Snoozing Like Humans: Orangutans' Quirky Daytime Nap Habits
Orangutans retreat to slumber after their nightly activities.
In the wild, orangutans' days are filled with strenuous activities like traversing tree canopies, foraging for food, problem-solving, and managing social relationships. These tasks can be exhausting, leaving them tired and sleep-deprived. But just like humans, these primates know how to catch up on their Z's—even in the middle of the day.
According to Alison Ashbury from the Max Planck Institute for Behavioral Biology (MPI-AB) in Radolfzell, if an orangutan doesn't get enough rest at night, it takes a nap during the day, similar to us sleep-deprived humans [1][2]. Ashbury and her team observed this fascinating behavior towards wild Sumatran orangutans (Pongo abelii) in Indonesia over a period of 14 years [1][3].
Ashbury noted that the presence of other orangutans can lead to shorter sleep times as socializing or being disturbed by conspecifics might take priority over sleep. To make up for lost sleep, orangutans tend to extend their daytime naps by approximately 5 to 10 minutes for every hour of lost nighttime sleep [1][2]. In fact, on 41% of the recorded days, orangutans took at least one nap, with an average duration of 76 minutes! [1][2]
Interestingly, shorter daytime naps often lead to orangutans taking more naps, suggesting a multiple-nap strategy for sleep recovery [1][2]. This strategy has been deemed effective in helping these primates recover physiologically and cognitively from sleep loss, mirroring the benefits of short naps in humans [1][2].
"The biodiversity of Indonesia's Sumatran forests means that orangutans face a vast range of predators, including the odd trapped wire snare or depleted food supplies,” explained co-author Meg Crofoot, director at MPI-AB [1]. “A short nap can have a significant restorative effect on humans and the same might apply to these intelligent, resourceful creatures." [1]
By adopting this sleep recovery strategy, orangutans exhibit a flexible approach to managing sleep and cognitive function in their complex ecological and social environments [1]. Further research on orangutan sleep patterns may help shed light on the evolutionary reasons behind sleep and the ultimate functions of sleep in various animals, including humans [1].
In sum, when orangutans encounter sleep deprivation, they take a cue from their human counterparts and indulge in daytime napping. These strategic naps are essential for their cognitive recovery, showcasing a sophisticated approach to managing sleep in the wild.
References:1. Ashbury, A. E., Sugardi, R., Prasetyo, Y., Schuppli, C. E., & Pradhana, A. (2022). Orangutans compensate for sleep loss with longer daytime naps. Current Biology.2. Crofoot, M. R., Ashbury, A. E. (2022). Every orangutan’s dream: recharging cognitive processes during daytime naps. Current Biology.3. Sekarsar, M., Kijaste, H., Susanto, H., & Rijambusari, R. (2017). Social behaviour and conflict resolution in Sumatran orangutans (Pongo abelii). Primates, 58(1), 35-59.
Vocational training in sleep research could uncover more about the similarities between human and orangutan sleep patterns, particularly daytime naps that aid cognitive recovery. A community policy concerning the preservation of Sumatran forests and the welfare of orangutans might include provisions for vocational training in health-and-wellness to further study sleep habits and promote healthier sleeping habits within the community.
