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

Abstract

The ecological and geographical differentiation and dynamics of the spring migration of water and semiaquatic birds of the Putorana Plateau are analyzed. In 1988–2007, eight points were surveyed in the northern, southern, western, and eastern parts of the region on an area of 250 000 km² using the method of route census. The water and semiaquatic avifauna of the Putorana Plateau during the spring migration includes 68 species. The tundra species (53%) from among the Anseriformes and Charadriiformes, accounting for 94%, make a significant contribution to the avifauna formation. Birds fly to the north, east, and west. They make stops at the river deltas that are freed from snow and ice early. The species distributed at stopover sites everywhere (38%), locally (22%), and pointwise (40%) are distinguished. Bird population density at stopovers is from 15 to 227 (on average (n = 8) 94) ind./km of shoreline. The population of birds on lakes is always much smaller than on adjacent river sections. The vast majority of individuals of almost all migratory species are united in monospecific and (rarely) polyspecific flocks. The entire spring migration of water and semiaquatic birds on the Putorana Plateau takes place from May 19 to June 27 and lasts on average (n = 10) 23 days. The main passage runs from May 25 to June 17 and lasts an average of (n = 8) 7 days. Spring migration is most intense in the west of the Putorana Plateau, where at least 20 000–30 000 individuals of aquatic and semiaquatic birds fly through the surveyed points. The passage is much weaker in the center and, especially, in the east of the region. There are 19 species among the dominants of water and semiaquatic habitats, including the common teal, Eurasian wigeon, northern pintail, grey-tailed tattler, and little stint.