How does the wolverine live?

Written by Nicklas Iversen | Last edited 1. June 2021

Apart from the females when they have young, the wolverine lives alone. You can learn more about the life of a wolverine on this page.

THE WOLVERINE’S LIFE BEGINS

Jerven fødes om vinteren, gjerne i februar-mars. Når de fødes er de hvite. Dette hjelper de små til å holde seg skjult i den hvite snøen. Jervevalpene veier under 100 gram når de fødes, men de vokser raskt. I april er jervevalpene klare til å farte rundt sammen med moren. Allerede etter et halvt år er de unge jervene nesten ferdig utvokst, og i september greier de seg som regel selv. De aller fleste jerver har flyttet hjemmefra i god tid før et år har gått. 

Wolverines are born in winter, usually in February-March. They are white at birth. This helps the kits (young wolverines) to stay hidden in the snow. Wolverine kits weigh less than 100 grams when they are born, but grow quickly. In April, the kits are ready to roam about with their mother. After just six months, the young wolverines are virtually fully grown, and in September they can generally manage by themselves. By far the majority of wolverines leave their birth territory during their first year.

Stor hannjerv. Finland 30.5.15

ADOLESCENCE

Når de unge jervene vandrer hjemmefra kan de vandre store avstander. Jervene kan dermed ende opp med å slå seg ned i en helt annen landsdel enn der de ble født. Målet er å finne et sted  som ikke er opptatt av jerver av samme kjønn, hvor det også finnes noen av motsatt kjønn å parre seg med.  Å finne et leveområde som ikke er opptatt er ikke så lett – og unge jerver vil streife over enorme områder til de enten finner et ledig område, eller blir sterke nok til å utfordre en eldre jerv. Hvis den lykkes vil den ta over området fra den eldre jerven.

When young wolverines leave home, they can roam over large distances. They may therefore end up settling in a completely different part of the country to the one they were born in. The aim is to find somewhere that is not inhabited by wolverines of the same sex, but where there are some of the opposite sex to mate with. Finding an unoccupied territory is not very easy, and young wolverines will roam across vast tracts of country until they either find a vacant area or grow strong enough to challenge an older wolverine. If they succeed, they will steal the area from the older animal.

Foto: Roger Brendhagen.

SETTING UP

If the wolverine finds a suitable area, it will set itself up there. It marks its territory with foul-smelling urine.

Wolverines have large territories. They will chase off wolverines of the same sex so as to avoid competition for mates and food.

Within its territory, the wolverine will have several daytime lairs, that is to say den sites where it sleeps during the day. The wolverine usually has fixed hiding places for food as well. It will use these larders to stockpile food.

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MATING AND BIRTH

Fosteret begynner ikke å utvikle seg før på vinteren. Dette gjør at valpene fødes på et fornuftig tidspunkt slik at de skal ha større sjanse for å overleve.

Wolverines become sexually mature at around three or four years of age. They mate in the summer between April and August. The long breeding season pays off for animals that live so spread out, as finding a partner is no easy matter! The animals go their separate ways after mating.

Much like bears, the embryo does not start to develop until the winter. The ability to be impregnated without the embryo developing immediately is called delayed embryonic development or embryonic diapause and is common in the animal kingdom. It ensures that wolverine kits are born at the right time and have the best chance of surviving.

The kits are born in an excavated snow den. It will usually adjoin a scree and have several rooms with different functions: toilet, larder and bedroom. Just like in our houses!

OLD AGE AND DEATH

Når jerven begynner å bli eldre, vil den som hos oss mennesker bli svakere. Og til slutt vil den kunne bli utfordret av en yngre og sterkere jerv. Om den gamle jerven taper, vil den nå begynne å leve et omstreifende liv, som da den var ungkar. 

As with us humans, the wolverine will become weaker when it’s getting older. Ultimately, it might be challenged by a younger, stronger wolverine. If the old wolverine loses, it will start to live an itinerant life, just like when it was a bachelor.

Wolverines normally live for ten or twelve years, but some have made it to eighteen.  Far from all wolverines manage to grow old. Many die in their first year of life – and are killed by other wolverines.

The primary cause of death for adult wolverines is hunting. Especially illegal hunting. It is not surprising, perhaps, that the wolverine is so scared of us humans!

 

This article has been written by Bjørn Henrik Stavdal Johansen, a nature guide at Visitor Centre Carnivore Flå.