Eagles are large, powerful Birds of Prey. They belong to several Genera which are not necessarily closely related to each other. They are Diurnal Birds which means that they are mostly active during daytime. Eagles are different from many other Birds of Prey mainly by their larger size, more powerful build, and heavier head and beak. Even the smallest Eagles, like the Booted Eagle has relatively longer and more evenly broad wings. Majority of the Eagle Species occur in Eurasia and Africa. Outside this area, just two Species (the Bald  and Golden Eagles) can be found in the United States and Canada, nine more in Central and South America, and three in Australia. An Eagle may resemble a Vulture in build and flight characteristics but has a fully feathered (often crested) head and strong feet equipped with great curved talons. There are approximately 59 different Species of Eagles. Scientists have categorised Eagles into Four Different Groups -  i) The Sea and Fish Eagles, ii) the Snake Eagles, iii) the Harpy Eagles, and iv) the Booted Eagles. Female Eagles are larger than the Males, outweighing them by as much as 30 percent. The age of Eagles varies with species; both the Bald Eagle and the Golden Eagle may survive 30 or more years.

Scientific Classification of Eagles

Kingdom - Animalia.
Phylum - Chordata.
Class - Aves.
Order - Falconiformes or Accipitriformes.
Family - Accipitridae.

Physical Features of Eagle

  • All most all Eagles have Fusiform shaped bodies, which means that they are rounded and tapering at both ends. This body shape reduces drag while flying.
  • One of the most striking feature of an Eagle is it's Heavy Curved Beak. It is made of Bone and covered by Horny Plates made of Keratin. The Hook at the tip is used for tearing. The Beak is strongly Hooked at the Tip and Sharp on the edges to slice tough skin.
  • Eagles have two ear openings that lie just behind and below the eyes. These are not visible as they are covered with feathers.
  • An Eagle's Wings are Long and Broad, making them effective for Soaring. To help reduce turbulence as air passes over the end of the Wing, the Tips of the feathers at the end of the Wings are Tapered so that when the Eagle fully extends its Wings, the Tips are widely separated.
  • Eagle's have extremely keen Eyesight enabling them to spot potential prey from a very long distance. Their eyes are set on either side of the head, facing forward. Their keen eyesight is the result of  extremely large pupils which cause minimal diffraction (scattering) of the incoming light.
  • Eagle's eyes are protected by an upper and lower eyelid as well as a Nictitating Membrane. The Nictitating Membrane acts as a third eyelid, moving horizontally across the eye starting at the inner corner. The Eagle can close the clear Membrane to protect the eye without losing vision. The Membrane spreads fluid across the eye, keeping the eye moist. These are also used as protecting agents, when flying on windy days or when dust and debris are in the air.
  • Most of the Eagles also have a Distinctive Shelf or Eyebrow above and in front of the eye. The Eyebrow is considered to shade the eye from the sun and provide physical protection.
  • Eagles have well- muscled and sturdy legs. The legs and feet are covered with scales.
  • An Eagle's foot consists of Four Toes. The First Toe points backward and the remaining Three point forward. Each Toe has a Claw, or Talon. Talons are made of keratin, a tough, fibrous protein, and are usually curved downwards. Strong Toes and Sturdy, Sharp Talons are very useful for for catching and carrying prey.
  • Eagles which kill and carry large prey, like Golden Eagles, have relatively long Hind Talons. Hind Talons are also used to strike down other birds in mid-flight.

Colour - Most Species of Eagles have subdued feather colours, mainly browns, rust, black, white, and some blues and greys. Many Species have an Immature Plumage and an Adult Plumage. Immature Bald Eagles are completely Brown in colouration, while Adults have a distinctive White Head and Tail.

Weight - Weight of the Eagles vary according to Species. Harpy Eagles weigh 14-18 pounds (7-9 kilograms for Females) while Males of Booted Eagle weigh about 700 grams (1.5 lbs) in Weight, with females close to 1 kilogram (over 2 lb).

Height
- Most Eagles are large in size, 60-90 cm (24-36 in.) in length with a 1.8 m (6 ft.) wingspan. The American Harpy Eagle is the largest of all the Eagles, with length of 110 cm (43.5 in.) and a 2.4 m (8 ft.) wingspan.

Geographical Range and Habitat of Eagles

Eagles are found in a variety of habitats. These include Forests, Wetlands, Lakes, Grasslands etc. They are found across most major land areas except Antarctica and New Zealand.

