Which eagle preys on sloths and monkeys?

The harpy eagle is an actively hunting carnivore and is an apex predator. Adults are near the top of a food chain but are preyed upon by snakes, jaguars and the much smaller ocelot. Its main prey are tree-dwelling mammals and a majority of the diet has been shown to focus on sloths and monkeys.

Research conducted by Aguiar-Silva between 2003 and 2005 in a nesting site in Parintins, Amazonas, Brazil, collected remains from prey offered to the nestling by its parents and after sorting them, concluded, in terms of individuals preyed upon, the harpy's prey basis was composed in 79% by sloths from two species: Bradypus variegatus amounting to 39% of the individual prey base, and Choloepus didactylus to 40%; various monkeys amounted to 11.6% of the same prey base.

In a similar research venture in Panama, where a couple of captive-bred subadults was released, 52% of the male's captures and 54% of the female's were of two sloth species (Bradypus variegatus and Choloepus hoffmanni). At one Venezuelan nest, the remains comprised sloths.

Monkeys regularly taken can include capuchin monkeys, saki monkeys, howler monkeys, titi monkeys, squirrel monkeys, and spider monkeys. Smaller monkeys, such as tamarins and marmosets, are seemingly ignored as prey by this species.