Australian Antarctic Division, Kingston, Tasmania, Australia.
E Miller Consulting, Hobart, Tasmania, Australia.
Sci Rep. 2018 Apr 3;8(1):5429. doi: 10.1038/s41598-018-23752-1.
The seasonal occupancy and diel behaviour of sperm whales (Physeter macrocephalus) was investigated using data from long-term acoustic recorders deployed off east Antarctica. An automated method for investigating acoustic presence of sperm whales was developed, characterised, and applied to multi-year acoustic datasets at three locations. Instead of focusing on the acoustic properties of detected clicks, the method relied solely on the inter-click-interval (ICI) for determining presence within an hour-long recording. Parameters for our classifier were informed by knowledge of typical vocal behaviour of sperm whales. Sperm whales were detected predominantly from Dec-Feb, occasionally in Nov, Mar, Apr, and May, but never in the Austral winter or early spring months. Ice cover was found to have a statistically significant negative effect on sperm whale presence. In ice-free months sperm whales were detected more often during daylight hours and were seldom detected at night, and this effect was also statistically significant. Seasonal presence at the three east Antarctic recording sites were in accord with what has been inferred from 20th century whale catches off western Antarctica and from stomach contents of whales caught off South Africa.
本研究使用长期部署在东南极的声学记录仪的数据，调查了抹香鲸（Physeter macrocephalus）的季节性栖息地和昼夜行为。开发了一种自动调查抹香鲸声学存在的方法，并对三个地点的多年声学数据集进行了特征描述和应用。该方法不关注检测到的咔哒声的声学特性，而是仅依靠两次咔哒声之间的间隔（ICI）来确定在一小时长的记录中的存在。分类器的参数是根据抹香鲸典型发声行为的知识来确定的。抹香鲸主要在 12 月至 2 月被发现，偶尔在 11 月、3 月、4 月和 5 月被发现，但从未在南极冬季或早春出现过。研究发现，冰盖对抹香鲸的存在有统计学上的显著负面影响。在无冰月份，抹香鲸在白天被发现的频率更高，很少在夜间被发现，这一效应也具有统计学意义。三个东南极录音点的季节性存在与从 20 世纪在西南极的鲸鱼捕捞和在南非捕捞的鲸鱼胃内容物中推断出来的情况一致。
