Some animals have a reputation that precedes them. Wolverines are absolutely one of those. Because of their small numbers and reclusive nature, very few people have been lucky enough to see one. Beyond that, stories about their “bad attitudes” and incredible feats have captured peoples’ imaginations. Of course, I’m no exception—the Gulo in Nature blog is named after them! In this Wildlife Spotlight post, let’s learn some wild wolverine facts.
1. Wolverines are actually giant weasels.
Although their English name seems to imply some relationship to wolves, a wolverine is a completely different animal. Nor are they bears, despite resembling them somewhat with their rounded ears and stocky bodies. In fact, wolverines are one of the largest extant members of the family Mustelidae. This family also includes weasels, stoats, badgers martins, ferrets, and otters.
Adult wolverines range from over 2 to close to 4 feet (60-109cm) in length and weighing in from 15 to over 60 pounds (~7-27kg). This makes them about the size of a Staffordshire terrier or Border collie. The only larger members of this family of tough carnivorous mammals are the sea otter (Enhydra lutris) and giant otter (Pteronura brasiliensis).
Want to learn more about animal families? Check out this beginner’s guide to taxonomy.
2. They occur in North America, Europe, and Asia
Wolverines actually occur on three continents, although their current range in each is relatively limited. The major remaining population centers for these elusive, far-ranging animals is:
- Western North America, especially in Alaska (United States) and Western Canada
- Fennoscandia (including Finland, Norway, Sweden, and Denmark) in Northern Europe
- Siberia, in Eastern Russia
Across this large range, scientists recognize two subspecies: Gulo gulo gulo in Eurasia, and Gulo gulo luscus in North America.
3. They have many names.
As you might expect given the many places that they are found, wolverines have different names all over the world. Combined with their fearsome reputation, this wide range has led to some fantastic monikers. In many Indigenous American languages (including East Cree and Innu-Aimun) the words for these animals are variations of kwikwaju, kwiikwahaachew, or carcajou. A bastardization of this name into English led to the nickname “quickhatch”.
Other English nicknames include:
- Woods devil
- Nasty Cat
- Skunk bear
The Norse name for the wolverine is Jarfr, which may come from a root word meaning “brown”. In many Romance languages like French and Spanish, the name literally means “Glutton”. In other words, one who eats a lot or has an endless appetite.
4. Their scientific name means “glutton”
As you might have guessed from their name in the romance languages, the wolverines’ voracious appetite is showcased in their Latin or scientific name, Gulo gulo. Like many species that were the first of their kind described by Carolus Linnaeus in the 18th century, wolverines have the same genus and species name. Because of this, their Latin name is the same word twice. Taking a look at the Eurasian subspecies, it’s actually three times (Gulo gulo gulo). I wonder how much you have to eat for your name to translate to “Gluttonous-gluttonous glutton”!
Why do species have scientific names?
5. They love mountains
Wolverines are big fans of cold and rugged terrain. While these tough animals once ranged over much of Northern North America, their range has shrunken to mostly include high-elevation areas. As you’ll learn later in this post, wolverines are particularly well-adapted for harsh and cold climates. Because of this, they still persist in mountainous areas that are too severe or remote for major human development.
With their warm fur, incredible strength and endurance, and low center of gravity, wolverines have an easy time traversing alpine areas. Cold temperatures, steep slopes, big snowfalls, and massive landscapes don’t bother them in the least. They are masters of the mountains, and, although rare everywhere, are most often seen at high elevations.
How much do wolverines love mountains and cold places? One male wolverine being tracked by conservation researchers crossed over a mountain during a storm in the dead of Winter! Given the speed of his progress, it might as well have been a summer’s day.
Curious how scientists describe the habitats of other animals? Check out this post!
6. Wolverines are well-equipped for winter travel
As you might have guessed, these fearsome and snow-loving creatures have some fantastic attributes to help them in their snowy homes. Their incredible attributes include:
- Broad, flat paws that can act as snowshoes. In fact, wolverines have five toe pads on their paws, rather than the four that canines and felines have. This also makes their tracks easy to recognize in the snow or mud!
- A thick, multilayered coat including long guard hairs. This incredible fur makes even frigid temperatures perfectly comfortable for them. Unfortunately, this incredible coat was part of why wolverines experienced population declines in the past. Because their coats were so warm and weather-resistant, people hunted them intensely for their pelts.
- Long, non-retractable claws. In addition to snowshoes, wolverines have fantastic crampons for running around on icy surfaces! Their long claws let them get traction even on solid ice, making them fantastic mountaineers.
- Short ears and a thick, square head. Wolverines’ short muzzle and squat ears help hold in heat and keep more sensitive organs safe from extreme cold.
- A wide, squat body with long, muscular legs. Wolverines’ build keeps their center of gravity relatively low, while offering a wide base for balance. Furthermore, their strong legs give them “clearance” like an all-terrain vehicle, and can help them traverse difficult landscapes with little problem.
All of these characteristics make wolverines fantastic tree climbers, in addition to mountain climbers. Just like their close cousins the fishers (Pekania pennanti) and martins (Martes sp.), they can scale trees readily if the need arises.
7. They have a reputation for punching well above their weight
In addition to a huge appetite, wide-ranging travel habits, and a fearlessness for rugged terrain, wolverines are also reputed to be amongst nature’s premier tough guys. As wolverine expert Doug Chadwick put it, hunters and other animals alike try to steer clear of their “bad attitude”. Despite their small size compared to other predators of the North woods, these critters have a famously “never back down” attitude.
