By Susan Milius
With the discovery of notably different dining habits among neighboring groups of chimpanzees, researchers may have some of their best examples yet of cultural traditions among animals.
One chimp group in the Taï National Forest in western Africa uses mostly rocks to hammer open the Coula nuts that are a seasonal staple of their diet, reports primatologist Lydia Luncz of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. Chimps living just to the east start the Coula season hammering with rocks but shift to easier-to-find chunks of wood as nuts lying on the ground soften and become easier to crack.
So does a third group of chimps living just several kilometers to the northwest. Living as the chimps do in such close quarters, neither genetics nor ecology likely influences the traditions of the chimps, Luncz and her colleagues argue in the May 22 Current Biology. These nutcracking quirks offer a tidy case study of an animal version of cultural differences.