Poleward shifts of avian winter ranges

Frank La Sorte

University of California, San Diego, USA

Anthropogenic climate change has resulted in a variety of ecological consequences, including positive latitudinal trends in species’ distributions. These poleward movements have been documented at the species and community level for a wide variety of taxa. However, most investigations have focused on partial range boundaries at the expanding edge of the range for a limited number of species. When examined at broader geographical scales, more complex associations are evident, characterized by the combined effect of climatic change and regional anthropogenic factors, reflecting the fact that dispersal success is determined in part by landscape structure and a species’ associations with anthropogenic activities. When community-level changes are considered, there is evidence that species are responding in a non-uniform fashion, with some species appearing to be in a better position ecologically and geographically to track changing climatic conditions. These trends are exacerbated in some cases by regional anthropogenic factors, resulting in community-level changes biased towards species that can disperse and utilize habitats within human-altered landscapes. Therefore, as climate change progresses, novel ecological associations and patterns will develop, reflecting the complex interplay of environmental and biological drivers structured, in large part, by the direct and indirect consequences of anthropogenic activities.