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.

3 .1 .6 . Redwing, Fieldfare, and Song Thrush Several thrush species occur in Pasvik, but only one of them, the Redwing, is com­ mon. This species breeds at high density and occurs in nearly all forest habitats of Pasvik. The two other species are uncommon and occur locally in certain habitats. Thrushes mainly feed on the ground, and the character o f their ecological niche is to a large extent defined by ground vegetation structure. Spatial distribution o f thrushes is governed by their foraging behaviour and the selection of specific feeding substrates with characteristic structure or soil, ground layer or herbs. The most characteristic feature of the foraging behaviour of thrushes is that they pick invertebrates from the ground. Redwings occur in forest habitats with ground layer mainly composed o f moss and lichens (Fig. 3.21). Such habitats are very common in Pasvik. This is the rea­ son behind the high numbers and broad biotopic distribution of Redwings. Redwing’s typical species-specific feature is that it prefers to forage in the areas with sufficiently soft, well moistened soil. The main feeding substrate of this species in Pasvik is the ground cover o f moss and lichens that resembles soft soil by its prop­ erties and allows Redwings to forage by their typical method. When foraging, the bird makes series o f hops, stops to look for prey or its potential position and makes several aimed picks, extracting food from the soil or the moss and lichen ground cover (Fig. 3.22). When feeding, the bird moves rather quickly, relatively seldom Figure 3.21. Spatial distribution o f the three thrush species in the forest ecosystems o f Pasvik. S.L. Eliseev The Redwing is the most common thrush in Pasvik. 141