From the Field

Researchers from the Max Planck Institute of Evolutionary Anthropology (MPI) are hard at work observing the Kokolopori bonobos, learning more about bonobo group interactions. We know that bonobo encounters tend to be far more peaceful than those of our other closest relatives, the chimpanzees, though not all bonobo interactions are uniformly positive. What sort of environment enables peaceful interactions, and what are the implications for human interactions? While our understanding of chimpanzee dynamics has informed our understanding of early—and even current—human group interactions, the importance of peaceful encounters has gotten less attention in our origin narrative. Trading, information sharing, and collaboration are keys to human success, and these types of positive interactions are worth considering more deeply. The research in Kokolopori is giving us much greater insight into the factors that influence bonobo gatherings, and these findings may help shed light on an overlooked part of our own nature.

Meet Ebony of the Ekalakala group; Photo credit: Martin Surbeck
Meet Ebony of the Ekalakala group
Photo credit: Martin Surbeck

As reported in our last newsletter, researchers were thrilled to discover that two of the habituated groups of bonobos, the Nkokoalongo and Ekalakala, meet and interact regularly within the Yetee forest. In August, they observed interactions with a third group, Bekako, which we are just beginning to habituate. Three-group gatherings are not well-described in scientific literature, so everyone in camp is quite excited to have the opportunity to witness this phenomenon firsthand. Maelle Lemaire, who is in charge of data collection, reports that initially some of the males reacted aggressively, vocalizing loudly and pulling branches. Some females ran to members of their own group, while others engaged in GG-rubbing and other affectionate behaviors. After all the bonobos calmed down, grooming between groups was observed. The groups stayed together for three days, separating to make their night nests and then walking together throughout the days. In September, eight individuals from Bekako stayed with the Ekalakala group for three weeks. Because the Bekako bonobos are not as well-habituated as the other groups, these bonobos tended to shy away from the researchers. Still, they managed to observe more grooming and GG-rubbing; the extended encounter was very peaceful. A less peaceful interaction between Ekalakala and Nkokoalongo in early October has caused the two groups to keep their distance for the last few weeks.

Maelle Lemaire and Axel Ruiz, research team managers; Photo credit: Sally Jewell Coxe
Maelle Lemaire and Axel Ruiz, research team managers
Photo credit: Sally Jewell Coxe

It is tempting to believe that bonobos are unfailingly friendly and welcoming; however, observations paint a more complex picture. In order to understand these nuances of behavior, two doctoral students from MPI have joined Maelle and Axel Ruiz (camp manager) in the forest. Stefano Lucchesi‘s research involves looking at variables like food distribution and ranging patterns to determine what drives proximity. Leveda Cheng observes individual behaviors and characteristics: who is peaceful, who is aggressive, who interacts with whom. Dr. Martin Surbeck, the head researcher on the project, summarizes their work by saying that Stefan is working on what brings groups together and Leveda is focusing on what happens when they do. Both of them are investigating fascinating aspects of bonobo life that will broaden our understanding of these amazing apes.

The researchers have been hard at work identifying and naming the bonobos they follow, an important part of recording accurate observations. Each of the groups has a theme for names: Nkokoalongo bonobos are named after musicians, Ekalakala after colors, and now Bekako after rivers. Researchers are going to have to come up with a new name soon—a baby was just born in the Ekalakala group! Mother and infant are both doing well, and all group members are curious and excited about the new arrival. So are we—and we can’t wait to find out if it’s a boy or a girl! Wild bonobos spend most of their time high in the trees, and mother bonobos keep their babies very close, making it hard to determine the sex of newborns. We will keep you updated as we learn more about the little one!

Baby bonobo at Kokolopori; Photo Credit: Sally Jewell Coxe
Baby bonobo at Kokolopori
Photo Credit: Sally Jewell Coxe