Department of Anthropology, University of California, Davis, Davis, United States.
Department for the Ecology of Animal Societies, Max Planck Institute of Animal Behavior, Konstanz, Germany.
Elife. 2022 Mar 1;11:e73695. doi: 10.7554/eLife.73695.
Sleep is fundamental to the health and fitness of all animals. The physiological importance of sleep is underscored by the central role of homeostasis in determining sleep investment - following periods of sleep deprivation, individuals experience longer and more intense sleep bouts. Yet, most sleep research has been conducted in highly controlled settings, removed from evolutionarily relevant contexts that may hinder the maintenance of sleep homeostasis. Using triaxial accelerometry and GPS to track the sleep patterns of a group of wild baboons (), we found that ecological and social pressures indeed interfere with homeostatic sleep regulation. Baboons sacrificed time spent sleeping when in less familiar locations and when sleeping in proximity to more group-mates, regardless of how long they had slept the prior night or how much they had physically exerted themselves the preceding day. Further, they did not appear to compensate for lost sleep via more intense sleep bouts. We found that the collective dynamics characteristic of social animal groups persist into the sleep period, as baboons exhibited synchronized patterns of waking throughout the night, particularly with nearby group-mates. Thus, for animals whose fitness depends critically on avoiding predation and developing social relationships, maintaining sleep homeostasis may be only secondary to remaining vigilant when sleeping in risky habitats and interacting with group-mates during the night. Our results highlight the importance of studying sleep in ecologically relevant contexts, where the adaptive function of sleep patterns directly reflects the complex trade-offs that have guided its evolution.
睡眠对所有动物的健康和体能都至关重要。睡眠的生理重要性突出表现在体内平衡在决定睡眠投入中的核心作用上——在经历了一段时间的睡眠剥夺后，个体经历更长、更强烈的睡眠发作。然而，大多数睡眠研究都是在高度控制的环境中进行的，与可能阻碍睡眠内稳态维持的进化相关背景相分离。我们使用三轴加速度计和 GPS 跟踪一组野生狒狒的睡眠模式（），发现生态和社会压力确实会干扰内稳态睡眠调节。狒狒在不熟悉的地方和与更多同伴睡觉时，会牺牲睡眠时间，而不管它们前一天晚上睡了多久，前一天运动了多少。此外，它们似乎并没有通过更强烈的睡眠发作来补偿失去的睡眠。我们发现，社交动物群体的集体动态特征一直持续到睡眠期，因为狒狒在整个晚上表现出同步的清醒模式，尤其是与附近的同伴。因此，对于那些生存依赖于避免捕食和发展社交关系的动物来说，在危险栖息地睡觉时保持警觉和与同伴在夜间互动可能比维持睡眠内稳态更为重要。我们的研究结果强调了在生态相关背景下研究睡眠的重要性，因为睡眠模式的适应功能直接反映了指导其进化的复杂权衡。
