Bringing Wolverines to Colorado
The North American wolverine (Gulo gulo luscus) was part of Colorado’s native fauna until it was extirpated during the early 1900s. Now CPW is restoring the species back to the state. The restoration of wolverines to Colorado was authorized by a bipartisan list of supporters in the 2024 Colorado State Legislature through the passage of SB24-171.
Bringing Wolverines to Colorado
The North American wolverine (Gulo gulo luscus) was part of Colorado’s native fauna until it was extirpated during the early 1900s. Now CPW is restoring the species back to the state. The restoration of wolverines to Colorado was authorized by a bipartisan list of supporters in the 2024 Colorado State Legislature through the passage of SB24-171.
About Wolverine
About the Species
Wolverines are solitary scavengers that live in boreal forests and tundra. With a reputation for being larger than life, they’re famous for their boldness, toughness and formidable attitude. Wolverines are members of Mustelidae, the weasel family. Though they may be weasels, they resemble a small bear with their stocky build and rounded ears. Their fur is dark brown to black, and the sides have a characteristic yellowish brown to whitish stripe. Like other weasels, wolverines have anal musk-producing glands.
Physical Characteristics
Wolverines are three feet long, with a short, brushy tail, just one-quarter its total length. Wolverines are the largest land-dwelling weasels, tipping the scale at 20 to 30 pounds or more. They have wide feet for walking on top of snow, and large claws that they use for climbing trees and digging.
Range
Wolverines live in high alpine environments in both North America and Eurasia. In North America, they occupy western mountains in Alaska and Canada; the southern portion of their current range extends into the contiguous United States, including Washington, Idaho, Montana and Wyoming. There is currently no known population in Colorado.
Habitat
Wolverines have a circumpolar distribution in the Northern Hemisphere, meaning they are found across the northern polar latitudes. They thrive in cold, high elevation environments, including the tundra, taiga, boreal and alpine biomes. In these habitats, daily temperatures can fall below freezing most of the year, growing seasons are short and snow persists into the summer months. The wolverine occupies a unique niche in these snow-covered environments by scavenging deer, elk and moose carcasses. By storing the leftovers in cold, rocky areas – a behavior called caching – wolverines keep the carcasses they find away from other scavengers as well as insects and bacteria.
In Colorado, nearly all historical and recent reports of wolverines are from higher elevation, alpine areas. Wolverines are very few and far between under even the best conditions, holding huge, exclusive territories; each wolverine essentially lives on its own alpine island. Until recently, the last confirmed wolverine sighting in Colorado was in 1919. Until recently, the last confirmed wolverine sighting in Colorado was in 1919. Occasional reports have been investigated, but no sighting has been officially documented since — except for one. In the spring of 2009, researchers with the Greater Yellowstone Wolverine Program tracked a wolverine traveling from Grand Teton National Park into north central Colorado. This was the first wolverine confirmed in the state in 90 years.
Diet
Wolverines are opportunistic foragers, feeding on just about any animal protein available. As scavengers, they feed mainly on elk, deer and moose carcasses. As predators, they hunt small rodents, rabbits, porcupines, marmots, birds and bird eggs. They may attack large game (for example, a weakened deer or other large prey, especially when it’s struggling through deep snow), but most ungulate remains in their diet are probably from carrion (the meat from a dead animal eaten by scavengers). Wolverines are legendary marauders of the North, renowned for their strength, cunning and viciousness. Pound for pound, they are probably no stronger than any smaller weasels, such as badgers, black-footed ferrets or otters.
Reproduction
Wolverines mate during the warmer months. Through “delayed implantation,” the embryo doesn’t start developing until January. Two to four young are born in late March or early April. The blind, toothless newborns grow rapidly, and will be half-grown when they disperse in autumn.
Have You Seen a Wolverine?
Help Colorado Parks and Wildlife biologists monitor wolverines on the landscapes by filling out this form. Please provide a photo or video, the exact location coordinates or other detailed information for confirmation purposes.