|Bald Eagle, Haliaeetus leucocephalus|
Eagle refers to large diurnal birds of prey from the order Accipitriformes, family Accipitridae, and characterized by resemblance to vultures when in flight, but bearing a fully-feathered head, large hooked beaks, robust body, and powerful talons capable of taking and killing live prey. They also have extremely sharp vision, allowing them to locate and track prey from an extreme distance. Because of their strength and majestic appearance, eagles have been prominently displayed as heraldic symbols of war and earthly power.
Eagles are typically two to three feet long and have wingspans from six to eight feet. The smallest eagle, Ayres' Hawk-eagle, (Hieraaetus ayresii), is only 16 inches long, while the largest eagles, the harpy eagle (Harpia harpyja), Steller's sea eagle (Haliaeetus pelagicus), and the Philippine eagle (Pithecophaga jefferyi) each approach 39 inches in length and weigh close to sixteen pounds.
Eagles have eyes positioned in their heads 30 degrees from the facial midline, giving them a field of view of 340 degrees. In eagles as large as 10 pounds, their eyes are as physically large as adult humans; unlike human eyes they are fixed in their sockets and do not rotate. Within each eye are two regions of the retina called “foveas” which are specialized for acute eyesight: the shallow fovea – which points forward 15 degrees right or left of the head axis - and the deep fovea, which has higher acuity and points forward as well, but with 45 degrees relative of the head axis. The end result is a light gathering power and magnification which gives eagles extremely keen eyesight - estimated to be four to eight times better than humans - enabling them to locate, discern, identify, and successfully kill an animal as small as a rabbit from a distance of two or more miles away.
The killing stroke is done with the feet, although recent studies have indicated that the feet function primarily to immobilize the prey, with the actual death resulting from blood loss and the commencement of feeding when the prey animal has been immobilized. Eagles have large, deeply-curved talons, with the third and fourth digits bearing talons larger than the other two. These talons - combined with a grip that has been estimated to be at least 400 psi (in golden and bald eagles) - ensure that the talons are driven deeply into the prey. In one instance, a trainer admitted that a trained harpy eagle - with a grip strength described as similar to the power of a rottweiler's jaws - got off the glove and onto his arm, and still in a relaxed state, drove its rear claw through the flesh to the bone.
Eagles are found on all continents except Antarctica, from the cold waters of the Arctic north to the tropical rain forests of Africa, Asia, and South America. They are monogamous, mating for life, and using the same nest every year, which is placed in an inaccessible site (called an eyrie), such as the top of a tree or a cliff face. The clutch of three to four eggs take six to eight weeks to hatch, but when hatched the young mature slowly, putting on their adult plumage in three to four years.
Use as symbols
The eagle's in heraldry is, next to the lion, the most widespread image portrayed on a crest, and have been used as symbols of government and imperial power since at least the time of the Babylonians. In stylized form they have been placed atop the standards of ancient Persia and Imperial Rome, where it was used on field standards of the Roman legions as well as on helmets and coins. A two-headed eagle was used as a coat of arms for the Byzantine Empire, than later as the standard for Charlemagne's Holy Roman Empire, Czarist Russia and the Hapsburg Austrian Empire. An Aztec legend of an eagle clutching a snake while sitting on a cactus led to the founding of the Aztec capital of Tenochtitlan, an"d later became the coat of arms for Mexico. The United States adopted the bald eagle (Haliaeetus leucocephalus) as its national emblem.
In traditions, myths and popular beliefs of early civilizations ancient peoples of the eagle is generally considered a symbol of domination and the divine. The symbolism was reinforced by the representation of eagle/animal hybrid beings such as the griffin or the harpies, which emphasized the strength or mental attitude through different animal body parts that were a part of these beings. In ancient Indian mythology, the Garuda is a snake-killing messenger of Vishnu. According to legend, the Sumerian king Gilgamesh was rescued by an eagle. For the ancient Greeks, the eagle was the symbol of the supreme olympic god Zeus, and in ancient Rome it was the sign of the supreme Roman deity Jupiter as well as the imperial power and in the apotheosis the sign of the divinity of the emperor.
In many North American Indian tribes the eagle is the messenger to the Creator, and to possess a feather means to honor the Creator in the highest and most humble way. It is also a symbol of bravery, and only awarded after a victory against an enemy has been won, and the tale told to the tribal elders afterwards.
Because of its status (specifically the bald eagle) as the national bird of the United States, it is a popular mascot for high school sports teams. This is especially true within Christian schools due to the eagle being referenced in Isaiah 40:31 as a symbol of the Lord renewing one's strength.
Species of eagle
- Subfamily Buteoninae - true eagles, sea eagles, hawk-eagles
- Genus Aquila
- Bonelli's eagle, Aquila fasciata
- Booted eagle, Aquila pennata
- Cassin's Hawk-eagle, Aquila africanus
- Eastern imperial eagle, Aquila heliaca
- Golden eagle, Aquila chrysaetos
- Greater spotted eagle, Aquila clanga
- Gurney's eagle, Aquila gurneyi
- Indian spotted eagle, Aquila hastata
- Lesser spotted eagle, Aquila pomarina
- Little eagle, Aquila morphnoides
- Spanish imperial eagle, Aquila adalberti
- Steppe eagle, Aquila nipalensis
- Tawny eagle, Aquila rapax
- Verreaux's eagle, Aquila verreauxii
- Wahlberg's eagle, Aquila wahlbergi
- Wedge-tailed eagle, Aquila audax
- Genus Geranoaetus
- Black-chested buzzard eagle, Geranoaetus melanoleucus
- Genus Haliaeetus
- African fish eagle, Haliaeetus vocifer
- Bald eagle, Haliaeetus leucocephalus
- Madagascar fish eagle, Haliaeetus vociferoides
- Pallas's fish eagle, Haliaeetus leucoryphus
- Sanford's sea eagle, Haliaeetus sanfordi
- Steller's sea eagle, Haliaeetus pelagicus
- White-bellied sea eagle, Haliaeetus leucogaster
- White-tailed eagle, Haliaeetus albicilla
- Genus Harpagornis (extinct)
- Haast's eagle, Harpagornis moorei
- Genus Harpia
- Harpy eagle, Harpia harpyja
- Genus Harpyhaliatus
- Genus Harpyopsis
- New Guinea harpy eagle, Harpyopsis novaeguineae
- Genus Hieraaetus
- Genus Ichthyophaga
- Genus Ictinaetus
- Black eagle, Ictinaetus malayensis
- Genus Lophaetus
- Long-crested eagle, Lophaetus occipitalis
- Genus Morphnus
- Crested eagle, Morphnus guianensis
- Genus Nisaetus
- Genus Polemaetus
- Martial eagle, Polemaetus bellicosus
- Genus Spizaetus
- Genus Stephanoaetus
- African crowned eagle, Stephanoaetus coronatus
- Subfamily Circaetinae: snake-eagles
- Genus Circaetus
- Genus Eutriorchis
- Madagascar serpent-eagle, Eutriorchis astur
- Genus Pithecophaga
- Philippine eagle, Pithecophaga jefferyi
- Genus Spilornis
- Genus Terathopius
- Bateleur, Terathopius ecaudatus