1. Conservation Biology Research Group, Department of Anatomy, Cell Biology and Zoology, University of Extremadura, Badajoz 06006, Spain
2. Ecology in the Anthropocene, Associated Unit CSIC-UEx, Faculty of Sciences, University of Extremadura, Badajoz 06006, Spain
3. Group For Quantitative Study of Snow and Ice, Department of Geosciences, University of Montana, 32 Campus Drive, Missoula, MT 59812, USA
4. Intermountain West Joint Venture, US Fish and Wildlife Service, 1001 S. Higgins Avenue, Missoula, MT 59801, USA
5. Departamento de Biotecnología, Facultad de Ciencias del Mar y Recursos Biológicos, Universidad de Antofagasta, Angamos 601, Antofagasta, Chile
6. Bird Ecology Lab, Instituto de Ciencias Marinas y Limnológicas, Universidad Austral de Chile, Campus Isla Teja, Valdivia, Chile
7. Department of Biological Sciences, University of South Carolina, 715 Sumter Street, Columbia, SC 29208, USA