National Geographic : 2010 Feb
nearby limb. en something remarkable hap- pens that has almost never been observed out- side of the Goualougo. Dinah spies a cloud of sweat bees emerging from a hole near the main trunk of the tree. She leaps to her feet, leaves Owen behind, and breaks o a branch about as thick and long as a human arm. With the blunt end she begins whaling away at the bark. She knows that some- where inside a hard-to-access crevice is a hive with a small cache of honey. Dinah's rhythmic thumping echoes loudly o the surrounding trees. She transfers the club to her foot and swings around to the other side of the trunk to get a better angle. en she rips a small twig o a nearby branch, dips it into the hive, and swirls it around like a knife at the bottom of a peanut butter jar. She pulls it out, sni s it, realizes there's no honey on it, throws it away, and starts pounding some more. She repeats the process, running through seven di erent dipping sticks. Finally, a er nearly 12 minutes of hammering at the disobliging hive, she plunges her nger into a crack and seems to yank out the slightest bit of honey, which goes straight into her mouth. But just as she is be- ginning to enjoy the fruits of her labor, Finn, the Moto community's alpha male and resident bully, descends from a nearby branch with his hair standing on end, seemingly outraged that a young upstart is enjoying a sugary delicacy in his presence. He lunges at Dinah, who drops her club and ees to another limb. Morgan and Sanz exchange high ves. " at's one of the best honey-pounding observations anyone has ever had!" Sanz exclaims gleefully. e fact that honey pounding hasn't been ob- served at other chimp research sites outside of central Africa suggests that it is not part of the species' innate behavioral repertoire, but rather is a learned skill that has been culturally trans- mitted. Part of what makes Dinah's behavior so intriguing is that she used two di erent kinds of tools---a big club and a thin twig---in sequence to accomplish her goal. is isn't the only form of serial tool use com- mon in the Goualougo. At the exact moment that we are watching Dinah attack the beehive, a camera trap set up near a termite mound half a mile away records another female chimp named Maya, a matron of the Moto community, engag- ing in what may be the most sophisticated form of serial tool use by any nonhuman animal. Maya arrives at the termite mound, a rock- hard, bulbous structure three times her height, carrying in her mouth several plant stems that she will use to sh out its high-calorie occu- pants. First she rams a thick twig into a termite hole and widens it by jiggling the stick vigor- ously. en she grabs a thin, exible stem that she plucked o a nearby Sarcophrynium plant. Chimps in other parts of Africa are known to sh for termites with implements like this, but Maya goes one step further and modi es the tool. She drags the last six inches of the stem through her teeth to create a wet, frayed end, like a paintbrush, and pulls it through her closed st to straighten out the bristles. With the dex- terity of a professional lock picker, she then threads the brush-tipped stem into the same hole, pulls it out, and nibbles o a couple bugs that cling to the wand's frayed edges. What's so remarkable about that fishing probe is that it represents a re nement. It's not just that some clever chimp gured out that it could break o a plant stem and use it to sh for termites---an impressive enough discovery in its own right---it's that some other chimp gured out a way to do it even better. And the brush tip is not merely a trivial upgrade. Mor- gan and Sanz have tried termite shing them- selves with both brush-tipped and unmodi ed sticks and found that they picked up ten times more termites with the frayed tool. Without a time machine, we'll never know how human culture began, but it must have looked some- thing like this: one simple discovery building on another. " e Goualougo is probably the only place on Earth where humans will ever have the Part of what makes Dinah's behavior so intriguing is that she used two different kinds of tools in sequence.