Black Howler
The black howler is a species of howler monkey, a large New World monkey, from northeastern Argentina, eastern Bolivia, eastern and southern Brazil, and Paraguay. Together with the brown howler, it is the southernmost member of the Alouatta genus. Only the adult male is black; adult females and juveniles of both genders are overall whitish to yellowish-buff. However, variations occur even among the adult males; some have patches of reddish-brown or buff fur. They live in groups of three to 19 individuals. The sex ratio is usually one to three males for every seven to nine females in a group. Mating occurs within the group. Named for their vocalizations, they may be heard most often around sunrise. This "dawn chorus" sounds much more like roaring than howling, and it announces the howlers' position as a means to avoiding conflict with other groups. The call can be heard up to 5 km away.