Efforts to tackle the current biodiversity crisis need to be as efficient and effective as possible given chronic underfunding. To inform decision-makers of the most effective conservation actions, it is important to identify biases and gaps in the conservation literature to prioritize future evidence generation. We used the Conservation Evidence database to assess the state of the global literature that tests conservation actions for amphibians and birds. For the studies in the database, we investigated their spatial and taxonomic extent and distribution across biomes, effectiveness metrics, and study designs. Studies were heavily concentrated in Western Europe and North America for birds and particularly for amphibians, and temperate forest and grassland biomes were highly represented relative to their percentage of land coverage. Studies that used the most reliable study designs - before-after control-impact and randomized controlled trials - were the most geographically restricted and scarce in the evidence base. There were negative spatial relationships between the numbers of studies and the numbers of threatened and data-deficient species worldwide. Taxonomic biases and gaps were apparent for amphibians and birds-some entire orders were absent from the evidence base-whereas others were poorly represented relative to the proportion of threatened species they contained. Metrics used to evaluate effectiveness of conservation actions were often inconsistent between studies, potentially making them less directly comparable and evidence synthesis more difficult. Testing conservation actions on threatened species outside Western Europe, North America and Australasia should be prioritized. Standardizing metrics and improving the rigor of study designs used to test conservation actions would also improve the quality of the evidence base for synthesis and decision-making. Article impact statement: Severe taxonomic and geographic bias in the literature that tests the effectiveness of conservation actions threatens evidence-based conservation efforts. This article is protected by copyright. All rights reserved.

中文翻译：

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保护中存在偏见的证据的挑战

鉴于长期资金不足，应对当前生物多样性危机的努力需要尽可能高效和有效。为了让决策者了解最有效的保护行动，识别保护文献中的偏见和差距以优先考虑未来的证据生成是很重要的。我们使用保护证据数据库来评估测试两栖动物和鸟类保护行动的全球文献状态。对于数据库中的研究，我们调查了它们在生物群落、有效性指标和研究设计中的空间和分类范围和分布。鸟类的研究主要集中在西欧和北美，尤其是两栖动物，温带森林和草原生物群落相对于其土地覆盖率的百分比具有很高的代表性。使用最可靠研究设计的研究——前后对照影响试验和随机对照试验——在证据基础上是地理上最受限制和最稀缺的。研究数量与全球受威胁和数据不足的物种数量之间存在负空间关系。两栖动物和鸟类的分类偏差和差距很明显——证据基础中没有一些完整的命令——而其他命令相对于它们所包含的受威胁物种的比例来说代表性很差。用于评估保护行动有效性的指标在研究之间往往不一致，这可能使它们的直接可比性降低，证据合成更加困难。测试西欧以外受威胁物种的保护行动，应优先考虑北美和澳大拉西亚。标准化指标和提高用于测试保护行动的研究设计的严谨性也将提高综合和决策证据基础的质量。文章影响声明：测试保护行动有效性的文献中存在严重的分类学和地理偏见，威胁着以证据为基础的保护工作。本文受版权保护。版权所有。本文受版权保护。版权所有。本文受版权保护。版权所有。