1. Sleep & Flight Group, Max Planck Institute for Ornithology—SeewiesenEberhard-Gwinner-Strasse, Starnberg 82305, Germany
2. Department of Experimental Ecology, University of UlmUlm 89069, Germany
3. Institute of Anatomy, University of ZurichZurich 8057, Switzerland
4. New York State MuseumAlbany, NY 12230, USA
5. Smithsonian Tropical Research InstituteBalboa, Ancon, Panama
6. Department of Ecology and Evolutionary Biology, Princeton UniversityPrinceton, NJ 08544, USA
7. e-obs Digital TelemetryMunich, Germany