Based on extensive data on the number and distribution of birds obtained during route surveys over the last 60 years, the classification of bird communities in Central Siberia is considered at the type level. The zonal and landscape–biotopic specificity of the identified types of ornithocomplexes is determined. The main directions of territorial changes in the bird communities are determined by afforestation and watering in combination with latitudinal zonality. Less significant differences in ornithocomplexes are associated with altitudinal zonation and built-up areas. The main natural and anthropogenic factors and hierarchy of their significance for the spatial differentiation of bird communities are established. The regional specificity of the spatial organization of bird communities in Central Siberia as compared with the East European and West Siberian plains is determined.

Based on extensive information on the numbers and distribution of birds obtained during route surveys over the past 60 years, a classification of the bird communities of Central Siberia is considered at the level of its types. The specificity of this classification is determined by the predominance of latitudinal-zonal types over non-zonal ones. The main directions of territorial changes in the bird communities are determined by afforestation and watering, combined with latitudinal zonation. Less significant differences in ornithocomplexes are associated with the altitudinal zone and built-up area concerned. The main natural and anthropogenic factors and the hierarchy of their importance for the spatial differentiation of the bird populations have been established. The regional specificity of the spatial organization of the bird communities in Central Siberia in comparison with the Eastern European and West Siberian plains is reduced to the manifestation of high-altitude zonation due to differences in mountain-tundra ornithocomplexes, a greater differentiation of forest ornithocomplexes and less represented non-zonal population types.

According to the results of winter bird counts conducted in 70 habitats over 12 years, in the period from 1982 to 2002, a hierarchical classification and a structural similarity graph of ornithocomplexes in the southwestern plains of Western Siberia and Northern Kazakhstan have been compiled. The hierarchical classification contains three types and nine subtypes of the ornithocomplex. The similarity graph (the spatial-typological structure of the ornithocomplex) is built at the level of subtypes and is represented by three rows (trends). The first and most significant of these series is determined by the influence of urbanization; forest cover; and, in part, by the development of the reed layer. The second series of territorial changes in ornithocomplexes is associated with changes in the built-up area and anthropogenic fodder in residential habitats. The third row is formed under the influence of afforestation and overgrowth. The characteristics of ornithocomplex subtypes are compared which contain information on the three most numerous bird species (leaders in abundance), their share in the community, population density, and background species richness. Based on the assessment of the degree of coincidence of the similarity of ornithocomplexes and environmental factors, a hierarchy of the influence of the main anthropogenic and natural factors that determine the formation of the winter population of birds has been established. The regional specifics and seasonal changes in the significance of environmental factors in the formation of winter bird communities of the Tobol-Irtysh forest steppe and steppe have been established.

Based on the results of studies conducted over the past 50 years, the modern avifauna of the Aldan Highlands is established to consist of 198 species, of which 175 are breeding species, 19 are migratory species, and four are vagrants. The taxonomic, faunal, and landscape–zonal structures of avian complexes are revealed. In all, 166 nesting species are recorded in the forest belt; 60 species, in the mountainous sparse woodland; and 22, in the mountain tundra areas. More than half of the species that nest in the forest belt are not distributed above its upper limit. The avifauna of the mountain balds, mainly of the mountain tundra, is better represented by widespread and boreal hypo-arctic species than by alpine and arctic–alpine ones.

The results of bird counts averaged over the first half of summer (May 16 to July 15) from 1880 to 2019 have been analyzed to identify the spatial-typological structure and organization of the ornithocomplexes of Northern Eurasia (with interruptions, and mainly since 1960). A total of 354 researchers participated in the collection of material (over 110 years). Data processing is carried out using multivariate statistics methods, including cluster analysis and linear qualitative approximation of communication matrices. The main territorial trends in bird assemblages and environmental factors correlating with them are identified, and the relationship between the spatial variability of ornithocomplexes and the heterogeneity of habitats is assessed. The fractality of the spatial differentiation of the bird assemblageis shown.

The bird communities of one of the least surveyed regions of Yakutia, the Aldan Upland, was studied on the basis of long-term records. The most complete and detailed hierarchical classification of bird communities was compiled for the first time. The spatial and typological structure of the bird population is revealed, and the significance of environmental factors in the formation of ornithocomplexes is estimated. Regional features of the formation of ornithocomplexes are established.

