An anthropologist from Iowa State University described chimps' behavior as "shocking" after one chimpanzee was killed at the research site in Fongoli, Senegal where she carried out her studies.
Both the fact that the community of chimpanzees killed one of their members and the abuse that followed the killing were unexpected, according to the specialist.
Jill Pruetz is a professor of anthropology at the Iowa State University, who established her research site in Fongoli back in 2001. The woman was the first specialist to witness chimpanzees using tools in their hunting process.
Chimps' Deadly Aggression An Unusual Phenomenon
In 2013, the anthropologist and her research team discovered the body of a former leader of the chimpanzee community in Fongoli, who had been exiled from the group for years. The dead chimpanzee, named Foudouko, was reportedly killed and cannibalized by members of the community. Following the animal's death, the abuses continued for four hours.
"It was very difficult and quite gruesome to watch. I couldn't initially make sense of what was happening, and I didn't expect them to be so aggressive with the body," noted Pruetz.
Most of the available information on how chimpanzees go through the grieving process is anecdotal. However, the anthropologist noted that the animals showed no sign of mourning while torturing the body of their former leader. Of the animals, the most signs of aggression were shown by the younger adult male chimpanzees.
"We report attacks by multiple chimpanzees on his dead body, most frequently by a young adult male and an older female. The latter also cannibalized the body. Coalitionary killing is rare among West African chimpanzees compared to the East African chimpanzee," noted the research.
The report of this occurrence, published in the International Journal of Primatology, documents that the only two animals who showed no aggressiveness were former allies of Foudouko. Although one of them hit the body and yelled at it, the anthropologist noted that the chimp's behavior was an attempt to rouse the dead animal and not to hurt it.
Chimps' Aggression Could Be Influenced By Man-Made Changes
There are numerous unusual aspects of this occurrence, according to the scientific report, the first of which is that the exiled animal had survived for such a long time in exile. The scientific community hasn't reported this type of isolated longevity in a long time. During the exile, Foudouko had been spotted interacting with former allies, but on very rare occasions and only in private conditions, which was all the more surprising as chimpanzees are very sociable animals, for whom long-term isolation can be very stressful.
Another odd occurrence is the deadly aggression. There is no scientific consensus regarding the causes of this behavior among these animals. However, there are very few primates to exhibit this behavior, but researchers are especially interested in finding the causes of these actions, since chimpanzees are an endangered species.
Concerning this interest, back in 2014, Pruetz also published a scientific paper on the importance of understanding the causes of aggression among chimps. The paper appeared in the journal Nature. One of the hypotheses of that research was that human changes can have an influence on the aggressiveness of the chimpanzee populations.
"You have people coming in disturbing parts of the habitat that are important for chimpanzees. In one village near another research site, the population went from 100 people to around 10,000. When you have a human influx like that the chimps don't have much choice but to move. If they move into another chimp community's home range, something is going to happen and not all the chimps are going to survive," Pruetz noted at the time.