The capacity to learn novel vocalizations has evolved convergently in a wide range of species. Courtship songs of male birds or whales are often treated as prototypical examples, implying a sexually selected context for the evolution of this ability. However, functions of learned vocalizations in different species are far more diverse than courtship, spanning a range of socio-positive contexts from individual identification, social cohesion, or advertising pair bonds, as well as agonistic contexts such as territorial defence, deceptive alarm calling or luring prey. Here, we survey the diverse usages and proposed functions of learned novel signals, to build a framework for considering the evolution of vocal learning capacities that extends beyond sexual selection. For each function that can be identified for learned signals, we provide examples of species using unlearned signals to accomplish the same goals. We use such comparisons to generate hypotheses concerning when vocal learning is adaptive, given a particular suite of socio-ecological traits. Finally, we identify areas of uncertainty where improved understanding would allow us to better test these hypotheses. Considering the broad range of potential functions of vocal learning will yield a richer appreciation of its evolution than a narrow focus on a few prototypical species.

This article is part of the theme issue ‘Vocal learning in animals and humans’.

学习新发声的能力已经在广泛的物种中趋同进化。雄性鸟类或鲸鱼的求爱歌曲通常被视为典型例子，暗示了这种能力进化的性选择背景。然而，不同物种学习发声的功能远比求爱多样化，涵盖了从个体认同、社会凝聚力或广告配对债券等一系列积极的社会背景，以及领土防御、欺骗性警报或引诱猎物。在这里，我们调查了学习到的新信号的不同用途和提议的功能，以建立一个框架来考虑超越性选择的声音学习能力的演变。对于可以为学习信号识别的每个函数，我们提供了使用未学习信号来实现相同目标的物种示例。考虑到一组特定的社会生态特征，我们使用这样的比较来产生关于声乐学习何时具有适应性的假设。最后，我们确定了不确定的领域，在这些领域中，改进的理解将使我们能够更好地检验这些假设。考虑到声乐学习的广泛潜在功能，将比狭隘地关注少数原型物种更深入地了解其进化。

这篇文章是主题问题“动物和人类的声乐学习”的一部分。