Wolverines are present in Wyoming. While their presence is confirmed, these tenacious members of the weasel family are rare and difficult to observe in their high-elevation habitats. Their secretive nature and low population densities contribute to their elusive reputation.
Wolverine Characteristics and Habitat in Wyoming
The wolverine (Gulo gulo) is the largest terrestrial species within the weasel family, known as mustelids. These animals typically weigh between 17 and 40 pounds and measure about 33 to 44 inches in length, including their tail. Males are generally larger than females. Wolverines are well-adapted to cold, snowy environments, displaying a robust build and large paws that aid in navigating deep snow.
In Wyoming, wolverines primarily inhabit mountain ranges. Their preferred habitat includes high-elevation subalpine and alpine landscapes, characterized by persistent snow drifts, talus fields, and den structures such as caves, rock crevices, or deep snow drifts. These conditions are found in areas like the Greater Yellowstone Ecosystem, which spans parts of Wyoming, and specifically within the Wind River Range, Teton Range, and Absaroka Mountains. They also utilize areas within the Bighorn Mountains, Medicine Bow Mountains, Gros Ventre, and Salt ranges.
Elusive Nature and Documented Presence
Wolverines are solitary animals that maintain vast home ranges, contributing to their low population density and elusive nature. Male wolverines can have territories covering hundreds of square miles, and same-sex adults typically avoid overlapping ranges. Their preference for rugged, remote terrain at high elevations also makes direct observation by humans infrequent.
Despite their reclusive habits, the presence of wolverines in Wyoming has been documented through various scientific methods. Remote camera traps are a primary tool, capturing images of these animals. DNA analysis from hair samples collected at bait stations confirms individual wolverine presence and helps identify unique individuals.
Tracking studies, sometimes involving collared animals, provide insights into their movements and dispersal patterns. Confirmed sightings, though rare, also contribute to understanding their distribution, with specific examples including the documentation of male and female wolverines in the Wind River Range in 2018, and a wolverine filmed in the Teton Range in 2022.
Conservation Status and Future Outlook
In November 2023, the North American wolverine in the contiguous United States was listed as a threatened species under the federal Endangered Species Act (ESA). This decision acknowledges the impacts of climate change and habitat fragmentation on the species. In Wyoming, wolverines are classified as Nongame Wildlife and are designated as a Species of Greatest Conservation Need.
The primary threats to wolverine populations include the reduction of persistent snowpack due to climate change. Female wolverines rely on deep snow for denning and raising their young, and warming temperatures are projected to shrink this essential habitat. Habitat fragmentation from human development and incidental take from traps set for other species also pose challenges to their survival.
Conservation efforts in Wyoming involve range-wide occupancy surveys conducted every five years to monitor population trends and distribution. These studies utilize camera traps and DNA analysis to track wolverine presence. While climate models suggest high-elevation snow may persist through mid-century, lower-elevation snowpack faces significant declines. Continued monitoring and consideration of wolverine habitat in land use decisions are important for their long-term prospects in the state.