WILD chimpanzees and gorillas stumbled accidentally onto a way to treat stomach bugs.
When afflicted by stomach pains, the apes often fold up bristly leaves and swallow them whole, allowing the rough, undigested material to pass through their guts and flush out intestinal parasites such as nematode worms. Now an experiment to investigate this behaviour suggests that it was inquisitiveness about novel foods, rather than a desire to cure themselves, that prompted the animals to try the technique in the first place.
Michael Huffman and Satoshi Hirata gave 11 chimpanzees at Kyoto University鈥檚 Primate Research Institute in Japan rough leaves from a plant the chimps had never seen before. Initially most of them wouldn鈥檛 touch the offering, but two animals, named Chloe and Reo, spontaneously folded and swallowed the leaves. Both chimps were healthy at the time and had never witnessed this behaviour. Four other chimps in the group later did the same, indicating that chimps can learn the behaviour from each other.
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The observations suggest that chimpanzees have a propensity to treat all leaves in this way. The scientists believe that chimps only began using the leaves as medicine once they learned to associate eating novel, bristly leaves with improved well-being.