1. Institute of Vertebrate Biology of the Czech Academy of Sciences, Brno, Czech Republic; e-mail: , janac@ibv.cz, 324243@mail.muni.cz, jurajda@ivb.cz
2. General Ecology, Institute for Zoology of the University of Cologne, Ecological Field Station Rees, Cologne, Germany; e-mail:
3. Department of Ecology and Vertebrate Zoology, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland; e-mail: