Khan Christin B, Markowitz Hal, McCowan Brenda
Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, California 94132, USA.
J Acoust Soc Am. 2006 Sep;120(3):1684-94. doi: 10.1121/1.2226530.
The goal of this research was to determine when harbor seal pup vocalizations become sufficiently distinctive to allow individual recognition. A total of 4593 calls were analyzed from 15 captive pups. Nineteen were harsh, broadband, staccato calls used in an aggressive context. The rest were tonal "mother attraction calls," having an inverted "v"- or "u"-shaped spectrogram with harmonics and a fundamental frequency around 200-600 Hz. Calls were individually distinctive even in pups less than 2 weeks old, suggesting that mothers may be able to recognize pup vocalizations at this early age. Classification rates from discriminant function analysis were generally comparable to those of other phocids and less than in otariids, supporting the theory that recognition is more highly developed in otariids. Significant differences were found between male and female pup calls, and there were significant interactions between pup sex and age. The results of this study should be interpreted with caution until the findings are verified in wild harbor seal pups.
本研究的目的是确定港海豹幼崽的叫声何时变得足够独特，以便进行个体识别。共分析了15只圈养幼崽的4593次叫声。其中19次是在攻击性情境中使用的刺耳、宽带、断奏叫声。其余的是音调“母性吸引叫声”，具有倒“V”形或“U”形频谱图，带有谐波，基频约为200 - 600赫兹。即使在不到2周大的幼崽中，叫声也具有个体独特性，这表明母亲可能在这个早期阶段就能识别幼崽的叫声。判别函数分析的分类率总体上与其他鳍脚类动物相当，低于海狗科动物，这支持了海狗科动物的识别能力更发达的理论。在雄性和雌性幼崽的叫声之间发现了显著差异，幼崽性别和年龄之间存在显著交互作用。在野生港海豹幼崽中验证这些发现之前，本研究结果应谨慎解释。
