Wolverine Distribution and Ecology in the North Cascades Ecosystem Final Progress Report (February 9, 2016) Keith B. Aubry, Ph.D. (Lead Principal Investigator), Research Wildlife Biologist, U.S. Forest Service, Pacific Northwest Research Station, Olympia, WA 98512; 360-753- 7685;
[email protected] John Rohrer, Supervisory Wildlife Biologist, U.S. Forest Service, Okanogan-Wenatchee National Forest, Winthrop, WA 98862; 509-996-4001;
[email protected] Catherine M. Raley, Wildlife Biologist, U.S. Forest Service, Pacific Northwest Research Station, Olympia, WA 98512; 360-753-7686;
[email protected] Scott Fitkin, District Wildlife Biologist, Washington Department of Fish and Wildlife, Winthrop, WA 98862; 509-996-4373;
[email protected] Frontispiece. Male wolverine being released from a livetrap at Easy Pass, Washington. 1 I. Introduction The wolverine (Gulo gulo) is one of the rarest mammals in North America and the least known of the large carnivores (Banci 1994). The wolverine is considered a sensitive species in the Pacific Northwest Region by the U.S. Forest Service, and a candidate species for listing as threatened or endangered by the state of Washington. On 13 August 2014, the U.S. Fish and Wildlife Service (USFWS) withdrew their 2013 proposed rule to list wolverine populations in the contiguous U.S. as “Threatened” under the Endangered Species Act (ESA; U.S. Fish and Wildlife Service 2013, 2014). The USFWS stated that “while there is significant evidence that the climate within the larger range of the wolverine is changing, affecting snow patterns and associated wolverine habitat, the specific response or sensitivity of wolverines to these forecasted changes involves considerable uncertainty at this time” (U.S.