Dunn’s team analyzed the biological “budget” of these primates and found a direct negative correlation: males with large ...

This photo provided by researchers shows a baby howler monkey clinging onto a young adult male capuchin monkey on Jicarón Island, Panama in September 2022. (Brendan Barrett/Max Planck Institute of ...

Howler infant number 5 on the back of a juvenile capuchin carrier, who is using stone tools at an anvil site in a stream bed. Usually, this behavior in females is described as adoption, thought to be ...

A group of male capuchin monkeys kidnapped baby howler monkeys – a different species – on a small island of Panama. Video shows the howler monkeys clinging to the male capuchin monkeys’ backs, but the ...