Relationship of chimpanzee leaf-swallowing to a tapeworm infection.

Leaf-swallowing by chimpanzees Pan troglodytes has been hypothesized to control parasites, but it has not yet been shown to be associated with specific parasitic infections. This report takes advantage of a tapeworm infestation among wild chimpanzees to examine whether leaf-swallowing was associated with the presence of tapeworms. Leaf-swallowing was monitored over 6.5 years in two chimpanzee communities in Kibale National Park (Uganda). In one community, tape-worms ?Bertiella studeri were found only during a seven-month period, when they occurred in every month. During this period, leaf-swallowing occurred at an unusually high rate, and dungs that contained tapeworm fragments tended to contain whole leaves. These data suggest that tape-worm infections increased the rate at which chimpanzees swallowed whole leaves. However, this does not mean that tapeworms were necessarily controlled as a result. © 1995 Wiley-Liss, Inc.