Phonation behavior of cooperatively foraging spinner dolphins
Phonation behavior of cooperatively foraging spinner dolphins
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DOI：
10.1121/1.2967477
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发表时间：
2009-01-01
影响因子：
2.4
通讯作者：
Au, Whitlow W. L.
中科院分区：
文献类型：
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作者：
Benoit-Bird, Kelly J.;Au, Whitlow W. L.
成群的飞旋海豚已经被证明可以合作驱赶小型猎物。据推测，强大的群体协调是由声学通信，特别是调频哨声。用多波束回声测深仪对夜间在声散射层内觅食的海豚群进行了观测，同时用4个水听器以6米的深度间隔测量了海豚声音的速率。哨声只在海豚不觅食和动物浮出水面时才被发现。点击率的差异，发现深度之间和不同的觅食阶段，但相对较低的观察表明，海豚积极喂养，尽管这些点击与回声定位信号的一致性。最高的点击率发生在散射层，在觅食状态之间的过渡。这表明，点击可以直接或间接地用于在觅食过程中提示群体运动，可能是通过检测其他个体在群体中的位置或担任直接的沟通角色，这与回声定位和沟通被划分的现有假设相反。通过点击进行通信将是有益的，因为信号的特性最大限度地减少了竞争海豚和大鱼窃听的机会。我们的研究结果是无法支持既定的模式海豚声通信，并建议在觅食旋转海豚的替代协调机制。
Groups of spinner dolphins have been shown to cooperatively herd small prey. It was hypothesized that the strong group coordination is maintained by acoustic communication, specifically by frequency-modulated whistles. Observations of groups of spinner dolphins foraging at night within a sound-scattering layer were made with a multibeam echosounder while the rates of dolphin sounds were measured using four hydrophones at 6 m depth intervals. Whistles were only detected when dolphins were not foraging and when animals were surfacing. Differences in click rates were found between depths and between different foraging stages but were relatively low when observations indicated that dolphins were actively feeding despite the consistency of these clicks with echolocation signals. Highest click rates occurred within the scattering layer, during transitions between foraging states. This suggests that clicks may be used directly or indirectly to cue group movement during foraging, potentially by detecting other individuals' positions in the group or serving a direct communicative role which would be contrary to the existing assumption that echolocation and communication are compartmentalized. Communicating via clicks would be beneficial as the signal's characteristics minimize the chance of eavesdropping by competing dolphins and large fish. Our results are unable to support the established paradigm for dolphin acoustic communication and suggest an alternate coordination mechanism in foraging spinner dolphins.