, May 24 -- A young howler monkey was seen clinging to the back of an older male monkey, tightly gripping its fur.

But the two weren't related - and they weren't even the same species.

Scientists reviewing camera footage from a small island in Panama discovered unexpected and unsettling behavior: capuchin monkeys were seen taking baby howler monkeys. At least 11 such incidents occurred between 2022 and 2023.

"This was an incredibly surprising discovery," said Zoe Goldsborough, a behavioral ecologist at Germany's Max Planck Institute of Animal Behavior. "We've never documented anything quite like this in the animal world."

The reasons behind the behavior remain unclear. Capuchins, which are roughly the size of house cats, live in Centr...