Species composition and structure of community of waterfowls and waterbirds wintering on the Dnieper near the Kaniv hydroelectric power station (central Ukraine). - V.N. Grishchenko, E.D. Yablonovska-Grishchenko, M.N. Gavrilyuk. - Berkut. 22 (1). 2013. - P. 1-13.
The stretch of the Dnieper downstream of the Kaniv hydroelectric power station (49.46 N, 31.28 E) is a most important wintering area of hydrophilous birds in central Ukraine. Due to working of the station, ice-free parts of water remain even during hard frosts. Wintering birds were studied in 1987–2013. Every winter season several counts were conducted. Their number and length depended on weather conditions. During mild winters, the area of open water was very large and birds did not concentrate near Kaniv. In total, we have registered 27 bird species. Mallard dominated with big interval from other species (64.9% of relative abundance). Goldeneye (15.7%) and Goosander (15.2%) were co-dominants. All the species were divided in four groups. 1. Birds wintering regularly and in large numbers (three above mentioned species). They wintered yearly or almost yearly, relative abundance exceeded 15%. 2. Birds wintering regularly but in small numbers (Caspian Gull and White-tailed Eagle). These birds wintered yearly or almost yearly, relative abundance ranged from 0.8% to 2.5%. 3. Birds wintering irregularly and in small numbers (15 species). They were found many times but less than in the half of seasons. Relative abundance did not exceed 0.2%. 4. Birds with only single accidental records (7 species). Number of birds changed during winter season. Some species were observed only at the beginning of winter and later disappeared or remained in small numbers. Numbers of other birds increased at the height of the season or fluctuated within the sizeable limits. Influence of weather conditions on number of wintering birds was analysed. Relative abundance of Goldeneye and Goosander rapidly increased with intensification of frosts. White-tailed Eagles concentrated near gatherings of ducks on ice-free water. Number of gulls was decreased. During the sharp changes of weather, the intensive migration of gulls and some other species downstream of the Dnieper was observed. During the study period, species diversity and number of many birds increased. Many species came to winter more regularly. Relative abundance of Goldeneye, Goosander, Caspian Gull and Mute Swan appreciably rose. Relative abundance of Mallard decreased but it is connected with number increasing of many other species. Number of wintering White-tailed Eagles has multiple increased but its proportion in the community remained small against this background. [Russian].
Key words: regularity of wintering, relative abundance, weather conditions, number, migration, fauna, rare species.
Address: V.N. Grishchenko, Kaniv Nature Reserve; Kaniv, 19000, Ukraine; e-mail: vgrishchenko@mail.ru.