Janik V M
School of Biology, University of St Andrews, Fife, UK.
J Comp Physiol A. 2000 Jul-Aug;186(7-8):673-80. doi: 10.1007/s003590000120.
This study measured SPLs of whistles of wild bottlenose dolphins (Tursiops truncatus) in the Moray Firth, Scotland, and estimated their active space, i.e. the distance at which another dolphin can perceive the whistle of a conspecific. Whistling dolphins were localized with a dispersed hydrophone array by comparing differences in the times of arrival of a whistle at different hydrophones. The mean source level for whistles was 158 +/- 0.6 dB re. 1 microPa. The maximum was 169 dB re. 1 microPa. The active space of these whistles was calculated taking into account transmission loss, ambient noise, the critical ratios and the auditory sensitivity of this species. The estimated radius of the active space of unmodulated whistles between 3.5 kHz and 10 kHz produced at maximum source level ranged from 20 km to 25 km in a habitat of 10 m depth and at sea state 0. At sea state 4 it ranged from 14 km to 22 km. For whistles of 12 kHz it dropped to 1.5-4 km. The results suggest that whistles can be used to maintain group cohesion over large distances but also that dolphins that researchers consider to belong to separate groups might be in acoustic contact.
本研究测量了苏格兰马里湾野生宽吻海豚（瓶鼻海豚）发出的哨声的声压级，并估算了它们的活动空间，即另一只海豚能够感知到同种海豚哨声的距离。通过比较哨声在不同水听器处到达时间的差异，利用分散的水听器阵列对发出哨声的海豚进行定位。哨声的平均声源级为158±0.6分贝（参考1微帕）。最大值为169分贝（参考1微帕）。在计算这些哨声的活动空间时，考虑了传播损失、环境噪声、临界比率以及该物种的听觉敏感度。在深度为10米、海况为0的栖息地中，最大声源级下产生的3.5千赫至10千赫未调制哨声的活动空间估计半径在20公里至25公里之间。在海况为4时，该半径在14公里至22公里之间。对于12千赫的哨声，活动空间半径降至1.5至4公里。研究结果表明，哨声可用于在远距离维持群体凝聚力，同时也表明研究人员认为属于不同群体的海豚可能存在声学联系。
