Monitoring of the birds in the Danube flood plain

In those parts of the Danube flood plain, where the changes of the hydrological regime have not a visible impact on the vegetation structure, the ornithocoenoses have not changed considerably up to present. A decrease in species diversity was registered in those localities, which were directly influenced by human activities related with the construction and and operation of the Gabcikovo barrage system, or in those localities, whose immediate surrounding was influenced by such activities. Deeper changes in the structure of bird communities in the Danube flood plain may be expected as early after a longer period, when the vegetation structure will have been changed more conspicuously. Limitation of breeding and occurrence of birds, especially of larger and shyer species, in the flood plain was caused by a larger degree of disturbance by people in consequence of opening almost whole within-dike area by cutting off the Danube branches from its main stream, construction of dams cross the branches, construction of forest roads for timber hauling etc. New-arisen water tables, especially the Cunovo reservoir, by-pass canal, tail race canal, seepage canals and various depressions arisen during the Gabcikovo barrage system construction and filled with water have a significance for waterfowl during passage and wintering, but in no case for their breeding.. (authors). 2 tabs