Poleward shifts and altered periodicity in boreal bird irruptions over six decades
Poleward shifts and altered periodicity in boreal bird irruptions over six decades
复制标题
六十年来北方鸟类入侵的极移和周期性变化
DOI：
10.1111/1365-2656.13917
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发表时间：
2023
影响因子：
4.8
通讯作者：
Zuckerberg, Benjamin
中科院分区：
文献类型：
--
作者：
Widick, Ivy V.;Young, Matthew A.;LaMontagne, Jalene M.;Strong, Courtenay;Zuckerberg, Benjamin
范围边界是物种分布和丰度的长期生物地理特征。然而，许多物种表现出动态范围边界，反映出迁徙行为的强烈季节性和年度变异性。作为兼性迁移的一种形式，入侵涉及到许多个体在其居住范围之外的移动，以响应气候变化、资源可用性和人口进程。在现代气候变化的影响下，许多物种经历了范围转移和物候变化，但入侵动态的时空变化却鲜为人知。我们量化了1960年至2021年北美东部北方鸟类入侵的地理变化和周期性。利用奥杜邦圣诞鸟类统计的9种雀类（包括几种近期种群数量下降的雀类）的数据，我们评估了南部范围和入侵边界的纬度趋势，并利用光谱小波分析表征了入侵的周期性。6种北方鸟类在其南部范围边界上表现出明显的北移，3种鸟类在其南部入侵边界上表现出明显的北移。在20世纪60年代和70年代，多物种之间的入侵周期是一致的，在前几十年里，多物种频繁和同步的入侵达到高潮（超级飞行）。物种间的一致性从20世纪80年代初开始减弱，因为超级飞行的周期性变得越来越无结构，最终在2000年以后的几十年里恢复了。北方鸟类被认为是北方森林的重要哨兵，向北移动和入侵周期的改变可能表明在北方森林中运行的气候和资源相关驱动因素发生了大范围的变化。
Range boundaries are long‐term biogeographic features of species distributions and abundance. However, many species demonstrate dynamic range boundaries, reflecting strong seasonal and annual variability in migratory behaviour. As a form of facultative migration, irruptions involve the movement of many individuals outside of their resident range in response to climate variability, resource availability, and demographic processes. Many species have experienced range shifts and altered phenology in response to modern climate change, but spatiotemporal changes in irruption dynamics are less well known. We quantified changes in the geography and periodicity of boreal bird irruptions across eastern North America from 1960 to 2021. Using data from Audubon's Christmas Bird Count for nine finch species, including several exhibiting recent population declines, we evaluated latitudinal trends in southern range and irruption boundaries and characterized irruption periodicity using spectral wavelet analysis. Six boreal birds exhibited significant northward shifts in their southern range boundaries and three species displayed shifts in their southern irruption boundaries. Irruption periodicity across multiple species was consistent across the 1960s and 1970s, culminating in frequent and synchronized irruptions of multiple species (superflights) during earlier decades. Coherence between species dampened beginning in the early 1980s as superflight periodicity became increasingly unstructured, finally reforming in recent decades, after 2000. Boreal birds are considered important sentinels of the boreal forests, and northward shifts and altered periodicity of irruptions may indicate broad‐scale changes in climate‐and resource‐associated drivers operating across the boreal forests.