As breeding areas are becoming warmer and wetter, climatic changes are likely to affect the distributions of millions of waterfowl in Eastern Canada. The objective of this study was to assess the potential effects of climate change on the breeding distribution and abundance of 12 common waterfowl species, by using a climate envelope modeling approach. Our response variables were species counts on 317 helicopter plots (25 km2) averaged over 22 years (1996–2017). We applied a covariate selection procedure to select the best subset of a panel of 170 climate covariates for each species, which we then used to fit quantile regression forest models. Climate change projections were applied to the waterfowl models to infer 2011–2100 abundances. From the projected abundances, we computed climate suitability indices that accounted for potential temporal mismatches between climate change and the biota, as well as the expected velocity of climate change. On average, with a maximum of 4 covariates per model, the variance explained was 41% for out-of-bag predictions. Overall, the magnitude of absolute projected changes peaked under the “high” greenhouse gas concentration trajectory (RCP8.5) and at the end of the century (2071–2100). Species-specific projections indicated that climate change would potentially increase the abundance and core distributions of 7/12 species, whereas 5/12 species would experience a decrease. In particular, large decreases were projected for Barrow’s goldeneye, an imperiled boreal cavity nester. Our spatially explicit indices of climate suitability deliver important information for targeting areas to preserve waterfowl, ecosystems, and the services they provide.

中文翻译：

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气候变化对加拿大东部繁殖水禽分布和丰度的预测影响

随着繁殖区变得越来越温暖和潮湿，气候变化可能会影响加拿大东部数百万水禽的分布。本研究的目的是通过使用气候包络模型方法评估气候变化对 12 种常见水禽物种的繁殖分布和丰度的潜在影响。我们的响应变量是 22 年（1996-2017 年）平均 317 个直升机地块（25 平方公里）的物种计数。我们应用协变量选择程序为每个物种选择一组 170 个气候协变量的最佳子集，然后我们将其用于拟合分位数回归森林模型。将气候变化预测应用于水禽模型以推断 2011-2100 年的丰度。从预测的丰度来看，我们计算了气候适宜性指数，这些指数解释了气候变化与生物群之间潜在的时间不匹配，以及气候变化的预期速度。平均而言，每个模型最多有 4 个协变量，袋外预测的方差解释为 41%。总体而言，绝对预测变化的幅度在“高”温室气体浓度轨迹（RCP8.5）和本世纪末（2071-2100）达到峰值。特定物种的预测表明，气候变化可能会增加 7/12 物种的丰度和核心分布，而 5/12 物种将减少。特别是，Barrow's goldeye，一种濒临灭绝的北腔巢穴鸟，预计会大幅减少。