Silence is sexy: Soundscape complexity alters mate choice in túngara frogs

Many animals acoustically communicate in large aggregations, producing biotic soundscapes. In turn, these natural soundscapes can influence the efficacy of animal communication, yet little is known about how variation in soundscape interferes with animals that communicate acoustically. We quantified this variation by analyzing natural soundscapes with the mid-frequency cover index and by measuring the frequency ranges and call rates of the most common acoustically communicating species. We then tested female mate choice in the túngara frog (Physalaemus pustulosus) in varying types of background chorus noise. We broadcast two natural túngara frog calls as a stimulus and altered the densities (duty cycles) of natural calls from conspecifics and heterospecifics to form the different types of chorus noise. During both conspecific and heterospecific chorus noise treatments, females demonstrated similar preferences for advertisement calls at low and mid noise densities but failed to express a...

许多动物在大规模聚集时通过声学方式交流，形成生物声景（biotic soundscapes）。反过来，这些自然声景会影响动物交流的有效性，但关于声景变化如何干扰声学交流动物这一问题，目前知之甚少。我们通过中频覆盖指数（mid - frequency cover index）分析自然声景，并测量最常见声学交流物种的频率范围和鸣叫率，以此量化这种变化。随后，我们在不同类型的背景合唱噪声中测试了túngara蛙（Physalaemus pustulosus）雌性的配偶选择行为。我们播放两种自然的túngara蛙鸣叫作为刺激，并改变同种和异种动物自然鸣叫的密度（duty cycles），从而形成不同类型的合唱噪声。在同种和异种合唱噪声处理中，雌性个体在低噪声和中噪声密度下对求偶鸣叫表现出相似的偏好，但未能表现出……