1. Department of Zoology and Laboratory of Ornithology Palacký University 17. listopadu 50 Olomouc 771 46 Czech Republic
2. Institute of Vertebrate Biology Academy of Sciences of the Czech Republic v. v. i., Květná 8 603 65 Brno Czech Republic
3. Department of Ecology Faculty of Science Charles University in Prague Viničná 7 128 44 Prague 2 Czech Republic
4. Department of Biological Sciences Mount Holyoke College South Hadley Massachusetts 01074 USA
5. Organismic & Evolutionary Biology Graduate Program University of Massachusetts, Amherst Amherst Massachusetts 01003 USA
6. Department of Psychology Hunter College and the Graduate Center The City University of New York 695 Park Avenue New York City New York 10065 USA