Data from: Extreme diversity in the songs of Spitsbergen’s bowhead whales

Almost all mammals communicate using sound, but few species produce complex songs. Two baleen whales sing complex songs that change annually, though only the humpback whale (Megaptera novaeangliae) has received much research attention. This study focuses on the other baleen whale singer, the bowhead whale (Balaena mysticetus). Members of the Spitsbergen bowhead whale population produced 184 different song types over a 3-year period, based on duty-cycled recordings from a site in Fram Strait in the NE Atlantic. Distinct song types were recorded over short periods, lasting at most some months. This song diversity could be the result of a possibly increasing population, or immigration of animals from other populations that are no longer isolated from each other by heavy sea ice. However, this explanation does not account for the within season and annual shifting of song types. Other possible explanations, is that the extraordinary diversity in songs is the result of weak selection pressure for interspecific identification or for maintain song characteristics or, alternatively, strong pressure for novelty in a small population.几乎所有哺乳动物都通过声音进行交流，但仅有少数物种能够发出复杂的鸣唱。有两种须鲸（baleen whale）能发出随年度变化的复杂鸣唱，不过目前学界对座头鲸（humpback whale, Megaptera novaeangliae）的研究关注度较高。本研究聚焦于另一种鸣唱的须鲸——弓头鲸（bowhead whale, Balaena mysticetus）。基于东北大西洋（NE Atlantic）弗拉姆海峡（Fram Strait）某一站点的占空比录音（duty-cycled recording）数据，研究团队在3年周期内记录到斯匹次卑尔根弓头鲸种群共产生184种不同的鸣唱类型。不同的鸣唱类型仅在短时段内被记录到，持续时长最多仅为数月。这种鸣唱多样性可能源于种群数量的潜在增长，或是来自其他种群的个体迁入——如今厚海冰已无法再将不同种群相互阻隔。然而，该解释无法涵盖鸣唱类型在季内与年度间的动态变化。其他可能的解释包括：一是种间识别或维持鸣唱特征的选择压力较弱，二是小型种群中对鸣唱新颖性的选择压力较强，二者共同造就了该种群极高的鸣唱多样性。