Wolverine

The Wolverine is the largest non-aquatic member of the weasel family in North America. Wolverines are medium-sized, burly, bear-like animals with short, thick-set legs and large paws. Its tail is short and bushy, the head is relatively large with short, rounded ears and small wide-set eyes. Males are larger, adults weighing up to 20kg while female wolverine weight up to 14kg.

Economic considerations

British Columbia has consistently been the top producer of wolverine pelts since the mid-1960s in Canada. Wolverine fur is resistant to the build-up of frost and has long been used as trim on parkas, especially in aboriginal communities. In addition to its status as a furbearer, the wolverine is also classified as a game animal. However, wolverine are killed only incidentally by hunters, rather than by specific directed effort and the kill is small, averaging less than three percent of the total provincial kill since the early 1990s.

Biology

Distribution and habitat

Most of the wolverine population live in the north of America, primarily in Alaska, Yukon and Northwest Territories, and British Columbia.

Within British Columbia, wolverines are relatively abundant in much of the northern two-thirds of British Columbia, and there is also a centre of abundance in the Columbia Mountains of southeastern British Columbia. The only areas of the province where wolverines normally do not live are the Lower Mainland, the dry sections of the Fraser and Okanagan valleys in the southern Interior, and the Queen Charlotte Islands.

Wolverines are generally associated with remote wilderness habitats, boreal forests arctic tundra of the north, but also in montane forests and alpine tundra. The most important features for wolverines is snow. Wolverines are adapted to snow, using it to create systems of snow caves and tunnels maybe 30m or more in length.

Food

The wolverine has been referred to the “hyena of the north” because it makes a significant portion of its living as a scavenger. That is particularly the case in winter during sever climatic conditions, starvations, or accidents (e.g., avalanches) when the primary fare is large mammal, ungulates killed by other carnivores, beached marine mammals and spawned-out salmon in costal areas. When it comes to feeding, wolverine are ultimate “generalist” and opportunist, and the list of species it has been known to consume is long. In the summer the wolverine’s foods include rodents (especially voles, marmots, and ground squirrels) young ungulates (mountain sheep, mountain goats, and caribou), birds and eggs, and various berries.

Social behavior

Wolverine populations consist of a stable core of adults, residents,  with distinct home ranges, and varying numbers of less established animals are referred to as transients. Transient wolverines are mostly dispersing young, but may also include older animals that have abandoned their home ranges because of injury, old age, or inadequate food supplies. Males are more mobile than females and are more common in the transient class. Transients are less secure than residents, often travelling in unfamiliar terrain. They are more regularly exposed to extreme hunger and are generally the most likely to encounter trap sets or to come into conflict with humans.

Activity and movements

Wolverines travel and forage normally alone, except for brief periods when animals are together as mated pairs or females with their pups.

Wolverines stay in their established home ranges but transient wolverines may travel longer distance in search of vacant home range areas. Daily movements of 30km or more are known to occur.

Reproduction

Wolverines mate in the summer (June and July), and the pups are born in the winter (February and March). The reproduction is relatively low, females cannot produce their first litters until they are two years old and the litter size are relatively small, averaging less than three pups.

Harvest management

In British Columbia wolverines are classified as forebears and as a game species. Since 1994, the wolverine has also been included on the provincial “Blue List,” a rating indicating that it is considered vulnerable and of high management priority. There are no open seasons for either trapping or hunting in the Vancouver Island, Lower Mainland, and Okanagan regions (where wolverines rarely occur), or for hunting in the Thompson and Cariboo regions. For those regions in which hunting of wolverines is allowed, season lengths range from eight weeks (1 November to 31 January) in the Kootenay Region to 20 weeks (15 September to 15 January) in the Skeena Region, and a bag limit of one applies in all areas. Open trapping seasons for wolverines in British Columbia are 8 to 12 weeks long, beginning on 1 November and ending on 31 January in the southern and central portions of the province (Thompson, Kootenay, and Cariboo regions) and on 28 February in most of the north (Skeena and Omineca-Peace regions).

Harvesting and systems

At the operational level, there are three main approaches that trappers may use to harvest wolverines sustainably, as follows:

Quota system: This system identifies a harvest goal of certain number of wolverines, and harvesting activities are stopped when that goal is reached.

Time-based system: Based either on long-term experience in a particular area or on particular considerations that are time sensitive including, pelt primness, and normal vulnerability patterns, this system develops a schedule in which traps are left set only for a pre-determined period which is shorter than the certain open season.

Area-based system: Also known as a “refuge” system, the basis for this approach is that portion of the available wolverine habitat is left unharvested, with the exception that will serve as a source for animals dispersing to areas where trapping or hunting does occur.

Conclusion

British Columbia is a part of the centre of many for wolverines in North America. In conclusion, wolverines naturally live in at low density groups, have a relatively low reproductive potential, and are believed to have the lowest resilience to harvesting pressure of all the British Columbia furbearers. Therefore the primary objective in trapline management for wolverines is to protect the breeding population and reproduction for their food supply.

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