Data from: Sex-dependent phenological plasticity in an arctic hibernator

Hibernation provides a means of escaping the metabolic challenges associated with seasonality, yet the ability of mammals to prolong or re-enter seasonal dormancy in response to extreme weather events is unclear. Here, we show that arctic ground squirrels in northern Alaska exhibited sex-dependent plasticity in the physiology and phenology of hibernation in response to a series of late spring snowstorms in 2013 that resulted in the latest snow-melt on record. Females and non-reproductive males responded to the >1 month delay in snow-melt by extending heterothermy or re-entering hibernation after several days of euthermy, leading to a >2-week delay in reproduction compared to surrounding years. In contrast, reproductive males neither extended nor re-entered hibernation, likely because seasonal gonadal growth and development and subsequent testosterone release prevents a return to torpor. Our findings reveal intriguing differences in responses of males and females to climatic stressors which can generate a phenological mismatch between the sexes.冬眠是哺乳动物规避季节性相关代谢挑战的有效生存策略，但目前学界对于哺乳动物在极端天气事件下延长冬眠时长或重新进入季节性蛰伏的能力仍不明确。针对2013年春季晚些时候的一系列暴雪引发有记录以来最晚融雪期的事件，我们对阿拉斯加北部的北极地松鼠（Arctic ground squirrel）展开研究后发现，该物种在冬眠生理与物候特征上表现出了性别依赖的可塑性。雌性个体与非繁殖期雄性个体针对融雪期推迟超过1个月的响应策略为延长异温性（heterothermy）时长，或是在维持数天常态体温（euthermy）后重新进入冬眠，这使得其繁殖周期较周边年份推迟了两周以上。与之相反，繁殖期雄性个体既未延长冬眠时长，也未重新进入冬眠，这大概率是因为季节性性腺生长发育以及后续的睾酮（testosterone）释放会阻止其再次进入蛰伏状态。本研究结果揭示了雌雄个体对气候胁迫的响应存在显著差异，这种差异可能引发两性间的物候错配（phenological mismatch）。