An encounter between the two groups of Kokolopori bonobos. Image credit: Liran Samuni (CC BY 4.0)
No human culture is quite like the next. Societies around the world show exceptional variety in their social norms, beliefs, customs, language and, of course, food. However, the origins of human culture still remain elusive.
Studying humans’ closest living relatives, the great apes, is one way to explore how human culture first appeared. Chimpanzees are often studied for this purpose, but other great apes, such as bonobos, are often overlooked. Yet bonobos are less territorial and more tolerant to others than chimpanzees, with different bonobo groups sharing feeding spots and hunting grounds. These traits actually make bonobos an ideal animal for investigating whether differences in group behaviour, such as feeding habits, are distinct cultural trends or just a result of their surrounding environments.
With this in mind, Samuni et al. studied the hunting and feeding patterns of two groups of wild bonobos in the Kokolopori Bonobo Reserve in the Democratic Republic of Congo. The two groups share approximately 65% of their home territory, allowing Samuni et al. to examine whether any differences in hunting preferences persisted when the two groups looked for prey in the same environment. The analysis would reveal whether social factors or environmental conditions influenced the hunting and feeding habits of each group.
Samuni et al. found the first bonobo group specialized in hunting duiker, a type of antelope, whereas the second group preferred to hunt tree-gliding rodents. However, the location and timing of the bonobo’s hunts did not determine which types of prey they hunted. Across their territory, and regardless of group size or the dynamics between males and females, the groups continued to hunt their preferred prey. This means ecology alone cannot explain bonobo feeding habits and instead, the findings provide a strong indication for cultural variation between the two groups.
Since social learning is a part of cultural development, the next challenge will be to determine if and how these group hunting preferences are learned by young bonobos in their social group. For now, these findings provide a glimpse into the emergence of group culture.
