The largest eagle species in the world is the Pithecophaga jefferyi or Philippine eagle. This species of eagle is on the critically endangered list due to the rapid decline in habitat, which is the tropical rainforest.
Philippine eagles, both male and female, have white underwings and bellies, while the top or back of the birds are dark brown with pale edging on the feathers. This species has a loud, high-pitched call and whistle. The eagles wing span averages around 6 and a 1/2 feet. In the terms of length, the birds average around 35 to 40 inches. There are heavier eagles in the word, but this species wins on size alone.