Department of Zoology, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502, Japan.
Proc Biol Sci. 2010 Apr 22;277(1685):1275-80. doi: 10.1098/rspb.2009.2047. Epub 2009 Dec 23.
Prey animals can reduce their risk of predation by detecting potential predators before encounters occur. Some animals gain information about nearby predators by eavesdropping on heterospecific alarm calls. Despite having well-developed ears, most lizards do not use vocal information for intraspecific communication, and few studies have shown practical use of the ears in wild lizards. Here, we show that the Madagascan spiny-tailed iguana (Oplurus cuvieri cuvieri) obtains auditory signals for predator detection. The Madagascan spiny-tailed iguana and the Madagascar paradise flycatcher (Terpsiphone mutata) are syntopic inhabitants of the Ampijoroa dry deciduous forest of Madagascar. The iguana and the flycatcher have neither a predator-prey relationship nor resource competition, but they have shared predators such as raptors and snakes. Using playback experiments, we demonstrated that the iguana discriminates mobbing alarm calls of the flycatcher from its songs and then enhances its vigilance behaviour. Our results demonstrate the occurrence of an asymmetrical ecological relationship between the Madagascan spiny-tailed iguana and the paradise flycatcher through eavesdropping on information about the presence of predators. This implies that indirect interspecific interactions through information recognition may be more common than generally thought in an animal community.
被捕食动物可以通过在遭遇潜在捕食者之前检测到它们，从而降低被捕食的风险。一些动物通过偷听同种异体的警报声来获取有关附近捕食者的信息。尽管大多数蜥蜴的耳朵发育良好，但它们并不将声音信息用于种内交流，而且很少有研究表明蜥蜴在野外会实际使用耳朵。在这里，我们表明马达加斯加刺尾鬣蜥（Oplurus cuvieri cuvieri）可以通过听觉信号来探测捕食者。马达加斯加刺尾鬣蜥和马达加斯加天堂鸟（Terpsiphone mutata）是马达加斯加 Ampijoroa 干燥落叶林中的同域居民。鬣蜥和天堂鸟之间既没有捕食者-猎物关系，也没有资源竞争，但它们有共同的捕食者，如猛禽和蛇。通过播放实验，我们证明了鬣蜥可以区分天堂鸟的警报声和其歌声，然后增强其警戒行为。我们的结果表明，通过偷听关于捕食者存在的信息，马达加斯加刺尾鬣蜥和天堂鸟之间存在着一种不对称的生态关系。这意味着通过信息识别产生的间接种间相互作用可能比人们普遍认为的在动物群落中更为普遍。
