The Wolverine is a carnivore and is the largest land-dwelling species in the Weasel Family (COSEWIC 2003, Wikipedia 2011). It is very strong for its size, with powerful jaws, sharp claws and a thick hide (Wikipedia 2011). It is a seldom-seen species, but is distinctive. Hatler et al. (2008) provide the following description: "It is a medium-sized, stocky, bear-like animal with short, thick-set legs and large paws. Its tail is conspicuous and bushy, though not long (less than one-third of the body length) and its head is large and broad to accommodate the heavy jaw musculature required for consumption of bone and frozen flesh. The ears are short and round in profile...and the eyes are small and wide set. The pelage is long, thick, glossy and generally dark brown to black...most specimens have a light-coloured lateral stripe extending from the shoulders along both sides and meeting at the base of the tail." The cream to yellow to brown stripes along with a pale forehead and light patches on the chin, throat and chest make this an easy species to identify.
Biology
Wolverines are good dispersers. COSEWIC (2003) says "Wolverines are able
to traverse rugged terrain, including tundra and glaciers that would act as barriers to
many species of mammals. Dispersal characteristics likely gave wolverines the
capacity to recolonize gaps in their distribution in Scandinavia (Vangen et al. 2001). However, long distance movements place individuals at greater risk of mortality due to predation, trapping, accident or starvation (Copeland 1996).
The large home range size of wolverines increases its susceptibility." Wolverines have an excellent sense of smell, which is important in scavenging.
Reproduction
The reproductive rate of wolverines is considered relatively low (COSEWIC 2003). Lofroth (2004) says "Wolverines breed between late April and early
September but embryos do not implant until
January. Sometime between late February and mid-
April, females give birth to between one and five
cubs. They nurse for 8–9 weeks after which they
leave the den but stay with mother for their first
winter learning to hunt. Young disperse in spring.
Natal dens are often underground.".
Diet
Wolverines are scavengers and predators and are opportunistic feeders that both hunt and eat carrion (COSEWIC 2003). Diet includes rodents, snowshoe hares, birds, and young ungulates. Researchers have shown, however, that small mammals and birds were relatively unimportant in Wolverine diet in their study areas (Lofroth et al. 2007). Snowshoe Hares are important in the diet of the Wolverine (COSEWIC 2003). Carrion may include caribou, moose, mountain sheep, mountain goats, deer, elk, fish and marine mammals. Wolverines will also eat plants, including berries. Researchers in BC have shown that caribou and marmots are important to denning females, and that marmots are important to adult females during the summer (COSEWIC 2003, Lofroth et al. 2007). Lofroth et al. (2007) carried out studies of Wolverine diet in BC.
Behaviour
Home range size varies for males (230-1580 km2) and females (50-400 km2), with the largest home ranges reported for dispersing adult males (avg. 3500 km2) (COSEWIC 2003). At higher elevations, females burrow into snow in February to create a den and this is used until May when the young are weaned. Success of dens is depended on late snow melt (snow provides insulation) and a nearby food source.
Habitat
This species lives in isolated northern areas (Wikipedia 2011). Hatler et al. (2008) say: "The Wolverine is generally associated with remote wilderness habitats, particularly the boreal forests and arctic tundra of the north, but it also occurs in montane forests and alpine tundra in the southern portions of its range. This species shows preference for high elevation and high latitude, and shows seasonal vertical migration (Hatler et al. 2008). The most important component of its habitat is snow. Based o the COSEWIC status report, "Habitats must have an adequate year-round supply of food that consists of
smaller prey species, such as rodents and snowshoe hares, used more in summer, and
the carcasses of larger animals, like moose and caribou, which are an important part of
the winter diet."
