BTReactionNormAnalysis

Dataset contains blue tit (Cyanistes caeruleus) breeding and oak (Quercus) budburst phenology obtained from a wild population in southern UK, 2002-2019. Nest boxes were examined every year in the breeding season and data recorded include laying date, clutch size, female ID, and number of 7-day-old chicks in the brood. Oak budburst dates associated with a brood record were obtained from trees surrounding a nest box by summarizing the mean dates at which trees reach budburst stages 1(budburst) to 6(fully tanninized). All dates were recorded as April Days (0 = 1st Apr). Z-scores represent annually standardized values.R script details statistical analyses to estimate among-individual variance in laying date-budburst reaction norm, and clutch size-laying date reaction norm, as well as selection pressures on these reaction norms.