Use of corvids’ nests by other bird species in Baikal Siberia and Mongolia

The paper presents the species composition of corvids in Baikal Siberia and Mongolia. More than 700 nests of 8 species of corvids in Transbaikalia, Baikal and Mongolia were examined. 133 cases of using nests of 5 species of corvids (Magpies, Eastern Carrion Crow, Rooks and Daurian Jackdaws) by other species of birds were noted. Nests of small corvids do not attract other birds. Nests of magpies are most commonly used; they are characterized by a specific structure. Of the 8 species that use corvid nests for nesting, Amur red-footed Falcon and long-eared owl are obligate tenants. Then goes Kestrel that prefers magpie nests. The number of these types in many places is determined by the abundance of magpies and crows. In recent years, due to the high number of magpies, the number of Amur falcons in the region is growing. They began following magpies to penetrate the outskirts of Ulan-Ude. Three species (Mallard, hobby, tree sparrows) are considered optional to be the tenants and three other species (Ruddy Shelduck, Long-eared Owl and House Sparrow) are considered to be random. Tree sparrows often nest in the magpie nests in natural habitats. Almost all types of tenants use old nests of the owners. Regional features in the use of corvid nests are revealed. Some species in different regions do not prefer the same nests of different types of corvids.