Wolverine

?
Wolverine
Conservation status: Vulnerable

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genus: Gulo
Pallas, 1780
Species: G. gulo
Gulo gulo
( Linnaeus, 1758)

The wolverine (Gulo gulo) is the largest terrestrial species of the Mustelidae or weasel family, and is also called the glutton or carcajou. It is the only species currently classified in the genus Gulo. Two subspecies are recognised, the Old World form Gulo gulo gulo and the New World form G. g. luscus.

Anatomy

The wolverine is a stocky and muscular omnivorous, but largely carnivorous, animal. It has glossy brownish-black hair with strips of light brown along the sides. The fur is long and dense and does not retain much water. This makes it very resistant to frost in the cold environment where wolverines live. The wolverine can weigh up to 30 kg (66 lb) (male), and is 70–110 cm (27–43 in) long with a 20 cm (8 in) tail. It resembles a small bear with a long tail. It has also been known to give off a strong, unpleasant odor, giving rise to the use of the term "skunk bear" to describe the animal.

Behaviour

The wolverine is both strong and ferocious and has been known to kill animals as large as moose. Its preference for reindeer have caused it to be hunted significantly in areas depending economically on caribou herds, and its status is sometimes in danger in such regions. It is generally not aggressive towards humans, preferring to avoid human contact. However, because a wolverine will attack an animal caught in a trap, early trappers often tried to kill them. They have been known, and have been filmed, to capture kills from other predators, such as polar bears or a wolf pack.

Wolverines mate in the wild, but implantation in the uterus is delayed until early winter, which delays the development of the fetus. Females often will not produce young when food is not abundant. The young, usually three or four, are born in the spring. The young "kits" develop rapidly, becoming adult size within the first year of up to thirteen years of life.

Range

A wolverine standing on a rock.
A wolverine standing on a rock.

It is currently found primarily in arctic regions such as Alaska, northern Canada, Siberia and Scandinavia. Before the widespread European settlement of North America, however, it was found as far south as the Sierra Nevadas in California. A small number remain in the Rocky Mountain states. The present worldwide wolverine population is unknown, although it appears that the animal has a very low population density throughout its range, possibly as a result of illegal hunting. Wolverines, especially males, require large home ranges. The wolverine is still trapped for its fur in some parts of its range.

In early 2006, The U.S. Forest Service trapped the first wolverine ever captured and fitted with a radio collar in a subalpine forest northwest of Mazama in north-central Washington in the Pacific Northwest.

Michigan Wolverines

The state of Michigan is known as the Wolverine State, and University of Michigan's sports teams are known as the Michigan Wolverines. However, the animal is hardly a common sight in the state. One was observed in February 2004 by hunters and biologists, marking the first time in roughly two centuries that a wolverine had been positively identified in Michigan. It is not known if that particular animal was a native of the state or if it had come there on its own or with the aid of humans.