Ecological and Geographical Structure and Dynamics of Spring Migration of Passeriform Birds on the Putorana Plateau

The ecological and geographical differentiation and dynamics of the spring migration of passeriform birds from the Putorana Plateau are analyzed. In 1988–2007, eight points were surveyed in an area of 250000 km2. The route census method was used. There are 58 species in the fauna of the spring migration period. Birds fly along the shore forest-edge strip along rivers or lakes in the northern, western, and eastern directions. The bird population density is 179–332 individuals (on average 231 individuals/km2, n = 4). A significant amplitude of daily indicators of species abundance and asynchrony between phenological phenomena in different species and in individuals of the same species are characteristic. The time interval during which the first individuals usually appear is 4–12 days for different species and 6–9 days for most of the species (on average, 8 days). Early migrants, such as horned lark, white wagtail, and dusky thrush, usually appear on May 25–June 4, May 22–June 1, and May 27–June 2, respectively. Late migrants, such as sand martin, house martin, common chiffchaff, and arctic warbler, usually appear on June 7–16, June 7–16, June 5–11, and June 10–18, respectively. The average duration of the entire spring migration for most of the species is 9–12 days and the duration of their main migration is 4–6 days. The configuration of the spring migration course is a combination of two–three waves of varying strength, but always with one distinct maximum. Significant outbreaks of migratory activity of birds are observed on days with the lowest air temperature and precipitation in the form of snow or rain. The comparative nature of the spring migration of closely related species in different seasons varies from complete synchronization of the waves of maximum migration to their absolute discrepancy.