Further range expansion of invasive animal species can be prevented by controlling their behavior. Acoustic repellent is a promising approach to deter problematic animals from ecologically sensitive areas. To develop an acoustic repellent system for a green anole that was introduced to the Ogasawara islands in Japan, this study evaluated the deterrent effect of (1) a pattern sound of machine noise and (2) a mixture of artificial and biologically relevant sounds. We created a sound level gradient inside a small experimental cage in a laboratory setting and measured whether green anoles avoided the vicinity of a speaker. In approximately 80% of cases, both the pattern machine sound and the mixture sounds prevented green anoles from stepping into the vicinity of a speaker (<24 cm). The mixture sounds maintained the deterrent effect at a middle distance from a speaker (<72 cm), whereas the pattern machine sound did not work as a strong acoustic repellent at this distance. These results imply that the mixing of biotic and abiotic sounds can improve the effective range of acoustic repellent for green anoles. However, several shortcomings of the acoustic repellent system were also highlighted. Since a green anole is an insectivore predator, our findings will contribute to protecting endangered native insect fauna from the predation of non-native lizard species.

中文翻译：

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人工声音和生物声音的混合提高了针对入侵蜥蜴物种的声音驱避剂的有效范围

通过控制入侵动物的行为可以防止其范围进一步扩大。声学驱避剂是一种很有前景的方法，可以阻止有问题的动物进入生态敏感区域。为了开发一种针对引入日本小笠原群岛的绿变色龙的声音驱避系统，本研究评估了（1）机器噪音的模式声音和（2）人工和生物相关声音的混合的威慑效果。我们在实验室环境中的一个小型实验笼内创建了声级梯度，并测量了绿变色龙是否避开扬声器附近。在大约 80% 的情况下，图案机声音和混合声音都会阻止绿变色蜥步入扬声器（<24 厘米）附近。混合声音在距扬声器的中等距离（<72厘米）处保持威慑效果，而模式机声音在该距离处不能起到强烈的声学排斥作用。这些结果表明，生物声音和非生物声音的混合可以提高绿变色蜥声学驱避剂的有效范围。然而，声学排斥系统的一些缺点也被凸显。由于绿变色龙是食虫捕食者，我们的研究结果将有助于保护濒临灭绝的本土昆虫区系免受非本土蜥蜴物种的捕食。