Data from: Nest size is predicted by female identity and the local environment in the blue tit, but is not related to genetic or foster mother's nest size

The potential for animals to respond to changing climates has sparked interest in intraspecific variation in avian nest structure since this may influence nest microclimate and protect eggs and offspring from inclement weather. However, there have been relatively few large-scale attempts to examine variation in nests or the determinates of individual variation in nest structure within populations. Using a set of mostly pre-registered analyses, we studied potential predictors of variation in the size of a large sample (803) of blue tit (Cyanistes caeruleus) nests across three breeding seasons at Wytham Woods, UK. Whilst our pre-registered analyses found that individual females built very similar nests across years, there was no evidence in follow-up (post hoc) analyses that their nest size correlated to that of their genetic mother or, in a cross-fostering experiment, to the nest where they were reared. In further pre-registered analyses, spatial environmental variability explained nest size variability at relatively broad spatial scales, and especially strongly at the scale of individual nestboxes. Our study indicates that nest structure is a characteristic of individuals, but is not strongly heritable, indicating that it will not respond rapidly to selection. Explaining the within-individual and within-location repeatability we observed requires further study.

Usage Notes

Final blue tit nest size dataNest sizes recorded by SCG in Wytham Woods, UK 2001-2003. Nest sizes were recorded as fraction of standardised nest box filled. Blue tits were identified using uniquely marked metal rings to give identities. Zone is the woodland compartment in Wytham Woods where the nest is.Final BT nest data LON 2018-2-6.csvBlue tit nest sizes for genetic mother-daughter pairsNest sizes (recorded as fraction of standardised nest box filled) of blue tit daughters and their genetic mothers, as recorded by SCG in Wytham Woods, Oxfordshire, UK in 2001-2003genetic depth2.csvBlue tit nest sizes for foster mother-daughter pairs 2Nest sizes (recorded as fraction of standardised nest box filled) of daughters and their foster mothers, as recorded by SCG in Wytham Woods, UK during 2001-2003 breeding seasons. Rrearing depth2.csvFinal R code used for analysis 2The R code that I wrote to analyse different factors controlling the nest size of blue tits in Wytham Woods, UK during the 2001-2003 breeding seasons using the data files attachedFinal BT nest size analysis code.R