I walk in an upscale neighborhood where the brick pillars holding up the 12-foot iron gate are topped with carved figures of eagles. They are the longstanding symbol of American strength and power. I’m sure that’s why the homeowners chose this particularly menacing eagle — to scare off would-be intruders. It may be a vulture or a buzzard, but for purposes of this article I’m calling it an eagle. The majestic birds have long been considered the iconic symbol of American freedom, although Ben Franklin wrote a private letter to his daughter saying, “For my own part I wish the bald eagle had not been chosen as the representative of our country,” according to Christopher Klein’s Aug. 31, 2018 article “Did Benjamin Franklin propose the turkey as the national symbol?” at history.com. The founding father argued that the eagle was “a bird of bad moral character” that “does not get his living honestly” because it steals food from the fishing hawk and is “too lazy to fish for himself.” In contrast, Franklin called the turkey “a much more respectable bird” and “a true original native of America.” While he considered the eagle “a rank coward,” Franklin believed the turkey to be “a bird of courage” that “would not hesitate to attack a grenadier of the British Guards who should presume to invade his farmyard with a red coat on.” Let’s learn more about that devilish bird, the eagle.
According to Wikipedia, eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some 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 — two in North America, nine in Central and South America and three in Australia.
Eagles are not a natural group, but denote essentially any bird of prey large enough to hunt sizeable — about 50 cm long or more overall — vertebrate prey.
Description
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 1 lb and 16 inches. 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 or 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 on 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 15-lb mule deer fawn. However, a few eagles may target prey considerably heavier than themselves; such prey is too heavy to fly with, 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 66 lbs, and a martial eagle even killed an 82-lb duiker, 7–8 times heavier than the preying eagle. Authors on birds David Allen Sibley, Pete Dunne and Clay Sutton described the behavioral difference between hunting eagles and other birds of prey thus — in this case the bald and golden eagles as compared to other North American raptors:
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 eagles.
Among the eagles are some of the largest birds of prey; only the condors and some of the Old World vultures are markedly larger. It is regularly debated which should be considered the largest species of eagle. They could be measured variously in total length, body mass or wingspan. Different lifestyle needs among various eagles result in variable measurements from species to species. For example, many forest-dwelling eagles — including the very large harpy eagle — have relatively short wingspans, a feature necessary for being able to maneuver in quick, short bursts through densely forested habitats. Eagles in the genus Aquila — though found almost strictly in open country — are superlative soarers and have relatively long wings for their size.
Top eagles based on weight, length and wingspan
Steller’s sea eagle
Steller's sea eagle (Haliaeetus pelagicus) is a large diurnal bird of prey in the family Accipitridae. It was originally described by Peter Simon Pallas in 1811. No subspecies are recognized. A sturdy eagle, it has dark brown plumage with white wings and tail, and yellow beak and talons. On average, it is the heaviest eagle in the world, at about 11 to 20 lbs, but may be below the harpy eagle (Harpia harpyja) and Philippine eagle (Pithecophaga jefferyi) in some standard measurements.
The Steller's sea eagle lives in coastal northeastern Asia and mainly preys on fish and water birds. The Kamchatka Peninsula in Far Eastern Russia is known for its relatively large population of these birds. Around 4,000 of these eagles live there.[4] Steller's sea eagle is listed as vulnerable on the International Union for Conservation of Nature's Red List of Threatened species.
Philippine eagle
The Philippine eagle (Pithecophaga jefferyi), also known as the monkey-eating eagle or great Philippine eagle, is an endangered species of eagle of the family Accipitridae which is endemic to forests in the Philippines. It has brown and white-colored plumage, a shaggy crest, and generally measures 2.82 to 3.35 feet in length and weighs 8.9 to 17.6 lbs.
It is considered the largest of the extant eagles in the world in terms of length and wing surface, with only Steller's sea eagle and the harpy eagle being larger in terms of weight and bulk. Among the rarest and most powerful birds in the world, it has been declared the Philippine national bird. It is critically endangered, mainly due to massive loss of habitat resulting from deforestation in most of its range. Killing a Philippine eagle is punishable under Philippine law by up to 12 years in prison and heavy fines.
Harpy eagle
The harpy eagle (Harpia harpyja) is a neotropical species of eagle. It is also called the American harpy eagle to distinguish it from the Papuan eagle, which is sometimes known as the New Guinea harpy eagle or Papuan harpy eagle. It is the largest and most powerful raptor found throughout its range and among the largest extant species of eagles in the world. It usually inhabits tropical lowland rainforests in the upper or emergent canopy layer. Destruction of its natural habitat has caused it to vanish from many parts of its former range, and it is nearly extirpated from much of Central America. In Brazil, the harpy eagle is also known as royal-hawk. The genus Harpia, together with Harpyopsis and Morphnus form the subfamily Harpiinae.
White-tailed eagle
The white-tailed eagle (Haliaeetus albicilla) is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae or accipitrids which includes other diurnal raptors such as hawks, kites and harriers. One of up to 11 members in the genus Haliaeetus — which are commonly called sea eagles — it is also referred to as the white-tailed sea-eagle. Sometimes, it is known as the ern or erne depending on spelling by sources, gray sea eagle and Eurasian sea eagle.
