Add Yahoo as a preferred source to see more of our stories on Google. Primatologist Susan Perry of UCLA has spent much of the past 35 years studying the complex social lives of white-faced capuchin ...

On an island in Panama, a fad that one researcher called "viscerally disturbing" has recently taken off among a group of young male monkeys. These adolescents and juveniles have started to kidnap the ...

A young male nicknamed Joker was probably the first to start carrying a howler monkey baby on his back for days on end. Then a group of other young males started to copy him. Here a white-faced ...

Observations of Coiba’s tool-using immature capuchin monkeys show them carrying abducted infant howler monkeys. What is the reason for this behavior? Vanessa Crooks Caught in the act! Capuchin monkeys ...