Ernie Janes / Black howler (Alouatta caraya) male and female, captive, occurs in Brazil and Paraguay. With digitally added leaf pattern.

Bernard Castelein / Bolivian red howler (Alouatta sara), Pampas del Yacuma Protected Area, Bolivia

Suzi Eszterhas / Colombian red howler monkey (Alouatta seniculus) mother and baby in tree. Northern Colombia.

Ernie Janes / Black howler (Alouatta caraya) captive, occurs in South America.

Claudio Contreras / Central American spider monkey (Ateles geoffroyi) juveniles hanging by tails and playing, Calakmul Biosphere Reserve, Yucatan Peninsula, Mexico, August

Edwin Giesbers / Brown headed spider monkey (Ateles fusciceps) mother and baby, captive occurs in Central and South America.

Edwin Giesbers / Brown headed spider monkey (Ateles fusciceps) group resting together, captive occurs in Central and South America.

Thomas Marent / Black-faced Spider Monkey (Ateles chamek) juvenile calling, Tambopata-Candamo Nature Reserve, Peru

Thomas Marent / Black Howler Monkey (Alouatta caraya) female, native to South America

Thomas Marent / Black Howler Monkey (Alouatta caraya) female, native to South America

Mark Bowler / Black spider monkey (Ateles chamek) calling, captive, Peru.

Cyril Ruoso / Man with Chamec spider monkeys (Ateles chamek) holding onto him as he walks through sanctuary. Ikamaperou Sanctuary, Amazon, Peru. October 2006.