All songbirds have their own species-specific song, and vocal variety among individuals of the same species is used for communication. Some aspects of vocal variety have been shown to relate to sender characteristics and thus to convey a potential message to receivers. During playback experiments, individuals show different response patterns, which provide evidence for perception, and thus meaning, of the vocal variety. Here, we tested the impact of two types of vocal variety: syllable diversity and syllable switching in the common chiffchaff, Phylloscopus collybita, in two separate playback experiments. We found that syllable diversity was a relatively fixed trait and that variation among individuals was likely to reflect some male quality triggering responses of different intensity. Higher rates of syllable switching did not elicit different responses but songs after playback showed that it is a dynamic trait, potentially contributing to motivational signalling together with other song parameters. The resolution of analyses in our experiments revealed subtle changes in vocal features over time in unprecedented detail. This approach unveiled an intricate combination of various vocal features during the response that may complement each other during vocal interactions. We believe future studies would benefit from the same resolution, through which one can explore advanced levels in animal communication.

中文翻译：

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普通chiffchaff音节多样性和音节转换交际价值的实验测试

所有鸣禽都有自己特定物种的歌声，同一物种个体之间的声音多样性被用于交流。声音多样性的某些方面已被证明与发送者的特征有关，因此可以向接收者传达潜在的信息。在回放实验中，个体表现出不同的反应模式，这为感知以及对声音变化的意义提供了证据。在这里，我们在两个独立的回放实验中测试了两种类型的声音变化的影响：普通 chiffchaff Phylloscopus collybita 中的音节多样性和音节切换。我们发现音节多样性是一个相对固定的特征，个体之间的差异可能反映了一些男性品质触发不同强度的反应。较高的音节切换率不会引起不同的反应，但播放后的歌曲表明这是一种动态特征，可能与其他歌曲参数一起有助于激励信号。我们实验中的分析分辨率以前所未有的细节揭示了声音特征随时间的微妙变化。这种方法揭示了在响应过程中各种声音特征的复杂组合，这些特征在声音交互过程中可能会相互补充。我们相信未来的研究将受益于相同的决议，通过它可以探索动物交流的高级水平。我们实验中的分析分辨率以前所未有的细节揭示了声音特征随时间的微妙变化。这种方法揭示了在响应过程中各种声音特征的复杂组合，这些特征在声音交互过程中可能会相互补充。我们相信未来的研究将受益于相同的决议，通过它可以探索动物交流的高级水平。我们实验中的分析分辨率以前所未有的细节揭示了声音特征随时间的微妙变化。这种方法揭示了在响应过程中各种声音特征的复杂组合，这些特征在声音交互过程中可能会相互补充。我们相信未来的研究将受益于相同的决议，通过它可以探索动物交流的高级水平。