The differences in small birds-migrants patterns of distribution within taiga area (= non fragmented massifs of boreal forests): examples based on some model for south-east Siberia passerine species groups. Part 1

Under consideration are dynamic processes of small passerine birds-migrants eco-geography in breeding time, in particular the patterns of distribution of forest insectivorous species within complex non-fragmented massifs of boreal forests (= taiga). These patterns in some cases can be better explained in terms of «proximate factors», i.e. proper demands of bird sociality and psychology (the necessity and capabilities to form an integral local breeding community consisting of several pairs, = parcella ) rather than by trivial trophic interactions with the environment and competition between close species. Some species show diffuse patterns of taiga filling. Many of them are those who communicate «above forest» on the tops of high trees and have strong, far audible male’s song (i.e. Pallas’s Leaf Warbler, Mugimaki Flycather). Some others are distributed by isolated small parcellas (i.e. Tristram’s Bunting, Pale-legged Warbler, Siberian Flycather). The males of such species are weak singers and some sing not high above the ground. The breeding parcellas are often correlate in its disposition with particular signal land-marks (i.e. network of small taiga rivers, top-ridges of forested hills etc.) rather than with particular habitat as a floristic unit and trophic complex. The signal land-marks navigate the searching behavior of small groups of individuals on the final stage of spring migration and make able effective meeting of males and females (which often arrive at different terms) and formation of vocally integrated settlement. Some species seem to be distributed by isolated pairs (i.e. Blue-and-White Flycather, White-throated Rock Thrush) but the males possess very strong song and many of them possibly also support active communication between neighbors. The subtle peculiarities of distribution of the pairs of these species can be better understood at microhabitat scale. Under detailed discussion and comparison of distribution and «habitat preferences» in different parts of taiga range, from Sikhote-Alin mountainous region (= Ussuriland, Far East of Russia) west to Yenisei River and Altai Mountains, are such groups of small passerines as “forest buntings» (4 species of genera Ocyris and Cristemberiza ), leaf warblers (7 species of genus Phylloscopus ), flycatchers (6 species of genera Muscicapa, Ficedula, Cyanoptila ), robins (3 species of genera Luscinia and Tarsiger ) and thrushes (5 species of genera Turdus, Zoothera, Petrophila ); also the pairs Wren - Asian Stubtail and Ashy Minivet - White-eye. The important basic conclusion is that some highly abstract models and rules of “evolutionary ecology”, which do not take into consideration a possibility of active flexible behavioral interactions with environment and quick adaptive behavioral responses of small social groups of birds on the basis of highly developed perceptive psychology and sociality, can explain little in the dynamic phenomena and socio-behavioral mechanisms of recent avian eco-geography. Moreover, all intraspecific differentiation in birds, in particular passerine birds, seems to belong to the level of fleeting and flexible processes of social evolution (isolation of indistinguishable eco-species and socio-species), which are not identical in its mechanisms to phenomena of proper biological (morpho-genetical) evolution.