Study Finds Chimps’ Behavior Following Death Deeply Disturbing

A professor of anthropology at Iowa State University, Jill Pruetz describes the behavior of chimps as disturbing after one of them was killed at her research site in Fongoli, Senegal. The fact that chimps would kill a member of their own community is extremely rare as most aggression is between communities but the abuse which followed was completely unexpected.

"It was very difficult and quite gruesome to watch....I could not initially make sense of what was happening, and I did not expect them to be so aggressive with the body," Pruetz said. She noted that she has witnessed so many things since she established the research site in 2001 as she was even the first to document by chimps. But she explained that what she saw in 2013 was completely different.

The researcher documented the chimps' behavior after discovering the body of Foudouko - a onetime leader of the Fongoli community that was exiled from the group for five years. The researchers reported in the video that many of the chimps, suspected to be Foudouko's killers, abused and cannibalized his body for nearly four hours, according to Science Daily.

Previous studies conducted on chimps have revealed information on how they grieve, but the researchers said the chimps were not in mourning and their reports built upon a study on lethal aggression conducted in 2014. They stated that the younger adult male chimps were the most aggressive with two of Foudouko's former allies being the only ones that did not show any aggression.

But the authors noted that one of the two did yell at and hit the body in an attempt to revive Foudouko. Few other animals display similar deadly aggression but the scientists in the field of primatology are not unanimous as to the cause of this behavior. In the instant case, the deadly behavior is said to be due to chimps' endangered status.

Pruetz previously thought that man-made environmental changes, which disrupt the chimps' habitat contributes a lot to the aggressive behavior the researchers observed but she cannot say definitively if that was the case with Foudouko's death.

She believes it is likely due to competition for a mate as there are more male chimps than females at Fongoli, thereby, bringing about a struggle for power with younger chimps. The skewed gender balance at Fongoli could also be linked to human factors as the researchers noted that local residents reported hunting for female chimps to get infants for pet trade.

Capturing just one female chimp every few years could have real influence on the community due to their slow life history. The fact that Foudouko survived in isolation for several years is quite unusual as such happening has never been recorded for a long time, according to Pruetz.

The researcher monitored Foudouko during the five years of his exile and found that he followed the group from a distance, and privately interacted with some of his former allies, but the interactions were rare. It was really surprising that he lived on the outskirts for so long, as chimps are very social, so this type of isolation would be very stressful.

Foudouko might have had a chance, if he had been more submissive, according to Science Alert. The researchers suspected that he was in the area during the days before his death and was still there with no indication that the group would kill him. Foudouko was feared by the other chimps and it could be that the younger chimps were disturbed that he would try to regain his power, and so decided to attack him. The researchers said the younger chimps outnumbered Foudouko's allies, and also have the advantage of being in their physical prime.

Pruetz noted that it was obvious that other chimps were still afraid of Foudouko even after the deadly attack as they showed signs of fear, especially when his body would jerk during the attacks. The researchers buried Foudouko after the chimps left his body, his bones will be exhumed for examination in the future. They published their reports and video in the International Journal of Primatology.