Distribution
Global Distribution
The wolverine is a holarctic species and can be found primarily in remote reaches of the Northern boreal forests and subarctic and alpine tundra across the entire Northern Hemisphere, with the greatest numbers in the U.S. state of Alaska, northern Canada, the Nordic countries of Europe, and throughout western Russia and Siberia (Wikipedia 2011). COSEWIC (2003) provides the following discussion on declines in this species: "Wolverine range in the contiguous United States has declined with human settlement
since the mid-19th century. It has been extirpated from most of its range in the
northeast, Great Lakes states and high plains where it occurred at low densities and
where the range limits were uncertain (deVos 1964, Hamilton and Fox 1987, Wilson
1982, Predator Conservation Alliance 2001; Figure 2). Populations in the western
6 states have suffered fragmentation and declines (Banci 1994). They may have ranged as far south as Arizona and New Mexico; however, tenuous populations currently inhabit only montane regions in Washington, Oregon, California, Idaho, western
Montana, Wyoming and Colorado (Banci 1994). Remnant populations also exist in the southern Rockies (Colorado; Kahn and Byrne 1998) and, possibly, Michigan and Maine."
Distribution in British Columbia
The distribution of Wolverines in British Columbia is not well known, although they occur widely and are reportedly relatively abundant in the northern two-thirds of the province (Hatler et al. 2008). There is also a centre of abundance in the Columbia Mountains in southeastern BC (Hatler et al. 2008). According to Hatler et al. (2008): "The only areas where Wolverines do not reguarly occur are the Lower Mainland, dry sections of the Fraser River and Okanagan Valleys in the southern interior, and the Queen Charlotte Islands." The last documented sighting on Vancouver Island was in 1981 (Hatler et al. 2008).
Taxonomy
COSEWIC (2003) provides the following information on the taxonomy of the Wolverine: "The wolverine, Gulo gulo (Linnaeus, 1758), was formerly known as Gulo luscus in North America; however, New and Old World forms have been shown to be conspecific
(Kurtén and Rausch 1959). Four subspecies are recognized in North America (Hall
1981), two of which occur in Canada; Gulo gulo luscus, found across Canada, Alaska
and the northwestern United States, and Gulo gulo vancouverensis, found on
Vancouver Island. Banci (1982) found little evidence for classifying the Vancouver
Island population as a distinct subspecies; however, it has undergone a high degree of
isolation since the Pleistocene, and is still recognized as a distinct subspecies (Nagorsen 1990, Resources Inventory Committee 2002). A complete study of variation
throughout the species’ range has been recommended (Nagorsen 1990)."
Comments
Based on a 2003 status report, COSEWIC, the federal Committee on the Status of Wildlife in Canada, assigned the Wolverine a status of 'special concern. They say: "Estimated total population size exceeds 13,000 mature individuals. Declines have been reported in Alberta and parts of British Columbia and Ontario. A distinct subspecies may be extirpated from Vancouver Island. Many pelts used locally are not included in official statistics, and harvest levels may be underreported. There is no evidence, however, of a
decline in harvest. There are no data on overall population trends other than those provided by local knowledge and harvest monitoring programs. This species’ habitat is increasingly fragmented by industrial activity, especially in the
southern part of its range, and increased motorized access will increase harvest pressure and other disturbances. The species has a low reproductive rate and requires vast secure areas to maintain viable populations." Habitat fragmentation results from forestry, hydroelectric developments, oil and gas and mineral exploration and
development, and transportation corridors (COSEWIC 2003).
COSEWIC 2003. COSEWIC assessment and update status report on the wolverine Gulo gulo in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. Available online.
Hatler, David F., David W. Nagorsen and Alison M. Beal. 2008. Carnivores of British Columbia. Royal BC Museum Handbook, Victoria.
LoFroth, Eric C. 2004. Wolverine page. Accounts and Measures for Managing Identified Wildlife. BC Ministry of Environment, Victoria. Available online.
LoFroth, Eric C., John A. Krebs, William L. Harrower & Dave Lewis. 2007.
Food habits of wolverine Gulo gulo in montane ecosystems of British
Columbia, Canada. Wildlife Biology 13, Supple. 2. Available online.
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC:
Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab
for Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
2025-02-08 3:40:00 PM]
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