Many species on endangered species lists such as the IUCN Red List (RL) are categorized using demographic factors such as numbers of mature individuals. Genetic factors are not currently used in the RL even though their explicit consideration, including effective population size (N_e) and expected heterozygosity-loss (H-loss), could improve the assessment of extinction risk. Here, we consider the estimation of N_e and H-loss in the context of RL species. First, we investigate the reporting of number of mature individuals for RL Endangered species, which is needed to estimate N_e and H-loss. We found 77% of species assessments studied here did not report methods used to estimate the number of mature adults, and that these assessments rarely report other important determinants of N_e (e.g., sex ratio, variance in family size). We therefore applied common rules of thumb to estimate N_e, and found that N_e was likely < 50 for at least 25% of the 170 RL Endangered species studied here. We also estimated mean expected H-loss for these species over the next 100 years, and found it to be 9–29%. These estimates of high H-loss and low N_e suggest that some species listed as Endangered likely warrant listing as Critically Endangered if genetic considerations were included. We recommend that RL and other assessment frameworks (i) report methods used for estimating the number of mature adults, (ii) include standardized information on species traits that influence N_e to facilitate N_e estimation, and (iii) consider using concepts like N_e and heterozygosity-loss in risk assessments.

IUCN红色名录（RL）等濒危物种清单上的许多物种都是使用人口统计因素（例如成熟个体的数量）进行分类的。即使在遗传因素中进行了明确考虑，包括有效种群规模（N _e）和预期杂合度损失（H损失），遗传因素仍未在RL中使用，但可以改善对灭绝风险的评估。在这里，我们考虑在RL物种的背景下对N _e和H损失的估计。首先，我们调查了RL濒危物种的成熟个体数量的报告，这需要估算N _e和H-失利。我们发现这里研究的77％的物种评估没有报告用于估计成年成年人数量的方法，并且这些评估很少报告N _e的其他重要决定因素（例如，性别比，家庭规模的差异）。因此，我们运用通用的经验法则来估计N _e，发现对于这里研究的170个RL濒危物种中的至少25％，N _e可能小于50。我们还估计了这些物种在未来100年的平均预期H损失，发现为9–29％。高H损失和低N _e的这些估计这表明，如果考虑遗传因素，某些被列为濒危物种可能需要列为极度濒危物种。我们建议RL和其他评估框架（i）报告用于估计成年成年人数量的方法；（ii）包括影响N _e的物种特征的标准化信息，以促进N _e的估计；以及（iii）考虑使用类似N的概念_e和杂合性损失的风险评估。