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The Eagle

Eagle Anatomy

Eagle is a common name for some members of the bird family Accipitridae, and belong to several genera that are not necessarily closely related to each other. Most of the more than sixty species occur in Eurasia and Africa. Outside this area, just eleven species can be found; two species (the Bald Eagle and Golden Eagle) in the United States and Canada, nine species in Central America and South America, and three species in Australia.

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General Information on Eagles

The smallest eagle species is the South Nicobar Serpent Eagle (Spilornis klossi), at 450 g and 40 cm. The largest eagle depends on what we are measuring by, as if by wingspan, the white-tailed eagle at 218.5cm is largest, if by weight, the 6.7kg Steller's Sea Eagle is largest, and if by length, the Phillipine Eagle is largest at 100cm.

Sub-Species of Eagle

FAMILY ACCIPITRIDAE

  • Subfamily Buteoninae – hawks (buzzards), true eagles and seaeagles

    • Genus Geranoaetus

      • Black-chested Buzzard-Eagle

    • Genus Harpyhaliaetus

      • Crowned Solitary Eagle

      • Montane Solitary Eagle

    • Genus Morphnus

      • Crested Eagle

    • Genus Harpia

      • Harpy Eagle

    • Genus Pithecophaga

      • Philippine Eagle

    • Genus Harpyopsis

      • Papuan Eagle

    • Genus Oroaetus

      • Black-and-chestnut Eagle

    • Genus Spizaetus

      • Cassin's Hawk-Eagle

      • Crested Hawk-Eagle

      • Mountain Hawk-Eagle

      • Blyth's Hawk-Eagle

      • Javan Hawk-Eagle

      • Sulawesi Hawk-Eagle

      • Philippine Hawk-Eagle

      • Wallace's Hawk-Eagle

      • Black Hawk-Eagle

      • Ornate Hawk-Eagle

      • Black-and-white Hawk-Eagle

    • Genus Lophaetus

      • Long-crested Eagle

    • Genus Stephanoaetus

      • Crowned Eagl

      • Martial Eagle

    • Genus Hieraaetus

      • Ayres' Hawk-eagle

      • African Hawk-Eagle

      • Little Eagle

        • Pygmy Eagle

    • Genus Lophotriorchis

      • Rufous-bellied Hawk-Eagle

    • Genus Aquila

      • Bonelli's Eagle

      • Booted Eagle

      • Golden Eagle

      • Eastern Imperial Eagle

      • Spanish Imperial Eagle

      • Steppe Eagle

      • Tawny Eagle

      • Greater Spotted Eagle

      • Lesser Spotted Eagle

      • Indian Spotted Eagle

      • Verreaux's Eagle

      • Gurney's Eagle

      • Wahlberg's Eagle

      • Wedge-tailed Eagle

    • Genus Ictinaetus

      • Black Eagle

    • Genus Haliaeetus

      • White-tailed Eagle

      • Bald Eagle

      • Steller's Sea Eagle

      • African Fish Eagle

      • White-bellied Sea Eagle

      • Sanford's Sea Eagle

      • Madagascar Fish Eagle

      • Pallas' Sea Eagle

    • Genus Ichthyophaga

      • Lesser Fish Eagle

      • Grey-headed Fish Eagl

 

  • Subfamily Circaetinae: snake-eagles

    • Genus Terathopius

      • Bateleur

    • Genus Circaetus

      • Short-toed Snake Eagle

      • Black-chested Snake Eagle

      • Brown Snake Eagle

      • Fasciated Snake Eagle

      • Western Banded Snake Eagle

    • Genus Spilornis

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        • Crested Serpent Eagle

        • Central Nicobar Serpent Eagle

        • Great Nicobar Serpent Eagle

        • Mountain Serpent Eagle

        • Sulawesi Serpent Eagle

        • Philippine Serpent Eagle

        • Andaman Serpent Eagle

    • Genus Eutriorchis

      • Madagascar Serpent

 

Skeleton and Muscles

 

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) 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 eagle species is the South Nicobar Serpent Eagle, at 450 g and 40 cm. 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. Eagles' eyes are extremely powerful, having up to 3.6 times human acuity for the martial eagle, which enables them to spot potential prey from a very long distance. 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.

 

 

 

 

Social and Feeding Behaviour

Social 

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.

 

Feeding

Due to the size and power of many eagle species, they are ranked at the top of the food chain as apex predators amongst the avian world. The type of prey varies from genus to genus. The Haliaeetus and Ichthyophaga eagles prefer to capture fish. The snake and serpent eagles of the genera Circaetus, Terathopius and Spilornispredominantly prey on the great diversity of snakes that are 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. Many other eagles, including the species-rich Spizaetus genus, 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.

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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. The Bald Eagle is noted for having flown with the heaviest load verified to be carried by any flying bird, since one eagle flew with a 6.8 kg mule deer fawn. However, a few eagles may target prey considerably heavier than themselves; such prey is too heavy to fly with and thus it is either eaten at the site of the kill or taken in pieces back to a perch or nest. Golden and Crowned Eagles have killed ungulates weighing up to 30 kg and a Martial Eagle even killed a 37 kg duiker, 7-8 times heavier than the predating eagle. Authors on birds David Allen Sibley, Pete Dunne and Clay Sutton, described the behaviorial difference between hunting eagles and other birds of prey thusly (in this case the Bald and Golden Eagles as compared to other North American raptors):

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They have at least one singular characteristic. It has been observed that most birds of prey look back over their shoulders before striking prey (or shortly thereafter); predation is after all a two-edged sword. All hawks seem to have this habit, from the smallest kestrel to the largest Ferruginous - but not the Eagles.

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