Behaviour of Eagle

Eagles are basically Solitary birds, getting together occasionally either to scavenge, mate and raise the chicks.

Eagles mate for life (they are monogamous) and use the same nest each year to raise their slow-developing young.

Eagles Claws are known as Talons. These are important tools for hunting and defence. Eagles kill their prey by penetrating its flesh with their talons. Eagles can open and close their talons at will.

An Eagles Tail is is very important for flight and manoeuvring. When an Eagle is soaring or gliding in flight, it spreads it's tail feathers in order to attain the largest surface area and increase the effect of thermals and up-drafts. The Tail also helps to slow down or stop suddenly when landing. It also assists in stabilization during a controlled dive or swoop toward prey.

Eagles use Thermals to great effect in Soaring. Thermal are rising currents of warm air and up-drafts generated by terrain, such as valley edges or mountain slopes. Soaring is accomplished with very little wing-flapping, enabling them to conserve energy. They also utilise these Thermals for Long-distance migration flights which are accomplished by climbing high in a thermal, then gliding downward to catch the next thermal, where the process is repeated.

Eagles build their Nests with twigs and sticks. These are generally built at a vantage point high in a tree or on a cliff in a permanent feeding territory. Most of the time the same Nest is used every season in which more twigs and branches of trees are added. With extra addition year after year, the refuse of the previous Nests starts decomposing beneath the new additions. Nests then become enormous, measuring up to ten feet across and weighing well over 1,000 pounds.

Eagles do not sweat, so they need to use other cooling methods such as perching in the shade, panting, and holding their wings away from their body.

Because chicks of the same clutch hatch over several days, the older, larger chicks are better able to compete for food. As a result, the youngest chick(s) in the nest often dies of starvation or is killed by a larger nest mate.

Diet of Eagle

Their Diet include reptiles, insects, fish, birds, mammals, molluscs, and carrion.

Reproduction of Eagles

Eagles generally reach Sexual Maturity at the age of about 5. Most Species of Eagles breed in that part of the season, when food is most available for raising young. They usually lay eggs in spring or early summer; but, the actual months differ depending on geographic location. Most Females incubate the eggs while the Male provides food for himself and the female. Incubation lasts four to seven weeks according to Species. Large Species tend to have longer incubation periods than Small Species. The Eaglets (usually two) do not develop adult markings until their third year, when they leave parental protection and seek their own mates and territories.

In Folklore and Culture

  • In ancient Greece Eagle was associated with Zeus, who sometimes turned himself into one in order to hurl his thunderbolts. In some Native American cultures the Eagle is the most typical representation of the Thunderbird, also associated with thunder and lightning. The Eagle is also associated with the sun, having sometimes been called in the Gaelic language Suil-na-Greine, Eye of the Sun.
  • Napoleon I, used the Roman Golden Eagle as the symbol of his new French empire.
  • Some Native American peoples revere Eagles as sacred religious objects and the feathers and parts of Bald  and Golden Eagles are often compared to the Bible and crucifix. Eagle feathers are often used in various ceremonies and are used to honour noteworthy achievements and qualities such as exceptional leadership and bravery. In the cultures of the Northwest Coast, Eagle is also a supernatural being and also the ancestor and features in the heraldic crests of important clans known as 'Totem Poles'.
  • In Hindu  religion, Garuda is a lesser Hindu divinity, usually the mount (vahanam) of Vishnu. Garuda is depicted as having the golden body of a strong man with a white face, red wings, and an Eagle's beak and with a crown on his head. This ancient deity was said to be massive, large enough to block out the sun.
  • Garuda's stature in Hindu religion can be gauged by the fact that an independent Holy Text Books - Upanishad, the Garudopanidad, and a Purana, the Garuda Purana, is devoted to him.
  • According to an old legend Eagle is the only animal that can look into the sun. According to the translation of St. Augustine, "The sun invigorates the eyes of Eagles, but injures our own."
  • Eagle also holds a deeper meaning. Eagle signifys an aerial perspective. It inspires us to take a new look at the problems and challenges of our lives, and suggests that when we don't readily find solutions it may be because our vision is too limited to see answers that lie just out of sight.
  • It was chosen as a national symbol of the United States in 1782 because of the bird’s long life, great strength, and majestic looks.
  • Eagles have been used by many nations as a national symbol, some of these are:
  1. The coat of arms of Germany has a Black Eagle.
  2. The coat of arms of Ghana has two Golden Eagles holding it.
  3. The coat of arms of Iceland has a Eagle holding it, as well as a Dragon, a Bull and a Giant.