Wolverine (Gulo gulo)


Class: Mammalia
Order: Carnivora
Family:    Mustelidae
Size:    Length: Up to 3 feet (91 cm)
Weight: 20 to 55 pounds (9 to 25 kg)
Diet: Large and small mammals such as caribou, deer, birds, mice and squirrels, as well as berries and roots 
Distribution: Northern Europe, Canada, Alaska and Greenland
Young:  2 to 4 kits, once every two or three years
Animal Predators:  Wolves and mountain lions
IUCN Status: Vulnerable
Terms: Young: Kit
Lifespan: Up to 10 years in the wild and up to 17 in captivity



·        The species name gulo means “glutton.”

·        Nicknames are “demon of the north” and “devil bear.”

·        Wolverines have poor eyesight and average hearing.

·        By the early 20th century, the wolverine was nearly wiped out in the United States.



Although the name suggests a relation to wolves, wolverines are actually members of the weasel family. They have short legs with large feet and long claws. Their fur is long and dark brown, with two yellow stripes that join across the shoulders, extend down their sides and join again on the tail. Their jaws are powerful, with long, sharp teeth. Males are approximately 30 to 40 percent larger than females.



Wolverines live in a grass-lined den within a cave or rock crevice, or a burrow that originally belonged to another animal. They are found throughout northern Europe, Canada, Alaska and Greenland.


Feeding Habits

Wolverines’ preferred method of obtaining food is to wait for another animal, such as a bear or cougar, to make a kill. The wolverine then threatens the animal by baring its impressive teeth and raising its hackles. When the larger animal departs, the wolverine takes over the fresh kill. Due to wolverines’ short legs and oversized feet, they are not adept at chasing or stalking and will instead hide in trees or behind rocks for an opportunity to pounce on their prey. However, because wolverines’ paws are disproportionately large and wide for their body size, they are able to walk on top of the snow, so in winter, they can more easily run down caribou and deer, who have difficulty running through deep snow. Wolverines’ diet also consists of small mammals, such as birds, mice and squirrels. They also eat berries and roots. 



Females have delayed implantation in order to put off the birth of their litter until an appropriate time (early spring). Reproduction rate is low, occurring mostly after the female is three years of age and only once every two to three years. Litters consist of two to four kits born with white fur covering their body, after a gestation period of 30 to 50 days. Although wolverines are considered polygamous, the parents of the litter both play a role in rearing the youngsters until they reach about 14 months of age, although the kits often stay with their mother up to two years. Wolverines are sexually mature at two to three years of age. 



Wolverines are the strongest and fiercest mammals of their size and are feared by larger animals such as bears and cougars. Although primarily nocturnal, they may be active both during the day and at night. Wolverines are territorial animals, marking their territory with secretions from their anal scent glands and urine, and are solitary, except during the mating season. They can climb trees quickly and are very good swimmers. 



Wolverines are listed by Environment Canada’s COSEWIC (Committee on the Status of Endangered Wildlife in Canada) as Special Concern in western Canada (Ontario, Saskatchewan, Manitoba, Yukon, British Columbia, Northwest Territories, Nunavut) and Endangered in eastern Canada (Quebec and Newfoundland). Hunting and trapping for fur has been a factor in their decline. 











Wolverine Wildlife Fact File, IM Pub, US