow stripe along each side.
Wolverines are so rarely seen and live so thinly spread in remote country that population trends are hard to judge, and a sudden drop could go unnoticed for years. Scientists use cameras that switch on by themselves to find them. In winters 2016 and 2017, researchers in Idaho, Montana, Washington and Wyoming searched random 15-km by 15-km cells and detected wolverines in 59 of 183 cells, or 34 percent. In that survey, 22,641 of 439,834 photos contained a wolverine. At many stations, most of those photos were of the same wolverine passing the camera again and again. People rarely see wolverines because they are few and live in remote places. From 2006 to 2009, researchers documented seven wolverines in eastern Yellowstone and the national forests next to it.
Wolverines were nearly gone from Montana in the early 1900s; they have been increasing in numbers and range since, with recovery starting in the northwest of the state. Trapping and predator control reduced the wolverine's range in the lower 48 states by the 1930s, and some recovery has happened since. Long ago wolverines also lived farther south in Europe and the United States, but people's activities removed them from many of those places. The Fish and Wildlife Service found that unsustainable trapping in southern Canada appears to have lowered the wolverine population in part of southern British Columbia and Alberta. In 2008, a young male wolverine tracked by scientists traveled 585 miles over several months, ending in Colorado, the first documented wolverine there since 1919. Wolverines usually live alone.
A 2023 genetic study covering the U.S.-Canada border looked at 887 individuals; it found low genetic diversity and increasing fragmentation at the southern edge of the range. Highways in southern British Columbia appeared to restrict females moving from Canada to the U.S. Wolverines in the U.S. Rockies are likely genetically interdependent. Even at full capacity, Yellowstone-area habitat would hold too few females to stay viable without genetic exchange with nearby populations. Scientists recognize two wolverine subspecies, the North American wolverine and the European wolverine, which differ mainly in their genes. The oldest known wolverine fossil, a new species named Gulo sudorus from the Gray Fossil Site in Tennessee, is from the Early Pliocene, between 4.9 and 4.5 million years ago. Wolverines live at low numbers everywhere in their range, because each one needs a very large home range.
Snow is crucial for wolverines: they use it for dens and for keeping food. In a study of 562 wolverine dens from Fennoscandia and North America, every one was at a site with snow that lasts into spring. Most wolverine dens found so far are complexes of snow tunnels built next to boulders or rocks. Climate models predicted that by 2050 the spring snowpack wolverines need for denning and hunting would remain only in parts of the southern Rocky Mountains, the Sierra Nevada, and greater Yellowstone. In 2018 the Fish and Wildlife Service projected snow loss to 2050 for two areas; its 2023 update projected loss to the end of the century across five areas and found losses would be greater in 2100 than in 2050. Frost does not build up on wolverine fur, so people in the Arctic have used it to trim the hoods of their coats.
As of November 2026, the U.S. Fish and Wildlife Service proposed listing the wolverine as threatened in 2013, decided in 2020 that listing was not warranted, was told by a Montana court in 2022 to reconsider, and finalized the listing in November 2023. Canada listed the wolverine as a species of special concern in 2018. As of November 2026, wolverine trapping in Montana was suspended before listing, with a statewide quota of zero, and taking a wolverine now falls under federal jurisdiction. As of November 2026, the IUCN Red List labels the wolverine Least Concern, its lowest level of worry. As of November 2026, a 2017 to 2022/23 count put Europe's wolverines at about 1,300, in two groups: about 900 in Scandinavia, which is stable, and about 400 in Karelia, which is increasing.
Wolverines mainly eat meat, but they also eat berries and other plant material. All year, they eat small and medium animals such as voles, squirrels, hares and birds. Much of what a wolverine eats comes from animals that have already died. To scavenge is to eat what was left behind. Wolverines eat many kinds of meat, from ground squirrels and rodents to, sometimes, moose or caribou, but more often they scavenge carcasses left by other predators and store them for later. In winter, wolverines often eat the leftovers of moose and caribou that other animals left behind or that died naturally. They store extra food in holes or under the snow to eat later; wolverines stay active all year and do not hibernate. Their large paws work like snowshoes on deep snow, and their long, curved claws help them climb.
Words to know
- fragmentation: broken-up habitat
- snowpack: lasting snow
- threatened: at risk
- Pliocene: an ancient time
- scavenge: eat leftovers
- subspecies: a regional type
