Migrations of Passeriformes on the Putorana Plateau

Abstract

The ecological structure and dynamics of seasonal migrations of passerines of the Putorana Plateau are analyzed. The route census method on transects of unlimited width is used. The Putorana Plateau is a junction of migration routes. Birds fly along the coastal-edge strip along rivers or lakes in the northern, western, eastern directions in spring, and in the southern, southwestern, western directions in autumn. Spring migration takes place from May 22 to June 20, lasts 8–17 days, for most species – 9–12 days. In the south of Putorana, spring migration takes place in a shorter time than in the north of the region. Autumn migration takes place from late July to late August, lasts 14–31 days, for most species – 20–26 days. During the entire migration, a more fleeting period of the main migration is expressed, when 70–80% of individuals fly. The bird population density in spring is 231, in autumn – 440 individuals/km². The population density is maximum in the south of Putorana, minimum in the north. Significant amplitude of daily abundance indices of species, asynchrony between phenological phenomena in different species and in individuals of the same species are characteristic. The course of migration is wave-like, with 1–4 bursts of migration activity per season. The intensity of migration is higher on days with the lowest air temperature. In autumn, synchronization of waves of maximum flight in related species does not occur. In spring, the dynamics of flight in related species varies in different years: from complete synchronization of waves of maximum flight to their absolute discrepancy.