The Bush as Pharmacy and Supermarket: Mechanisms and Functions of Plant Use by Human and Non-human Primates at Gashaka

Abstract

Both human and non-human primates exploit the plant resources of the woodland-savannah in Nigeria’s Gashaka area. We generated a database on the usage of more than 300 plant species that serve as food (including beverages and seasoning), medicine, or implements. We supplemented previously unpublished reports with original survey data and data accumulated by primate researchers. We compared four consumer groups, i.e., humans, domestic animals, baboons, and chimpanzees. Two case studies refer to discernible medicinal effects of plant use by non-human primates. One case concerns baboons, which consume African black plum; this has a contraceptive effect and potentially reduces mortality ­during the rainy season. A second case concerns chimpanzees, which swallow intact leaves of a coarse herbaceous plant, a practice that expels parasitic worms. We also reflect on potential co-evolutionary processes that lead to a preference for certain plant families and plant parts. The Gashaka area is clearly still under researched, as many taxa with ascribed medicinal values are not yet included in a standard compendium of medicinal plants in Nigeria. Future work should also engage with traditional concepts of how to classify plants, and explore plant properties in more detail as this might affect their usage as nutrition, for treatments, or as equipment. One would also want to work towards a further merger of ethno-botany and zoo-botany with its emerging sub-discipline of animal self-medication.