微小呼吸与类声带颤音喉部发声区缓解大守宫（Gekko gecko）求偶鸣叫的呼吸限制

文献信息

中文摘要

背景： 壁虎是少数使用声学信号进行领地防御、吸引配偶和发出痛苦信号的现生非鸟爬行动物之一。尽管此前被认为缺乏灵活性，雄性大守宫在嘈杂环境条件下会通过切换到更长、更响亮的鸣叫类型来表现出声音可塑性。然而，它们似乎面临限制更长持续时间鸣叫的呼吸约束。方法：为检验这一假设，我们将声学分析与基于深度学习的姿态估计相结合，以量化自发广告鸣叫期间的呼吸动力学。结果：鸣叫仅在呼气期间以恒定速率产生，支持呼吸约束限制鸣叫持续时间的假设。大守宫使用两种机制来增加双音鸣叫的持续时间。第一，双音鸣叫包含一个吸气性的“微小呼吸”——这一特征此前仅与鸣禽相关。第二，双音鸣叫持续时间通过添加末端脉冲而增加，其声学特征提示声带在空气高效的声带颤音发声区中振荡。这些发现表明，大守宫的广告鸣叫作为呼吸能力的诚实信号发挥作用。我们还观察到发声期间耳开口缓慢闭合，表明一种保护听觉系统免受自身产生响亮声音的机制。与鸟类和哺乳动物的反射性听觉衰减机制不同，这种反应似乎与发声-呼吸活动紧密协调，代表了与鼓膜听觉相关的额外进化创新。结论：

英文摘要

Geckos are among the few non-avian reptiles that use acoustic signals for territorial defence, mate attraction and distress signalling. Although previously considered inflexible, male tokay geckos exhibit vocal plasticity by switching to longer, louder call types in noisy environmental conditions. However, they seem to face respiratory constraints limiting longer duration calls. To test this hypothesis, we combined acoustic analysis with deep learning-based pose estimation to quantify respiratory dynamics during spontaneous advertisement calling. Calls were produced exclusively during expiration at a constant rate, supporting the hypothesis that respiratory constraints limit call duration. Tokays use two mechanisms to increase bi-note call duration. First, bi-notes contain an inspiratory 'mini-breath'-a feature previously associated only with songbirds. Second, bi-note duration is increased by adding terminal pulses, whose acoustic signatures suggest vocal fold oscillation in the air-efficient vocal fry register. These findings suggest that tokay advertisement calls function as honest signals of respiratory capacity. We also observed slow closure of the ear opening during vocalizations, indicating a mechanism for protecting the auditory system from self-generated loud sounds. Unlike the reflexive auditory attenuation mechanisms of birds and mammals, this response appears tightly coordinated with vocal-respiratory activity, representing an additional evolutionary innovation associated with tympanic hearing.