SummaryElusive species are challenging to study and conserve because basic elements of their biology may be unknown. Specimens of opportunity provide a means of collecting information on these species and may be critical for elusive species’ conservation. We used snowball sampling to identify Sowerby’s beaked whale (Mesoplodon bidens) specimens in museums and research institutions. Snowball sampling proved highly effective: we located 180 specimens from 24 institutions in North America and Europe, 62 of which were not listed in online collections databases, resulting in the largest collated dataset for this species. Analysis of these data resulted in several new findings for this species, including significant morphological variation between specimens from different collection regions, suggesting the presence of previously unidentified population structuring in this species. These data provide critical information regarding this species and demonstrate the effectiveness of specimens of opportunity for elusive species research and conservation. We recommend other researchers consider snowball sampling when designing research projects utilizing specimens of opportunity. Our results demonstrate the usefulness of snowball sampling and specimens of opportunity to elusive species research and conservation, and the methods of our study can be readily adapted for other species.

中文翻译：

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机会标本为难以捉摸的鲸鱼物种的研究和保护提供重要信息

摘要难以捉摸的物种难以研究和保护，因为它们生物学的基本要素可能是未知的。机会标本提供了一种收集这些物种信息的方法，可能对难以捉摸的物种的保护至关重要。我们使用雪球抽样来识别索尔比喙鲸（中齿龙) 博物馆和研究机构的标本。雪球抽样证明非常有效：我们从北美和欧洲的 24 个机构中找到了 180 个标本，其中 62 个未在在线收藏数据库中列出，从而形成了该物种最大的整理数据集。对这些数据的分析导致该物种的一些新发现，包括来自不同采集区域的标本之间的显着形态差异，表明该物种存在以前未识别的种群结构。这些数据提供了有关该物种的重要信息，并证明了机会标本对难以捉摸的物种研究和保护的有效性。我们建议其他研究人员在利用机会样本设计研究项目时考虑滚雪球抽样。