Social environments can shape animal communication. Although mutual courtship displays are generally thought to function in private communication between a male and a female, we provide experimental evidence that they work in a broader social context than previously thought. We examined the audience effect on mutual courtship in blue-capped cordon-bleus, a socially monogamous songbird. This species is characterized by conspicuous courtship shared between sexes: Both sexes sing songs and sometimes add a unique dance display that looks like human tap dancing. We found that in both sexes, multimodal courtship displays (song accompanied by dance) were promoted in the presence of an audience, especially if it was the opposite sex. In contrast, unimodal displays (song without dance) were suppressed by audiences. Because birds directed the courtship dancing toward their partners (but not the audience), multimodal courtship displays are likely meant to advertise their current mating status to other cordon-bleus.

中文翻译：

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情侣炫耀：观众在鸣禽中促进雄性和雌性多模式求爱展示。


社会环境可以塑造动物的交流。尽管相互求爱展示通常被认为在男性和女性之间的私人交流中起作用，但我们提供的实验证据表明，它们在比之前想象的更广泛的社会背景中发挥作用。我们研究了观众对蓝冠蓝冠鸟（一种社会性一夫一妻制鸣禽）相互求爱的影响。该物种的特点是两性之间有明显的求爱行为：两性都会唱歌，有时还会表演一种独特的舞蹈，看起来像人类的踢踏舞。我们发现，无论男女，都会在观众面前进行多模式求爱展示（歌曲伴舞），尤其是异性的情况下。相比之下，单峰表演（没有舞蹈的歌曲）则受到观众的压制。由于鸟类将求偶舞蹈引向它们的伴侣（而不是观众），因此多模式求爱表演可能是为了向其他蓝带鸟宣传它们当前的交配状态。