First lethal attacks by chimpanzees on gorillas observed
Chimpanzees are common in East and Central Africa and live with gorillas in some areas such as the Loango National Park in Gabon. "Interactions between chimpanzees and gorillas have so far been considered as relatively relaxed", says Simone Pika. Lethal encounters between the chimpanzees and gorillas have so far never been documented. "Our observations provide the first evidence that the presence of chimpanzees can have a lethal impact on gorillas. We now want to investigate the factors triggering these surprisingly aggressive interactions," says Tobias Deschner. What exactly happened? Lara M. Southern, PhD student and first author of the study, recalls the first observation in 2019: "At first, we only noticed screams of chimpanzees and thought we were observing a typical encounter between individuals of neighboring chimpanzee communities. But then, we heard chest beats, a display characteristic for gorillas, and realized that the chimpanzees had encountered a group of five gorillas." In the encounters, which lasted 52 and 79 minutes, the chimpanzees formed coalitions and attacked the gorillas. The authors from Osnabrück and Leipzig suggest several explanations for the interspecies violence observed including hunting and food competition between the species: "It could be that sharing of food resources by chimpanzees, gorillas and forest elephants in the Loango National Park results in increased competition and sometimes even in lethal interactions between the two great ape species", says Tobias Deschner.