The wolverine (Gulo gulo) is a powerful, elusive, and resilient member of the weasel family, Mustelidae. Known for its strength and ability to thrive in harsh environments, this carnivore is the largest terrestrial mustelid.
Global Distribution
Wolverines have a circumpolar distribution across the northern latitudes of the Northern Hemisphere. Their range primarily corresponds with the boreal zone, encompassing arctic and subarctic regions and boreal forests. Wolverines generally occur south to about 37 degrees North in North America and 50 degrees North in Eurasia.
North American Range
In North America, the wolverine’s distribution extends from the Aleutian Islands of Alaska eastward throughout Canada and south into the northern Rocky Mountains. Canada serves as a significant stronghold, with wolverines inhabiting much of its northern and western regions, including British Columbia, Yukon, Northwest Territories, and Nunavut. Alaska also supports substantial wolverine populations.
The presence of wolverines in the contiguous United States is more fragmented and sparse. They are primarily found in high-elevation, remote areas of states such as Montana, Idaho, Wyoming, and Washington. Historical records indicate a broader but discontinuous range, which significantly contracted by the mid-1900s largely due to human persecution and habitat loss. Currently, an estimated 300 wild wolverines remain in these fragmented groups within the contiguous U.S.
Eurasian Range
Across Eurasia, wolverines are widely distributed, particularly in Russia, which likely holds the world’s largest population. Their presence spans Siberia, from the Ural Mountains eastward to Kamchatka, generally following the boreal taiga zone. In some areas of Russia, their distribution extends from the Mongolian border north to the Arctic Ocean.
In Europe, significant wolverine populations exist in the Nordic countries, including Norway, Sweden, and Finland, mainly north of latitude 60° N. Historically, their distribution was more extensive. Today, fragmented and smaller populations may be found in parts of Europe outside the Nordic region, although some of these populations are critically endangered or potentially extirpated. Wolverines are also found in Mongolia, particularly in the Altai Mountains along the western borders with Russia and China, and in northern China, though the Chinese population is small.
Preferred Habitats and Environmental Influences
Wolverines require extensive wilderness areas, primarily inhabiting vast, undisturbed tracts of subarctic and arctic tundra, boreal forests, and alpine regions. These environments offer the large territories necessary for this wide-ranging species, with male home ranges sometimes exceeding 620 square kilometers.
An environmental influence on wolverine distribution is the presence of deep, persistent snowpack. Female wolverines rely on deep snow for denning, where they give birth and raise their young. This requirement for snow that persists late into the spring dictates their presence in cold climates, as warm temperatures are not tolerated well. Climate change, which affects snowpack duration and depth, directly impacts the suitability of these habitats, potentially reducing their range.
Conservation Status and Threats to Their Range
Globally, the wolverine is classified as “Least Concern” by the IUCN, due to its wide distribution and large populations. However, regional status varies considerably, from secure in some areas to endangered or potentially extirpated in others. For instance, in Europe, the species is listed as “Vulnerable”.
In the contiguous United States, the wolverine population was listed as a threatened species under the Endangered Species Act in November 2023. Threats impacting wolverine populations and their range include habitat fragmentation resulting from human development, such as roads, logging, and energy extraction. Climate change represents a significant threat, as rising temperatures reduce the persistent snowpack essential for denning and food caching. This loss of snow-dependent habitat is predicted to shrink their range, with estimates suggesting a potential loss of 23% of habitat in the contiguous U.S. within 30 years and up to 63% over 75 years. Human-wildlife conflict and incidental trapping also contribute to pressures on wolverine populations.