The ecological patterns of landscape differentiation of the bird fauna and community of northern taiga in Central Siberia at altitudes of 100–1000 m a.s.l. have been analyzed. The flat left bank of the Lena River basin and low-mountain areas of the Putorana and Vilyui plateaus was surveyed in 2002–2020. The route census method was used on transects with an unlimited width. The degree of commonality of the taxonomic structure and species composition of nesting avifauna is high (156 species). A number of species (n = 14) have been recorded nesting at a distance of 100–250 km from the known boundaries of their ranges for the first time. The taxonomic structure of the nesting avifauna corresponds to the zonal and landscape features of the North Asian taiga, dominated by species of orders Passeriformes, Charadriiformes, Anseriformes, and Falconiformes (total 83

According to the results of bird counts carried out in 138 habitats over 12 years, a hierarchical classification and a structural graph of the similarity of ornithocomplexes in the plain southwestern part of Western Siberia and Northern Kazakhstan have been compiled in the period from 1982 till 2002. The hierarchical classification contains six types of bird populations. The similarity graph is built at the level of types and is represented by three rows (trends). One row consists of bird complexes of residential and recreational areas; the second, of wetlands; and the third, of forest, forest-field, and steppe habitats. The classification taxa characteristics contain information on the three most numerous bird species (leaders in abundance), their share in the community, population density, and the background species wealth. Based on the assessment of the similarity coincidence degree for the of bird communities and environmental factors, a hierarchy of the impact of the main anthropogenic and natural factors, determining the bird population formation, has been established.

The analysis of all data on the number and distribution of small mammals in Western Siberia over the past 120 years has established that 20 out of 28 species recorded in the northern taiga make up their communities. A similar structure of dominance is generally preserved in the small mammal communities of the northern taiga. The main dominant species, northern red-backed vole, Laxmann's shrew, and the common shrew, predominate almost everywhere. The other six codominant species (Eurasian pygmy shrew and tundra shrew and voles: root vole, common European field vole, European bank vole, and gray red-backed vole) dominate only in certain areas. The remaining 11 species, which are both widely and narrowly distributed, make up a small part of the communities. The increase in the species richness of communities to the east (from 15 to 19 species) is determined by the increase in the number of Siberian species. In general, in the studied area of the northern taiga, the largest contribution to small mammal communities is made by representatives of the Siberian fauna type, with the exception of the western part of the subzone, where European species predominate.

The results of bird route censuses, conducted on the territory of the Aldan Highland in the first half of summer and generally covering the period from 2000 to 2019, were analyzed. The total length of the routes was about 2815 km. A total of 116 initial variants of the bird population were used. Based on the results of multivariate factor analysis for 160 species registered in these censuses, a hierarchical classification of their preference for habitats was drawn up. The classification showed that 45 % of birds prefer forests, woodlands and burned areas, 26.2 % - water bodies and their banks, 13.8 % - bogs and meadows, 9.4 % - villages and cities, 5.6 % - mountain tundra. A comparative analysis with a similar classification for the Altai Highland has been performed. The main differences in the territorial distribution of bird species in the Aldan Highland and Altai lie in a smaller number of identified types of preferences in our region. Due to the homogeneity of forest biotopes and the absence of the steppe, forest-steppe, subnival, and nival zones in the Aldan Highland, the corresponding landscapes are not represented here, which determines the absence of the steppe, forest-meadow-steppe, meadow-bog, and subnival types. Similarly to Altai, the forest, tundra and synanthropic types of preference are distinguished in the Aldan Highland.

Population density, species richness, and total biomass of birds in Central Siberia increase toward the south. The greatest values are noted in terrestrial natural landscapes: for the total abundance of birds, they are in the southern forest type of communities; for species richness, they are in the meadow–field type; and for total biomass, they are in the subarctic plain–tundra type. In industrial–technogenic and southern residential types, the density and biomass of bird communities increase and the species richness decreases in comparison with natural ornithocomplexes. In aquatic habitats, the total abundance of birds and their species richness decrease and biomass increases when compared with terrestrial ones. The representation of types of fauna in bird communities (by number of individuals) is determined by the zones of their landscape preference, which have ecological similarity with the areas of their formation. Since birds actively choose tiers with the most favorable thermal, trophic, and protective conditions, their vertical biotopic distribution to some extent does not correspond to the tier structure of their habitats.

