Department of Psychology, Ecology, Evolution, and Behavior Program, University at Buffalo, The State University of New York, Park Hall, Buffalo, NY, 14260, USA.
Anim Cogn. 2022 Oct;25(5):1133-1149. doi: 10.1007/s10071-022-01675-9. Epub 2022 Sep 4.
Singing humpback whales are highly versatile vocalizers, producing complex sequences of sounds that they vary throughout adulthood. Past analyses of humpback whale song have emphasized yearly variations in structural features of songs made collectively by singers within a population with comparatively little attention given to the ways that individual singers vary consecutive songs. As a result, many researchers describe singing by humpback whales as a process in which singers produce sequences of repeating sound patterns. Here, we show that such characterizations misrepresent the degree to which humpback whales flexibly and dynamically control the production of sounds and sound patterns within song sessions. Singers recorded off the coast of Hawaii continuously morphed units along multiple acoustic dimensions, with the degree and direction of morphing varying across parallel streams of successive units. Individual singers also produced multiple phrase variants (structurally similar, but acoustically distinctive sequences) within song sessions. The precision with which individual singers maintained some acoustic properties of phrases and morphing trajectories while flexibly changing others suggests that singing humpback whales actively select and adjust acoustic elements of their songs in real time rather than simply repeating stereotyped sound patterns within song sessions.
唱歌的座头鲸是高度多功能的发声者，它们能在整个成年期产生复杂的声音序列。过去对座头鲸歌声的分析强调了由一个群体中的歌手集体创作的歌曲在结构特征上的年度变化，而相对较少关注个体歌手在连续歌曲上的变化方式。因此，许多研究人员将座头鲸的歌唱描述为一个过程，在这个过程中，歌手们产生重复的声音模式序列。在这里，我们表明，这种描述方式歪曲了座头鲸在歌曲演奏过程中灵活和动态地控制声音和声音模式产生的程度。在夏威夷海岸外记录的歌手们沿着多个声学维度连续地改变单元，变形的程度和方向在连续单元的平行流中变化。个体歌手也在歌曲演奏过程中产生了多种短语变体（结构相似但声学上不同的序列）。个体歌手在灵活地改变其他声学特性的同时，还能精确地保持某些短语和变形轨迹的声学特性，这表明唱歌的座头鲸在实时积极地选择和调整其歌曲的声学元素，而不是在歌曲演奏过程中简单地重复刻板的声音模式。
