Mark Bowler / Andean / Rio mayo titi monkey (Callicebus oenanthe) sitting in tree, Alto Mayo, Peru, Endangered species

Thomas Marent / Coppery Titi (Callicebus cupreus) monkey, Amacayacu National Park, Colombia

Luiz Claudio Marigo / Black-fronted / Masked titi monkey (Callicebus nigrifrons) with young in Atlantic Rainforest, Minas Gerais State, Southeastern Brazil.

Kevin Schafer / Urubamba Brown Titi Monkey (Callicebus urubambensis) juvenile, Tambopata National Reserve, Peru

Rod Williams / Male Red titi monkey (Callicebus cupreus) carrying baby, Captive, found in Brazil/Peru

Rod Williams / Red Titi monkey (Callicebus cupreus) captive, from Brazil and Peru

JIM CLARE / Two Dusky titi monkeys {Callicebus moloch} on branch, Amazon, South America

Miles Barton / Dusky titi monkey {Callicebus moloch} young, captive, from South America

Miles Barton / Dusky titi monkey {Callicebus moloch} male carrying 4-month young on his back, captive, from South America

JIM CLARE / Dusky titi monkey (Callicebus moloch) pair with young, Amazonia, South America

Rod Williams / Dusky titi monkeys {Callicebus moloch} female with young, captive from Amazonia

Luiz Claudio Marigo / Masked titi monkey {Callicebus nigrifrons} atlantic rainforest, Brazil