Huang Andrew C, Bishop Christine A, McKibbin René, Drake Anna, Green David J
Environment and Climate Change Canada, Delta, BC, Canada.
Department of Biological Sciences, Center for Wildlife Ecology, Simon Fraser University, Burnaby, BC, Canada.
BMC Ecol. 2017 Aug 10;17(1):29. doi: 10.1186/s12898-017-0139-7.
Long-distance migratory birds in North America have undergone precipitous declines over the past half-century. Although the trend is clear, for many migrating species underpinning the exact causes poses a challenge to conservation due to the numerous stressors that they encounter. Climate conditions during all phases of their annual cycle can have important consequences for their survival. Here, using 15 years of capture-recapture dataset, we determined the effects of various climate factors during the breeding, wintering, and migrating stages on the annual survival of a western yellow-breasted chat (Icteria virens auricollis) population breeding in southwestern Canada.
El Niño effects over the entire annual cycle had little influence on the annual apparent survival of yellow-breasted chats. However, we found evidence that wind conditions during migration, specifically average westerly wind speed or the frequency of storm events, had significant adverse effects on adult annual apparent survival. In comparison, precipitation levels on wintering ground had little to no influence on adult annual apparent survival, whereas growing degree days on the breeding ground had moderate but positive effects.
In the face of climate change and its predicted impacts on climate processes, understanding the influence of weather conditions on the survival of migrating birds can allow appropriate conservation strategies to be adopted for chats and other declining neotropical migrants.
在过去的半个世纪里，北美洲的长途候鸟数量急剧下降。尽管趋势很明显，但对于许多迁徙物种来说，由于它们面临众多压力因素，确定确切的致危原因对保护工作构成了挑战。它们年度周期各阶段的气候条件会对其生存产生重要影响。在此，我们利用15年的环志重捕数据集，确定了繁殖、越冬和迁徙阶段的各种气候因素对在加拿大西南部繁殖的西部黄胸鹀（Icteria virens auricollis）种群年存活率的影响。
厄尔尼诺现象对整个年度周期的影响对黄胸鹀的年表观存活率影响较小。然而，我们发现有证据表明，迁徙期间的风况，特别是平均西风风速或风暴事件的频率，对成年个体的年表观存活率有显著的不利影响。相比之下，越冬地的降水量对成年个体的年表观存活率几乎没有影响，而繁殖地的积温则有适度但积极的影响。
面对气候变化及其对气候过程的预测影响，了解天气条件对候鸟生存的影响有助于为黄胸鹀和其他数量减少的新热带迁徙鸟类制定适当的保护策略。
