Annual reproductive success relative to trill quality, male quality, and male mating success, with the effects that remained statistically significant after correction for multiple testing in bold.

Trill measures were the dependent variables, and reproductive success the independent variables, in mixed-effects models controlling for male identity, year, trill type, pitch, trill duration, and the time of the trill in the song. For male quality and mating success measures, reproductive success was the dependent variable, in mixed models controlling for year and male identity. For age, the effect estimate is the difference between second-year and after-second-year males, and the effect size is Cohen’s d. For continuous variables, effect estimates are the slope, and the effect size is partial r. Abbreviations: WP, within-pair. EP, extra-pair.