BIRD COMMUNITIES OF ANTHROPOGENIC WATER HABITATS ON ZITNY-OSTROV ISLAND (DANUBE REGION)

During six years of ornithological investigations (since April 1988 till July 1994) we found 185 bird species in the anthropogenic water habitats. This number represents 52.40% of all species found up to present in the whole territory of Slovakia. Almost one half of them (84 species) nested in the investigated habitats and localities. Among the found species, 109 species were bound to water areas and 76 species to dams, dikes, and bank vegetation. As to the dominance and frequency categories, four species were eudominant (Cygnus olor, Anas platyrhynchos, Fulica atra, Larus ridibundus), four species were dominant (Vanellus vanellus, Riparia riparia, Hirundo rustica, Corvus frugilegus); eleven species were euconstant (Podiceps cristatus, Ardea cinerea, Cygnus olor, Anas platyrhynchos, Aythya ferina, A. fuligula, Fulica atra, Larus ridibundus, Motacilla alba, Pica pica, and Corvus frugilegus). The bank vegetation has a great significance for the occurrence of birds in the investigated area. The species composition of the birds in the anthropogenic habitats in the investigated area is influenced considerably by the barrage system of Gabcikovo, which is important above all for the migrating and hibernating waterfowl.