Rod Williams / Night monkey {Aotus trivirgatus} juvenile, captive, from Central and South America

Roland Seitre / Northern Night Monkey (Aotus trivirgatus) climbing branch, in rainforest, Brazil.

Roland Seitre / Northern Night Monkey (Aotus trivirgatus) climbing down branch, Brazil.

Roland Seitre / Northern Night Monkey (Aotus trivirgatus)

Pete Oxford / Huaorani Indian girl with her night monkey (Aotus) pet. Gabaro Community, Yasuni National Park, Ecuador, June 2007.

Nick Gordon / Northern night / owl monkey (Aotus trivirgatus) (known locally as Douracoulis) next to passion fruit vine, Amazonia, Brazil

JIM CLARE / Night monkey {Aotus trivirgatus} Amazon, South America

Pete Oxford / Captive Night monkey {Aotus sp} caught for illegal wildlife trade, Amazonia, Ecuador

Rod Williams / Douroucouli / Night monkey {Aotus trivirgatus} captive, from Central and South America

Luiz Claudio Marigo / Night monkey / Douroucouli {Aotus trivirgatus} rainforest, Brazil

Claus Meyer / Northern Night Monkey (Aotus trivirgatus) portrait, Amazon ecosystem, Brazil

Claus Meyer / Northern Night Monkey (Aotus trivirgatus) portrait, Amazon ecosystem, Brazil

Claus Meyer / Northern Night Monkey (Aotus trivirgatus) portrait, Amazon ecosystem, Brazil

Joel Sartore / Photo Ark / Three-striped night monkey (Aotus trivirgatus) portrait, Faunia Zoo, Madrid. Captive, occurs in South America.

Joel Sartore / Photo Ark / Three-striped night monkey (Aotus trivirgatus) portrait, Faunia Zoo, Madrid. Captive, occurs in South America.

Stephen Dalton / Owl monkey (Aotus trivirgatus) head portrait. Captive.