Flying in silence: Echolocating bats cease vocalizing to avoid sonar jamming.
Flying in silence: Echolocating bats cease vocalizing to avoid sonar jamming.
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DOI：
10.1073/pnas.0804408105
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发表时间：
2008-09-02
影响因子：
11.1
通讯作者：
Moss, Cynthia F
中科院分区：
文献类型：
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作者：
Chiu, Chen;Xian, Wei;Moss, Cynthia F
虽然人们已经认识到回声定位蝙蝠可能会受到同种生物信号的干扰，但对这一问题的研究主要集中在调整发射信号的时频上，以尽量减少干扰。在这里，我们报告了蝙蝠用来避免干扰的一种令人惊讶的新策略，即沉默。在对大褐蝙蝠（Eptesicus fuscus）飞行和发声行为的定量研究中，我们发现蝙蝠在与同种动物飞行时，会有相当长的沉默时间。这里定义的沉默行为是一对蝙蝠中至少有一只停止发声超过0.2秒（200毫秒），当它们的距离小于1米时，沉默行为发生的几率高达76%(7对蝙蝠平均40%)，而当一只蝙蝠单独飞行时，沉默行为发生的几率仅为0.08%。成对蝙蝠的空间分离、前进方向和叫声设计的相似性与这种沉默行为的流行有关。我们的数据表明，蝙蝠使用沉默作为一种策略，以避免邻居声呐发声的干扰，同时倾听特定产生的声音信号来指导方向。基于先前对蝙蝠听觉中脑的神经生理学研究，我们假设环境声音（包括其他蝙蝠发出的声音）和积极的回声定位会引起不同神经元群的神经活动。我们的研究结果提供了令人信服的证据，证明回声定位蝙蝠在主动和被动感知之间切换，以应对复杂的声学环境，这些结果对整个动物王国的导航和通信研究具有广泛的意义。
Although it has been recognized that echolocating bats may experience jamming from the signals of conspecifics, research on this problem has focused exclusively on time-frequency adjustments in the emitted signals to minimize interference. Here, we report a surprising new strategy used by bats to avoid interference, namely silence. In a quantitative study of flight and vocal behavior of the big brown bat (Eptesicus fuscus), we discovered that the bat spends considerable time in silence when flying with conspecifics. Silent behavior, defined here as at least one bat in a pair ceasing vocalization for more than 0.2 s (200 ms), occurred as much as 76% of the time (mean of 40% across 7 pairs) when their separation was shorter than 1 m, but only 0.08% when a single bat flew alone. Spatial separation, heading direction, and similarity in call design of paired bats were related to the prevalence of this silent behavior. Our data suggest that the bat uses silence as a strategy to avoid interference from sonar vocalizations of its neighbor, while listening to conspecific-generated acoustic signals to guide orientation. Based on previous neurophysiological studies of the bat's auditory midbrain, we hypothesize that environmental sounds (including vocalizations produced by other bats) and active echolocation evoke neural activity in different populations of neurons. Our findings offer compelling evidence that the echolocating bat switches between active and passive sensing to cope with a complex acoustic environment, and these results hold broad implications for research on navigation and communication throughout the animal kingdom.