Laura Erickson's For the Birds

This extraordinary bird of prey, the largest eagle of the American tropics, is endangered in part because it’s relatively tame so easily killed by humans, but primarily because of loss of its rainforest habitat. It’s huge, females weighing up to 20 pounds in the wild, but has a fairly small wingspan, allowing it to maneuver through the forests where it preys on monkeys and sloths. My only experience with one was in a driving rain in the Darien Province of Panama, close to the Colombian border, where our birding group saw a full-grown, sopping wet fledgling near the nest.

The Harpy Eagle figures in the Guinness Book of World Records:

Harpy Eagle: Strongest bird of prey. The bird of prey capable of killing and carry away the largest animal is the female harpy eagle (Harpia harpyja), which in spite of its weight of up to 9 kg (20 lb) can manage to hunt animals of equal or superior size.