ИСТИНА

Extra-pair paternity in the Pied Flycatcher is a common phenomenon in the Moscow region and other parts of species’ range. We investigated the relation between EPP and parental care. We estimated feeding rate of parents, which reared 9-13-days chicks, and the number and the size of preys in each delivered food portion. The proportion of broods reared by single females was 8%. Beside single females and paired social parents, regular helpers and few of occasional visitors also took part in the rearing of young. These helpers and visitors had no genetic offspring in nest-boxes, where they were observed. The proportion of broods with extra-pair chicks was higher in the nestboxes of single females in comparison with other nests. The reasons of this phenomenon as well as the peculiarities of parental behaviour of pairs with extra-pair chicks are discussed.