(Orangutans are remarkably intelligent. This individual, from the Great Ape Trust of Iowa, spontaneously whistles. Another orangutan was recently filmed cleaning itself off with a washcloth. Credit: Smithsonian National Zoological Park)
The two-minute clip, shot on an 86 degree day at the zoo, shows the orangutan dipping a washcloth in water, ringing it out and wiping its face and upper body. The primate even mops up spilt water droplets afterward.
A smaller orangutan carefully watches and wants to check out the washcloth, but is gently moved aside.
Most likely, the adult orangutan was taught this behavior — since the washcloth was provided — but it appears to be acting spontaneously, putting his knowledge to good use on a hot day when a cleansing cool-off was refreshing.
Since the little orangutan was watching, the behavior will most likely be passed down. Some years ago, Duke University scientists proved that orangutans have culture, permitting them to learn new things and share that knowledge with others.
Carel van Schaik of Duke and colleagues presented evidence for cultural transmission of 24 behaviors among orangutans. These include:
– using leaves as protective gloves or napkins;
— using sticks to poke into tree holes to obtain insects, to extract seeds from fruit or to scratch body parts;
— using leafy branches to swat insects or gather water;
— "snag-riding," the orangutan equivalent of a sport in which the animals ride falling dead trees, grabbing vegetation before the tree hits the ground;
— emitting sounds such as "raspberries," or "kiss-squeaks," in which leaves or hands are used to amplify the sound;
— building sun covers for nests or, during rain, bunk nests above the nests used for resting.
In the above cases, I believe the orangutans were just using what was available to them in the wild. If such studies include zoo chimps, which have access to human "tools" like washcloths, the list could probably go on and on.
The last common ancestor of humans and orangutans is thought to have lived about 15 million years ago, so the primate drive to learn and share knowledge (even if it's via unwanted eavesdropping) go way back. We share 96.4 percent of our DNA with orangutans.
Van Schaik said such findings "suggest that the first ancestral man-apes must have had a pretty solid evolutionary cultural foundation on which to build."
Environment helps in that process. The orangutan exhibit at the Tama Zoo opened on April 28, 2005 and took almost 2 years and around 1 billion yen to build, according to Tokyo Guidebook. The exhibit includes a tall "Sky Walk" where the orangutans can swing across towers between living areas. If orangutans poke sticks into a large ant hill-type structure, they are rewarded with a sticky paste, similar to how they'd be rewarded with ants in the wild. The orangutans even have a vending machine that they operate to get drinks for themselves.
Here you can see the primates cleaning away, doing housekeeping as well as personal cleanup. (I like how this elderly female, "Gypsy," has to sniff the cloth after most wipes.) She also shows how versatile a straw hat can be, since she first uses it as a head topper, next as a toy/edible, and finally as a container and mold for soil.