Modern climate warming, dynamics and development of new plots of bird areas as population adaptation to anthropogenic landscapes of Eastern Siberia

Abstract

The article discusses the features of the formation of new plots of the areas for birds in the anthropogenic landscapes of Eastern Siberia under the conditions of modern climate warming. It is emphasized that at the initial stages of this process, the warming was not intense and hardly noticeable (the beginning of the 19th - the first half of the 20th centuries). However, already at that time there was a clear trend towards the expansion of bird areas to the north and east. This process has progressed as the trend towards climate warming intensifies. In the second half of the 20th century, some typically western bird species reached Eastern Siberia. At the same time, extensive and prolonged droughts in the east of Central Asia caused a strong counter flow of dispersing birds to the west and north. In a number of bird species, mixing of the streams of dispersing birds was observed, and often these were closely related species. This indicates the formation of gaps in their once common areas that arose during periods of sharp cooling in previous climatic epoch. In the middle of the 20th century, the anthropogenic development of Eastern Siberia was very high. This facilitated the movement of birds of open landscapes far north. This fact is also emphasized by the oncoming flows of birds settling to the east and west as a result of severe and prolonged droughts in Central Asia. The birds of these streams crossed the Baikal rift zone (the northeastern zoogeographic boundary) and went far to the north - to the Central Yakut lowland and the tundra zone. The data obtained show that the development of new territories by birds and the expansion of their areas is associated with intense climate warming. The development of the territory by man only contributed to the movement of birds to new regions, due to the formation of more suitable habitats for birds (open and mosaic landscapes). Consequently, the intensification of climate warming, coinciding with the expansion of bird areas to the north, indicates that it was warming, and not intensive development of the territory by humans, that played the leading role in this process. The entire process currently observed is the adaptation of birds to the dynamic conditions of the new climatic period.