Budka Michał, Deoniziak Krzysztof, Tumiel Tomasz, Woźna Joanna Teresa
Department of Behavioural Ecology, Faculty of Biology, Adam Mickiewicz University, Poznan, Poland.
Laboratory of Insect Evolutionary Biology and Ecology, Institute of Biology, University of Bialystok, Bialystok, Poland.
PLoS One. 2018 Feb 7;13(2):e0191716. doi: 10.1371/journal.pone.0191716. eCollection 2018.
Animals-including conservation biologists-use acoustic signals to recognise and track individuals. The majority of research on this phenomenon has focused on sounds generated by vocal organs (e.g., larynx or syrinx). However, animals also produce sounds using other parts of the body, such as the wings, tail, legs, or bill. In this study we focused on non-syrinx vocalisation of the great spotted woodpecker, called drumming. Drumming consists of strokes of a bill on a tree in short, repeated series, and is performed by both males and females to attract mates and deter rivals. Here, we considered whether the great spotted woodpecker's drumming patterns are sex-specific and whether they enable individual identification. We recorded drumming of 41 great spotted woodpeckers (26 males, 9 females, 6 unsexed). An automatic method was used to measure the intervals between succeeding strokes and to count strokes within a drumming roll. The temporal parameters of drumming that were analysed here had lower within- than between-individual coefficients of variation. Discriminant function analyses correctly assigned 70-88% of rolls to the originating individual, but this depended on whether all individuals were analysed together or split into males and females. We found slight, but significant, differences between males and females in the length of intervals between strokes-males drummed faster than females-but no difference in the number of strokes within a roll. Our study revealed that temporal patterns of drumming in the great spotted woodpecker cannot be used for unambiguous sex determination. Instead, discrimination among individuals may be possible based on the intervals between strokes and the number of strokes within a roll. Therefore, it is possible that differences in the temporal parameters of drumming may be used by birds to identify each other, as well as by researchers to aid in census and monitoring tasks.
包括保护生物学家在内的动物会使用声学信号来识别和追踪个体。关于这一现象的大多数研究都集中在发声器官（如喉部或鸣管）发出的声音上。然而，动物也会用身体的其他部位发出声音，比如翅膀、尾巴、腿或喙。在本研究中，我们聚焦于大斑啄木鸟的非鸣管发声，即啄木声。啄木声由喙在树上短促、重复地敲击组成，雄性和雌性都会发出啄木声来吸引配偶和威慑对手。在此，我们探讨了大斑啄木鸟的啄木模式是否具有性别特异性，以及它们是否能够用于个体识别。我们记录了41只大斑啄木鸟（26只雄性、9只雌性、6只未区分性别的）的啄木声。使用一种自动方法来测量连续敲击之间的间隔，并统计一次啄木声中的敲击次数。此处分析的啄木声的时间参数在个体内部的变异系数低于个体之间的变异系数。判别函数分析正确地将70 - 88%的啄木声归属于发出该声音的个体，但这取决于所有个体是一起分析还是分为雄性和雌性分别分析。我们发现雄性和雌性在敲击间隔长度上存在细微但显著的差异——雄性啄木速度比雌性快——但在一次啄木声中的敲击次数上没有差异。我们的研究表明，大斑啄木鸟啄木声的时间模式不能用于明确的性别判定。相反，基于敲击间隔和一次啄木声中的敲击次数，有可能对个体进行区分。因此，鸟类可能利用啄木声时间参数的差异来相互识别，研究人员也可以借助这些差异来辅助进行普查和监测工作。
