1. Department of Migration, Max Planck Institute of Animal Behavior, Radolfzell, Germany
2. Department of Biology, University of Munich, Munich, Germany
3. Department of Biology, University of Konstanz, Konstanz, Germany
4. TU Braunschweig, Zoological Institute, Braunschweig, Germany
5. North Carolina Museum of Natural Sciences and Department of Forestry and Environmental Resources, North Carolina State University, Raleigh, NC, USA
6. Department of Biological Sciences, Southeastern Louisiana University, Hammond, LA, USA