Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning, Guangxi, China.
Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Science, Menglun, Mengla, Yunnan, China.
Behav Processes. 2021 Apr;185:104345. doi: 10.1016/j.beproc.2021.104345. Epub 2021 Feb 2.
Although the contact calls of birds have been studied for their acoustic properties, limited research has investigated their repetitive nature. The rate of contact calls could be related to movement, with recruiting birds signalling their location, or it could help maintaining spacing between group mates, or give information about the environment where both signaller and receiver are located. If maintaining spacing, higher call rates would be expected in denser vegetation; alternatively, if birds gain information about predation risk from the cessation of contact calling, then open areas might elicit higher call rate. We studied how contact call rate in groups of Swinhoe's White-eyes (Zosterops simplex) was influenced by vegetation, collecting a total of 800 recordings. After statistically controlling for group size, the vegetation effect was weak and inconsistent. However, flying individuals produced a distinct flight call consisting of repeated notes similar to contact calls, and group-level contact call rate increased before flights, particularly when birds flew into the group. Therefore, we believe that contact call rate indicates information about individual or group movements, and could function as a continuous signal about the need for recruitment. We encourage further studies investigating how habitat, risk and audience influence contact call rate.
虽然鸟类的联络叫声已经因其声学特性而被研究，但对其重复性的研究却很有限。联络叫声的频率可能与运动有关，求偶鸟发出信号以告知其位置，或者有助于保持群体成员之间的距离，或者提供关于信号发出者和接收者所处环境的信息。如果是为了保持距离，那么在植被更密集的地方应该会有更高的叫声频率；或者，如果鸟类通过停止联络叫声来获得有关捕食风险的信息，那么开阔区域可能会引发更高的叫声频率。我们研究了蜂虎（Zosterops simplex）群体中联络叫声的频率如何受到植被的影响，共收集了 800 个录音。在对群体大小进行统计控制后，植被的影响很微弱且不一致。然而，飞行个体发出一种独特的飞行叫声，由重复的音符组成，类似于联络叫声，并且在飞行前，特别是当鸟类飞入群体时，群体级别的联络叫声频率会增加。因此，我们认为联络叫声的频率表明了个体或群体运动的信息，并且可能作为有关招募需求的连续信号。我们鼓励进一步研究如何通过栖息地、风险和观众来影响联络叫声的频率。
