A spring cold snap is followed by an extreme reproductive failure event in a mountain population of Pied Flycatchers Ficedula hypoleuca.

CapsuleVery low and anomalous temperatures in early spring of 2010 were followed by the only massive reproductive failure event recorded in 24 years in a population of Pied FlycatchersFicedula hypoleucabreeding at 1200 m altitude in central Spain. AimTo estimate the effects of an extreme climatic event on reproductive success in a montane population of a long-distance migratory bird. MethodsWe compared nestling growth and mortality in nests of different brood sizes in the context of a brood manipulation experiment. ResultsTotal failure affected 36% of the broods and only 2.5 nestlings on average were raised to fledging age. Most mortality affected broods in the second week of nestling life. Fledglings attained very low values for mass and wing length compared with long-term averages. Subsequent local recruitment was the lowest for any cohort in 24 years. The typical date-dependent decrease in breeding success in the population was inverted. ConclusionBreeding success was markedly affected by a weather event happening one month before hatching and lasting only a few days. An increased frequency of extreme weather events as predicted by some climate change scenarios may dramatically affect insectivorous avian populations in the future. [ABSTRACT FROM AUTHOR]