Amazon black howler

The Amazon black howler (Alouatta nigerrima) is a species of howler monkey, one of the New World monkeys, found only in the south-central Amazon of Brazil. As its common name suggests, it typically appears entirely black. Until 2001 most authorities counted it as a subspecies of the red-handed howler, or as a taxonomically insignificant variation of it, although its distinctness had been pointed out much earlier, and it is now treated as a species in its own right. It belongs to the genus Alouatta, the howler monkeys, within the family Atelidae. The source describes its diet simply as leaves, which makes it a leaf-eating monkey of the Amazonian forest.