Number and distribution of Mute Swans, Cygnus olor, Bewick's Swans, C. bewickii, and Whooper Swans C. cygnus in the West Siberian plain

Abstract

Bird census data from the West Siberian plain, USSR, were analysed to give population estimates for three swan species. The Mute Swan only inhabits the steppe and forested steppe and numbers about 6,000 individuals. Bewick’s Swans are only found in the forest-steppe during the spring migration, although they are also found in the arctic tundra which was not censused The average number of Whooper Swans decreases from the forest-tundra northwards to the southern taiga, then increases towards the forest steppe and decreases again in the steppe. The population is mainly concentrated in the northern taiga. A total of 316,000 Whooper Swans were counted in the whole of the West Siberian plain during the first half of summer. The accuracy of this population estimate is discussed.