Eagles

**Eagle** is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, not all of which are closely related. Most of the 60 species of eagle are from Eurasia and Africa. Outside this area, just 14 species can be found—2 in North America, 9 in Central and South America, and 3 in Australia.

Eagles are large, powerfully built birds of prey, with heavy heads and beaks. Even the smallest eagles, such as the booted eagle (*Aquila pennata*), which is comparable in size to a common buzzard (*Buteo buteo*) or red-tailed hawk (*B. jamaicensis*),
 have relatively longer and more evenly broad wings, and more direct,
faster flight – despite the reduced size of aerodynamic feathers. Most
eagles are larger than any other raptors apart from some vultures. The smallest species of eagle is the South Nicobar serpent eagle (*Spilornis klossi*),
 at 450 g (0.99 lb) and 40 cm (16 in). The largest species are discussed
 below. Like all birds of prey, eagles have very large, hooked beaks for ripping flesh from their prey, strong, muscular legs, and powerful talons.
 The beak is typically heavier than that of most other birds of prey.
Eagles' eyes are extremely powerful. It is estimated that the martial eagle, whose eye is more than twice as long as a human eye, has a visual acuity 3.0 to 3.6 times that of humans. This acuity enables eagles to spot potential prey from a very long distance. This keen eyesight is primarily attributed to their extremely large pupils which ensure minimal diffraction (scattering) of the incoming light. The female of all known species of eagles is larger than the male.

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 a female, as they are bigger
than the male. The parents take no action to stop the killing.

Due to the size and power of many eagle species, they are ranked at the top of the food chain as apex predators in the avian world. The type of prey varies by genus. The *Haliaeetus* and *Ichthyophaga* eagles prefer to capture fish, though the species in the former often capture various animals, especially other water birds, and are powerful kleptoparasites of other birds. The snake and serpent eagles of the genera *Circaetus*, *Terathopius*, and *Spilornis* predominantly prey on the great diversity of snakes found in the tropics of Africa and Asia. The eagles of the genus *Aquila* are often the top birds of prey in open habitats, taking almost any medium-sized vertebrate they can catch. Where *Aquila* eagles are absent, other eagles, such as the buteonine black-chested buzzard-eagle
 of South America, may assume the position of top raptorial predator in
open areas. Many other eagles, including the species-rich genus *Spizaetus*,
 live predominantly in woodlands and forest. These eagles often target
various arboreal or ground-dwelling mammals and birds, which are often
unsuspectingly ambushed in such dense, knotty environments. Hunting
techniques differ among the species and genera, with some individual
eagles having engaged in quite varied techniques based their environment
 and prey at any given time. Most eagles grab prey without landing and
take flight with it, so the prey can be carried to a perch and torn
apart.