Paired comparisons of song and male quality measures for extra-pair (EP) males and the within-pair (WP) males they cuckolded; no effect was statistically significant after correcting for multiple testing.

For song variables, I constructed a mixed model with role (EP vs. WP) as a fixed effect; year, trill type, pitch, trill duration, and timing of the trill within the song as fixed covariates; and male identity and group as random effects. Means for the trill measures are least squares means, and consistency scores are back-transformed. All other tests were paired t-tests. Mean for each group and the effect size (Cohen’s d) for the difference is given.*2300 observations were included (for males present in more than one comparison per year, all trills measured for that male in that year were included multiple times).

针对鸣声变量，本研究构建了混合效应模型：以角色（EP vs. WP）作为固定效应，以年份、颤音类型、音高、颤音时长以及歌曲内颤音出现时机作为固定协变量，并将雄性个体身份与群体作为随机效应。颤音测量指标的均值为最小二乘均值（least squares means），一致性得分经反变换得到。其余所有检验均采用配对t检验。本研究同时给出了各组的均值以及组间差异的效应量（科恩d值，Cohen’s d）。*共纳入2300条观测数据（对于每年参与多次对比的雄性个体，该年度内该个体所有被测颤音均被多次纳入分析）。