Determinants of heart rate in Svalbard reindeer reveal mechanisms of seasonal energy management

Seasonal energetic challenges may constrain an animal’s ability to respond to changing individual and environmental conditions. Here we investigated variation in heart rate, a well-established proxy for metabolic rate, in Svalbard reindeer, a species with strong seasonal changes in foraging and metabolic activity. In 19 adult females we recorded heart rate, subcutaneous temperature and activity using biologgers. Mean heart rate more than doubled from winter to summer. Typical drivers of energy expenditure, such as reproduction and activity, explained a relatively limited amount of variation (2–6% in winter and 16–24% in summer), compared to seasonality which explained 75% of annual variation in heart rate. The relationship between heart rate and subcutaneous temperature depended on individual state via body mass, age and reproductive status, and the results suggested that peripheral heterothermy is an important pathway of energy management in both winter and summer. While the seasonal p...

季节性能量胁迫可能会限制动物应对个体状态与环境条件变化的能力。本研究以觅食与代谢活动存在显著季节性变化的斯瓦尔巴群岛驯鹿为研究对象，针对心率这一公认的代谢率替代指标的变异特征展开调查。本研究采用生物记录仪（biologgers）对19头成年雌性个体的心率、皮下温度与活动水平进行了记录。个体平均心率从冬季至夏季增幅超过一倍。相较于解释了75%年度心率变异度的季节性因素，能量消耗的典型驱动因子（如繁殖与活动水平）仅能解释相对有限的变异量（冬季为2%~6%，夏季为16%~24%）。心率与皮下温度之间的关联会通过体重、年龄以及繁殖状态受个体状态的调控，研究结果表明，外周异温现象是冬季与夏季能量管理的重要途径。尽管季节性……