Aix galericulata Grus japonensis

         Birds became one more object for the research of biodiversity integral factors in the Far-Eastern ecoregion. Since birds are highly mobile species, the presence of migrating, wintering birds or accidental birds of passage in the analysis can be considered as "noise". Therefore, the present study assessed abundance of nesting birds only, 317 species of which are known in the Far-Eastern ecoregion. It has been found that species abundance of birds depends upon zonality and macroclimatic factors to a very slight extent. Within the bounds of the Far-Eastern ecoregion the centers of the highest abundance of ornithological fauna are located in the less afforested and swamped river and lake plains of Middle Amur Lowland, Tumangan River delta, lower reaches of Amgun river, Khankaisk-Razdolninsky and Zeya-Bureya plains.
         As temporal and seasonal components play an important role within the structure of ornithological fauna, well-being of the regional diversity of birds depends to a considerable extent on the environmental quality of the areas where part of their life cycle passes.