end of the herb into a brush tip. Some individuals were also observed biting the end of the tool with their incisors to pull apart the fibers. First described as brush-stick by Sugiyama for chimpanzees of Campo. Absent at Mahale. See video. Budongo Study area of Pan troglodytes schweinfurthii in Budongo Forest Reserve, Uganda. Research organized by Reynolds, continuing from 1990 to present. Pioneer studies done by and F. Reynolds in 19 219 3, by Y. Sugiyama in 19 19 9, and A. Suzuki in 19 91970. bump See pass with body contact. butt See push head into ventral. buttress-beat See drum. Bwindi Study area of Pan troglodytes schweinfurthii in Bwindi Impenetrable National Park, Uganda. Research organised by C. Stanford from 199 to 2005. C C call See