Howler monkeys (genus Alouatta monotypic in subfamily Alouattinae) are among the largest of the New World monkeys and one of only a few nest-building monkeys. Fifteen species are currently recognised. Previously classified in the family Cebidae, they are now placed in the family Atelidae. These monkeys are native to South and Central American forests. Threats to howler monkeys include human predation, habitat destruction and being captured for captivity as pets or zoo animals. These monkeys are famous for their loud howls, which can travel three miles through dense rainforest.