Changes in the species composition of birds under the influence of climatic factors on the example of avifauna of the south of Eastern Transbaikalia

In recent decades (1995-2020) avifauna of Transbaikalia has undergone significant changes in the species composition and number of birds. So, for example, we have identified the Bewick's swan and the bean goose during flyby. Visitations of steppe species from the territory of Mongolia, in particular, the cinereous vulture and the upland buzzard, have become more frequent. At the same time, there is a decrease in the number of some waterfowls and semiaquatic birds, such as the black-throated loon, the great crested grebe, the Eurasian bittern, swimming harriers, cranes, etc. These changes in avifauna of the region are obviously associated with the climate shift, which highly weights towards the hydrological conditions (droughts - moistening).