Playful primates break up fights, spin in circles, and bend branches for acrobatics

Chimpanzee moms break up fights

It’s time to head back to school, and for kids, that means getting ready to resume their usual playground antics. Unfortunately, what starts as innocent roughhousing between peers can sometimes get a little too rough. When that happens, parents and other grown-ups occasionally step in to make sure nobody gets hurt.

Humans aren’t the only great apes that break up fights among their children. Chimpanzee and bonobo mothers keep watch over the playing grounds of African forests. All it can take is a distress call from a screeching young chimpanzee to send a mother racing into action.

“If anything serious is happening, like if someone is really aggressing their child or [the child is] afraid, they’re right there,” says Cat Hobaiter, a primatologist at the University of St. Andrews who studies chimpanzee communication in the wild. “I’ve seen a mom drop out of a huge tree faster than her kid can hit the ground.”

Bonobos also jump into action to protect their young ones. But a recent study suggests that at least some of their helicopter-parent tendencies might be dampened compared with those of chimpanzees. Researchers found that chimpanzee mothers intervened much more often in their children’s fights than bonobo mothers (Anim. Behav. 2023, DOI: 10.1016/j.anbehav.2023.11.015).

Why do chimps spin in circles?

If you ever have the chance to sit among a group of wild chimpanzees, you might see them making communicative gestures that mean they’re asking for food or even flirting. Then there’s another motion that, to the untrained eye, may seem to make no sense at all: pirouetting.

Why wild juvenile chimpanzees pirouette—spin in circles—has eluded researchers. When Hobaiter’s group analyzed observations recorded during several pirouettes, her team was able to figure out what the motion means: stop!

“It’s a way of saying ‘Stop playing with me,’ ” Hobaiter tells Newscripts. “They do somersaults or pirouettes, and it usually means ‘Stop doing what you’re doing.’ ”

Monkey acrobatics

Chimpanzees aren’t the only primates with puzzling behaviors in the forests of eastern Africa. High up in the canopy, colobus monkeys make great, terrifying leaps between trees.The adult monkeys weigh only about as much as a human toddler, but they use their size to their advantage. Researchers recently discovered that colobus monkeys occasionally use sturdy tree branches as makeshift springboards. The small primates pump branches up and down or side to side, which helps the animals spring their way across large gaps in the canopy (Am. J. Biol. Anthropol. 2024, DOI: 10.1002/ajpa.24914).

Judith Janisch, a behavioral biologist at the Max Planck Institute for Evolutionary Anthropology, was recording video of the animals to study the anatomy of their movement in trees. When she and her student noticed the monkeys making their leaps of faith, they couldn’t look away.

“It was just like ‘Oh wow, this is really cool. We should get this on a camera,’ ” Janisch tells Newscripts. After analyzing the jumping footage, she and her colleagues confirmed that the monkeys were using the branches to increase their velocity at the start of their jump.The scientists also observed that juveniles didn’t weigh enough to do the branch-assisted jumps by themselves. Adult colobus monkeys would then use their own body weight to pump the branches, letting the scared young ones leap across large gaps.

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