Here a white-faced capuchin monkey perches on a tree branch in Manuel Antonio National Park in Costa Rica. A group from the same genus has been observed with stolen howler monkey babies on a small ...

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 ...