Hatching asynchrony has been recorded in many altricial bird species. Also, more than 70% of clutches of the Red-breasted Flycatcher hatched asynchronously. The annual variation in the proportion of asynchronous clutches depended on median dates of egg laying, in the years when females started egg laying later more asynchronous clutches were observed. The females from synchronous clutches started egg laying significantly earlier than females from asynchronous clutches and were more synchronised with the peak of caterpilars. No differences in clutch size and number of fledglings between asynchronous and synchronous clutches were found. The frequency of females that started incubation earlier showed no significant difference when mated with either after-2nd-year or 2nd-year males. Also, breeding success was not significantly different between broods of various hatching types and was 87% for asynchronous clutches and 94% for synchronous clutches. The time of breeding and high predation pressure could be main reasons for females of the Red-breasted Flycatcher to start incubation before laying the last egg of its clutch.
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