PDF(Pubmed)
Abstract：
OBJECTIVE: Trailing-edge populations at the low-latitude, receding edge of a shifting range face high extinction risk from climate change unless they are able to track optimal environmental conditions through dispersal.
METHODS: We fit dispersal models to the locations of 3165 individually-marked black-throated blue warblers (Setophaga caerulescens) in the southern Appalachian Mountains in North Carolina, USA from 2002 to 2023. Black-throated blue warbler breeding abundance in this population has remained relatively stable at colder and wetter areas at higher elevations but has declined at warmer and drier areas at lower elevations.
RESULTS: Median dispersal distance of young warblers was 917 m (range 23-3200 m), and dispersal tended to be directed away from warm and dry locations. In contrast, adults exhibited strong site fidelity between breeding seasons and rarely dispersed more than 100 m (range 10-1300 m). Consequently, adult dispersal kernels were much more compact and symmetric than natal dispersal kernels, suggesting adult dispersal is unlikely a driving force of declines in this population.
CONCLUSIONS: Our findings suggest that directional natal dispersal may mitigate fitness costs for trailing-edge populations by allowing individuals to track changing climate and avoid warming conditions at warm-edge range boundaries.
METHODS: We fit dispersal models to the locations of 3165 individually-marked black-throated blue warblers (Setophaga caerulescens) in the southern Appalachian Mountains in North Carolina, USA from 2002 to 2023. Black-throated blue warbler breeding abundance in this population has remained relatively stable at colder and wetter areas at higher elevations but has declined at warmer and drier areas at lower elevations.
RESULTS: Median dispersal distance of young warblers was 917 m (range 23-3200 m), and dispersal tended to be directed away from warm and dry locations. In contrast, adults exhibited strong site fidelity between breeding seasons and rarely dispersed more than 100 m (range 10-1300 m). Consequently, adult dispersal kernels were much more compact and symmetric than natal dispersal kernels, suggesting adult dispersal is unlikely a driving force of declines in this population.
CONCLUSIONS: Our findings suggest that directional natal dispersal may mitigate fitness costs for trailing-edge populations by allowing individuals to track changing climate and avoid warming conditions at warm-edge range boundaries.
摘要：
目标：低纬度地区的后缘种群，变化范围的后退边缘面临着气候变化带来的高灭绝风险，除非它们能够通过扩散来跟踪最佳环境条件。
方法：我们将散布模型拟合到北卡罗来纳州南部阿巴拉契亚山脉的3165只单独标记的黑喉蓝莺（Setophagacaerulescens）的位置，美国从2002年到2023年。该种群中黑喉蓝莺的繁殖丰度在较高海拔的较冷和较湿润地区保持相对稳定，但在较低海拔的较温暖和较干燥地区却有所下降。
结果：幼莺的散布距离中位数为917m（范围23-3200m），和分散倾向于远离温暖干燥的地方。相比之下,成虫在繁殖季节之间表现出很强的位置保真度，很少分散超过100m（范围10-1300m）。因此,成年散粒比出生散粒更紧凑和对称，这表明成年人的扩散不太可能是这个人口下降的驱动力。
结论：我们的研究结果表明，定向出生扩散可以通过允许个体跟踪气候变化并避免温暖边缘范围边界的变暖条件来减轻后缘人群的健身成本。
方法：我们将散布模型拟合到北卡罗来纳州南部阿巴拉契亚山脉的3165只单独标记的黑喉蓝莺（Setophagacaerulescens）的位置，美国从2002年到2023年。该种群中黑喉蓝莺的繁殖丰度在较高海拔的较冷和较湿润地区保持相对稳定，但在较低海拔的较温暖和较干燥地区却有所下降。
结果：幼莺的散布距离中位数为917m（范围23-3200m），和分散倾向于远离温暖干燥的地方。相比之下,成虫在繁殖季节之间表现出很强的位置保真度，很少分散超过100m（范围10-1300m）。因此,成年散粒比出生散粒更紧凑和对称，这表明成年人的扩散不太可能是这个人口下降的驱动力。
结论：我们的研究结果表明，定向出生扩散可以通过允许个体跟踪气候变化并避免温暖边缘范围边界的变暖条件来减轻后缘人群的健身成本。
