Genetic tools that identify species from trace DNA samples could supplement traditional survey methods to clarify distributional limits of rare species. For species with legal habitat protection, elevational limits of distributions are used to determine where management actions may affect endangered species. The endangered Sierra Nevada yellow-legged frog (Rana sierrae) generally is found down to 1,370 m, but in the Plumas National Forest, California, USA, there are a number of historical records below this elevation, resulting in protections extending to 1,067 m. This species is phenotypically similar to the foothill yellow-legged frog (R. boylii), with which it occasionally hybridizes. We used a combination of genetic methods to investigate the fine-scale distribution of the Sierra Nevada yellow-legged frog in the Plumas National Forest. We collected and analyzed environmental DNA (eDNA) samples from all accessible lower elevation sites with records of Sierra Nevada yellow-legged frog (n = 17) and swabbed 220 individuals for genetic identification from 2016–2018 to clarify the distribution of this endangered species. We created a climatic suitability model using the validated Sierra Nevada yellow-legged frog records and current (1970–2000) climate models to assess additional highly suitable localities for Sierra Nevada yellow-legged frog presence using eDNA capture. We did not confirm detection of Sierra Nevada yellow-legged frog eDNA at any historical sites and identified all swabbed individuals from below 1,370 m (n = 144) as foothill yellow-legged frogs. We located a new Sierra Nevada yellow-legged frog site (at 1,919 m) during surveys guided by the climatic suitability model. It does not appear after extensive eDNA and genetic sampling that the Sierra Nevada yellow-legged frog occurs below 1,370 m in this portion of their range at present. Our results show that eDNA sampling can be used as an effective management tool to evaluate historical locations and previously unknown suitable localities for current presence of a species of interest. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.

中文翻译：

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使用环境 DNA 评估内华达山脉黄腿蛙的分布

从微量 DNA 样本中识别物种的遗传工具可以补充传统的调查方法，以澄清稀有物种的分布范围。对于具有合法栖息地保护的物种，分布的海拔限制用于确定管理行动可能影响濒危物种的位置。濒临灭绝的内华达山脉黄腿蛙（Rana sierrae）一般在1,370 m以下被发现，但在美国加利福尼亚州的Plumas国家森林中，该海拔以下有多项历史记录，导致保护范围延伸至1,067 m。该物种在表型上类似于山麓黄腿蛙（R. boylii)，它偶尔会与之杂交。我们使用遗传方法的组合来研究普拉马斯国家森林中内华达山脉黄腿蛙的精细分布。我们从所有可到达的低海拔地点收集并分析了环境 DNA (eDNA) 样本，并记录了内华达山脉黄腿蛙 ( n = 17) 并在 2016-2018 年间对 220 个人进行了基因鉴定，以阐明这种濒危物种的分布。我们使用经过验证的内华达山脉黄腿蛙记录和当前（1970-2000 年）气候模型创建了一个气候适宜性模型，以使用 eDNA 捕获评估其他非常适合内华达山脉黄腿蛙存在的地区。我们没有确认在任何历史遗址检测到内华达山脉黄腿蛙的 eDNA，并确定了 1,370 m ( n = 144）作为山麓黄腿蛙。在气候适宜性模型指导的调查期间，我们找到了一个新的内华达山脉黄腿蛙栖息地（海拔 1,919 m）。经过广泛的 eDNA 和基因采样，内华达山脉黄腿蛙目前并未出现在其分布范围的这一部分 1,370 m 以下。我们的结果表明，eDNA 采样可以作为一种有效的管理工具来评估历史位置和以前未知的适合当前存在的感兴趣物种的位置。© 2021 作者。由 Wiley Periodicals LLC 代表野生动物协会出版的《野生动物管理杂志》。