Extreme weather events are increasing in frequency and intensity as a result of modern climate change. During winter, species may be especially vulnerable to extreme weather as they are surviving on scarce resources and living at the edge of their thermal limits. We compiled data from eBird, a global citizen science initiative, to examine how 41 eastern North American birds shifted their occurrence and abundance patterns immediately following two recent extreme weather events each affecting > 2 million km², the intrusion of a polar vortex and a winter heat wave. eBird data is continuously collected at high spatiotemporal resolution across large spatial extents, allowing us to compare species' responses immediately before and after these extreme events with trends in other winters across geographic scales. Overall, we found that birds responded differently to each extreme weather event. Bird occurrence rates did not change following the polar vortex, but where species occurred, population density was temporarily reduced, suggesting reductions in number of individuals driven by decreases in behavioral activity or temporary movement out of the area. However, birds demonstrated widespread increases in occurrence and increases in density and number of individuals where they occurred for at least 20 days after the heat wave, hinting at longer-term range changes. Smaller-bodied, warm-adapted passerines tended to be most sensitive to extreme weather and responded most negatively to the polar vortex and most positively to the heat wave, while larger-bodied, cold-adapted waterbirds expressed only mild responses to either event. Thus, certain species may be exceptionally sensitive to extreme weather events while others are less sensitive. As climate change progresses and climatic variability increases, researchers and managers must better quantify the broad-scale sensitivity of different species to multiple types of extreme weather events.

中文翻译：

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极端的冬季天气在地理尺度上扰乱了鸟类的出现和数量模式

由于现代气候变化，极端天气事件的频率和强度都在增加。在冬季，物种可能特别容易受到极端天气的影响，因为它们依靠稀缺资源生存并生活在热极限的边缘。我们收集了来自全球公民科学倡议 eBird 的数据，以研究 41 只北美东部鸟类如何在最近两次极端天气事件之后立即改变它们的出现和数量模式，每次极端天气事件影响超过 200 万平方公里²，极地涡旋和冬季热浪的入侵。eBird 数据在大空间范围内以高时空分辨率连续收集，使我们能够将这些极端事件前后的物种反应与地理尺度上其他冬季的趋势进行比较。总的来说，我们发现鸟类对每个极端天气事件的反应不同。极地涡旋之后鸟类的出现率没有变化，但在物种出现的地方，种群密度暂时减少，这表明由于行为活动减少或暂时离开该地区而导致个体数量减少。然而，在热浪过后至少 20 天，鸟类的发生率和密度和数量都出现了广泛的增加，暗示更长期的范围变化。体型较小、适应温暖的雀鸟往往对极端天气最敏感，对极地涡旋的反应最消极，对热浪的反应最积极，而体型较大、适应寒冷的水鸟对任何一种事件都只表现出轻微的反应。因此，某些物种可能对极端天气事件异常敏感，而其他物种则不太敏感。随着气候变化的进展和气候变率的增加，研究人员和管理人员必须更好地量化不同物种对多种极端天气事件的广泛敏感性。适应寒冷的水鸟对这两种情况都只表现出轻微的反应。因此，某些物种可能对极端天气事件异常敏感，而其他物种则不太敏感。随着气候变化的进展和气候变率的增加，研究人员和管理人员必须更好地量化不同物种对多种极端天气事件的广泛敏感性。适应寒冷的水鸟对这两种情况都只表现出轻微的反应。因此，某些物种可能对极端天气事件异常敏感，而其他物种则不太敏感。随着气候变化的进展和气候变率的增加，研究人员和管理人员必须更好地量化不同物种对多种极端天气事件的广泛敏感性。