Projected increases in the variability of both temperature and precipitation will result in the greater likelihood and magnitude of extreme weather (e.g., cold snaps, droughts, heat waves) with potential implications for animal populations. Despite the ecological consequences of extreme weather, there are several challenges in identifying extreme events and measuring their influence on key demographic processes in free‐living animals. First, there is often a mismatch between the spatial and/or temporal resolution of biological and climate data that could hinder our ability to draw accurate inferences about how species and populations respond to extreme events. Second, there are multiple approaches for identifying an extreme event ranging from statistical definitions (e.g., standardized deviates) to species‐specific biological thresholds. Lastly, the impacts of extreme weather on species can vary as a function of differences in exposure and intrinsic sensitivity to climate variability. In the Northern Hemisphere, rapid warming has contributed to a “wobblier” jet stream that promotes the higher likelihood of cold Arctic air moving southward and leading to more extreme winter conditions. Due to these conditions, the Upper Midwest experienced two of the coldest winters in the past 35 yr during 2014 and 2015. We combined radiofrequency identification technologies with fine‐scale weather data and standard capture–mark–recapture analyses to estimate weekly and overwinter survival rates of a common winter passerine, the Black‐capped Chickadee (Poecile atricapillus), in a near continuous fashion. Using both statistical and biological definitions of weather extremes, we found that declining ambient temperatures reduced survival (despite the presence of favorable microclimates), and that biologically defined thresholds of extreme weather were better at explaining variation in survival than statistical ones. Moreover, habitat fragmentation interacted with temperature to modify the exposure of birds to extreme weather with survival consequences, but sensitivity, as measured by body condition, did not appear to play a significant role. These results provide a novel contribution to the understanding of how extreme weather may interact with local‐ and landscape features to influence the demography of species and populations, and suggest potential opportunities for climate‐change adaptation in human‐dominated landscapes.

中文翻译：

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极端到底有多极端？人口统计方法可告知极端事件的发生和生态相关性

预计温度和降水可变性的增加将导致极端天气（例如，寒潮，干旱，热浪）的可能性和强度更大，对动物种群有潜在的影响。尽管极端天气对生态造成了影响，但在识别极端事件并衡量其对自由生存动物的关键人口统计过程的影响方面仍存在一些挑战。首先，生物学和气候数据在空间和/或时间分辨率上常常不匹配，这可能会阻碍我们就物种和种群对极端事件的反应做出准确推断的能力。其次，从统计定义（例如，标准偏差）到特定物种的生物阈值，有多种识别极端事件的方法。最后，极端天气对物种的影响会随暴露程度的差异和对​​气候变化的内在敏感性而变化。在北半球，迅速变暖导致了“喷气式”喷气流，这促使北极冷空气向南移动的可能性更高，并导致更极端的冬季条件。由于这些条件，中西部上西部地区在2014年和2015年经历了过去35年中最冷的两个冬季。我们将射频识别技术与精细的天气数据以及标准的捕获-标记-捕获分析相结合，以估计每周和越冬的生存率常见的冬季雀形目，黑冠山雀（在北半球，迅速变暖导致了“喷气式”喷气流，这促使北极冷空气向南移动的可能性更高，并导致更极端的冬季条件。由于这些条件，中西部上西部地区在2014年和2015年经历了过去35年中最冷的两个冬季。我们将射频识别技术与精细的天气数据以及标准的捕获-标记-捕获分析相结合，以估计每周和越冬的生存率常见的冬季雀形目，黑冠山雀（在北半球，快速变暖导致了“喷气式”喷气流，这促使北极冷空气向南移动的可能性增加，并导致更极端的冬季条件。由于这些条件，中西部上西部地区在2014年和2015年经历了过去35年中最冷的两个冬季。我们将射频识别技术与精细的天气数据以及标准的捕获-标记-捕获分析相结合，以估计每周和越冬的生存率常见的冬季雀形目，黑冠山雀（猪锥虫），以近乎连续的方式呈现。使用极端天气的统计和生物学定义，我们发现环境温度的下降会降低生存率（尽管存在有利的微气候），而生物学上定义的极端天气阈值比统计阈值更能解释生存率的变化。此外，栖息地的破碎与温度相互作用，改变了鸟类在极端天气下的暴露，从而带来了生存后果，但是根据身体状况测得的敏感性似乎并未发挥重要作用。这些结果为理解极端天气如何与局部和景观特征相互作用以影响物种和种群的人口分布提供了新的贡献，