Primatologist Susan Perry of UCLA has spent much of the past 35 years studying the complex social lives of white-faced capuchin monkeys, at a field site she established in one of the remaining patches ...

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 ...

Animal abduction: Biologists documented five male capuchin monkeys carrying at least eleven different infant howler monkeys -- a behavior never before seen in wild primates. Rise and spread: The ...