Introductory gestures before songbird vocal displays are shaped by learning and biological predispositions

Numerous animal displays begin with introductory gestures. For example, lizards start their head-bobbing displays with introductory push-ups and many songbirds begin their vocal displays by repeating introductory notes (INs) before producing their learned song. Among songbirds, the acoustic structure and the number of INs produced before song vary considerably between individuals in a species. While similar variation in songs between individuals is a result of learning, whether variation in INs are also due to learning remains poorly understood. Here, using natural and experimental tutoring with male zebra finches, we show that mean IN number and IN acoustic structure are learned from a tutor. Interestingly, IN properties and how well INs were learned, was not correlated with the accuracy of song imitation and only weakly correlated with some features of songs that followed. Finally, birds artificially tutored with songs lacking INs still repeated vocalizations that resembled INs, befor...众多动物的展示行为均以预备手势作为起始环节。例如，蜥蜴的头部摆动展示会以预备性俯卧撑动作开启，而多数鸣禽在发出习得鸣唱前，会通过重复预备音符（Introductory Notes，INs）来开启其鸣唱展示。在同一鸣禽物种中，不同个体间鸣唱前产出的INs的声学结构与数量均存在显著差异。尽管鸣唱个体间的鸣唱差异源于学习过程，但INs的差异是否同样由学习所致，目前仍尚不明确。本研究以雄性斑胸草雀为对象，结合自然育幼与实验性教导范式，证实其鸣唱前的INs平均数量与声学结构均源于对亲代导师的学习。有趣的是，INs的各项属性及其学习效果，与鸣唱模仿的准确率并无关联，仅与后续鸣唱的部分特征存在微弱相关性。最后，经人工播放不含INs的鸣唱进行教导的斑胸草雀，仍会在……前重复发出类似INs的鸣叫声。