Female Bonobos Assert Their Dominance Over Males by Banding Together, New Study Suggests
Bonobos, which are among our closest living relatives, live in rare societies where females tend to outrank males, even though males are larger and stronger. Scientists compiled decades of observations to explain why
/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/accounts/headshot/Sara_-_Headshot_thumbnail.png)
Male bonobos are big, loud animals—and they can be aggressive. Yet, despite the males being larger and stronger than their female counterparts, bonobos live in female-dominated societies, a fact that has long puzzled scientists. Now, a new study offers an explanation: girl power.
A team of researchers observed six wild bonobo communities in the Democratic Republic of the Congo across three decades, between 1993 and 2021. They noticed that by banding together, female bonobos asserted their dominance over males. The findings were published in the journal Communications Biology on April 24.
“We have found what everybody already knows—that when you work together, you’re more successful and you gain power,” says lead author Martin Surbeck, a behavioral ecologist at Harvard University, to Jason Bittel at National Geographic.
Female-dominated social structures are rare among mammals, especially those with larger males. But in bonobo groups, females often decide when to mate and who gets to eat food first. So, scientists wanted to learn what tips the outcome of a conflict in favor of the females.
The researchers found that female bonobos will form coalitions, usually of three to five animals. In 85 percent of cases when these groups showed aggression, it involved ganging up on male bonobos. And in 61 percent of those fights, the females are victorious.
“You can win a conflict by being stronger, by having friends to back you up, or by having something that someone wants and cannot take by force,” says Surbeck in a statement. For these primates, the strategy seems to be to team up.
When females target a male who has acted out of line—such as by trying to harm a young bonobo—they might all chase after him through the trees, screaming loudly. They may also inflict serious injuries to the male.
These attacks can get pretty violent, Surbeck adds to Dino Grandoni at the Washington Post. Witnessing one, he says, “really makes you like, ‘Gosh, male bonobo, I would not overstep certain boundaries.’”
These coalitions, the researchers suggest, are what allow female bonobos to achieve higher social ranks. The average female bonobo outranks 70 percent of the males in her community, according to the study. But this number varied across populations, suggesting that while females have earned high status in bonobo societies, this dominance doesn’t go unchallenged.
/https://tf-cmsv2-smithsonianmag-media.s3.amazonaws.com/filer_public/9b/9d/9b9d037c-ac4a-4479-8851-dc5be27c7384/low-res_fruth_2025_web_banner.jpg)
Bonobos, along with chimpanzees, are humans’ closest living relatives. As such, “these data also provide support for the idea that humans and our ancestors have likely used coalitions to build and maintain power for millions of years,” says Laura Simone Lewis, a biological anthropologist at the University of California, Berkeley, who was not involved in the study, to National Geographic.
“This study could provide insight into how women could build power to better protect ourselves from male violence—by forming and maintaining coalitions, or alliances, with one another, just like our bonobo cousins,” she adds to the Washington Post.
Christopher Krupenye, a professor at Johns Hopkins University who studies cognition in primates, notes to the Washington Post that while the study successfully compiles a large set of data to come to its conclusion, more observations are needed to find out whether the coalitions are what give the females their power, or whether they form because females already have power.
“In concert with related work in chimpanzees and other primates, it seems very likely that coalitions have been a tool for building and maintaining power for millions of years, dating back at least to our common ancestor with the other apes,” Krupenye adds.
Still, the study suggests male dominance is not inevitable. Great apes, the study indicates, can be flexible in their social structures.
To learn more about bonobos—and, by extension, ourselves—the researchers say the primates must be protected. Currently, the Democratic Republic of the Congo is the only place on Earth where bonobos live in the wild.
“Bonobos are an endangered species,” Surbeck tells the New York Times’ Annie Roth. “As our closest living relative, they help us look into our past. If we lose them, we lose a mirror for humanity.”
