Environmental variables potentially affecting selection on egg-laying date in the pied flycatcher.

We tested the effect of the interaction of the following environmental variables with (centred) egg-laying date on reproductive success: (1) weather variables during the breeding season, calculated for two periods: nestling period and the first weeks after fledging, (2) caterpillar biomass during the breeding season, both the timing relative to the birds’ egg-laying date and the amount of caterpillar biomass (1993–2010 only), and (3) weather variables when the fledglings recruit into the breeding population: the minimum temperatures, averaged for one and two years after fledging, during the females’ “arrival period” (see main text). Estimates from multivariate generalised linear mixed models (GLMMs) with year and female identity as random effects and Poisson or Binomial error distribution and corresponding link-functions. Significant p-values are given in bold. The number of fledglings cannot be affected by environmental variables that occur after fledging so these were not tested (n/a in the Table).Environmental variables potentially affecting selection on egg-laying date in the pied flycatcher.