Abstract

Four years of ornithological observations were conducted on the eastern slope of the Tibet–Qinghai Plateau in September–October 2011–2012 and 2017–2018. The species composition of common birds in nine isolated forest islands were studied, and the proportions of species from various faunistic groups were determined. A comparison of the bird complexes from different locations revealed regional specificity in each of them, this being related to the landscape and altitudinal characteristics, area, and ecological parameters of the localities. The local aviafauna can be determined as Palaearctic with a high percentage of endemic and subendemic species. Oriental species constituted a significant proportion only on the southern macroslope of the Qinling Range, which apparently represents the northern periphery of a wide transitional zone between the Palearctic and Oriental regions. A specific seasonal aspect of the species composition is attained due to fall bird migrations from the northern regions of the Palearctic. Among the special features of the region is the wide penetration of forest birds into open spaces along intrazonal habitats and the intrusion of species from open areas into the borders of forest biotopes during the migration period. There is also an ecological group associated mainly with ecotones.