Eagles are large, powerfully built birds of prey, with a heavy head and beak. Even the smallest eagles, like the Booted Eagle (which is comparable in size to a Common Buzzard or Red-tailed Hawk), have relatively longer and more evenly broad wings, and more direct, faster flight. (Despite reduced size in aerodynamic feathers) Most eagles are larger than any other raptors apart from some vultures. Species named as eagles range in size from the South Nicobar Serpent Eagle, at 500 g (1.1 lb) and 40 cm (16 in), to the 6.7 kg (14.7 lbs) Steller's Sea Eagle and the 100 cm (39 in) Philippine Eagle. Like all birds of prey, eagles have very large hooked beaks for tearing flesh from their prey, strong muscular legs, and powerful talons. The beak is typically heavier than most other birds of prey. They also have extremely keen eyesight which enables them to spot potential prey from a very long distance.[2] This keen eyesight is primarily contributed by their extremely large pupils which ensure minimal diffraction (scattering) of the incoming light. The female of all species of eagle known are larger than the male.[3][4]
Eagles normally build their nests, called eyries, in tall trees or on high cliffs. Many species lay two eggs, but the older, larger chick frequently kills its younger sibling once it has hatched. The dominant chick tends to be the female, as they are bigger than the male. The parents take no action to stop the killing.
