Many species are poorly known, with the sum of our knowledge represented by specimens in museums. For assessment of conservation status the most enigmatic and challenging species are probably those known only from a single specimen. We examine the potential persistence of such species using the orchid flora of Madagascar as a case study. We apply a statistical method that tests the likelihood of species presence in relation to the time when a species was collected and a measure of annual collection effort, calculated in three ways based on specimen collection over time. The results suggest that as of 2000 up to nine of the 236 orchid species known from a single specimen may be inferred to be extinct under at least one of the three methods of estimating collection effort and extinction. In addition, up to two additional species are likely to be extinct by 2018 assuming no new collections were made by that time. Substantial collection effort and/or additional evidence will be needed to reach a decision on the persistence of more recently observed species known only from a single collection. This represents a challenge for conservation practitioners.

中文翻译：

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推断仅从单个标本中已知的物种的灭绝

许多物种鲜为人知，博物馆中的标本代表了我们知识的总和。对于保护状况的评估，最神秘和最具挑战性的物种可能是那些仅从单个标本中获知的物种。我们以马达加斯加的兰花植物群作为案例研究，研究了此类物种的潜在持久性。我们应用了一种统计方法，该方法测试物种存在的可能性与收集物种的时间和衡量年度收集工作量的关系，根据随时间推移的标本收集以三种方式计算。结果表明，截至 2000 年，从单个标本中已知的 236 种兰花中，有多达 9 种可能在估计采集工作量和灭绝的三种方法中的至少一种下被推断为灭绝。此外，假设到那时没有新的收藏品，那么到 2018 年，多达两个额外的物种可能会灭绝。需要大量的收集工作和/或额外的证据才能就仅从单个收集中知道的最近观察到的物种的持久性做出决定。这对保护从业者来说是一个挑战。