“Wolverines are perhaps the most sensitive indicators of ecological integrity … due to biological characteristics and their dependence on large, connected ecosystems.” — Committee on the Status of Endangered Wildlife in Canada
Wolverine captured by citizen wildlife monitors in the North Cascades in 2012. Click to enlarge and zoom out of image close-up.
Also recognized by the Great Northern Landscape Conservation Cooperative as a conservation target, this tough and wide-ranging member of the weasel family was an easy selection as an Iconic Species of Cascadia. As far back as the 1800s, records show that the Cascade Mountains were a home for wolverines. It is thought that wolverines disappeared from the America’s west coast in the early to mid-1900s, and that the North Cascades of Washington were later recolonized by individuals from British Columbia’s coastal ranges. At present, the North Cascades is home to a resident population of wolverines with home ranges often extending onto both sides of the border representing the species’ southernmost extent along the Pacific Coast.
In the last eight years, thirteen individuals have been captured as part of a coordinated transboundary telemetry study led by Keith Aubry with the Pacific Northwest Research Station, and an additional four have been identified from DNA analysis. This research has produced a Cascadian cast of characters that we are able to follow throughout the season and over time as the research continues.
Inhabiting the area around the timberline, wolverines primarily restrict themselves to areas with spring snow cover. Estimates based on telemetry data suggest the Cascades population has significantly larger home ranges than other North American populations such as in the Rocky Mountains. Another difference between these two western mountain populations is their genetics – wolverines in the North Cascades share a genetic signature found in a number of Canadian populations, but missing from the American Rockies.
Anticipated impacts from climate change are an obvious concern for the future of wolverine populations, given the close relationship between wolverine populations and deep, persistent snow depth. Models indicate this region is expected to maintain a well connected landscape with suitable habitat into the future, but much information is still needed on our transboundary resident population and its connections.
Read a report on wolverines in Cascadia with basic background information, climate change considerations, and opportunities and needs for adaptation planning and projects unique to this species. Report prepared in summer 2013 by Cascadia Partner Forum intern Brynn Arborico.
Activity areas of 7 radio-collared wolverines captured in the North Cascades of Washington (K. Aubry and C. Raley, U.S. Forest Service, unpubl. data).
Additional species resources
- Meet our Cascadian cast of wolverine characters (link downloads a PDF prepared by Cathy Raley of the PNW Research Station)
- King 5 news video – North Cascades Wolverines featuring wolverines and researchers in the field.
- North Cascades Wolverine video produced by the Skagit Environmental Endowment Commission on this unique transboundary species in the Cascades and coordinated transboundary research underway.
- The Wolverine Foundation – a international website dedicate to sharing information on this species.
- US Fish and Wildlife Service wolverine webpage including proposed listing information.
- Climate change predicted to shift wolverine distributions, connectivity, and dispersal corridors. McKelvey et al, 2011.
- Course statewide scale connectivity models for wolverine produced by the Washington Wildlife Habitat Connectivity Working Group are available in the Washington Connected Landscapes Project: Statewide Analysis including maps, data layers, and a species background write up on wolverine (Pg. 127 of Appendix A).