Climate change shifts dispersal corridors

Increasing temperatures due to climate change can be particularly detrimental to boreal species that rely on extensive snow depth and snow persistence into early spring for breeding. If seasonal winter conditions shorten each year and habitat becomes more fragmented, populations can lose connectivity and become genetically isolated, leading to a decreased likelihood of population persistence. McKelvey et al. tackle this conservation dilemma by focusing on wolverines in the western United States, whose obligate association with snow cover means that they are highly vulnerable to population isolation as increased temperatures shrink habitat availability and connectivity.

Using multiple fine scale modeling techniques to determine future snow persistence over different climate projections, the authors are able to create a long term prediction for wolverine persistence in the region. They conclude that spring snow cover is likely to decrease and snow-covered areas are likely to shrink over the next century to as little as one-third their current extent, although there are large areas such as the Greater Yellowstone Area that will remain as suitable wolverine habitat. However, with a higher cost to dispersal and fewer areas to disperse to for successful breeding, it is likely that the geographic extent and connectivity of wolverine populations will decline. Managers that are able to plan for this shift in habitat by focusing on conservation of populations in the largest regions with long-term snow persistence and maintaining connectivity between these regions present the best opportunity to ensure population persistence in the area.

Resources

McKelvey, K. S., J. P. Copeland, M. K. Schwartz, J. S. Littell, K. B. Aubry, J. R. Squires, S. A. Parks, M. M. Elsner, and G. S. Mauger. 2011. Climate change predicted to shift wolverine distributions, connectivity, and dispersal corridors. Ecological Applications 21(8), 2882-2897.