Fit for a family: Prenatal adjustments and post-natal consequences of family size in a wild bird [dataset]

Data associated to the statistical analyses described in the scientific article titled "Fit for a family: Prenatal adjustments and post-natal consequences of family size in a wild bird " (to be published). In this study, blue tit nestlings were crossfostered between nests of similar and different family size to test the effect of matching/mismatching prenatal (original family size) and postnatal (foster family size) environments on their behaviour. For this, we determined their stress reactivity at day 8 of age with a handling stress test (breathing rate) and a tonic immobility test, and, at day 13, recorded the interactions within the nest to characterize their competitive (begging intensity) and social (weighted degree) behaviour. Additionally, we also registered body mass growth.