The birds of Pasvik / E. I. Khlebosolov, O. A. Makarova, O. A. Khlebosolova [et al. ; English transl. Nikita Chernetsov]. - Ryazan : Golosgubernii, 2007. - 175 с. : ил., портр.

A B C D Е -------------------------------------------------------------------- PhyllOSCOpUS trochillus i------------------------------------------------------- 1 Fringilla montifringilla i-------------------------------------------------------------------------------------- 1 Turdus iliacus i----------------------------- : Turdus torquatus i------------------------------------------------------------------------------------- нAcanthis flammea ------------------------------------------------------- 1 Anthus pratensis i-------------------------------------------------------------------- Cyanosylvia svecica i----------------------------------------------- Oenanthe oenanthe ------------------ 1 Motacilla alba Figure 2.12. A ltitudinal distribution o f common species o f passerines in Pasaritunturi m o u n ­ tains. A — foothill birch forest in the valleys; В —birch forest on the m ountain slope; С — the crooked birch forest; D —mountain tundra; E —bare rocks. In m oun tain birch forests vertical belts w ith different vegetation structure are strongly pronounced , and thus different bird population o c cu r there (Fig. 2.12). Some birds occur only in one belt, whereas others breed across several vertical belts. For instance, the Ring Ouzel only occurs in the lower belt o f the m oun tain birch forest along the valleys o f rivers, streams, and near the lakes. Willow Warblers breed in all the three belts o f the birch forest and are the most comm on birds there. This species practically does not penetrate into tund ra habitats, but may occu r in the scrub along the shores o f lakes in the closed depressions o f the m oun tain tundra. The Brambling breeds in the lower and m iddle belt o f th e birch forest. In the crooked birch forest the breeding density o f Bramblings is low, and in the m ountain 110