Subarctic singers: Humpback whale (Megaptera novaeangliae) song structure and progression from an Icelandic feeding ground during winter

Humpback whale songs associated with breeding behaviors are increasingly reported outside of traditional low latitude breeding grounds. Songs from a subarctic feeding ground during the winter were quantitatively characterized to investigate the structure and temporal changes of the songs at such an atypical location. Recordings were collected from 26. January to 12. March, 2011, using bottom mounted recorders. Humpback songs were detected on 91% of the recording days with peak singing activities during 9.–26. February. The majority of the recordings included multiple chorusing singers. The songs were characterized by a) common static themes which transitioned consistently to predictable themes, b) shifting themes which occurred less predictably and c) rare themes. A set median sequence was found for four different periods (sets) of recordings (approximately 1 week each). The set medians were highly similar and formed a single cluster indicating that the sequences of themes sung in this ...与繁殖行为相关的座头鲸（Humpback Whale）鸣唱声，在传统低纬度繁殖场之外的区域被报道的案例正日益增多。本研究对冬季于亚北极觅食场录制的座头鲸鸣唱声进行了定量特征分析，以探究这类非典型分布区域内的鸣唱声结构及其时序变化规律。本次研究于2011年1月26日至3月12日期间，采用海底固定式记录仪采集了相关录音数据。在91%的有效录制日内均可检测到座头鲸鸣唱声，其鸣唱活动的峰值时段为2月9日至26日。多数录音片段中均可观测到多头座头鲸同时鸣唱的合唱现象。该类鸣唱声具有三类典型特征：a) 常见的固定主题序列，可稳定过渡至可预测的后续主题；b) 随机性较强的可变主题；c) 极少出现的稀有主题。研究人员在四段各时长约一周的独立录制周期（即数据集分组）中，均提取到了一组中位数主题序列。各分组的中位数主题序列相似度极高，共同形成单一聚类簇，表明该区域内座头鲸鸣唱的主题序列...