The black howler (Alouatta caraya), also known as black-and-gold howler, is a species of howler monkey, a large New World monkey, from northeastern Argentina, eastern Bolivia, eastern and southern Brazil, and Paraguay. Only the adult male is black; adult females and juveniles of both genders are overall whitish to yellowish-buff. They live in groups of 3 to 19 individuals (usually 7 to 9). The sex ratio is usually one to three males for every seven to nine females in a group. Mating occurs within the group.