SPATIAL DISTRIBUTION AND HABITAT PREFERENCES OF WINTERING WATERFOWL IN CENTRAL BOHEMIA

A Winter Waterfowl Census in Central Bohemia was carried out in Central Bohemia in the seasons 2003/04 and 2004/05 once a month between the middle of November and the middle of March. 270 km of four rivers and 31 reservoirs were a subject of investigation. The course of temperature in the studied winters was very different and influenced total abundance as well as spatial distribution of particular species. We distinguished species assemblages characteristic for different types of winter sites. Anas platyrhynchos was a dominant species in all localities. Cygnus olor, Larus ridibundus, and Fulica atra were found on rivers within human settlements, especially on the Vltava River in Prague. Aythyaferina and A. fuligula were the other dominant species in Prague. A river section representing the largest river flow was characterized by Bucephala clangula. Mergus merganser were found on all rivers. The only little river was characterized with a high density of Cinclus cinclus. A deep and large drinking-water reservoir with rugged banks hosted northern diving species (M. merganser, B. clangula, Mela-nitafusca, Gavia arctica). Sand pit lakes were important resting sites (e.g. for M. merganser, A. ferina, A. fuligula and A. platyrhynchos). Fishponds were characterized by A. platyrhynchos and the largest fishpond also by Anser fabalis and A. albifrons.