Move, Adapt, or Die: Lagopus leucura Changes in Distribution, Habitat and Number at Glacier National Park, Montana.

Abstract

—Because of the “montane island” effect and relative rates of climate change, alpine species may be particularly affected by changing climate. White-tailed Ptarmigan (Lagopus leucura) are adapted to life in the alpine cold, but may be less well-adapted to hot summer temperatures. In 1996 and 1997, ptarmigan living in Glacier National Park (GNP) were closely associated with remnant snow and free water in the late summer, a resource that is rapidly changing in distribution and extent as climate changes. We examined White-tailed Ptarmigan distribution, habitat, and numbers in 2009-2010 for comparison with 1996-1997 data. Briefly, five areas within GNP were searched for ptarmigan during August. Habitat data including microclimate were collected at flock locations. Microclimate at ptarmigan flock locations differed from other areas nearby. Flocking ptarmigan appeared to be less numerous than described in 1996 and 1997, and mean flock locations on Logan Pass moved 335 m upslope between the 1990s and 2009 and 2010. Ptarmigan in 2009 and 2010 chose habitat that had the same coverage of vegetation and rock as 1996 and 1997, but contained less snow and water, was farther from snow and water, contained lower soil moisture content, was higher in elevation, and steeper in slope. Our study demonstrates that White-tailed Ptarmigan in GNP have changed distribution, altered habitat preferences, and perhaps on a local scale, experienced declining population numbers in late summer. Received 1 March 2011, accepted 20 June 2011. BENSON, D., AND M. CUMMINS. 2011. Move, adapt, or die: Lagopus leucura changes in distribution, habitat, and number at Glacier National Park, Montana. Pages 237–246 in R. T. Watson, T. J. Cade, M. Fuller, G. Hunt, and E. Potapov (Eds.). Gyrfalcons and Ptarmigan in a Changing World, Volume I. The Peregrine Fund, Boise, Idaho, USA. http://dx.doi.org/10.4080/gpcw.2011.0121