Spatial structure and dynamics of the seasonal migration of passerines (Passeriformes, Aves) on the Putorana plateau, Siberia

The ecological structure and dynamics of the seasonal migrations of passerines of the Putorana Plateau, Siberia are analyzed. The route counting method on transects of unlimited width is used. On the Putorana Plateau as a junction of migration routes birds fly along the coastal-edge strip along rivers or lakes in the northern, western or eastern directions in spring, and in the southern, southwestern, western directions in autumn. Spring migration takes place from May 22 to June 20, lasting 8–17 days and restricted to 9–12 days for most species. In the south of Putorana, spring migration lasts shorter than in the north of the region. Autumn migration takes place from late July to late August, lasting 14–31 days and restricted to 20–26 days for most species. During the entire migration, a more fleeting period of the main migration is expressed, when 70–80% individuals fly. The bird population density in spring amounts to 231 individuals/km², vs 440 in autumn. The population density reaches the maximum in the south of Putorana, the minimum in the north. Significant amplitudes of daily abundance indices of species and 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 the waves of maximum flight does not occur in related species. In spring, the dynamics of flight in related species vary in different years, ranging from complete synchronization of the waves of maximum flight to their absolute discrepancy.