Native to eastern Bolivia and Paraguay, the White-eared Titi Monkey is locally known as the Huicoco de Bolivia. Photo from Santa Barbara Zoo, California. In context at www.dixpix.ca/Amazon/fauna/primates/index.html
It is known as the Black Howler, but only the males are black. It ranges from eastern Bolivia to northern Argentina. This one is at the Mendoza Zoo in the latter. Locally known as Mono Caraya. In context at www.dixpix.ca/Amazon/fauna/primates/index.html