ABSTRACT Capsule: Two distinct song types were identified for male European Nightjars Caprimulgus europaeus with their relative frequency of use changing through the breeding season, indicating a possible link to paired status. Aims: To test whether two song types could be defined in audio recordings and whether use differed in relation to the paired status of males. Methods: Unattended acoustic recording devices were placed at a Nightjar study site in Nottinghamshire, United Kingdom, and recordings of churring vocalizations were made during two periods of the breeding season. These recordings were then analyzed to identify the presence/absence of the song terminal phrase and associated audible features. Results: Two distinct song types were identified in the recorded audio data that differed in their terminal phrasing and overall song duration. The number of Nightjar songs with a terminal phrase increased significantly between the two sampling periods, from lower levels during the site arrival period, to higher levels during the first clutch initiation period. Conclusion: This study showed that the use of Nightjar song types appears to vary through the breeding season, with males being more likely to produce song with a terminal phrase during the first clutch initiation period, when they are more likely to be paired or in the presence of a female. The unattended acoustic recording method may provide a minimally intrusive means of assessing the number of Nightjar breeding pairs and not just singing males.

中文翻译：

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欧洲 Nightjar Caprimulgus europaeus 中不同歌曲类型的鉴定

摘要胶囊：雄性欧洲夜鹰 Caprimulgus europaeus 确定了两种不同的歌曲类型，它们的相对使用频率在整个繁殖季节发生变化，表明可能与配对状态有关。目的：测试是否可以在录音中定义两种歌曲类型，以及使用是否因男性的配对状态而异。方法：无人值守的录音设备放置在英国诺丁汉郡的 Nightjar 研究地点，并在繁殖季节的两个时期录制了嗡嗡声。然后分析这些录音以识别歌曲终端短语的存在/不存在和相关的可听特征。结果：在录制的音频数据中识别出两种不同的歌曲类型，它们的终端短语和整体歌曲持续时间不同。从站点到达期间的较低水平到第一个离合器启动期间的较高水平，在两个采样周期之间，具有终结短语的 Nightjar 歌曲数量显着增加。结论：这项研究表明，夜鹰歌曲类型的使用似乎在整个繁殖季节有所不同，雄性更有可能在第一个离合开始阶段发出带有终止短语的歌曲，当它们更有可能配对或处于女性的存在。无人值守的声学记录方法可以提供一种评估夜鹰繁殖对数量的最低限度的干扰手段，而不仅仅是唱歌的雄性。在第一次离合器启动期间达到更高的水平。结论：这项研究表明，夜鹰歌曲类型的使用似乎在整个繁殖季节有所不同，雄性更有可能在第一个离合开始阶段发出带有终止短语的歌曲，当它们更有可能配对或处于女性的存在。无人值守的声学记录方法可以提供一种评估夜鹰繁殖对数量的最低限度的干扰手段，而不仅仅是唱歌的雄性。在第一次离合器启动期间达到更高的水平。结论：这项研究表明，夜鹰歌曲类型的使用似乎在整个繁殖季节有所不同，雄性更有可能在第一个离合开始阶段发出带有终止短语的歌曲，当它们更有可能配对或处于女性的存在。无人值守的声学记录方法可以提供一种评估夜鹰繁殖对数量的最低限度的干扰手段，而不仅仅是唱歌的雄性。