ИСТИНА

We considered monogamy, polygamy and extra-pair paternity in the Pied Flycatcher as different reproductive strategies and analysed the effect of their interaction in the population breeding near Moscow. The proportion of broods with extra-pair chicks reached 28.6%. The proportion of extra-pair chicks was 12.6% among all chicks. Both values were close to the maximal representative values reported for other European populations of this species. The number of genetic fathers per brood varied from one to three. The proportion of broods with extra-pair chicks was not influenced by breeding dates. We tested the hypothesis according to which bigamous males had more chances to be cuckolded, especially in their first broods. Monitoring of local population revealed about 5% of potentially bigamous males which were observed as social parents of two broods per breeding season. On average, these birds were older and had more conspicuous plumage than other males. The proportion of broods with extra-pair chicks tended to be higher in broods of bigamous males in comparison with monogamous ones. Among broods of bigamous males, the proportion of extra-pair chicks was higher in first broods than in second broods. These results, although preliminary, support the idea that cuckoldry can be the cost of polygamous strategy in Pied Flycatcher males.