Mammals in the far north are exposed to extreme seasonal changes in environmental conditions, such as temperature and photoperiod, which have notable effects on animal physiology and behaviour. The wolverine (Gulo gulo) is a carnivore with a circumpolar distribution and well-adapted to extreme environmental conditions. Still, ecophysiological studies on free-ranging wolverines are lacking. In this study, we used abdominally implanted body temperature loggers in combination with GPS collars with acceleration sensors on 14 free-ranging wolverines in northern Sweden to study daily and seasonal variation in body temperature and activity patterns. We used generalized additive mixed modelling to investigate body temperature patterns over time and Lomb-Scargle periodogram analysis to analyse circadian rhythms. We found that wolverines have an average core body temperature of 38.5 ± 0.2 °C with a daily variation of up to 6 °C. Body temperature patterns varied between reproductive states. Pregnant females showed a distinct decrease in body temperature during gestation. Wolverines were active both in day and night, but displayed distinct activity peaks during crepuscular hours. However, body temperature and activity patterns changed seasonally, with a gradual change from a unimodal pattern in winter with concentrated activity during the short period of day light to a bimodal pattern in autumn with activity peaks around dusk and dawn. Wolverines were less likely to display 24-h rhythms in winter, when hours of day light are limited. The combination of different biologging techniques gave novel insight into the ecophysiology, activity patterns and reproductive biology of free-ranging wolverines, adding important knowledge to our understanding of animals adapted to cold environments at northern latitudes.

中文翻译：

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繁殖和环境因素对金刚狼体温和活动模式的影响

远北地区的哺乳动物暴露在环境条件的极端季节性变化中，例如温度和光周期，这对动物的生理和行为有显着影响。金刚狼 (Gulo gulo) 是一种食肉动物，具有极地分布，能很好地适应极端环境条件。尽管如此，仍缺乏对自由放养的狼獾的生态生理学研究。在这项研究中，我们在瑞典北部的 14 只自由放养的狼獾身上使用了腹部植入的体温记录器和带有加速度传感器的 GPS 项圈，以研究体温和活动模式的每日和季节性变化。我们使用广义加性混合模型来研究随时间变化的体温模式，并使用 Lomb-Scargle 周期图分析来分析昼夜节律。我们发现金刚狼的平均核心体温为 38.5 ± 0.2 °C，每日变化高达 6 °C。体温模式因生殖状态而异。孕妇在妊娠期间表现出明显的体温下降。金刚狼在白天和晚上都很活跃，但在黄昏时分表现出明显的活动高峰。然而，体温和活动模式随季节变化，从冬季的单峰模式逐渐变化，在短日照时间内活动集中，秋季的双峰模式在黄昏和黎明左右活动达到高峰。在白天光照时间有限的冬季，金刚狼不太可能表现出 24 小时的节律。不同生物测井技术的结合为生态生理学提供了新的见解，