Bonobos are quite different from the peace-loving primates long thought, researchers say, after finding that males show more aggression toward each other than chimpanzees.
Bonobos and chimpanzees are humans' closest living relatives. While chimpanzees are known to exhibit aggression toward each other, sometimes to the death, bonobos are not known to kill each other and have long been thought to live more harmoniously. This difference has led to the theory that natural selection is acting against male bonobo aggression.
The new study turns that idea on its head, showing that bonobos show more male-to-male aggression than chimpanzees, even when researchers looked specifically at cases where males got into fights.
“This is a species with very complex behaviors, so just limiting the species to hippies doesn't work. That doesn't work in this study. It's too simplistic,” said the study's lead author, Boston University. said Dr. Maud Mugino.
“I think what we know now is that bonobos and chimpanzees use aggression, and they use it in different ways. And they have different strategies related to it. “The interesting area to explore now is why and when these different strategies evolved,” she says, adding that an interesting area to explore now is why and when these different strategies evolved.
Writing in the journal Current Biology, Mousino and colleagues tracked 12 male bonobos in three communities in the Kokoropoli Bonobo Reserve in the Democratic Republic of the Congo and 14 in two communities in Gombe National Park in Tanzania. It describes how they tracked a male chimpanzee.
The researchers tracked each male individually during waking hours and observed interactions with other members of the species, including aggressive physical contact and other aggressive behaviors such as lunging and chasing. The effect was recorded.
Overall, the researchers recorded 521 aggressive interactions involving bonobos tracked over 2,047 hours, and 654 aggressive interactions among identified chimpanzees over 7,309 hours.
The researchers found that despite previous studies that found chimpanzees display more severe forms of aggression, including murder, infanticide, and sexual coercion, the results of the current study show that aggressive behavior between males is less common in chimpanzees. This was 2.8 times more common in bonobos than in humans, especially when it involved physical contact, the researchers said. The frequency is 3.0 times.
In both species, more aggressive males were more successful in mating with females.
But while not the epitome of chivalry, male bonobos treated females differently than chimpanzees. The researchers found that male-to-female aggression was lower and female-to-male aggression was more common in the former than in the latter. The researchers found that female bonobos often outrank males in social groups.
“From the literature, for example, men and women [bonobos] They form close associations…and we don't see that in chimpanzees,” Moosino said, noting that humans also form such associations.
The researchers found that in male bonobos, only 1% of attacks involved primate solidarity, compared to 13% in chimpanzees, a finding that may explain the low frequency of aggression in chimpanzees. He added that there is.
“Of course, it's more risky when you have multiple adversaries because they can be completely overwhelmed,” Mugino said.