THE BEST REST AFTER A LONG DAY OF WORK

Here’s a review of the little chimp’s day so far: Dozing on mama’s tummy, nearly climbing a medium-high tree, examining small creatures in a puddle (not tasty), duking it out with two buddies (and winning), and opening a nut with a rock. This young chimpanzee has obviously earned a rest. Like their human counterparts, animals in the family of the great apes (gorillas, orangutans, and chimpanzees) establish new brain connections in their sleep as they process newly acquired knowledge. In other words, sleep is making this young chimp more intelligent. Chimpanzees love nothing more than getting a good dose of sleep—10 to 12 hours out of 24 if you add naps to the 8 or 9 hours they get each night. Researchers have discovered that young chimps—once they have grown too big for their mother’s arms—construct very comfortable nests in tree canopies, often using rare species to maximize comfort. In Uganda, a chimp’s first choice is Ugandan ironwood, also known as muhimbi. Researchers found it accounted for 74% of the wood chosen, even though it accounted for less then 10% of the trees in the region. Chimps build a new nest every night and use a weaving technique to make it firm and stable. Why a new nest every night? Chimpanzees are highly social and presumably want to prevent fleas from inhabiting bedding and infesting them and their friends.