Ringler Max, Szipl Georgine, Hödl Walter, Khil Leander, Kofler Barbara, Lonauer Michael, Provin Christina, Ringler Eva
Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Drive South, Los Angeles, CA 90095-1606 USA.
Department of Integrative Zoology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
Behav Ecol Sociobiol. 2017;71(8):114. doi: 10.1007/s00265-017-2340-2. Epub 2017 Jul 12.
Acoustic ranging allows identifying the distance of a sound source and mediates inter-individual spacing and aggression in territorial species. Birds and mammals are known to use more complex cues than only sound pressure level (SPL), which can be influenced by the signaller and signal transmission in non-predictable ways and thus is not reliable by itself. For frogs, only SPL is currently known to mediate inter-individual distances, but we hypothesise that the strong territoriality of Dendrobatids could make the use of complex cues for ranging highly beneficial for this family. Therefore, we tested the ranging abilities of territorial males of (Dendrobatidae, Aromobatinae) in playback trials, using amplitude-normalized signals that were naturally degraded over distance, and synthetic signals that were masked with different levels of noise. Frogs responded significantly less to signals recorded from larger distances, regardless of SPL and signal-to-noise ratio (SNR), but showed no differential response to natural minimum and maximum SNRs across the typical communication range in wild populations. This indicates that frogs used signal amplitude and SNR only as ancillary cues when assessing the distance of sound sources and relied instead mainly on more complex cues, such as spectral degradation or reverberation. We suggest that this ability mediates territorial spacing and mate choice in . Good ranging abilities might also play a role in the remarkable orientation performance of this species, probably by enabling the establishment of a mental acoustic map of the habitat.
Acoustic ranging allows the distance of vocalizing competitors and mates to be identified. While birds and mammals are known to use complex cues such as temporal degradation, frequency-dependent attenuation and reverberation for ranging, previous research indicated that frogs rely only on signal amplitude (sound pressure level) to assess the distance of other callers. The present study shows for the first time that also poison frogs can make use of more complex cues, an ability which is likely to be highly beneficial in their territorial social organization and probably can also be used for orientation.
声学测距可用于确定声源的距离，并调节领地性物种的个体间间距和攻击性。已知鸟类和哺乳动物会使用比声压级（SPL）更复杂的线索，声压级可能会受到信号发出者和信号传输的不可预测影响，因此其本身并不可靠。对于青蛙来说，目前已知只有声压级能调节个体间距离，但我们推测箭毒蛙强烈的领地性可能使利用复杂线索进行测距对该科非常有益。因此，我们在回放试验中测试了（箭毒蛙科，丛蛙亚科）领地雄性青蛙的测距能力，使用了随距离自然衰减的幅度归一化信号，以及被不同程度噪声掩盖的合成信号。无论声压级和信噪比（SNR）如何，青蛙对从较大距离记录的信号反应明显减少，但在野生种群的典型通信范围内，对自然最小和最大信噪比没有差异反应。这表明青蛙在评估声源距离时仅将信号幅度和信噪比作为辅助线索，而是主要依赖于更复杂的线索，如频谱衰减或混响。我们认为这种能力调节了的领地间距和配偶选择。良好的测距能力也可能在该物种卓越的定向表现中发挥作用，可能是通过建立栖息地的心理声学地图来实现的。
声学测距可以确定发声的竞争者和配偶的距离。虽然已知鸟类和哺乳动物使用诸如时间衰减、频率依赖性衰减和混响等复杂线索进行测距，但先前的研究表明青蛙仅依靠信号幅度（声压级）来评估其他鸣叫者的距离。本研究首次表明，毒蛙也可以利用更复杂的线索，这种能力在它们的领地社会组织中可能非常有益，并且可能也可用于定向。
