Long-Distance Wolverine Dispersal from Wyoming to Historic Range in Colorado

Wolverines (Gulo gulo) within the conterminous U.S. exist as a metapopulation dependent upon individuals dispersing between patches of habitat to persist. Dispersal events can be difficult to document for long-ranging carnivores, but have implications for understanding gene flow and connectivity between both currently occupied and historically occupied habitat. Here, we describe the long-distance dispersal of a subadult, male wolverine (M56) from a reproductive population in northwest Wyoming to northern Colorado where wolverines had been absent for 90 years. M56 was ultimately killed in North Dakota in 2016, the first verified wolverine in that state in over 200 years. Following capture and collaring, we collected aerial VHF telemetry locations as M56 navigated potential barriers, including interstate highways and subdivisions, and travelled extensively outside of primary wolverine habitat through the arid grasslands and shrublands of the Wyoming Basin Ecoregion. Straight-line distances for dispersals from Wyoming to Colorado (516 km) and from Colorado to North Dakota (826 km) are the longest straight-line dispersal distances reported for the species at this time. The Wyoming Basin Ecoregion M56 traversed is dominated by sagebrush and topography less rugged than that typical of the high elevation, mountainous habitat wolverines use in the conterminous U.S. This dispersal event offers evidence of connectivity between occupied habitat in Wyoming and unoccupied habitat within the species' historic range in Colorado and provides a detailed account of the path M56 took through atypical habitat.