Wolverine
Gulo gulo
Status: Not Listed
Classification: Mammal
Description
Wolverines have a wide variety of nicknames. They are known throughout the contiguous United States as the glutton, woods devil, Indian devil, and ommeethatsees (a Cree Indian word), carcajou, quickhatch, nasty cat, and skunk bear. It is the largest land-living species in the weasel family, or mustelids. The wolverine usually weighs between 17 and 40 pounds, stands up to 1.5 feet tall, and is generally 33 to 44 inches long (including tail). The male is larger than females.
Range
Historically the wolverine was in the Sierra Nevada mountains of California and the southern Rocky Mountains in Colorado, Wyoming, and New Mexico. Wolverine populations are currently known in the North Cascades Range in Washington; the Northern Rockies of Montana, Idaho, Wyoming; and a small portion of Oregon (Wallowa Range). The wolverine also resides in Alaska, Canada, and Russia.
The wolverine ranges widely, up to 15 miles a day, and needs lots of habitat. Home ranges can vary from 100 to 600 square miles. In the lower 48, they live primarily at high altitudes with alpine vegetation, but can venture to lower elevations. It is estimated that 25 to 300 live in the lower 48 states.
In 2008 and 2009, one wolverine was recorded on motion-detector cameras in the northern Sierra Nevada mountains. It is not believed to be part of a resident population, possibly having come from somewhere in the Rocky Mountains. Wildlife biologists were awed and excited by the sighting of a lone wolverine in California in 2008 and 2009, but nonetheless the risks posed by climate change indicate that the future is challenging for wolverines in the lower 48 states.
Diet
Wolverines are ferocious predators that prey mostly on mammals such as rabbits and rodents. They are also scavengers, eating the carrion (carcasses) of large animals such as caribou, deer, and elk to help them through the winter when other food is scarce.
Life History
A male is polygamous, usually having several mates with several smaller female territories within its larger territory. Females raise the young without any male assistance. A female makes her birthing den in deep snow, usually requiring five or more feet of snow to protect the young from cold and predators. For this reason, dens are usually high up at 7,000 feet or more in altitude. Wolverines usually produce one or two kits, who are born from mid-February through March. They use the dens usually until May, so finding an area that has snow into late spring is important. Wolverines may reach anywhere from five to 13 years.
Conservation
Wolverines in the lower 48 states are under consideration for protection under the Endangered Species Act. Although the wolverine has very specific habitat needs, was never a common species, and was widely persecuted, the primary reason now for a threatened listing is climate change. Wolverines need deep snow to birth and rear their young. As snowpack continues melting earlier each year, aggressive action must be taken to reduce the carbon pollution driving climate change, and to consider climate impacts in wolverine conservation efforts.
Once heavily persecuted and likely eliminated from the lower 48 states, the wolverine returned on its own over the past 50 years. It is estimated that due to climate change, within 30 years, about 30 percent of wolverine habitat in the lower 48 states will be gone. Within about 70 years, an estimated 60 percent of their habitat will be lost in the lower 48 states. With snowpack melting earlier, scientists project wolverine habitat will shrink significantly by the end of the century.
Fun Fact
The wolverine, like most mustelids, has scent glands with a strong odor they use for marking territory and sexual signaling.
