Wolverine

Pound-for-pound

A wolverine weighing 15 kg can drag a carcass five times its weight through deep snow and has been documented driving wolves, cougars, and polar bears off kills. The combination of extremely dense musculature, powerful jaws capable of crushing frozen bone, and an aggressive temperament that doesn’t register threat from larger animals makes it an almost mythological predator for its size.

Gulo means “glutton” in Latin — reflecting the medieval European perception of the animal as endlessly ravenous. The name wolverine itself may derive from a Dutch or German word for “wolverine-like” nature.

A life in snow

Wolverines are superbly adapted to life in deep snow:

• Large, snowshoe-like feet — spread weight to move effectively in deep snow
• Semi-plantigrade gait — walks on the soles of its feet like a bear, giving traction
• Thick, waterproof, frost-resistant fur — historically used by indigenous Arctic peoples to line hoods because it doesn’t frost from breath

A wolverine’s territory can span 1,500 km² for males — one of the largest home ranges of any terrestrial carnivore relative to body size. A single individual may travel 45 km in a day.

Caching food

Wolverines are among the few mammals that regularly cache food under snow. They can locate and excavate caches buried under meters of snow, sometimes weeks later — a behavior likely supported by olfactory memory rather than spatial memory.

Climate sensitivity

Wolverines depend on persistent spring snowpack to den in — females give birth in snow dens that stay cool enough to preserve cached food for the nursing period. As climate change reduces late-season snowpack at lower elevations, wolverine populations are contracting northward and upward in elevation. The US Fish & Wildlife Service listed them as a threatened species in 2023.