Variation in white-tailed deer (Odocoileus virginianus) mortality during winter affects population growth in cold climates. Across the northern extent of their range, mortality increases with colder temperatures and snow. Few studies have examined the relationships between winter conditions and deer mortality, and no studies have concurrently studied this relationship for different ages of deer across multiple years and landscapes. We used recently developed cause-specific mortality models to evaluate temporal and age-class variation in deer mortality in farmland areas and compared to published results from forest areas in Wisconsin, USA, from 2011–2014. We then used temporally varying snow and temperature covariates to predict mortality trends using telemetry information from 860 deer. Cause-specific mortality in the farmland varied by age and year, similar to results from previous research in the forest. Human-related mortality was the leading cause of mortality in the farmland during most years and ranged from 4.3% to 10.3% for juveniles and 3.6% to 9.1% for adults from 2011–2014. Very little predation occurred in the farmland, and this differed from previous research in the forest where predation was the leading cause of mortality. During more severe winters (2013 and 2014), other mortality, usually associated with starvation, was the leading cause of mortality for juveniles in the farmland but not adults. In the forest, we found support for saturating effects of accumulated snow depth days >30.5 cm and accumulated temperature days >0°C on mortality. We also found support for the relationship of mortality with accumulated temperature days >0°C in the farmland but no relationship with snow depth. Deer tolerate sustained cold temperatures, but the timing of winter to spring transition is more important for deer survival in both forested and agricultural areas. In the absence of empirical survival information, managers can use our model to predict annual winter effects on deer survival, which can provide improved inference compared to traditional winter severity indices. Our results suggest changes in predator abundance may have minor influence on overwinter survival compared to winter weather. Based on mortality estimates from previous research, the highest predation rates on juvenile deer in the forest occurred when wolf (Canis lupus) counts were lowest and when wolf abundance was highest, juvenile deer predation rates were lowest. © 2021 The Wildlife Society.

中文翻译：

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白尾鹿、天气和捕食：对预测鹿死亡率的冬季严重程度的新理解

白尾鹿（Odocoileus virginianus）的变异) 冬季死亡率会影响寒冷气候下的人口增长。在其分布范围的北部，死亡率随着气温和降雪的降低而增加。很少有研究研究冬季条件与鹿死亡率之间的关系，也没有研究同时研究不同年龄和景观中不同年龄鹿的这种关系。我们使用最近开发的特定原因死亡率模型来评估农田地区鹿死亡率的时间和年龄等级变化，并与美国威斯康星州森林地区 2011-2014 年公布的结果进行比较。然后，我们使用来自 860 只鹿的遥测信息，使用随时间变化的雪和温度协变量来预测死亡率趋势。农田的特定原因死亡率因年龄和年份而异，与之前在森林中的研究结果相似。在大多数年份，人为相关的死亡率是农田死亡的主要原因，从 2011 年到 2014 年，青少年死亡率为 4.3% 至 10.3%，成人为 3.6% 至 9.1%。农田很少发生捕食，这与之前在森林中的研究不同，在森林中，捕食是导致死亡的主要原因。在更严酷的冬季（2013 年和 2014 年），通常与饥饿有关的其他死亡是农田中幼鱼而非成鱼的主要死亡原因。在森林中，我们发现累积积雪深度天数 >30.5 cm 和积温天数 >0°C 对死亡率的饱和效应的支持。我们还发现支持死亡率与积温天数的关系 > 农田0°C，但与积雪深度无关。鹿可以忍受持续的寒冷温度，但冬季到春季过渡的时间对于森林和农业地区的鹿生存更为重要。在缺乏经验生存信息的情况下，管理人员可以使用我们的模型来预测每年冬季对鹿生存的影响，与传统的冬季严重程度指数相比，这可以提供更好的推断。我们的结果表明，与冬季天气相比，捕食者丰度的变化可能对越冬生存的影响较小。根据先前研究的死亡率估计，森林中幼鹿的最高捕食率发生在狼（但冬季到春季过渡的时机对于森林和农业地区的鹿生存更为重要。在缺乏经验生存信息的情况下，管理人员可以使用我们的模型来预测每年冬季对鹿生存的影响，与传统的冬季严重程度指数相比，这可以提供更好的推断。我们的结果表明，与冬季天气相比，捕食者丰度的变化可能对越冬生存的影响较小。根据先前研究的死亡率估计，森林中幼鹿的最高捕食率发生在狼（但冬季到春季过渡的时机对于森林和农业地区的鹿生存更为重要。在缺乏经验生存信息的情况下，管理人员可以使用我们的模型来预测每年冬季对鹿生存的影响，与传统的冬季严重程度指数相比，这可以提供更好的推断。我们的结果表明，与冬季天气相比，捕食者丰度的变化可能对越冬生存的影响较小。根据先前研究的死亡率估计，森林中幼鹿的最高捕食率发生在狼（我们的结果表明，与冬季天气相比，捕食者丰度的变化可能对越冬生存的影响较小。根据先前研究的死亡率估计，森林中幼鹿的最高捕食率发生在狼（我们的结果表明，与冬季天气相比，捕食者丰度的变化可能对越冬生存的影响较小。根据先前研究的死亡率估计，森林中幼鹿的最高捕食率发生在狼（Canis lupus ) 计数最低，当狼丰度最高时，幼鹿的捕食率最低。© 2021 野生动物协会。