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The article summarizes 34 years (1980-2014) of the original observations of the genesis and evolution stages of the Caspian lagoons. A model of the formation and evolution of the coastal lagoons has been worked out. It can be applied to the modelling of the global geoecological scenario along all the world's coasts characterized by a steady transgression of their marine areas. The lagoons had been formed in a "bottleneck", a narrow migration corridor, traversed by the largest migration route of trans-Palearctic species in Russia. This route is part of the West Siberian-East African migration range. Year round bird censuses (n = 746) were taken by the author in 1995-2014 along two key routes in the regions of Turalinskaya and Sulakskaya lagoons of Daghestan (the western coast of the Middle Caspian Sea). The meridional orientation of lagoons, location of the migration trajectory and a wide range of habitats in the study area contribute to the preservation of 294 Eurasian bird species. After formation of the lagoons, the breeding avifauna of the Caspian Sea Region of Central Daghestan has added 32 taxa. Among the species recorded at the lagoons, 50 are included in the IUCN Red List, Red Data Books of Russia and Daghestan. The reconstruction analysis of the migration trajectory compiled according to the data of the Russian Bird Ringing Centre allowed us to determine the population distribution geography for the birds regularly migrating along the western coast of the Caspian Sea and refine borders of the West Siberian-East African migration range. Thus, according to the information received, the current migratory range should be greatly extended to cover the area from the British Isles in the West Palearctic to Lake Baikal in the east, including the extreme west and south of Africa.

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Aim. The paper summarizes the data on bird counts carried out in 1995–2018 in Piedmont Dagestan. Information on the following points was obtained for the first time: composition of bird species, their average abundance, residence status, faunal‐genetic structure, ecological pattern of the avifauna, as well as the features of territorial distribution of birds in Piedmont Dagestan.Methods. Bird counts were carried out on routes without limiting the transect width, with further separate recalculation per area according to the average detection ranges for groups. The faunal‐genetic structure was determined using a standard procedure. The ecological classification is based on the original differentiation of birds according to their occurrence in preferred habitats. The obtained data were processed using cluster, factor and correlation analyses.Results. Of 127 bird species recorded in Piedmont Dagestan, widespread representatives of European, European‐Chinese, Mediterranean, as well as Mongolian fauna predominate, which is associated with the availability of suitable habitats. In the course of cluster analysis, we identified three groups of key areas, reflecting the abundance‐based similarities between bird populations in the studied area. The constructed structural graph illustrates the spatial‐typological organization of the bird population in Piedmont Dagestan. It is established that the development of bird communities in the compared key areas has not only a similar but also distinctive ecological pattern, formed under the influence of such environmental factors as high‐altitude gradient, availability of warmth and water, forest area, rocky outcrops, as well as open areas and man‐made landscapes.Conclusion. The specific ecological pattern of the avifauna in Piedmont Dagestan was developed due to the contribution of both adapted populations of migratory birds of the plains, nesting in the foothills, and to that of the resident communities of typically mountain birds, whose qualitative and quantitative composition changes under the integrated influence of environmental regulatory factors.