Harpy Eagles Hunt Adult Monkeys in Rainforest Canopy

Harpy eagles hunt adult monkeys and other large arboreal mammals in the dense canopy of lowland tropical forests from southern Mexico to the Amazon Basin. The birds weigh up to 9 kilograms, with legs thicker than a child's wrist and rear talons exceeding 12 centimeters in length. These features allow them to grip and subdue prey that can weigh nearly as much as the eagle itself.

Harpy eagles perch silently beneath the canopy before launching short-range ambushes rather than soaring overhead. Their short broad wings and long tails enable tight maneuvering among branches where longer wings would be a hindrance. A 1989 study in The Condor recorded an attempted attack on an adult howler monkey.

One year later, a 1990 study in The Wilson Bulletin documented a successful capture of an adult male red howler monkey.

A 2024 study in the American Journal of Primatology examined remains left by harpy eagle predation and identified puncture marks and skeletal damage consistent with talon grip force. Sloths form a substantial portion of the diet in many regions because they are slow-moving and calorie-rich.

Monkeys present higher risk because they can fight back and issue alarm calls. According to the IUCN Red List, habitat destruction is the primary threat to the species. The eagles require large territories of intact forest and raise one chick every two or three years.