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 ...

A 33-year study reveals how monkey group size changes survival. Climate, food, and competition all shape how these animals ...

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 33-year study of white-faced capuchin monkeys in Costa Rica found that extreme climate events like El Niño and La Niña can undermine the benefits of large social groups, altering long-standing ...

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 ...