Chimpanzees attacking and killing gorillas in the wild are observed for the first time

(CNN) – They were observed for the first time deadly chimpanzee attacks gorillas in the wild, according to a team of researchers.

Experts who observed dozens of chimpanzees in Gabon’s Loango National Park hoped they were relaxing among the gorillas.

However, while the two species are usually playful, the researchers were surprised to witness occasional fierce attacks.

“At first, we only noticed chimpanzee screams and thought we were observing a typical encounter between individuals from neighboring chimpanzee communities,” Lara M. Southern, lead author of the study, said in a news release.

“But then we heard chest beating, a characteristic gorilla display, and we realized that the chimpanzees had encountered a group of five gorillas,” he added, referring to the first attack the team saw in 2019.

The group, from the University of Osnabrück and the Max Planck Institute for Evolutionary Anthropology in Germany, published the findings Monday in the magazine Nature.

In the two encounters they recorded, which lasted 52 and 79 minutes, the chimps formed coalitions and launched attacks on the gorillas.

Silverback gorillas and adult females fought back and defended their young. The two silverbacks and several adult females escaped, but two baby gorillas were separated from their mothers and killed, the authors wrote.

“Our observations provide the first evidence that the presence of chimpanzees can have a lethal impact on gorillas. Now we want to investigate the factors that trigger these surprisingly aggressive interactions,” said Tobias Deschner, a primatologist at the Max Planck Institute for Evolutionary Anthropology.

The attacks were especially surprising given the way the two groups of animals had previously behaved. “The interactions between chimpanzees and gorillas have so far been considered relatively relaxed,” said Simone Pika, a cognitive biologist at the University of Osnabrück.

“We have regularly observed both species interacting peacefully in the trees to search for food. Our colleagues in the Congo even witnessed playful interactions between the two great ape species,” said Pika.

About 45 chimpanzees were observed for the study, which aimed to analyze their relationships, use of tools, communication and hunting skills, among other characteristics.

Chimpanzees and gorillas were observed in Loango National Park as part of the study.

The authors suggested that sharing food with other species could have caused the outbreaks. “It could be that chimpanzees, gorillas and jungle elephants sharing food resources in Loango National Park causes increased competition and sometimes even lethal interactions between the two great ape species,” he said. Deschner.

Loango National Park is a large protected area on the Gabon coast in western sub-Saharan Africa. It is home to elephants, buffalo and other species.

The region is home to the western lowland gorilla, which is a critically endangered species.

Chimpanzees are an endangered species, according to the International Union for Conservation of Nature.