Materials collected in the flatland and highland parts of Western Siberia in the second half of the summer in 1954–2016 have been used to analyze the zonal and provincial aspects of the biotope distribution of the northern red-backed vole Myodes rutilus. The previously reported preference of the species for flatland and mountain forests with the contribution of dark coniferous tree species within the taiga zone of the plain, northeastern Altai, and Kuznetsk Alatau has been confirmed. Cluster analysis of the matrix of similarity coefficients of the abundance has been performed and used to classify northern red-backed vole habitats according to the optimality of environmental conditions (favorability) for this species. At the same time, this classification is a cluster arrangement of the abundance representations at the territory under consideration. Five types of conditions—optimal, suboptimal, subpessimal, pessimal, and extremal—have been identified, with the first type divided into two subtypes. The differences in northern red-backed vole abundance between habitat subtypes are less pronounced than the differences between the types. The classification and the structural graph reveal the dependence of abundance on a range of factors and regimens (inseparable combinations of factors). The factors for the entire Western Siberia are as follows: heat and water supply, macrorelief characteristics (plain or mountains), vegetation type, degree of afforestation, species composition of the tree stand in the forests, flooding during seasonal floods, waterlogging, ploughing, and the degree of area development. The zone-subzone differences affect the distribution of the species under consideration only on the plain, whereas provinciality and altitude zonation affect the distribution only in the mountains. The strongest correlation with northern red-backed vole distribution in Western Siberian habitats is observed for heat and water supply (zonality and subzonality on the plain and altitude zonation in the mountains). Our studies of the distribution of this vole refine the results of analysis performed by our predecessors and give a more detailed pattern of species distribution over the habitats.

The paper provides information on the population and fauna of birds of the least studied in this respect territory mountains of the eastern part of Southern Siberia. According to the results of modЕ.В. ШЕМЯКИН, Л.Г. ВАРТАПЕТОВ, АРК.П. ИСАЕВ 88 ПРИРОДНЫЕ РЕСУРСЫ АРКТИКИ И СУБАРКТИКИ, Т. 25, No3, 2018 ern information and literary sources, 193 species of birds were recorded in the territory of the Aldan Upland, of which 166 species were recorded as nesting species, the remaining species were encountered during the migration, it should be noted that during the study, random bird encounters were recorded, which were transferred to the list as migratory. As a result of research, the current composition of avifauna of the surveyed region is increased by 14 species, and nesting – by 19 species. During the research in the territory of the Aldan Upland, five new bird species were discovered (Pale-legged Leaf-warbler, Radde’s Warbler, Asian Brown Flycatcher, Grey-streaked Flycatcher, Barn Swallow). Probably, new information on the findings of these species of birds for the study area is due to the insufficient knowledge of the territory of the Aldan Upland in the past. The following rare species of birds are listed in the Red Data Book of the Russian Federation: Black Stork, Siberian Crane, Hooded Crane, Golden Eagle, Osprey, Peregrine Falcone, White-tailed Sea-eagle, Siberian Grouse, Far Eastern Curlew, Eurasian Eagle-owl and Great Grey Shrike.

Based on long-term route surveys, the bird population is studied in the least ornithologically investigated subzone of western Siberia, in the middle taiga all along its length from the Trans-Ural region to the Yenisei valley and in all types of landscapes. It is established that the species richness of the birds and the population density increase under replacement of dark coniferous species with small-leaved species, the impact of the floodplain regime and eutrophic swamping, and an increase in mosaicism and productivity of biocoenoses. It is noted that a decrease in the number of species and individuals in bird communities is associated with the replacement of dark coniferous small-leaved forests by pine forests or wooded mesotrophic and eutrophic bogs and then upland bogs. It is shown that the frequent trends of impoverishment of bird communities are determined by industrial and residential transformation of landscapes and the transition from land habitats to water ones.