The blue whale Balaenoptera musculus (Linnaeus, 1758) was the target of intense commercial whaling in the 20th century, and current populations remain drastically below prewhaling abundances. Reducing uncertainty in subspecific taxonomy would enable targeted conservation strategies for the recovery of unique intraspecific diversity. Currently, there are 2 named blue whale subspecies in the temperate to polar Southern Hemisphere: the Antarctic blue whale B. m. intermedia and the pygmy blue whale B. m. brevicauda. These subspecies have distinct morphologies, genetics, and acoustics. In 2019, the Society for Marine Mammalogy’s Committee on Taxonomy agreed that evidence supports a third (and presently unnamed) subspecies of Southern Hemisphere blue whale subspecies, the Chilean blue whale. Whaling data indicate that the Chilean blue whale is intermediate in body length between pygmy and Antarctic blue whales. We collected body size data from blue whales in the Gulfo Corcovado, Chile, during the austral summers of 2015 and 2017 using aerial photogrammetry from a remotely controlled drone to test the hypo thesis that the Chilean blue whale is morphologically distinct from other Southern Hemisphere blue whale subspecies. We found the Chilean whale to be morphologically intermediate in both overall body length and relative tail length, thereby joining other diverse data in supporting the Chilean blue whale as a unique subspecific taxon. Additional photogrammetry studies of Antarctic, pygmy, and Chilean blue whales will help examine unique morphological variation within this species of conservation concern. To our knowledge, this is the first non-invasive small drone study to test a hypothesis for systematic biology.

中文翻译：

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从无人机图像中非侵入性收集的体型数据表明智利蓝鲸在形态上不同（Balaenoptera musculus Linnaeus 1758）

蓝鲸 Balaenoptera musculus（Linnaeus，1758 年）是 20 世纪激烈商业捕鲸的目标，目前的种群数量仍然大大低于捕鲸前的数量。减少亚种分类学的不确定性将使有针对性的保护策略能够恢复独特的种内多样性。目前，南半球温带至极地有2个已命名的蓝鲸亚种：南极蓝鲸B. m. intermedia 和侏儒蓝鲸 B. m. 短尾鱼。这些亚种具有不同的形态、遗传和声学。2019 年，海洋哺乳动物学会的分类委员会同意有证据支持南半球蓝鲸亚种智利蓝鲸的第三个（目前未命名）亚种。捕鲸数据表明，智利蓝鲸的体长介于侏儒蓝鲸和南极蓝鲸之间。我们在 2015 年和 2017 年的南半球夏季期间，使用遥控无人机的航空摄影测量从智利Gulfo Corcovado 的蓝鲸身上收集了体型数据，以测试智利蓝鲸在形态上不同于其他南半球蓝鲸的假设亚种。我们发现智利鲸鱼的整体体长和相对尾长在形态上都处于中间，从而与其他不同的数据一起支持智利蓝鲸作为一个独特的亚种分类群。对南极、侏儒和智利蓝鲸进行的其他摄影测量研究将有助于检查这一受保护物种内独特的形态变异。据我们所知，