The wolverine (Gulo gulo), also called the carcajou, glutton, quickhatch, or skunk bear, is the largest still living land-dwelling mustelid species of the family Mustelidae.
It is a muscular and stocky carnivore, with less resemblance to other mustelid but similar to a small bear. The wolverine is also spelled as wolverene. Gulo (the scientific name) is a Latin word for a glutton.
It has a reputation for strength and ferocity out of proportion to its size. Some reports indicate that the wolverine can kill prey much larger than itself.
It is a solitary animal that interacts only during the mating season. It occurs in remote reaches of the subarctic & Northern boreal and alpine tundra of the Northern Hemisphere.
There are large populations of wolverine in the U.S. state of Alaska, Northern Canada, western Russia, Siberia, and the mainland Nordic countries of Europe. The wolverine is listed on the IUCN Red List of Threaten Species as Least Concern.
There has been a decline in the total population since the 19th century due to range reduction, trapping, and habitat fragmentation.
The wolverine is extinct from the southern end of its European range.
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With a broad and rounded head, short legs, short rounded ears, and small eyes, it is more similar to a bear than a mustelid.
Its large five-toed paws with plantigrade posture and crampon-like claws enable it to climb up trees, over steep cliffs, and snow-covered peaks with ease.
An adult wolverine ranges from 26 to 42 in (65 to 107 cm), a tail of 6 ½ to 10 in (17 to 26 cm), and a weight of 12 to 55 lb (5.5 to 25 kg). Some exceptionally large males weigh up to 71 lb (32 kg).
One outsized individual was reported to weigh 77 lb (35 kg). A study gotten from Northwest Territories of Canada revealed that the average weight of female wolverines was 22 lb 4 oz (10.1 kg) and that of males 33 lb 12 oz (15.3 kg).
In a report from Alaska, the median weight of 10 males was 36 lb 13 oz (16.7 kg) while the average of 2 females was 21 lb 3 oz (9.6 kg). In Ontario, the average weight of males and females was 30 lb 0 oz (13.6 kg) and 21 lb 13 oz (9.9 kg) respectively.
The mean weight of wolverines was significantly lower in a report from the Yukon, averaging 16 lb 1 oz (7.3 kg) in females and 24 lb 15 oz (11.3 kg) in males. In Finland, the mean weight was claimed as 24 lb 4 oz – 27 lb 12 oz (11 – 12.6 kg).
The mean weight of male and female wolverines in Norway was listed as 32 lb 3 oz (14.6 kg) and 22 lb (10 kg) respectively. Shoulder height is reported from 12 – 18 in (30 – 45 cm).
It is regarded as the largest extant terrestrial mustelids. However, only the marine-dwelling sea otter, the semi-aquatic African clawless otter, and the giant otter of the Amazon basin are larger.
The wolverine is known to possess a highly hydrophobic fur that is thick, oily, and dark-coloured. Due to the fact previously mentioned, the wolverine fur is popular among trappers and hunters as a lining in parkas and jackets in Arctic conditions.
Each individual has a unique light-silvery facial mask. Several individuals display conspicuous white hair patches on their chests or throats.
Similar to other mustelids, wolverines have potent anal scent glands used for sexual signalling and marking territory. Due to the pungent odour produced by the anal scent, the wolverine was given the nicknames nasty cat and skunk bear.
Some males form lifetime relationships with 2 or 3 females. Mating season occurs in the summer, although, the implantation of the embryo (blastocyst) in the uterus is delayed till early winter. During food scarcity, females occasionally do not produce young.
The gestation period may last 30 to 50 days, and litters of 2 or 3 young are born in the spring. Newborn wolverines are called kits. Kits are known to experience fast growth, reaching adult size within just a year.
The lifespan of a wolverine in the wild is around 8 – 10 years, but in captivity, they live for 15 – 17 years.
Hunting and diet
Wolverines are known to be primarily scavengers as well as hunters. They feed on the carrion of other predators. Wolverines are versatile and powerful predators.
Prey species include squirrels, porcupines, beavers, chipmunks, moles, marmots, rabbits, gophers, mice, rats, voles, lemmings, shrews, caribou, white-tailed deer, roe deer, sheep, mule deer, cattle, goats, moose, bison, and elk.
Smaller predators are often preyed on including mink, martens, Eurasian lynx, foxes, weasels, and wolf and coyote pups. The wolverine’s diet also includes roots, birds’ eggs, seeds, birds (especially geese), berries, and insect larvae.
Wolverines live primarily in isolated boreal, arctic, and alpine regions of northern Canada, Siberia, Alaska, and Fennoscandia.
They are endemic to the Russian Far East, the Baltic countries, European Russia, Mongolia, and northeast China. Wolverines occur in the North Rocky Mountains in Montana, Idaho, Wyoming, and Oregon & the North Cascades in Washington.