Wolverine

Wolverine • Gulo gulo

Järv

The genus name gulo means “glutton”, because wolverines were thought to be extremely voracious. People had seen how a reindeer killed by a wolverine could disappear over night. In actual fact, a wolverine divides up its prey and hides it is various places to save food for later.

Classification

The wolverine is part of the mustelidae (weasel) family. They are usually classed as one of the largest members of the family.

Appearance

The wolverine has bushy dark-brown fur, which makes it look larger than it is.  It is coarsely built with short legs, large paws, a flat head and a thick, bushy tail.

Wolverines are well adapted to life in snowy climates. In the winter, they develop thick warm winter fur and their large hairy paws act as snowshoes.

Ecology

The wolverine lives alone and often roams across large areas. It is very territorial and both sexes defend their territory against other wolverines. A female’s territory covers about 100 sq km, while a male’s is much larger – about 400 sq km.

Reindeer are the wolverine’s most important prey. The wolverine also catches foxes and hares in the winter. Additionally, wolverines eat animal carcasses and like to steal other predators’ catches. In the summer they eat birds, small rodents, berries and carcasses.

Wolverines have a very well developed sense of smell and are good tree climbers.

They are average reindeer hunters. Their best conditions are when there is a thin frozen crust on the snow, which bears the distributed weight of the wolverine’s “snowshoes” but collapses under a reindeer’s hooves.

Wolverines divide up and hide their prey in cracks in cliffs, under rocks and in the snow. These meat stores last them a long time.

Wolverines mark their territory with urine, faeces, or with special secretions from glands on their bellies. To spread this secretion, the wolverine stands over a low bush and rubs its glands against the branches.

Female wolverines rear their cubs alone; the cubs stay with their mother from birth in late winter/early spring until late autumn the same year.

Reasons for decline

Wolverines were hunted intensively for a long time – partly for their coveted fur and partly because they were a threat to reindeer farming. Until 1969, when the wolverine became protected, a bounty was paid for each dead wolverine.

The wolverine has no enemies besides other wolverines and humans. However, in North America it has been observed that bears and wolves can kill wolverines.  Infanticide occurs among wolverines, just like among bears. This means that male wolverines kill the young of other males so that the females will become receptive for mating with the rival males and will give birth to their young.

The species is classified as “endangered” (EN) on the Red List of the Swedish Species Information Centre. On the global Red List it is in the “vulnerable” (VU) category; it is also one of the species in the EU’s Habitats Directive.

Conservation work

The species has slowly recovered after becoming protected in 1969 and there are now about 500 wolverines in Sweden. Illegal hunting does take place.

Populations around the world

The wolverine around the world

Wolverines live in mountainous areas, but in recent years they have started to spread to forested areas in northern Sweden, Norrland.

The species is circumpolar, which means that it is found in the northernmost areas of Europe, Asia and North America.

NEWS