A Mantled Howler Monkey (Alouatta palliata), known for it's call, eating leaves in tree; Nosara, Guanacaste Province, Costa Rica, Central America

An adult mantled howler monkey, Alouatta palliata, in the forest of Caletas Reserve, Osa Peninsula, Costa Rica, Central America

Adult mantled howler (Alouatta palliata), Barro Colorado Island, Gatun Lake, Panama, Central America

Mantled Howler Monkey (Alouatta palliata), named for its call, eating leaves in tree, Nosara, Guanacaste Province, Costa Rica, Central America

Mantled Howler Monkey (Alouatta palliata), named for its call, eating leaves in tree, Nosara, Guanacaste Province, Costa Rica, Central America

Mantled Howler Monkey (Alouatta palliata), La Fortuna, Arenal, Alajuela Province, Costa Rica, Central America

Mantled Howler Monkey (Alouatta palliata) male in a tree, Soberania National Park, Panama

Mantled howler (Alouatta palliata) adult male howling on his territory, Pacific coast, Costa Rica