Wintering of waterbirds in the area of Dnieper Hydroelectric Power Station in 2015 – 2019

Abstract

Monitoring of ornithofauna in wintering areas of waterbirds is an important component of the vulnerable bird species conservation and species diversity as a whole. The environmental conditions are favorable for wintering of waterbirds in the lower tail of the Dnieper River hydroelectric power station (HES) that determines the mass concentration of birds in this area. The species composition and abundance of waterbirds were studied at the Dnieper River HES (47.856N, 35.073E) during winters of 2015-2019. In total 77,741 individuals of waterbirds of 26 species, 8 families and 7 orders were counted. Bird counts were conducted in December and January. The water area and coast of the Dnieper River were inspected visually from the dam of HES to the bridge across the Dnieper River in the city of Zaporizhzhia. During the research period, 12 to 18 waterbirds species were found in the wintering bird communities. The number of birds in communities ranged from 5318 to 17072 individuals. Mergus merganser was an absolute dominant of winter communities in January of 2016 and 2017, years with prolonged frosts and persistent ice formation. The index of concentration of dominance was the highest in those years (0,49). In winters of 2017/2018–2018/2019 the temperature regime was milder, and the dominant species was Larus canus. The subdominant species was Larus cachinnans. The index of concentration of domination was then the lowest, 0,22. The ratio of birds of protected species in wintering bird communities did not exceed 0.5 % in the Dnieper River HES area in winters of 2015/2016–2018/2019. Winter communities of 2008-2009 were most similar to those observed in 2016-2017 (CS = 0,74). By the ratios of each species the winter communities of 2008/2009 years were the most similar to the communities of 2015/16 (CN = 0,73).