The wolverine (Gulo gulo) is an uncommonly large member of the weasel family (Mustelidae) that occurs in the subarctic and boreal forests of North America and northern Eurasia. The wolverine is famous for its aggressive, combative nature and its remarkable strength. Although the wolverine is only a medium-sized animal, it can dominate much larger animals during an aggressive encounter at a food source. For example, wolverines are capable of driving away a bear, or a group of wolves, from an animal carcass. If the movement of a moose or deer is hampered by snow, it can be killed by a single, much smaller wolverine.
Wolverines typically have a body length of 5.5-8.5 ft (2-2.5 m) plus a tail of about 8-12 in (20-30 cm). Adult animals weigh 30-60 lb (14-28 kg). Female wolverines are typically smaller than males. Wolverines have a long, dense, rather lustrous fur, usually dark brown or black. They generally have lighter brown-colored bands on each side of the body, extending from the shoulders to the rump.
Wolverines are rather omnivorous in their feeding habits. They are primarily eaters of carrion, that is, animals
that have died of natural causes, or have been killed by other species of predators. The wolverine has powerful jaws and teeth, and it can crush the bones of dead animals to extract the nutritious marrow. Their food of carrion is mostly located by smell, as wolverines have rather poor vision. Wolverines sometimes kill their own prey. However, this only happens opportunistically, because these animals are rather slow moving and often cannot run down a healthy prey animal. Wolverines will also eat bird eggs, insect larvae, and berries when these foods are abundant. Wolverines are famous for their avaricious appetite, as is reflected in some of their alternative common names, such as glutton.
Adult wolverines are solitary animals, and they are active throughout the year. The territories of male wolverines can be very large, as much as thousands of square kilometers in extent, but shared with several resident females. Wolverines move over their territories with a persistent, loping gait, but they are also adept at climbing trees in pursuit of prey.
The fur of the wolverine is very highly regarded by northern peoples for use in the ruff around the hood of parkas. Wolverine fur is relatively effective at repelling the moisture emitted during breathing, so it does not frost up to the degree of other furs.
Wolverines are indicators of wilderness and of ecosystems that are relatively unaffected by humans. Unfortunately, trapping has eliminated wolverines from much of their natural range, and they are becoming increasingly rare in those ranges where they still manage to hang on. Currently, wolverines are classified as a "vulnerable" species, meaning that the species is not critically endangered or otherwise endangered, but is facing a high risk of extinction in the wild in the medium-term future. The affected wolverine populations include those of Canada, the United States, Finland, Norway, Russia, and Sweden. It is critical that this special animal of wild landscapes be allowed to survive in its remaining territories, and perhaps be reintroduced to parts of its former range where suitable habitat still remains.