Abstract Threatened species lists are important policy tools for species conservation, and they are often used to help prioritize recovery actions. Current listing processes, such as the IUCN red list threat assessment, rely on accepted correlates of extinction risk, especially population size. Population size appears to be an effective indicator for threatened vertebrate species, but it is less relevant for invertebrate species, where population sizes are rarely known. Furthermore, many invertebrate species are dependent upon a host species for survival and reproduction, and thus host population sizes would be better indicators of (co-)extinction vulnerability. Improving listing criteria to be relevant to invertebrates is important, because faunal biodiversity consists predominantly of invertebrate species (>98%) and invertebrates likely represent a majority of the current global sixth mass extinction event. Here, we propose including the degree of host specificity of a dependent invertebrate species to threatened host species as an additional correlate of extinction proneness, where there is a continuum from generalist dependents to dependents that are completely specialized to use a single host species per life stage. For highly specialized dependent taxa, we recommend that that threat category assigned to the dependent species should match the threat category assigned to the host species. Incorporating this correlate of extinction risk into threatened species policy, such as the IUCN red list, could rapidly increase the rate of assessments for many invertebrates and justify their inclusion, where previously they may have been considered data deficient.

中文翻译：

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将共灭绝纳入威胁评估和政策将迅速提高受威胁物种清单的准确性

摘要 受威胁物种清单是物种保护的重要政策工具，通常用于帮助确定恢复行动的优先级。当前的列名程序，例如 IUCN 红色名录威胁评估，依赖于公认的灭绝风险相关性，尤其是种群规模。种群规模似乎是受威胁脊椎动物物种的有效指标，但它与无脊椎动物物种的相关性较小，因为种群规模很少为人所知。此外，许多无脊椎动物物种的生存和繁殖依赖于宿主物种，因此宿主种群规模将是（共同）灭绝脆弱性的更好指标。改进与无脊椎动物相关的列入标准很重要，因为动物群生物多样性主要由无脊椎动物物种组成 (> 98%）和无脊椎动物可能代表了当前全球第六次大规模灭绝事件的大部分。在这里，我们建议将依赖的无脊椎动物物种对受威胁的宿主物种的宿主特异性程度作为灭绝倾向的额外关联，其中存在从通才依赖到完全专门用于每个生命阶段使用单一宿主物种的依赖的连续体. 对于高度专业化的依赖类群，我们建议分配给依赖物种的威胁类别应与分配给寄主物种的威胁类别相匹配。将灭绝风险的这种相关性纳入濒危物种政策，例如 IUCN 红色名录，可以迅速提高对许多无脊椎动物的评估率，并证明将它们包括在内，