Data from: Behavioural tuning in a tropical amphibian along an altitudinal gradient

Males of the Coqui treefrog, Eleutherodactylus coqui, produce a distinct two-note ‘co-qui’ advertisement call from sunset to midnight throughout most of the year. Previous work established that both the spectrotemporal aspects of the call and the frequency of highest inner-ear sensitivity changes with altitude above sea level. These variations are such that the frequency of the emitted co-note closely matches the frequency to which the inner-ear is most sensitive. Given this parallel variation, we expected that the call-evoked behavioural response of male Coqui treefrogs would also show an altitude-dependence, and hypothesized that males would produce their most robust acoustical territorial response to advertisement calls that match calls from their own altitude. We tested this hypothesis in the field by studying the vocal response behaviour of Coquis to playbacks of synthetic, altitude-dependent conspecific calls, and indeed found that the most robust vocal responses were obtained using stimuli closely matching the calls from the same altitude.科奎树蛙（Eleutherodactylus coqui）的雄性个体在一年中的多数时段，会于日落至午夜期间发出独特的双音节"co-qui"广告鸣叫。既往研究证实，该鸣叫的声谱时间特性与内耳最高敏感度的频率均会随海拔高度发生变化。这种变化呈现出高度匹配的规律：鸣叫中"co"音节的频率与内耳最敏感的频率高度吻合。基于这种平行变化关系，我们推测雄性科奎树蛙的鸣叫诱发行为反应同样存在海拔依赖性，并提出假设：雄性个体对与其自身海拔匹配的同种广告鸣叫，会展现出最强的声学领地应答行为。我们通过野外实验验证了这一假设，研究了科奎树蛙对合成的、随海拔变化的同种鸣叫回放的发声应答行为，结果确实证实，当刺激信号与同海拔个体的鸣叫高度匹配时，可获得最强的发声应答。