Anna M. Pidgeon Volker C. Radeloff Andrew J. Allstadt H. Resit Akcakaya Wayne E. Thogmartin Stephen J. Vavrus Patricia J. Heglund Brooke L. Bateman 2015 <h3 class="Heading">Context</h3> <p id="Par1" class="Para">Threats to wildlife species from extreme events, such as droughts, are predicted to increase in frequency and magnitude with climate change. Extreme events can cause mortality and community-level changes, but for some mobile species, movement away from areas affected may be a viable option.</p> <h3 class="Heading">Objectives</h3> <p id="Par2" class="Para ParaOneEmphasisChild">We examined the effect of extreme weather on spatial patterns of abundance for an irruptive grassland bird species, the Dickcissel (<i class="EmphasisTypeItalic">Spiza americana</i>).</p> <h3 class="Heading">Methods</h3> <p id="Par3" class="Para">We calculated route-level annual abundances and abundance anomalies from 1980 to 2012 from North American Breeding Bird Survey data, and classified the Dickcissel&rsquo;s range into core and edge regions using these abundances. We then compared abundances in the core and edge regions to the standardized precipitation evapotranspiration index, a measure of drought, in linear regressions.</p> <h3 class="Heading">Results</h3> <p id="Par4" class="Para">We found that Dickcissel irruptions in the northern range edges were related to drought conditions in the range core, potentially a consequence of birds being &lsquo;pushed&rsquo; to the range edge when weather was unsuitable. Specifically, Dickcissels moved into refuge sites containing a high proportion of cultivated crops, with higher vegetation greenness, than those areas they leave during drought years.</p> <h3 class="Heading">Conclusions</h3> <p id="Par5" class="Para">In a changing climate where more frequent extreme weather may be more common, conservation strategies for weather-sensitive species may require consideration of habitat in the edges of species&rsquo; ranges, even though non-core areas may be unoccupied in &lsquo;normal&rsquo; years. Our results highlight the conservation importance of range edges in providing refuge from extreme events, such as drought, and climate change.</p> application/pdf 10.1007/s10980-015-0212-6 en Springer The importance of range edges for an irruptive species during extreme weather events article