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Wolverines and Climate Change Publication

Congratulations to Dr. Kevin McKelvey of the U.S. Forest Service Rocky Mountain Research Station and his eight co-authors for the publication of their study, “Climate change predicted to shift wolverine distributions, connectivity, and dispersal corridors.”

This study is important because it presents some of the best available information on the projected effects of climate change on wolverines in the western U.S.  Current wolverine habitat was modeled based on areas with persistent spring snow cover as described by Copeland et al. (2010).  Global climate model projections were compiled and downscaled to the Pacific Northwest and Rocky Mountain regions to project how wolverine habitat may change during the next century.  A second method was employed that simply projected the effects on wolverine habitat if spring snow melt was to occur two weeks earlier.  Changes to connectivity within the U.S. northern Rocky Mountains wolverine population were projected as well, using methods described by Schwartz et al. (2009).  The results and implications for wolverine conservation are discussed.  A draft version of this paper was the basis behind the U.S. Fish and Wildlife Service’s recent finding that Endangered Species Act protections are warranted for wolverines in the contiguous U.S.

Climate change predicted to shift wolverine distributions, connectivity, and dispersal corridors.  By Kevin S. McKelvey, Jeffrey P. Copeland, Michael K. Schwartz, Jeremy S. Littell, Keith B. Aubry, John R. Squires, Sean A. Parks, Marketa M. Elsner, and Guillaume S. Mauger.  Ecological Society of America PrePrint available online at:  http://www.esajournals.org/toc/ecap/0/0

ABSTRACT [1]

Boreal species sensitive to the timing and duration of snow cover are particularly vulnerable to global climate change. Recent work has shown a link between wolverine habitat and persistentspring snow cover through May 15, the approximate end of the wolverine’s reproductive denning period. We modeled the distribution of snow cover within the Columbia, Upper Missouri and Upper Colorado River Basins using a downscaled ensemble climate model. The ensemble model was based on the arithmetic mean of 10 Global Climate Models (GCMs) that best fit historical climate trends and patterns within these 3 basins. Snow cover was estimated from resulting downscaled temperature and precipitation patterns using a hydrologic model. We bracketed our ensemble model predictions by analyzing warm (miroc 3.2) and cool (pcm1) downscaled GCMs. Because MODIS-based snow cover relationships were analyzed at much finer grain than downscaled GCM output, we conducted a second analysis based on MODIS-based snow cover that persisted through May 29, simulating the onset of spring 2 weeks earlier in the year. Based on the downscaled ensemble model, 67% of predicted spring snow cover will persist within the study area through 2030-2059, and 37% through 2070-2099. [2] Estimated snow cover for the ensemble model during the period 2070-2099 was similar to persistent MODIS snow cover through May 29th. Losses in snow cover were greatest at the southern periphery of the study area (Oregon, Utah, and New Mexico) and least in British Columbia, Canada. Contiguous areas ofspring snow cover become smaller and more isolated over time, but large (>1,000 km2) contiguous areas of wolverine habitat are predicted to persist within the study area throughout the 21st century for all projections. Areas that retain snow cover throughout the 21st century are British Columbia, north-central Washington, northwestern Montana, and the GreaterYellowstone Area. By the late 21st century, dispersal modeling indicates that habitat isolation at or above levels associated with genetic isolation of wolverine populations becomes widespread. Overall, we expect wolverine habitat to persist throughout the species range at least for the first half of the 21st century, but populations will likely become smaller and more fragmented.



[1] All underlining within this Abstract is added.

[2] In other words, a one third loss in 20-50 years, and nearly two-thirds loss in 60-90 years.

Click on the link below for a memo that excerpts the key findings of this study, which we post here in an effort to encourage its understanding and application in decisions affecting wolverine conservation in the West.

Download: McKelvey_etal_2011_dg