“Sleep well!”, You would like to call this orangutan lady as she makes a nap in the canopy. As researchers around Alison Ashbury found out of the University of Konstanz, wild orangutans, just like we humans, make powernaps during the day when they have got too little sleep at night. “These naps may help the orangutans to recover physiologically and cognitively after a bad night, just as it is in humans,” assumes Ashbury’s colleague Margaret Crofoot.
As the team found out, lack of sleep on Orang-Utans appears on cold nights or if they sleep near fellow species instead of sleeping alone. But why? “Imagine you stay with your friends for a long time or your roommate snores so loud in the morning that you have to get up early. I think it is similar,” explains Ashbury. Convention then competes with sleep – or both get in the way of each other.
However, if everything fits, the great apes sleep up to 13 hours. At first glance, that sounds a lot, but is probably absolutely necessary if you consider the exhausting days of the Orangutans. “Moving through the canopy, finding food, solving problems, maintaining social relationships – all of these are exhausting and cognitively demanding tasks,” emphasizes Ashbury.
The examined population on Sumatra is also one of the most culturally complex ones. She uses tools and shows impressive problem solving skills. Good sleep is therefore all the more important for the gray cells of the great apes. Or is it the other way around? “Either you need these high-quality naps to meet your cognitive requirements, or your cognitive skills arise from making so often high-quality naps in day nests,” says senior author Caroline Schuppli from the Max Planck Institute for Behavioral Biology. In any case, the following applies: a high on the nap!