Although mostly from unsubstantiated reports, many stories tell of wolverines scaring grizzly bears (Ursus arctos horribilis) and gray wolves (Canis lupus) away from carcasses upon which they were feeding. Hunters and trappers also frequently reported being terrified to find snarling angry wolverines chasing them despite having one or more legs caught in a snare! Furthermore, there have been accounts of wolverines taking down prey like deer or even moose that are much larger than themselves!
With their fearsome snarl, intimidating teeth, and strong bite force, wolverines are certainly formidable. It’s easy to consider how a much larger animal might back off to avoid injury even if it could likely overpower a wolverine.
8. Wolverine moms make dens out of snow
The wolverines’ love of high, cold places is closely linked to their reproductive cycle. Unlike many mammals that are born in Spring, young wolverines are born at the beginning of Winter. Although this might seem odd, it fits with their strategy for raising their young.
Mother wolverines make dens deep in the snow to provide a well-insulated and safe place to nurse and keep their young. They raise their kits throughout the Winter, and will travel with them as the weather gets warmer in Spring and Summer. However, in order to make a safe Winter den, they need a lot of snow. That snow needs to stick around long enough for the kits to grow big enough to move around on their own and no longer require milk.
Because of that, wolverines need large snowdrifts with many feet of snow piled up, and these are often hard to find outside of mountainous areas. As average temperatures get warmer at higher elevations every year, it may get more difficult for wolverine moms to find good denning sites.
How does climate change affect other wildlife and animal species?
9.Wolverines find food by both hunting and scavenging
Given their reputation as a glutton, you have to wonder what it is that wolverines are so fond of eating. Like other members of the mammalian order Carnivora, wolverines are big meat eaters. And they aren’t particularly choosy about where they get their meat, either!
Specifically, wolverines get their food by both hunting and scavenging. In other words, they are perfectly at home chasing down and overpowering live prey but also eating dead meat from carcasses. Wolverines more often hunt small animals like rodents and rabbits, but may also take larger prey. Because of their fantastic adaptations for traversing deep snow, wolverines have a distinctive advantage in Winter hunting. By catching animals like moose, deer, or wild sheep while they are stuck in deep snow, they can easily outmaneuver and and hunt them despite being much smaller.
Spending all of their time in snowy mountain habitats, wolverines can also take advantage of dangerous elements that act in their favor. Avalanches, deep freezes, and winter storms can kill wildlife while also preserving their bodies in the cold. Wolverines have an excellent sense of smell, capable of detecting food through depths of up to 20 feet (~6.5m) in the snow! This enables them to find and capitalize on lots of available food throughout the Winter.
Wolverines’ sense of smell and great adaptations to cold have even caught the attention of avalanche rescuers, who are considering their use as rescue animals.
10. They can crush bones and eat frozen meat with specialized teeth
As you might have guessed from their Winter scavenging habits, wolverines eat a lot of frozen meals. Beyond that, they also have intense caloric needs due to their high metabolism and active, aggressive lifestyles. Because of this, wolverines need to eat as much as possible from food sources that they do manage to find, especially in the Winter.
To help with this, they have an extremely strong bite and very sturdy teeth. This enables them not only to take down large prey when given the opportunity, but also to bite through bone and frozen meat when feeding. Wolverines even have special back molars that are turned sideways. These molars are a key adaptation for tearing meat and crushing open bones to access the nutritious marrow inside.
11. Wolverines can travel large distances and have huge home ranges
Like other predatory animals, wolverines need a lot of space to get all the food that they need. They are especially extreme in this behavior, however, and tend to range far and wide in their use of space. This means that wolverines can cover a lot of different habitats within their territories. Unfortunately from a conservation perspective, it also means that they don’t do well when natural areas are fragmented by development. Wolverines need huge, contiguous or uninterrupted natural areas to roam and complete their life cycles.
How much space does a wolverine need, exactly? Their ceaseless wanderings can amount to something like 15 or more miles of trekking per day, sometimes straight over mountain peaks and ridges. Within a given year, a single wolverine typically keeps a home range of between 100 to 600 square miles (259-1,550km2)!
12. Female wolverines can delay pregnancy after mating
Although wolverines do all their romancing in the Summer, we learned earlier that wolverine moms have their babies in the Winter to nest in the snow. So how does that work? Male and female wolverines typically cross paths and mate during warmer months, presumably when food is more available.
Once a female wolverine has mated, she can actually delay the implementation of the embryo into her uterine wall. In other words, she can hit the “pause” button on getting pregnant! The fertilized embryo(s) will wait a couple of months until her body gives the signal, and then implant and begin development. That way, females can have the Summer and Fall to put on weight in preparation for pregnancy, and have enough snowpack to make a nice den for their kits when the time comes.
13. Baby wolverines are white
How’s this for an adorable wolverine fact? When wolverine kits are born, they come out snow white! You’d never guess from all the beautiful browns, blacks, and tans of the adults’ luxurious, warm fur.
Wolverine moms will typically give birth to 2-3 young in early Winter, and keep them safe in a den that they burrow deep in the snow. The little youngsters blend in well with the white snow for their first couple weeks of life. As they get older, they start to take on more and more color like their mother. She may move them from place to place as they grow, depending on how easy it is to find safe dens in which to keep them.
Want to learn more about wolverines?
Be sure to check out The Wolverine Foundation, a fantastic non-profit organization dedicated to the study and conservation of wolverines around the world.
Fancy hearing about wolverines from the experts? I recently sat down for a Nature Guys Podcast episode with wildlife author and fellow wolverine fanatic Doug Chadwick to talk about these amazing animals. This episode covers Chad’s adventures studying wolverines and recent events with major implications for their conservation. Check it out!
Thanks for reading!
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