ABSTRACT Migratory birds are demonstrating changes in phenology linked to climate change. Understanding these changes requires connecting events that occur over the multiple regions occupied during their annual cycle. The Burrowing Owl (Athene cunicularia) is a species of concern in North America, with pronounced declines in regions of the Great Plains. Using a dataset that spanned 10 breeding sites from South Dakota to northern Mexico in various years during 1989–2017, we observed both advances and delays in nesting along with increasing variation in nest initiation dates. We examined the effects of a large-scale climate system (El Niño Southern Oscillation), drought, and local weather patterns throughout the annual cycle as potential predictors of early and late nesting. Moisture conditions during the winter and spring migratory period had the greatest influence on nest phenology. Years with more intense drought on winter and migratory grounds increased the probability of nests initiating late relative to early. Correspondingly, wet conditions were associated with an increased probability of early nest initiation. Drought likely has cascading ecological effects that negatively influence food abundance for Burrowing Owls, resulting in delays in the ability of individuals to meet energetic demands required for migration. How climate change will impact Burrowing Owl phenology is important considering a projected increase in the magnitude and frequency of drought and declining owl population trends.

中文翻译：

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穴鸮（Athene cunicularia）在非繁殖地受干旱影响的巢物候

摘要 候鸟正在展示与气候变化相关的物候变化。了解这些变化需要将在其年度周期中占据的多个区域发生的事件联系起来。穴鸮（Athene cunicularia）是北美洲令人担忧的物种，在大平原地区数量明显减少。使用跨越 1989 年至 2017 年期间从南达科他州到墨西哥北部的 10 个繁殖地点的数据集，我们观察到筑巢的进展和延迟以及筑巢起始日期的变化越来越大。我们研究了整个年度周期中大规模气候系统（厄尔尼诺南方涛动）、干旱和当地天气模式的影响，作为早期和晚期筑巢的潜在预测因子。冬春季洄游期间的水分条件对巢的物候影响最大。冬季和迁徙地干旱更严重的年份增加了相对较早开始筑巢的可能性。相应地，潮湿的条件与早期筑巢的可能性增加有关。干旱可能会产生连锁生态效应，对穴居猫头鹰的食物丰度产生负面影响，导致个体满足迁徙所需能量需求的能力延迟。考虑到干旱程度和频率的预计增加以及猫头鹰种群下降趋势，气候变化将如何影响穴居猫头鹰物候学很重要。冬季和迁徙地干旱更严重的年份增加了相对较早开始筑巢的可能性。相应地，潮湿的条件与早期筑巢的可能性增加有关。干旱可能会产生连锁生态效应，对穴居猫头鹰的食物丰度产生负面影响，导致个体满足迁徙所需能量需求的能力延迟。考虑到干旱程度和频率的预计增加以及猫头鹰种群下降趋势，气候变化将如何影响穴居猫头鹰物候学很重要。冬季和迁徙地干旱更严重的年份增加了相对较早开始筑巢的可能性。相应地，潮湿的条件与早期筑巢的可能性增加有关。干旱可能会产生连锁生态效应，对穴居猫头鹰的食物丰度产生负面影响，导致个体满足迁徙所需能量需求的能力延迟。考虑到干旱程度和频率的预计增加以及猫头鹰种群下降趋势，气候变化将如何影响穴居猫头鹰物候学很重要。干旱可能会产生连锁生态效应，对穴居猫头鹰的食物丰度产生负面影响，导致个体满足迁徙所需能量需求的能力延迟。考虑到干旱程度和频率的预计增加以及猫头鹰种群下降趋势，气候变化将如何影响穴居猫头鹰物候学很重要。干旱可能会产生连锁生态效应，对穴居猫头鹰的食物丰度产生负面影响，导致个体满足迁徙所需能量需求的能力延迟。考虑到干旱程度和频率的预计增加以及猫头鹰种群下降趋势，气候变化将如何影响穴居猫头鹰物候学很重要。