ABS 2022
Cultural Behaviors Exhibited by Chimpanzees in Gishwati Forest, Rwanda
Aaron Rundus, Rebecca Chancellor, Lauren Apostolou, John Carbone, Daniel Freeman, Taylor Heckman, James Kelley, Jennifer Kratz, Grace Lombardo, Hailey Morgan, Carli Marshall, Ayianna Petty, Tyler Soto. West Chester University, West Chester, PA, United States

Chimpanzees (Pan troglodytes) exhibit a large variety of cultural behaviors across populations. Here we report the first observations of cultural behavior in chimpanzees living in Gishwati forest, Rwanda, an isolated montane rainforest remnant. Between December 2008-September 2010, we examined chimpanzee fecal samples and recorded behavioral observations during habituation follows. We found that the Gishwati chimpanzees swallowed whole leaves of the clinging aneilema (Aneilema aequinoctiale) shrub, which has been hypothesized as a tool for self-medication to expel intestinal parasites. We found the leaves of this shrub in 70 of 1,696 (4%) fecal samples. We also observed ten tool sites, in which chimpanzees had stripped and sharpened tree branches to dig into subterranean stingless bee (Meliponini sp.) nests. In addition, we found the remains of Meliponini bees in 15 (1%) fecal samples. Finally, we observed the chimpanzees handclasp grooming, which has been described as a social custom in chimpanzees. These data contribute to our broader understanding of chimpanzee cultural transmission and highlight the importance of documenting cultural diversity in heavily impacted forests.