Authors
Maciej Bonk
Institute of Nature Conservation, Polish Academy of Sciences, Kraków, Poland
Rafał Bobrek
Polish Society for the Protection of Birds, Marki, Poland
Jacek Dołęga
University of Agriculture in Cracow, Department of Ichthyobiology and Fisheries, Kraków, Poland
Witold Strużyński
Warsaw University of Life Sciences SGGW, Division of Zoology, Department of Animal Environment Biology, Animal Sciences Faculty, Warsaw, Poland