Understanding the demographic drivers of range contractions is important for predicting species' responses to climate change; however, few studies have examined the effects of climate change on survival and recruitment across species' ranges. We show that climate change can drive trailing edge range contractions through the effects on apparent survival, and potentially recruitment, in a migratory songbird. We assessed the demographic drivers of trailing edge range contractions using a long-term demography dataset for the black-throated blue warbler (Setophaga caerulescens) collected across elevational climate gradients at the trailing edge and core of the breeding range. We used a Bayesian hierarchical model to estimate the effect of climate change on apparent survival and recruitment and to forecast population viability at study plots through 2040. The trailing edge population at the low-elevation plot became locally extinct by 2017. The local population at the mid-elevation plot at the trailing edge gradually declined and is predicted to become extirpated by 2040. Population declines were associated with warming temperatures at the mid-elevation plot, although results were more equivocal at the low-elevation plot where we had fewer years of data. Population density was stable or increasing at the range core, although warming temperatures are predicted to cause population declines by 2040 at the low-elevation plot. This result suggests that even populations within the geographic core of the range are vulnerable to climate change. The demographic drivers of local population declines varied between study plots, but warming temperatures were frequently associated with declining rates of population growth and apparent survival. Declining apparent survival in our study system is likely to be associated with increased adult emigration away from poor-quality habitats. Our results suggest that demographic responses to warming temperatures are complex and dependent on local conditions and geographic range position, but spatial variation in population declines is consistent with the climate-mediated range shift hypothesis. Local populations of black-throated blue warblers near the warm-edge range boundary at low latitudes and low elevations are likely to be the most vulnerable to climate change, potentially leading to local extirpation and range contractions.

中文翻译：

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迁徙鸣禽的气候介导的种群动态在后缘和范围核心之间不同

了解范围收缩的人口驱动因素对于预测物种对气候变化的反应很重要；然而，很少有研究探讨气候变化对跨物种分布范围的生存和补充的影响。我们表明，气候变化可以通过对迁徙鸣禽的表观生存和潜在招募的影响来推动后缘范围收缩。我们使用黑喉蓝莺 ( Setophaga caerulescens)的长期人口统计数据集评估了后缘范围收缩的人口驱动因素) 在繁殖范围的后缘和核心跨越海拔气候梯度收集。我们使用贝叶斯分层模型来估计气候变化对表观生存和补充的影响，并预测到 2040 年研究地块的种群生存能力。到 2017 年，低海拔地块的后缘种群在当地灭绝。后缘的中海拔地块逐渐下降，预计到 2040 年将灭绝。人口下降与中海拔地块的气温变暖有关，尽管在低海拔地块的结果更加模棱两可，那里的年数较少数据。人口密度在范围核心稳定或增加，尽管预计到 2040 年气温变暖会导致低海拔地块的人口减少。这一结果表明，即使是该范围地理核心内的种群也容易受到气候变化的影响。当地人口减少的人口驱动因素因研究地块而异，但气温升高通常与人口增长率和表观存活率下降有关。在我们的研究系统中，明显的生存率下降可能与远离质量差的栖息地的成年移民增加有关。我们的结果表明，人口对变暖温度的反应是复杂的，并且取决于当地条件和地理范围位置，但人口下降的空间变化与气候介导的范围转移假设一致。