The ecology of whooper swan (Cygnus cygnus) in the European north-east of Russia

Distribution, number and reproduction of Whooper Swan nesting in the Nenets Autonomous District and the Komi Republic is studied. Nesting displacement to the north and growth of number of birds in the region reflect the general tendency occurring in the extensive area of the species. The population structure of Whooper Swan in the investigated territory in June-September consisted of pairs (over 36%), single birds (11,6%) and small groups (3-17 individuals). Population density of birds (without young birds of current year) in July-September flactuated from 0.5 to 4.1 individuals per 10 km. 18.5% on the average, of Whooper Swan population participated in reproduction. Laying contained from 2 to 7, on the average 4.75 eggs, broods totaled from 1 to 6, on the average 2.3 cygnets.