JASCO Applied Sciences, 32 Troop Avenue, Suite 202, Dartmouth, Nova Scotia B3B 1Z1, Canada.
Fisheries and Oceans Canada, Bedford Institute of Oceanography, 1 Challenger Drive, Dartmouth, Nova Scotia, Canada.
J Acoust Soc Am. 2019 Apr;145(4):2305. doi: 10.1121/1.5095404.
Humpback whale songs have been described worldwide and studies exploring non-song vocal behavior continue to expand; however, studies on the transition periods when whales shift to and from the seasonal behavioral state of singing are lacking and may be potentially informative regarding the proximal factors controlling the onset and offset of humpback whale male singing. Acoustic recorders collected data off eastern Canada continuously from the Bay of Fundy in the fall of 2015 and near-continuously off northeast Nova Scotia in the spring of 2016. Humpback whale acoustic occurrence and behavior were identified by systematically reviewing a subset of acoustic recordings for presence before analyzing the highest quality recordings for behavior. The onset of singing in the fall was gradual over a period of about three weeks with an intermediate form, termed "song fragment," occurring prior to full songs. In comparison, singing in the spring seemed to end abruptly with few song fragments. Song fragments could be produced by juveniles learning to sing for the first time or mature males preparing for breeding activities prior to migrating to southern breeding grounds. The authors propose an alternative hypothesis that the timing and manner of transitions could be driven by physiological processes similar to those documented in songbirds.
座头鲸的歌声在世界范围内都有被描述，而探索非歌曲发声行为的研究也在不断扩展；然而，关于座头鲸从季节性发声状态向歌唱状态转变和过渡的研究却很少，这些研究可能有助于了解控制座头鲸雄性发声开始和结束的近端因素。声学记录仪从 2015 年秋季的芬迪湾（Bay of Fundy）到 2016 年春季的新斯科舍省东北部连续采集数据。通过系统地检查声学记录中存在的部分记录，识别座头鲸的声学出现和行为，然后再分析最高质量的记录以了解行为。秋季的歌唱开始是一个渐进的过程，大约持续了三周，在此期间会出现一种中间形式，称为“歌曲片段”，然后才是完整的歌曲。相比之下，春季的歌唱似乎突然结束，很少有歌曲片段。歌曲片段可能是由首次学习唱歌的幼鲸或准备迁徙到南方繁殖地进行繁殖活动的成熟雄性产生的。作者提出了一种替代假设，即过渡的时间和方式可能是由与鸣禽中记录的类似的生理过程驱动的。
