Species distribution models (SDMs) provide insights into species' ecology and distributions and are frequently used to guide conservation priorities. However, many uses of SDMs require model transferability, which refers to the degree to which a model built in one place or time can successfully predict distributions in a different place or time. If a species' model has high spatial transferability, the relationship between abundance and predictor variables should be consistent across a geographical distribution. We used Breeding Bird Surveys, climate and remote sensing data, and a novel method for quantifying model transferability to test whether SDMs can be transferred across the geographic ranges of 129 species of North American birds. We also assessed whether species' traits are correlated with model transferability. We expected that prediction accuracy between modeled regions should decrease with 1) geographical distance, 2) degree of extrapolation and 3) the distance from the core of a species' range. Our results suggest that very few species have a high model transferability index (MTI). Species with large distributions, with distributions located in areas with low topographic relief, and with short lifespans are more likely to exhibit low transferability. Transferability between modeled regions also decreased with geographical distance and degree of extrapolation. We expect that low transferability in SDMs potentially resulted from both ecological non-stationarity (i.e. biological differences within a species across its range) and over-extrapolation. Accounting for non-stationarity and extrapolation should substantially increase the prediction success of species distribution models, therefore enhancing the success of conservation efforts.

中文翻译：

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影响物种分布模型中可转移性的因素

物种分布模型 (SDM) 提供对物种生态和分布的洞察，并经常用于指导保护优先事项。但是，SDM 的许多用途都需要模型可迁移性，这是指在一个地方或时间建立的模型能够成功预测不同地方或时间的分布的程度。如果一个物种的模型具有很高的空间可转移性，丰度和预测变量之间的关系应该在整个地理分布中保持一致。我们使用育种鸟类调查、气候和遥感数据以及一种量化模型可转移性的新方法来测试 SDM 是否可以在 129 种北美鸟类的地理范围内转移。我们还评估了物种的特征是否与模型可转移性相关。我们预计建模区域之间的预测精度应随着 1）地理距离、2）外推程度和 3）与物种范围核心的距离而降低。我们的结果表明，很少有物种具有高模型可转移性指数（MTI）。分布范围大、分布在地形起伏低的地区和寿命短的物种更有可能表现出低可转移性。建模区域之间的可转移性也随着地理距离和外推程度而降低。我们预计 SDM 中的低可转移性可能是由于生态非平稳性（即物种在其范围内的生物学差异）和过度外推造成的。