Signal detection is crucial to survival and successful reproduction, and animals often modify behavioral decisions based on information they obtained from the social context. Undeniably, the decision-making in male-male competition and female choice of anurans (frogs and toads) depends heavily on acoustic signals. However, increasing empirical evidence suggests that additional or alternative types of cue (e.g., visual, chemical, and vibratory) can be used to detect, discriminate and locate conspecifics in many anuran species. Nevertheless, few studies have investigated whether conspecific odor cues affect male’s calling behavior. In this study, we conducted an experiment to investigate whether and how different chemical cues (male odors, female odors, and stress odors) from conspecifics affect male’s calling strategies in serrate-legged small treefrogs (Kurixalus odontotarsus), and whether the combined chemical and acoustic stimuli have additive effects on calling behavior or not. We found that compared with female odors, male K. odontotarsus reduced calling investment in response to male odors or stress odors, in the absence of rival’s advertisement calls. When odor stimuli and advertisement calls were presented simultaneously, however, there were no differences in the vocal response of focal males among odor groups. These results provide evidence that male treefrogs switch calling investment according to different odor cues from conspecifics, and further demonstrate that calling behavior can be affected by chemical cues in anuran species. Our study highlights the potential role of airborne chemical cues in sex identification and contributes to increase our understanding of anuran communication.

中文翻译：

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同种气味线索在锯齿腿小树蛙中诱导不同的声音反应，但仅在没有声音信号的情况下

信号检测对于生存和成功繁殖至关重要，动物经常根据从社会环境中获得的信息来修改行为决策。不可否认，雄性竞争和雌性无尾目（青蛙和蟾蜍）选择的决策在很大程度上取决于声学信号。然而，越来越多的经验证据表明，可以使用其他或替代类型的线索（例如，视觉、化学和振动）来检测、区分和定位许多无尾猿物种中的同种物种。然而，很少有研究调查同种气味线索是否会影响男性的呼唤行为。在这项研究中，我们进行了一项实验来调查不同的化学线索（男性气味、女性气味、和压力气味）影响雄性在锯齿腿小树蛙（Kurixalus odontotarsus）中的叫声策略，以及化学和声学刺激的组合是否对叫声行为具有累加效应。我们发现，与雌性气味相比，雄性 K. odontotarsus 在没有竞争对手的广告呼叫的情况下，减少了响应男性气味或压力气味的呼叫投资。然而，当气味刺激和广告呼叫同时呈现时，气味组中焦点男性的声音反应没有差异。这些结果证明，雄性树蛙会根据来自同种的不同气味线索转换叫声投资，并进一步证明叫声行为可能会受到无尾目物种的化学线索的影响。