Description of the fixed effects and model types used to analyse each reproductive parameter.

<p>Fixed effects (in order of appearance in table). trt  =  treatment (fed or control), HD  =  standardized hatching date of earliest brood for that individual or pair, yr  =  year, maleage  =  male age (young (yearling) or old (2+)), chicks  =  number of nestlings alive at time of measurement, chickage  =  age of chicks (7 or 8 days old), found  =  standardized date nest found. Male ID/Female ID  =  individual identity of male/female. GLMM  =  Generalized linear mixed model fit by maximum likelihood, GLM  =  General linear model, LME  =  Linear mixed model fit by maximum likelihood.</p><p>Description of the fixed effects and model types used to analyse each reproductive parameter.</p

Model-averaged parameter estimates (estimates of fixed effects included in models with ΔAICc<i>_i</i> ≤2 with contributions to average weighted by <i>w</i>AICc<i>_i</i> of model), unconditional standard errors and 95% confidence intervals.

<p>Interactions are indicated by x.</p><p>Hatching date (1 =  1^st May) and date found (date nest discovered; 1 =  1^st May) were standardized before being input in models as fixed factors.</p><p>Model-averaged parameter estimates (estimates of fixed effects included in models with ΔAICc<i>_i</i> ≤2 with contributions to average weighted by <i>w</i>AICc<i>_i</i> of model), unconditional standard errors and 95% confidence intervals.</p

The effect of food supplementation on chick wing length.

<p>Variation in wing length (mean ±95% confidence limits) in relation to age for fed and control chicks in 2009 and 2010.</p

Appendix A. Two tables of competing model structures of detection probability (p) of adult and first-year wheatears.

Two tables of competing model structures of detection probability (p) of adult and first-year wheatears

Correlation matrix of reproductive parameters investigated in this study.

<p>Values are Pearson's correlation coefficients between pairs of reproductive parameters per territory per year, with male identity used to represent territory.</p><p>HD  =  hatching date of first clutch, Clutch size  =  number of eggs in first clutch, Egg size  =  mean egg volume per first clutch, Hatched eggs  =  number of eggs in first clutch that hatched, Chick wing  =  mean maximum wing chord of chicks per nest, First fledglings  =  Number of young that fledged from first nesting attempts, Attempts  =  number of breeding attempts per male per season, Fledglings per season  =  number of young fledged per male per season.</p><p>Correlation matrix of reproductive parameters investigated in this study.</p

Appendix B. Two tables of model averaged survival estimates of adult and first-year wheatears.

Two tables of model averaged survival estimates of adult and first-year wheatears

Distribution of dates of hatching of first clutches in 2009 and 2010 according to treatment.

<p>Density estimation curves shown to aid interpretation (solid  =  fed, dashed  =  control).</p