Anuran calls are usually species-specific and therefore valued as a tool for species identification. Call characteristics are a potential honest signal in sexual selection because they often reflect male body size. Po...Anuran calls are usually species-specific and therefore valued as a tool for species identification. Call characteristics are a potential honest signal in sexual selection because they often reflect male body size. Polypedates megacephalus and P. mutus are two sympatric and morphologically similar tree frogs, but it remains unknown whether their calls are associated with body size. In this study, we compared call characteristics of these two species and investigated any potential relationships with body size. We found that P. megacephalus, males produced six call types which consisting of three distinct notes, while P. mutus males produced five types consisting of two types of notes. Dominant frequency, note duration, pulse duration, and call duration exhibited significant interspecific differences. In P. megacephalus, one note exhibited a dominant frequency that was negatively correlated with body mass, snout-vent length, head length, and head width. In P. mutus, the duration of one note type was positively correlated with body mass and head width. These differences in call characteristics may play an important role in interspecific recognition. Additionally, because interspecific acoustic variation reflects body size, calls may be relevant for sexual selection. Taken together, our results confirmed that calls are a valid tool for distinguishing between the two tree-frog species in the field.展开更多
Geographical divergence in acoustic signals is often affected by multiple selective pressures.Environmental factors are expected to shape signals by adjusting for greater propagation efficiency.Nevertheless,such habita...Geographical divergence in acoustic signals is often affected by multiple selective pressures.Environmental factors are expected to shape signals by adjusting for greater propagation efficiency.Nevertheless,such habitat-driven hypotheses have not been well-examined with multi-signal and multi-habitat types included simultaneously.In this study,we evaluated call similarity of the spot-legged treefrog(Polypedates megacephalus),characterized by multiple call types,from 11 geographic populations across Hainan Island.We also examined multiple factors(i.e.body mass,temperature,altitude,and vegetation)among different acoustical geographic clusters,and tested whether the variation in acoustic length and frequency among different habitats was in accordance with the predic-tion derived from the acoustic adaptation hypothesis.We showed that P.megacephalus from Hainan Island included 3 acoustic geographic clusters:the northeasternflatlands,the southwest mountains,and the hills around the moun-tains.We also showed that environmental factors(i.e.altitude and vegetation)varied across these 3 acoustically distinct areas.Moreover,the duration of the different call types supported the hypothesis that they should have opti-mal transmission in their own habitats.Thus,our results reveal the roles of ecological selection in the geographical divergence of anuran acoustic signals.展开更多
基金supported by the National Natural Science Foundation of China (31260518 to JW)the Education Department of Hainan Province (00501023523)
文摘Anuran calls are usually species-specific and therefore valued as a tool for species identification. Call characteristics are a potential honest signal in sexual selection because they often reflect male body size. Polypedates megacephalus and P. mutus are two sympatric and morphologically similar tree frogs, but it remains unknown whether their calls are associated with body size. In this study, we compared call characteristics of these two species and investigated any potential relationships with body size. We found that P. megacephalus, males produced six call types which consisting of three distinct notes, while P. mutus males produced five types consisting of two types of notes. Dominant frequency, note duration, pulse duration, and call duration exhibited significant interspecific differences. In P. megacephalus, one note exhibited a dominant frequency that was negatively correlated with body mass, snout-vent length, head length, and head width. In P. mutus, the duration of one note type was positively correlated with body mass and head width. These differences in call characteristics may play an important role in interspecific recognition. Additionally, because interspecific acoustic variation reflects body size, calls may be relevant for sexual selection. Taken together, our results confirmed that calls are a valid tool for distinguishing between the two tree-frog species in the field.
基金supported by the Natural Science Foundation of Hainan Province(2019RC175)the Postdoctoral Research Program in Hainan Province(RC2100004064)the Academician working platform project in Hainan Province.
文摘Geographical divergence in acoustic signals is often affected by multiple selective pressures.Environmental factors are expected to shape signals by adjusting for greater propagation efficiency.Nevertheless,such habitat-driven hypotheses have not been well-examined with multi-signal and multi-habitat types included simultaneously.In this study,we evaluated call similarity of the spot-legged treefrog(Polypedates megacephalus),characterized by multiple call types,from 11 geographic populations across Hainan Island.We also examined multiple factors(i.e.body mass,temperature,altitude,and vegetation)among different acoustical geographic clusters,and tested whether the variation in acoustic length and frequency among different habitats was in accordance with the predic-tion derived from the acoustic adaptation hypothesis.We showed that P.megacephalus from Hainan Island included 3 acoustic geographic clusters:the northeasternflatlands,the southwest mountains,and the hills around the moun-tains.We also showed that environmental factors(i.e.altitude and vegetation)varied across these 3 acoustically distinct areas.Moreover,the duration of the different call types supported the hypothesis that they should have opti-mal transmission in their own habitats.Thus,our results reveal the roles of ecological selection in the geographical divergence of anuran acoustic signals.
