Abstract Despite their large vocal repertoires and otherwise highly versatile singing style, male mockingbirds (Mimus spp.) sometimes sing in a highly repetitive fashion. We conducted a playback experiment to determine the possible signal value of different syllable-presentation patterns during simulated male intrusions in the Tropical Mockingbird (Mimus gilvus), testing the hypothesis that more repetitive singing represents a stronger threat and generates a stronger aggressive response. Responses were measured in terms of approach and singing behavior and were analyzed using McGregor’s (1992) multivariate method. We also introduce the use of survival analysis for analyzing response variables for which subjects do not perform the behavior in question in at least one of the replicates (known as “right-censored variables” in the statistical literature). As predicted by theory, experimental subjects responded more aggressively to songs composed of a single note than to variable ones. However, versatility at the between-song level had an opposite effect: high song-switching rates generated stronger responses than low ones. Given the lack of a statistical interaction between within-song versatility and switching rate, we conclude that these two parameters may serve independent purposes and possibly transmit different information. We discuss the possibility that the signal value of variation in vocal versatility lies in the mediation of territorial conflicts, the attraction of female partners, the mediation of conflicts over access to reproductive females, or some combination of these functions. Respuestas de Machos de Mimus gilvus a Variación en Versatilidad Vocal Dentro- y Entre-cantos

中文翻译：

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雄性热带知更鸟 (MIMUS GILVUS) 对歌曲内和歌曲间多样性变化的反应

摘要 尽管雄性知更鸟 (Mimus spp.) 的歌唱曲目丰富且具有其他方面的高度通用性，但它们有时会以高度重复的方式唱歌。我们进行了一项回放实验，以确定在模拟雄性模仿热带知更鸟 (Mimus gilvus) 期间不同音节呈现模式的可能信号值，测试更重复的歌唱代表更强威胁并产生更强攻击性反应的假设。响应根据方法和歌唱行为进行测量，并使用 McGregor (1992) 的多变量方法进行分析。我们还介绍了使用生存分析来分析受试者在至少一个重复中没有执行相关行为的响应变量（在统计文献中称为“右删失变量”）。正如理论所预测的那样，实验对象对由单个音符组成的歌曲的反应比对可变音符的反应更积极。然而，歌曲之间的多功能性产生了相反的效果：高歌曲切换率比低歌曲转换率产生更强的反应。鉴于歌曲内多功能性和切换率之间缺乏统计交互，我们得出结论，这两个参数可能用于独立的目的，并可能传输不同的信息。我们讨论了声音多样性变化的信号价值在于调解领土冲突的可能性，女性伴侣的吸引力，调解获得生殖女性的冲突，或这些功能的某种组合。Respuestas de Machos de Mimus gilvus a Variación en Versatilidad Vocal Dentro- y Entre-cantos