1. Dept of Migration and Immuno-Ecology; Max Planck Inst. for Ornithology; Am Obstberg 1 DE-78315 Radolfzell Germany
2. Dept of Biology; Univ. of Konstanz; Germany
3. Alterra Wageningen-UR, Team Animal Ecology, Ecotoxicology and Wildlife Management; Wageningen the Netherlands
4. Inst. for Wetlands and Waterfowl Research (IWWR) e.V.; Verden (Aller) Germany
5. Inst. of Geography, Russian Academy of Sciences; Moscow Russia
6. Dept of Animal Ecology; Netherlands Inst. of Ecology (NIOO-KNAW); Wageningen the Netherlands
7. Computational Geo-Ecology, Dept of Science; Inst. for Biodiversity and Ecosystem Dynamics, Univ. of Amsterdam; the Netherlands