Abstract：
Some mammal species inhabiting high-latitude biomes have evolved a seasonal moulting pattern that improves camouflage via white coats in winter and brown coats in summer. In many high-latitude and high-altitude areas, the duration and depth of snow cover has been substantially reduced in the last five decades. This reduction in depth and duration of snow cover may create a mismatch between coat colour and colour of the background environment, and potentially reduce the survival rate of species that depend on crypsis. We used long-term (1977-2020) field data and capture-mark-recapture models to test the hypothesis that whiteness of the coat influences winter apparent survival in a cyclic population of snowshoe hares (Lepus americanus) at Kluane, Yukon, Canada. Whiteness of the snowshoe hare coat in autumn declined during this study, and snowshoe hares with a greater proportion of whiteness in their coats in autumn survived better during winter. However, whiteness of the coat in spring did not affect subsequent summer survival. These results are consistent with the hypothesis that the timing of coat colour change in autumn can reduce overwinter survival. Because declines in cyclic snowshoe hare populations are strongly affected by low winter survival, the timing of coat colour change may adversely affect snowshoe hare population dynamics as climate change continues.
摘要：
居住在高纬度生物群落中的一些哺乳动物物种已经进化出一种季节性蜕皮模式，这种模式在冬季通过白色大衣和夏季通过棕色大衣改善伪装。在许多高纬度和高海拔地区，在过去的五十年中，积雪的持续时间和深度已大大减少。积雪深度和持续时间的减少可能会在涂层颜色和背景环境颜色之间产生不匹配。并可能降低依赖隐匿的物种的存活率。我们使用长期（1977-2020年）野外数据和捕获-标记-重新捕获模型来检验以下假设：外套的白度会影响克鲁恩雪鞋野兔（Lepusamericanus）周期性种群的冬季表观存活率，育空地区,加拿大。在这项研究中，秋天雪鞋野兔外套的白度下降了，秋天，雪鞋野兔的外套中白度比例更高，冬季则存活得更好。然而,春季外套的白度不会影响随后的夏季生存。这些结果与以下假设一致：秋季外套颜色变化的时间会减少越冬的存活率。因为周期性雪鞋野兔种群的减少受到冬季低存活率的强烈影响，随着气候变化的持续，皮毛颜色变化的时间可能会对雪鞋野兔的种群动态产生不利影响。
