The importance of conserving migratory populations is recognized across a variety of ungulate taxa, yet the demographic benefits of migration remain uncertain for ungulate populations that exhibit partial migration. We hypothesized that migratory pronghorn (Antilocapra americana) would experience greater survival compared to residents by moving longer distances to avoid severe winter weather and access higher quality forage. We used a Bayesian time‐to‐event approach to analyze the fates of 175 radio‐collared adult female pronghorn monitored over 8 biological years (2004–2011) in the Northern Sagebrush Steppe ecosystem. Annual survivorship of migratory pronghorn was 7% higher on average compared to residents but not statistically different. Migratory pronghorn had higher survivorship in summer and winter compared to residents, and few mortalities were observed during the short autumn and spring migration periods. Mortality risk for both movement tactics intensified under more severe winter weather; winter weather severity alone best explained annual pronghorn mortality risk. The top model predicted survival rates to decline on average by 56% over the range of observed winter climatic conditions. To minimize human impacts to pronghorn during extreme climatic events, we recommend working with transportation departments and land managers to enhance pronghorn crossings of roads and railroads, and landholders to modify fences to wildlife‐friendly standards. © 2020 The Authors. Journal of Wildlife Management published by Wiley Periodicals, LLC on behalf of The Wildlife Society.

中文翻译：

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部分迁移人口的年度叉角羚生存

在许多有蹄类动物的分类群中，保护迁徙人口的重要性已得到公认，但是对于有部分迁徙的有蹄类动物，迁徙的人口统计学优势仍然不确定。我们假设迁移性叉角羚（Antilocapra americana），与居民相比，可以通过更长距离避开严冬的天气并获得更高质量的草料，从而获得更大的生存率。我们使用贝叶斯时间-事件方法分析了北部鼠尾草草原生态系统中在8个生物年（2004-2011年）中监测的175头有无线电领的成年雌性叉角羚的命运。迁徙叉角羚的年生存率平均比居民高7％，但无统计学差异。与居民相比，迁徙的叉角羚在夏季和冬季的存活率更高，在短暂的秋季和春季迁徙期间几乎没有死亡。在更恶劣的冬季天气中，两种运动策略的死亡率风险都增加了；仅冬季天气的严重程度就可以最好地解释每年叉角羚死亡的风险。最高模型预测，在观测到的冬季气候条件下，生存率平均下降56％。为了在极端气候事件中将人类对叉角羚的影响降到最低，我们建议与运输部门和土地管理人员合作，以加强公路和铁路的叉角螺交叉，并与土地所有者合作，将围栏修改为符合野生动植物标准的篱笆。©2020作者。Wiley Periodicals，LLC代表野生动物协会出版的《野生动物管理杂志》。