圈养瓶鼻海豚对20 kHz连续声信号的行为响应研究

Behavioral responses of captive bottlenose dolphins(Tursiops truncatus) to a continuous 20 kHz pure tone

将20 kHz连续声信号作为刺激信号,测试了厦门某海湾圈养的两只瓶鼻海豚对该信号的行为变化。通过对比信号发射期与间歇期海豚相对声源的水面距离、露出水面的次数以及水下发出的click定位声信号的数目等变化,判断发射信号对海豚行为的影响。给出了瓶鼻海豚对测试信号产生躲避行为的声压级门限(154±2 dB re 1μPa,rms),并与鼠海豚的躲避声压门限级进行了对比。结果表明:信号发射期,瓶鼻海豚移离了声源位置,增加了露出水面的次数,水下发出click声信号的次数明显减少。因此,瓶鼻海豚对20kHz连续信号产生了行为改变。

Two captive bottlenose dolphins housed in a float cage in a Bay were subjected to a continuous 20 kHz tonal signal. The behavioral responses of dolphins were judged by comparing the surface distances relative to the sound source, number of surfacings, and number of the echolocation clicks production of the dolphins, during test periods and baseline periods. The avoidance threshold sound pressure level （SPL） for a continuous 20 kHz tonal signal for the bottlenose dolphins was estimated to be 154 ±2 dB （re 1 #Pa, rms）. In addation, the comparison between the avoidance threshold SPL for harbor porpoises to a 50 kHz continuous signal and bottlenose dolphins to a 20 kHz continuous signal was also studied. The results showed that the dolphins moved away from the sound source and came to the surface more frequently during the test periods than the baseline periods, but they produced clicks significantly fewer. Therefore, a continuous 20 kHz tonal signal seems to deter bottlenose dolphins from an area.