Shifts in hatch dates do not provide pied flycatchers with a rapid ontogenetic route to adjust offspring time schedules to climate change

1. Environments change rapidly, and it is unclear whether organisms with complex life-styles, such as avian migrants, are able to adjust sufficiently. For understanding human impacts on ecosystem functioning, it is crucial to understand how well, and by which mechanisms species are able to adapt.
2. To improve the understanding of migrants’ ability to adjust their annual timing to climate change, we investigated ontogenetic hatch date effects on adult spring migration timing and female egg laying dates. We experimentally delayed hatch dates of pied flycatchers Ficedula hypoleuca by one week in three breeding seasons by delaying incubation onset. We investigate if natural and experimental (shifts in) hatch date affected timing of recruiting individuals up to at least three years after the manipulation.
3. Spring arrival dates were positively correlated to natural variation in hatch dates in three of the five years considered, but no such effects were found in egg laying. Experiments sh...