National Marine Mammal Foundation: 3131, 2240 Shelter Island Dr, San Diego, CA 92106, USA.
National Marine Mammal Foundation: 3131, 2240 Shelter Island Dr, San Diego, CA 92106, USA.
Behav Processes. 2022 Aug;200:104690. doi: 10.1016/j.beproc.2022.104690. Epub 2022 Jun 14.
Bottlenose dolphins have individually distinct signature whistles that are characterized by a stereotyped frequency-time contour. Signature whistles are commonly exchanged with short time delays between calls. Dolphin whistles are produced by pressurized nasal sacs that increase and then decrease in pressure over emission. This study found that the relative amplitude modulation pattern over time exhibited the same fade-in and then fade-out pattern in the signature whistles of eight bottlenose dolphins at the Navy in San Diego, CA. Both the initial and final five percent of the whistle's duration also had significantly lower mean relative amplitude than the center five percent. The current analyses of the amplitude-time relationship was then integrated to a previously reported model of the negative relationship between relative log amplitude and log peak frequency. This produced a more robust model for accounting for the predictable aspects of the more broadly non-stereotyped amplitude modulations of signature whistles. Whether dolphins can intentionally manipulate these amplitude features or they are simple by-products of the sound production system, and further whether they are perceived and utilized by receivers, is an exciting area for continued research.
宽吻海豚的哨声具有独特的个体特征，其频率时间轮廓具有一定的模式。这些哨声通常以短的时间延迟进行交换。海豚的哨声是通过加压的鼻囊产生的，在排放过程中鼻囊的压力会增加然后减少。本研究发现，在加利福尼亚州圣地亚哥的海军中，8 只宽吻海豚的特征哨声中，相对幅度调制模式随时间表现出相同的渐强然后渐弱的模式。哨声持续时间的初始和最后 5%的平均相对幅度也明显低于中心 5%的平均相对幅度。目前对幅度-时间关系的分析被整合到之前报道的相对对数幅度与对数峰值频率之间负相关的模型中。这为解释特征哨声更广泛的非定型幅度调制的可预测方面提供了一个更稳健的模型。海豚是否可以有意地操纵这些幅度特征，或者它们只是声音产生系统的简单副产品，以及它们是否被接收者感知和利用，这是一个令人兴奋的研究领域。
