Aridland breeding bird communities of the United States are among the most vulnerable to drought, with many species showing significant population declines associated with decreasing precipitation and increasing temperature. Individual breeding bird species have varied responses to drought which suggests complex responses to changes in water availability. Here, we evaluated the influence of water deficit, an integrative metric of drought stress, on breeding bird communities within 3 distinct aridland habitat types: riparian, pinyon-juniper, and sagebrush shrubland. We used 12 years of breeding bird survey data from 11 national parks and monuments in the Northern Colorado Plateau Inventory and Monitoring Network (NCPN). We used a multivariate community-level approach to test for the effect of annual water deficit on the bird communities in the 3 habitats. We found that bird communities responded to water deficit in all 3 habitat types, and 70% of the 30 species–habitat combinations show significant relationships between density and variation in water deficit. Our analyses revealed that the direction and magnitude of species responses to water deficit were habitat-dependent. The habitat-specific responses we observed suggest that the adaptive capacity of some species depends on the habitat in which they occur, a pattern only elucidated with our habitat-based approach. The direction and magnitude of the relationships between predicted densities and annual water deficit can be used to predict the relative sensitivity of species within habitat climate changes. These results provide the first attempt to determine how the indirect effect of changes in water availability might affect aridland breeding birds in distinct habitat types. Linking breeding bird density to annual water deficit may be valuable for predicting changes in species persistence and distribution in response to climate change.

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基于栖息地的方法来确定干旱对干旱地区鸟类群落的影响

美国的干旱地区繁殖鸟类群落是最容易受到干旱影响的群体之一，许多物种的数量显着下降，这与降水减少和气温升高有关。个体繁殖鸟类对干旱有不同的反应，这表明对水供应变化的复杂反应。在这里，我们评估了缺水（干旱压力的综合指标）对 3 种不同干旱地区栖息地类型（河岸、松柏-杜松和山艾灌木丛）内繁殖鸟类群落的影响。我们使用了来自北科罗拉多高原清单和监测网络 (NCPN) 中 11 个国家公园和纪念碑的 12 年繁殖鸟类调查数据。我们使用多元社区层面的方法来测试年度缺水对 3 个栖息地鸟类群落的影响。我们发现鸟类群落对所有 3 种栖息地类型的缺水都有反应，并且 30 种栖息地组合中的 70% 显示出密度和缺水变化之间的显着关系。我们的分析表明，物种对缺水反应的方向和幅度取决于栖息地。我们观察到的特定栖息地的反应表明，某些物种的适应能力取决于它们所在的栖息地，这种模式只有通过我们基于栖息地的方法才能阐明。预测密度和年度缺水之间关系的方向和大小可用于预测物种在栖息地气候变化中的相对敏感性。这些结果首次尝试确定水资源可用性变化的间接影响如何影响不同栖息地类型的干旱地区繁殖鸟类。将繁殖鸟类密度与年度缺水量联系起来，对于预测物种持续性和分布因气候变化而发生的变化可能很有价值。