Langmore Group, Research School of Biology, Australian National University, Building 46, Canberra, 0200, Australia.
Australian National Wildlife Collection, National Research Collections Australia, CSIRO, Canberra, 2601, Australia.
Sci Rep. 2021 Jan 15;11(1):1605. doi: 10.1038/s41598-020-79852-4.
Natural history collections are often plagued by missing or inaccurate metadata for collection items, particularly for specimens that are difficult to verify or rare. Avian eggshell in particular can be challenging to identify due to extensive morphological ambiguity among taxa. Species identifications can be improved using DNA extracted from museum eggshell; however, the suitability of current methods for use on small museum eggshell specimens has not been rigorously tested, hindering uptake. In this study, we compare three sampling methodologies to genetically identify 45 data-poor eggshell specimens, including a putatively extinct bird's egg. Using an optimised drilling technique to retrieve eggshell powder, we demonstrate that sufficient DNA for molecular identification can be obtained from even the tiniest eggshells without significant alteration to the specimen's appearance or integrity. This method proved superior to swabbing the external surface or sampling the interior; however, we also show that these methods can be viable alternatives. We then applied our drilling method to confirm that a purported clutch of Paradise Parrot eggs collected 40 years after the species' accepted extinction date were falsely identified, laying to rest a 53-year-old ornithological controversy. Thus, even the smallest museum eggshells can offer new insights into old questions.
自然历史藏品常常受到馆藏物品元数据缺失或不准确的困扰，尤其是对于那些难以核实或罕见的标本。由于分类群之间存在广泛的形态模糊性，鸟类蛋壳尤其难以识别。可以从博物馆蛋壳中提取 DNA 来提高物种鉴定的准确性；然而，目前这些方法在小博物馆蛋壳标本上的适用性尚未经过严格测试，这阻碍了它们的应用。在这项研究中，我们比较了三种采样方法，以从 45 个数据不足的蛋壳标本中进行基因鉴定，包括一个据称已灭绝的鸟类蛋。通过优化的钻孔技术来提取蛋壳粉末，我们证明即使是最小的蛋壳也可以获得足够的 DNA 进行分子鉴定，而不会对标本的外观或完整性造成显著影响。这种方法证明优于擦拭外表面或采样内部；然而，我们也表明这些方法是可行的替代方法。然后，我们应用我们的钻孔方法来确认，40 年前在该物种被公认灭绝日期之后收集的所谓天堂鹦鹉蛋是错误鉴定的，从而结束了一个 53 年的鸟类学争议。因此，即使是最小的博物馆蛋壳也可以为旧问题提供新的见解。
