Wolverine

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Carnivora
Family: Mustelidae
Genus: Gulo
Scientific name: Gulo gulo

Characteristics

The wolverine is a powerfully built long-haired animal, somewhat resembling a small, short-legged bear, with markings similar of those of a skunk. The back is arched, and the tail is bushy. The feet are large and well furred, with long, non-retractile claws.

Males are 31 to 51 inches long, including an 8- to 9-inch-long tail. They stand 12 to 14 inches at the shoulder and weigh 20 to 45 pounds. Females are about one quarter smaller. Because of its size, stocky form, and long coat, the wolverine cannot be easily mistaken for any other mammal.

The head is broad and short snouted with small and rounded ears, small eyes, massive teeth, and powerful jaws. The neck is short and powerfully muscled, as are the shoulders. The senses of smell and hearing are good, but eyesight is poor.

The fur is long, with coarse guard hairs and thick underfur when prime. The color and texture vary with the individual. Usually, they are dark brown above the pale lateral stripes, which run from shoulders to rump, merging at the rump and extending along the top of the tail. In some individuals, the contrast is very distinct, while in others, it is faint. The under parts are dark, often with irregular white or orange markings at the throat and a bright orange patch on the belly, indicating the location of a gland.

The wolverine walks in a flat-footed manner. The hind feet, in fact, resemble the feet of a man. It travels in several gaits, but a sort of run with long bounding strides is the most common. It is not a particularly fast runner but can travel tirelessly over long distances.

The wolverine is a courageous animal that is respected and avoided by other predators. Even cougar and grizzly bear have been known to abandon a kill on the approach of a wolverine. Wolverines will often urinate on carcasses, fouling them so that no other animal will eat them.

Life Cycle

Both sexes reach reproductive maturity during their second summer. Mating takes place from April to October. A delayed implantation occurs, with an active gestation period of 60 days. The young are born in late March or early April. One to four young are born in dens located under protective rockslides, natural caves, under the roots of trees, or windfalls. The young are covered with fine white hair. The females give the young extensive care for up to one year, after which she drives them from her territory.

Food

Wolverines mainly eat the flesh of mammals or birds. They are generally too large to subsist well on small game, too small to effectively kill large game regularly, and too slow to pursue swift animals. As a result, they often resort to scavenging carrion. Often, they subsist almost entirely on winter killed animals or the kills of other predators. The wolverines will hunt and kill whenever the opportunity presents itself, and they are tireless and persistent in their hunting activities. They will take a wide variety of foods, including hares, mice, lemmings, ground squirrels, chipmunks, marmots, and beaver. Berries are often eaten in late fall. When food is scarce, the wolverine will attempt to kill big game animals, and there are authentic records of attacks upon mountain goats, moose, deer, and elk.

Habitat

Little is known about the habits of the wolverine. They are creatures of the northern wilderness, frequenting heavily wooded, broken, rugged, and mountainous areas. The primary wolverine habitat in Montana is the coniferous forest types of the Rocky Mountains. Wilderness is an essential habitat component, as it requires large areas to roam over in solitude. Wolverines avoid water or even heavy rain, if possible, but will cross small water obstacles when necessary.

Population

Wolverines are never abundant but are sparsely scattered over extensive areas. As a result, they seem to maintain a stable but low population most of the time. They need wilderness areas where they can avoid conflicts with man. The most viable and widespread population of wolverines in the contiguous 48 states occurs in the Rocky Mountains of Montana.

Distribution and Status

Wolverines occur in the western third of Montana in the Rocky Mountain range. They are a furbearer and are managed and protected.