Elevation-related differences in annual survival of adult food-caching mountain chickadees are consistent with natural selection on spatial cognition
Elevation-related differences in annual survival of adult food-caching mountain chickadees are consistent with natural selection on spatial cognition
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DOI：
10.1007/s00265-020-2817-2
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发表时间：
2020-03-11
影响因子：
2.3
通讯作者：
Pravosudov, V. V.
中科院分区：
文献类型：
--
作者：
Benedict, L. M.;Pitera, A. M.;Pravosudov, V. V.
生活在山地梯度上的动物经历了不同的冬季气候，这可能导致与生存相关的性状的差异选择。与低海拔地区相比，温带气候的高海拔地区冬季更严酷，积雪更大、持续时间更长，这可能会导致对在这些严酷条件下改善健康状况的特征有更强的选择。对于生活在恶劣的高海拔环境中的觅食山雀，个体在与取回食物相关的空间认知能力上的差异与越冬存活的显著差异有关。与低海拔相比，在高海拔地区越冬所需性状的更强预测选择有望导致更高的成虫年存活率，尽管环境条件更恶劣，这表明在第一个冬季存活的个体更适合在随后的类似选择事件中生存。在这里，我们使用贝叶斯分层Cormack-Jolly-Seber(CJS)模型来估计和比较在高海拔和低海拔地区成年山雀3年的存活率。我们发现，尽管环境条件要恶劣得多，但成虫在高海拔地区的存活率一直较高，这支持了我们的假设，即在我们的高海拔研究地区，对越冬生存相关性状(如空间认知)的选择比在低海拔地区更强。
Animals inhabiting montane gradients experience varying winter climates that may result in differential selection on survival-related traits. Higher elevations in temperate climates are characterized by harsher winters with greater and longer-lasting snow cover compared to lower elevations, potentially leading to stronger selection for traits that improve fitness under these harsher conditions. For food-caching mountain chickadees, Poecile gambeli, inhabiting harsh high elevation environments, individual variation in spatial cognitive abilities related to cache retrieval is associated with significant differences in overwinter survival. Compared to lower elevations, stronger predicted selection on traits needed for overwinter survival at higher elevations can be expected to result in higher adult annual survival despite harsher environmental conditions, indicating that individuals that survive their first winter are better suited to survive similar subsequent selection events. Here, we used a Bayesian hierarchical Cormack-Jolly-Seber (CJS) model to estimate and compare survival of adult mountain chickadees at higher and lower elevations over 3 years. We showed that adult survival was consistently higher at higher elevations despite much harsher environmental conditions, supporting our hypothesis that selection on overwinter survival-related traits (such as spatial cognition) is stronger at our high elevation study area than at lower elevations.