Hauber Mark E, Moskát Csaba
Advanced Science Research Center and Programs in Biology and in Psychology, Graduate Center of the City University of New York, New York, NY, USA.
Natural History Museum, Budapest, Hungary.
Anim Cogn. 2025 Jun 5;28(1):45. doi: 10.1007/s10071-025-01966-x.
Acoustic communication in obligate brood parasitic common cuckoos (Cuculus canorus) plays an important role both in social contacts within its own and with other species (including its many hosts). For example, the female cuckoo's bubbling call putatively mimics the call of the Eurasian sparrowhawk (Accipiter nisus) to serve as defence from host songbirds mobbing the parasitic female. However, several other, both raptorial and harmless, sympatric bird species also have similar vocalizations to the bubbling call (including the Eurasian kestrel, Falco tinnunculus, and the Eurasian green woodpecker, Picus viridis). Bubbling calls are also used by female cuckoos for conspecific communication with male conspecifics and so the discrimination of acoustically similar con- vs. heterospecific calls should be functionally relevant for cuckoos. We expanded upon a published playback study with all the above species' calls presented to male cuckoos. The subjects approached the speaker in 100% when conspecific females' bubbling calls were played back, but rarely (6-12%) did so when either acoustically similar natural calls of sympatric species were used. However, as structurally the bubbling call has no harmonic overtones, but the calls of the other species contain them, we also conducted playbacks with manipulated sound files where the harmonics were removed. Harmonic-free heterospecific calls attracted male cuckoos more often (40-50%) than natural heterospecific calls but still less so than the natural conspecific call. These results reveal the functional importance of the presence of harmonical overtones in heterospecific calls as they can serve to reduce perceptual auditory errors in male cuckoos.
obligate brood parasitic common cuckoos (Cuculus canorus) 的声学通讯在其自身物种内部以及与其他物种（包括其众多宿主）的社交接触中都起着重要作用。例如，雌性杜鹃的咕咕叫声据称模仿了欧亚雀鹰（Accipiter nisus）的叫声，以此来抵御宿主鸣禽对寄生雌性的围攻。然而，其他几种同域分布的鸟类，包括猛禽和无害鸟类，也有与咕咕叫声相似的发声（包括欧亚红隼，Falco tinnunculus，以及欧亚绿啄木鸟，Picus viridis）。雌性杜鹃也会用咕咕叫声与同种雄性进行同种通讯，因此，区分声学上相似的同种与异种叫声对杜鹃来说在功能上应该是相关的。我们扩展了一项已发表的回放研究，向雄性杜鹃播放上述所有物种的叫声。当回放同种雌性的咕咕叫声时，受试雄性杜鹃100%会靠近扬声器，但当使用同域物种声学上相似的自然叫声时，它们很少（6 - 12%）会这样做。然而，由于咕咕叫声在结构上没有谐波泛音，而其他物种的叫声含有谐波泛音，我们还对声音文件进行了处理，去除谐波后进行回放。无谐波的异种叫声比自然异种叫声更常吸引雄性杜鹃（40 - 50%），但仍比自然同种叫声吸引雄性杜鹃的频率低。这些结果揭示了异种叫声中谐波泛音存在的功能重要性，因为它们可以减少雄性杜鹃在听觉感知上的错误。
