Colourful traits in females are suggested to have evolved and be maintained by sexual selection. Although several studies have evaluated this idea, support is still equivocal. Evidence has been compiled in reviews, and a handful of quantitative syntheses has explored cumulative support for the link between condition and specific colour traits in males and females. However, understanding the potential function of females' colourful traits in sexual communication has not been the primary focus of any of those previous studies. Here, using a meta-analytic approach, we find that evidence from empirical studies in birds supports the idea that colourful female ornaments are positively associated with residual mass and immune response, clutch size and male-mate preferences. Hence, colourful traits in female birds likely evolved and are maintained by sexual selection as condition-dependent signals.

雌性的多彩特征被认为是通过性选择进化并维持的。尽管有几项研究评估了这一想法，但支持仍然模棱两可。评论中已经收集了证据，并且一些定量综合已经探索了对男性和女性的状况与特定颜色特征之间联系的累积支持。然而，了解女性丰富多彩的特征在性交流中的潜在功能并不是以前任何研究的主要焦点。在这里，我们使用荟萃分析方法发现，来自鸟类的实证研究证据支持这样的观点，即色彩缤纷的雌性装饰品与残余质量和免疫反应、窝数和雄性择偶偏好呈正相关。因此，雌鸟的多彩特征很可能是通过性选择作为条件依赖性信号而进化和维持的。