До гніздової біології дрозда-омелюха Turdus viscivorus L. i дрозда білобрового Turdus iliacus L. у Західному Поліссі

Abstract

The article highlight sissues breeding biology of rarespecies and scous thrushes –Mistle Thrush and Redwing in Western Polissia. Oological, nidological performance, character distribution of Mistle Thrush and Redwing were analysed. The changes in body weightan dincrease the length of itsparts in postembryonic development of Mistle Thrush were studied. It is shown that the biotype allocation, peculiarities of nestling, nidological and oological indices of Mistle Thrush and Redwing ( Turdus iliacus ) from the territory of Western Polissia don’t essentially differ from those from the other territories. Preliminary data as for presence of directly-proportional dependence between the likeness in nest building and geographical distance between thrushes’ populations have been received. It is ascertained that in postembryonal development of Mistle Thrush and other kinds of Thrushes [3, 12] correlation of different parts of body and organs by definitiveness and rates of growth depends on their functional role in the organism at different stages of development. In the moment of hatch of chicks of Mistle Thrush the most developed are its head and axial skeleton, the least developed are – elements of foot and wings. At the moment of leaving the nest (14 th day), elements of the wing were formed for 93–99 %, elements of foot – for 97.3–99.5 %. Keywords : thrushes, nesting biology, postembryonic development, Western Polissia.