Eagles are the top predators of the emergent layer of the tropical rainforest.

Most other predators are unable to reach the inhabitants of the high emergent trees.

The harpy eagle, which lives in the Amazon rainforest, is one of the largest eagles on Earth.

The Philippine eagle, or monkey-eating eagle, also one of the world's largest eagles, lives in the tropical rainforests of the Philippines.

The crowned eagle dominates the emergent layer of the African rainforest.

All three eagles occupy the same ecological niche in the rainforest. Thus, their structure and biology are also similar.

As with most hawks and eagles, the female harpy is larger than the male. She weighs about 20 pounds (9kg) and is about 3 feet (90cm) long from head to tail.

The harpy eagle's feet are noticeably large - about the size of a man's hand - and tipped with lethally sharp, curved claws. Once these feet grasp their prey, it has little hope of escape.

The harpy's shortened and broadened wing profile is an adaptation to its forest top environment.

With its rounded wings, the harpy can generate sufficient lift to move almost vertically through the forest.

When flying between the trees, the short wings give the harpy great agility as well as speed.

It does not soar over the landscape, as do many other eagles. Instead, it moves from tree to tree in short flights, looking and listening intently for the sounds of suitable prey, particularly monkeys and sloths.

Its gray coloration  makes it inconspicuous as it searches for prey.

Both the Philippine and crowned eagles have similar hunting and flight patterns, although the crowned eagle frequently hunts in the lower levels of the forest and sometimes even at ground level, taking such prey as bushbuck and antelope.

All three types of eagles have similar nests.

The male and female work together to build a large, irregular platform of twigs in the emergent trees branches.

These nests may be as much as 150 feet high.

The eagles have a variety of calls. The African crowned eagle has a shrill call. The Philippine eagle's call is a weak, whistling sound.

Young harpy eagles make high-pitched screams when they are hungry. Adult screams are lower pitched. Adult harpy eagles also make soft, croaking noises.