The flood plain of the Medveditsa River in the middle current is characterised by various fauna of birds. Nowadays significant transformations of local fauna, influenced by climatic conditions and anthropogenous loadings, are observed. In the valley of the river the most significant factor influencing communities of birds is the flood mode. The purpose of the work is the birds faunogenetic structure analysis of the Mededitsa river flood plain, and also it`s dynamics under the conditions of degradation of an inundated hydrological cycle.