The dynamics of the bird population in the forest ecosystems of Eastern Siberia (South Baikal) under the conditions of the modern climate changes

Abstract

The work was carried out on a key site with an area of more than 50 km2 on the right bank of the source of the Angara river (South Baikal) in 2010-2020 The studies were carried out in winter and summer periods, based on the standard technique used in Russia for these purposes. The studies fall on a period of strong warming close to the maximum, most likely a centuries-old climate cycle. It is shown that the dynamics of population density and species diversity of birds in the winter and summer seasons at this time are very different. The summer period is by wavelike (cyclical) changes characterized, without a pronounced trend. In winter, on the contrary, there is a well-pronounced trend towards a noticeable decrease in these indicators. The different responses of birds to climate changes are undoubtedly by the initial factors operating at their areas determined. In the summer period - the drying up of the territory of Central Asia and the resettlement of birds, especially waterfowl and waterfowl, to the northern borders of their areas. In the winter period - by situations in the optima of wintering habitats, which also shifted somewhat to the north (even in sedentary bird species). These materials indicate the strong impact of climate change on the environment.