Hikers and overseas travelers quickly learn the gut-wrenching consequences of drinking unfiltered water. Now it appears that chimpanzees and baboons in Senegal catch on as well. Both primates dig holes in the sand near pools of stagnant water in riverbeds, allowing relatively clean water to well up from the water table. Researchers say this activity may one day join the growing list of culturally transmitted ape behaviors.
As rivers and streams disappear during the dry season in their woodland habitat, the animals ignore pools of standing water and instead dig new holes nearby, Anh Galat-Luong and Gérard Galat of the French Institute of Research for Development in Dakar reported last month at a meeting of the Francophone Society of Primatology in Paris. Their tests showed that the standing water was teeming with pathogens such as Escherichia coli and Aeromonas hydrophila, but the water in newly dug holes was clean. Digging for water in itself is not unusual, they say--but it hadn't been observed when surface water was available.
The scientists are hoping to determine if individuals each discover on their own the unpleasant effects of drinking stagnant water, or if they learn to dig fresh holes by watching other family members. Such observations would help researchers who are documenting primate "cultural" behaviors, such as nut cracking and ant fishing, that are passed on from one group member to another, says Christophe Boesch of the Max Planck Institute of Evolutionary Anthropology in Leipzig.
