Treefrogs adjust their acoustic signals in response to harmonics structure of intruder calls

Spectral properties of animal acoustic signals may help individuals to assess the characteristics of rivals and to adjust their competitive strategies in territorial disputes. Thus, we hypothesize that the distribution of energy across frequency bands in anuran calls determine behavioral responses in male-male competition. Using playback experiments, we investigated the relevance of the harmonic calls in the acoustic communication of the treefrog Dendropsophus minutus. We exposed territorial males to three synthetic acoustic stimuli composed of aggressive notes: (1) standard call (all harmonics and peak frequency corresponding to the second band); (2) inverted-energy call (all harmonics and peak frequency corresponding to the first band); and (3) concentrated-energy call (all energy contained in the second harmonic). Males responded aggressively to all stimuli, mainly by increasing the rate and duration of their aggressive notes. However, when exposed to stimuli with different harmonic ...动物声学信号的频谱特性可帮助个体评估竞争者的特征，并在领地争端中调整自身的竞争策略。据此，我们提出如下假说：无尾两栖类鸣声的能量在各频带的分布格局，将决定雄性间竞争中的行为反应。本研究采用回放实验，探究了谐波鸣声在迷你树蛙（Dendropsophus minutus）声学通讯中的相关性。我们将领地雄性个体暴露于三种由攻击性鸣唱音节构成的合成声学刺激：（1）标准鸣声（包含全部谐波，峰值频率对应第二频带）；（2）能量倒置鸣声（包含全部谐波，峰值频率对应第一频带）；（3）能量集中鸣声（所有能量均集中于第二谐波）。雄性个体对所有刺激均表现出攻击性反应，主要通过提升攻击性鸣唱音节的发放速率与持续时长实现。然而，当暴露于具有不同谐波……