Zoo Atlanta, Atlanta, GA 30315-1440, USA.
J Acoust Soc Am. 2009 Nov;126(5):2721-32. doi: 10.1121/1.3224720.
A range of acoustic characteristics typically carry information on individual identity in mammalian calls. In addition, physical similarities in vocal production anatomy among closely related individuals may result in similarities in the acoustic structure of vocalizations. Here, acoustic analyses based on source-filter theory were used to determine whether giant panda bleats are individually distinctive, to investigate the relative importance of different source-(larynx) and filter-(vocal tract) related acoustic features for coding individuality, and to test whether closely related individuals have similarities in call structure. The results revealed that giant panda bleats are highly individualized and indicate that source-related features, in particular, mean fundamental frequency, amplitude variation per second, and the mean extent of each amplitude modulation, contribute the most to vocal identity. In addition, although individual pairwise relatedness was not correlated with overall acoustic similarity, it was highly correlated with amplitude modulation rate and fundamental frequency range, suggesting that these acoustic features are heritable components of giant panda bleats that could be used as a measure of genetic relatedness. The ecological relevance of acoustically signaling information on caller identity and the potential practical implications for acoustic monitoring of population levels in this endangered species are discussed.
一系列声学特征通常携带哺乳动物叫声中个体身份的信息。此外，亲缘关系密切的个体在发声器官解剖结构上的物理相似性可能导致发声的声学结构相似。在这里，基于声源滤波器理论的声学分析被用于确定大熊猫叫声是否具有个体独特性，研究不同的声源（喉）和滤波器（声道）相关声学特征对编码个体身份的相对重要性，并测试亲缘关系密切的个体在叫声结构上是否存在相似性。结果表明，大熊猫叫声具有高度的个体独特性，并表明声源相关特征，特别是基频、每秒幅度变化和每个幅度调制的平均幅度，对声音识别贡献最大。此外，尽管个体间的亲缘关系与整体声学相似性没有相关性，但与幅度调制率和基频范围高度相关，这表明这些声学特征是大熊猫叫声中可遗传的组成部分，可以作为遗传亲缘关系的衡量标准。讨论了在这种濒危物种的叫声中，声音信号对呼叫者身份的生态意义以及对种群水平声学监测的潜在实际意义。
