Ernie Janes / Howler monkey (Alouatta caraya) resting in tree, Costa Rica.

Ernie Janes / Black howler (Alouatta caraya) male female pair. Captive, occurs in South America, with digitally added leaf pattern.

Bernard Castelein / Paraguyan howler monkey (Alouatta caraya) male and female, Pampas del Yacuma Protected Area, Bolivia

Bernard Castelein / Paraguyan howler (Alouatta caraya) female, Pampas del Yacuma Protected Area, Bolivia

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

Andy Rouse / Black Howler Monkey (Alouatta caraya) howling , Pantanal, Brazil

Hermann Brehm / Black Howler Monkey (Alouatta caraya) in tree, Pantanal, Brazil

Gabriel Rojo / Black howler monkey (Alouattacaraya) male and female in tree, Ibera Marshes, Corrientes Province, Argentina

Nick Garbutt / Black howler monkey (Alouatta caraya) resting in riverine forest canopy. Tributary of Cuiaba River, Mato Grosso, Pantanal, Brazil. September.

Thomas Marent / Black Howler Monkey (Alouatta caraya) male, Pantanal, Brazil

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