The implications of mid-latitude climate extremes for North American migratory bird populations
The implications of mid-latitude climate extremes for North American migratory bird populations
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中纬度极端气候对北美候鸟种群的影响
DOI：
10.1002/ecs2.1261
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发表时间：
2016
期刊：
影响因子：
2.7
通讯作者：
D. Sheldon
中科院分区：
文献类型：
--
作者：
F. A. Sorte;W. Hochachka;Andrew Farnsworth;A. Dhondt;D. Sheldon
在全球气候变化的影响下，预计中纬度极端气候事件的发生频率将增加。这对候鸟种群的影响还不清楚。2012年3月，北美中纬度地区经历了一次极端变暖事件，使春季生态生产力的物候提前，导致夏季生产力水平降低。在这里，我们测试的预测：（1）短距离候鸟，由于地理上的接近和更灵活的迁徙行为，应该提前他们的春季迁徙物候;（2）繁殖种群，由于夏季生产力较低，应该有减少的发生。我们使用eBird数据库中353种鸟类的出现数据来计算2012年相对于2010-2014年平均值的每周出现异常。我们确定了在2012年3月期间具有异常大的正发生异常的物种和在2012年7月至8月期间具有异常大的负发生异常的物种。对于每个类别，我们总结了迁移策略，地理分布，以及与温度和生态生产力的年度关联。短距离移民的冬季和繁殖范围相交的中纬度地区提前春季迁徙物候在3月（n = 21）。长距离移民的冬季和繁殖分布弱相关的中纬度地区发生率较低，在夏季（n = 32）。这两个类别共有5个物种。在物种的冬季范围内，温度和生态生产力高于预期在3月;在物种的繁殖范围内，生态生产力低于预期在夏季。这些差异在21名短途移民中最为明显。与我们的预期一致，中纬度极端气候及其相关生态后果广泛影响了该区域内的鸟类迁徙和繁殖活动。我们的研究结果表明，短途移民更具灵活性和弹性，而长途移民群体则处于明显的劣势，如果这些事件的频率增加，这种劣势可能会加剧。
Mid-latitude climate extremes are projected to increase in frequency under global climate change. How this may affect migratory bird populations is not well understood. The mid-latitudes of North America experienced an extreme warming event during March 2012 that advanced the spring phenology of ecological productivity, resulting in lower levels of productivity during the summer. Here, we test the predictions that: (1) short-distance migratory birds, due to geographic proximity and more flexible migratory behavior, should advance their spring migration phenology; and (2) breeding populations, due to lower summer productivity, should have reduced occurrences. We used occurrence data for 353 bird species from the eBird database to calculate weekly occurrence anomalies for 2012 relative to the 2010–2014 average. We identified species having unusually large positive occurrence anomalies during March 2012 and species having unusually large negative occurrence anomalies during July–August 2012. For each category, we summarized migration strategies, geographic distributions, and annual associations with temperature and ecological productivity. Short-distance migrants whose winter and breeding ranges intersect the mid-latitudes advanced their spring migration phenology during March (n = 21). Long-distance migrants whose winter and breeding distributions were weakly associated with the mid-latitudes had lower occurrences during the summer (n = 32). Five species were shared between the two categories. Within species’ winter ranges, temperature and ecological productivity were higher than expected during March; within species’ breeding ranges, ecological productivity was lower than expected during the summer. These differences were strongest for the 21 short-distance migrants. Following our expectations, mid-latitude climate extremes and associated ecological consequences broadly affected avian migration and breeding activities within the region. Our findings suggest short-distance migrants are more flexible and resilient, whereas populations of long-distance migrants are at a distinct disadvantage, which may intensify if the frequency of these events increases.