BIRD COMMUNITIES OF THE GRAVEL PITS OF WESTERN SLOVAKIA

During our ornithological investigation of the gravel pits carried our in western Slovakia in the years 1990-1997 we found in 14 localities 117 bird species. This number represents 33 % of all species found in Slovakia up to now. 61 species of them were bound to water biotopes. F rom among the found species fifty species are risk bird species. The c haracteristic species of gravel pits in the investigated regions are e udominant and dominant, resp. euconstant nidificants: Podiceps cristat us. Cygnus olor, Anser anser, Anas platyrhynchos. Aythya ferina, A. fu ligula, Larus ridibundus, Fulica atra, Riparia riparia. Motacilla alba and Acrocephalus arundinaceus. In this kind of biotopes species diver sity is dependent mainly on the water and shore vegetation and terrain dissection, i.e. existence and number of islands in the locality. The investigated localities are important landscape segments substituting the liquidated marsh biotopes.