1. Department of Zoology, South Parks Road, Oxford OX1 3PS, UK
2. Centre for Animal Migration Research, Department of Biology, Lund University, SE-22362 Lund, Sweden
3. Department of Biology, University of Pisa, Via A. Volta 6, I-56126 Pisa, Italy
4. School of Biological Sciences, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
5. AG Neurosensorik/Animal Navigation, IBU, Research Center for Neurosensory Science, Carl von Ossietzky-Universität, Oldenburg, D-26111 Oldenburg, Germany
6. Department of Biology, Lund University, SE-22362, Sweden
7. FB Biowissenschaft, J. W. Goethe-Universität, Siesmayerstrasse 70, D-600054 Frankfurt am Main, Germany
8. Department of Psychology and J. P. Scott Center for Neuroscience, Mind and Behavior, Bowling Green State University, Bowling Green, OH 43403, USA