ABSTRACT The length-frequency distribution of sperm whales (Physeter macrocephalus) was studied on the east coast of NZ using passive acoustic recorders moored offshore of Kaikoura, Cape Palliser and Castlepoint. Sperm whale’s echolocation signals are unique among odontocete species. Their clicks are composed by multiple pulses resulting from the sound transmission within the whale head. The total length of the whales can be estimated by measuring the time delay between these pulses. A total of 997 length measurements were obtained from click trains using cepstral analysis (mean = 14.6 m; min = 9.6 m; max = 18.3 m; std = 1 m). The size-frequency distributions at all three locations were similar, although animals smaller than 12 m were not present offshore of Kaikoura. Animals of various sizes appeared to be present all year round, with no apparent seasonality in the occurrence of any size class.

中文翻译：

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新西兰东海岸抹香鲸（Physeter macrocephalus）的声学估计大小分布

摘要 新西兰东海岸抹香鲸（Physeter macrocephalus）的长度频率分布使用停泊在凯库拉、帕利瑟角和卡斯尔波因特近海的被动声记录器进行了研究。抹香鲸的回声定位信号在齿科动物中是独一无二的。它们的咔嗒声由鲸鱼头部内的声音传输产生的多个脉冲组成。可以通过测量这些脉冲之间的时间延迟来估计鲸鱼的总长度。使用倒谱分析从咔嗒声序列中获得了总共 997 个长度测量值（平均值 = 14.6 m；最小值 = 9.6 m；最大值 = 18.3 m；std = 1 m）。尽管凯库拉近海不存在小于 12 m 的动物，但所有三个位置的大小频率分布相似。各种大小的动物似乎一年四季都在出现，