Data from: Ecological and social pressures interfere with homeostatic sleep regulation in the wild

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 tri-axial accelerometry and GPS to
track the sleep patterns of a group of wild baboons (Papio anubis), 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.