While found across a very wide range, today breeding as far west as Greenland and Iceland across to as far east as Hokkaido, Japan, they are often scarce and very spottily distributed as a nesting species, mainly due to human activities. These have included habitat alterations and destruction of wetlands, about 100 years of systematic persecution by humans from the early 1800s to around World War II, followed by inadvertent poisonings and epidemics of nesting failures due to various manmade chemical pesticides and organic compounds — which have threatened eagles since roughly the 1950s and continue to be a potential concern. Due to this persecution, the white-tailed eagle was considered endangered or extinct in several countries. However, some populations have recovered well due to some governmental protections and dedicated conservationists and naturalists protecting habitats and nesting sites and partially regulating poaching and pesticide usage, as well as careful reintroductions into parts of their former range.
White-tailed eagles usually live most of the year near large bodies of open water, including both coastal saltwater areas and inland freshwater — wetlands, lakes, bogs and rivers — and require an abundant food supply and old-growth trees or ample sea cliffs for nesting.[4][10] This raptor is both a powerful apex predator and an opportunistic scavenger, mainly subsisting on fish and birds — largely water birds — among nearly any other available prey. They are considered a close cousin of the bald eagle (Haliaeetus leucocephalus), which occupies a similar niche in North America.
Martial eagle
The martial eagle (Polemaetus bellicosus) is a large eagle native to sub-Saharan Africa. It is the only member of the genus Polemaetus. A species of the booted eagle subfamily Aquilinae, it has feathering over its tarsus. One of the largest and most powerful species of booted eagle, it is a fairly opportunistic predator that varies its prey selection between mammals, birds and reptiles. Its hunting technique is unique as it is one of few eagle species known to hunt primarily from a high soar, by swooping on its quarry. An inhabitant of wooded belts of otherwise open savanna, this species has shown a precipitous decline in the last few centuries due to a variety of factors. The martial eagle is one of the most persecuted bird species in the world. Due to its habit of taking livestock and regionally valuable game, local farmers and game wardens frequently seek to eliminate martial eagles, although the effect of eagles on this prey is almost certainly considerably exaggerated. Currently, the martial eagle is classified with the status of Endangered by the IUCN.
Wedge-tailed eagle
The wedge-tailed eagle (Aquila audax) is the largest bird of prey in Australia and is also found in southern New Guinea. It has long, fairly broad wings, fully feathered legs, and an unmistakable wedge-shaped tail.
The wedge-tailed eagle is one of 12 species of large, predominantly dark-colored booted eagles in the genus Aquila found worldwide. A large brown bird of prey, it has a wingspan up to 9 feet 4 inches and a length up to 3 feet 6 inches.
Crowned eagle
The crowned eagle, also known as the African crowned eagle or the crowned hawk-eagle (Stephanoaetus coronatus) is a large bird of prey found in sub-Saharan Africa; in Southern Africa it is restricted to eastern areas. Its preferred habitats are principally riparian woodlands and various forests. The crowned eagle is the only extant member of the genus Stephanoaetus. A second species, the Malagasy crowned eagle (Stephanoaetus mahery) became extinct after humans settled on Madagascar.
At least 90% of the diet is mammalian; the usual prey taken by populations shows pronounced regional differences. Throughout its range the principal prey items are small ungulates such as duikers and chevrotains, rock hyrax and small primates such as monkeys. Birds and large lizards are barely taken.
Although the crowned eagle's long tail imparts an overall length up to 35 inches, it is somewhat less massive and has a considerably shorter wingspan than Africa's largest eagle, the martial eagle (Polemaetus bellicosus). It is nevertheless considered Africa's most powerful eagle when measured in terms of the weight of its prey items. It often preys on mammals such as bushbuck (Tragelaphus scriptus), exceptionally weighing up to 66 lbs albeit usually much less. The crowned eagle possesses unusually large talons and strong legs, and may kill by crushing the skull. The eagle is also ferocious; some records from beneath a nest show the remains of a large, male Sooty mangabey weighing 24 lbs.
Due to their ecological similarities, the crowned eagle is considered to be the African counterpart of the harpy eagle (Harpia harpyja). Thanks to its bold and highly conspicuous behavior, it is exceptionally well-studied for a large, forest-dwelling eagle. Due to a relatively high level of habitat adaptability, it was until recently considered to be faring well by the standards of large, forest-dependent raptors. However, today it is generally thought that it is decreasing far more than was previously perceived due to the almost epidemic destruction of native tropical African forest. It is now listed by the IUCN as Near Threatened.
Golden eagle
The golden eagle (Aquila chrysaetos) is one of the best-known birds of prey in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. These birds are dark brown, with lighter golden-brown plumage on their napes. Immature eagles of this species typically have white on the tail and often have white markings on the wings. Golden eagles use their agility and speed combined with powerful feet and massive, sharp talons to snatch up a variety of prey, mainly hares, rabbits and marmots and other ground squirrels. Golden eagles maintain home ranges or territories that may be as large as 77 square miles. They build large nests in cliffs and other high places to which they may return for several breeding years. Most breeding activities take place in the spring; they are monogamous and may remain together for several years or possibly for life. Females lay up to four eggs, and then incubate them for six weeks. Typically, one or two young survive to fledge in about three months. These juvenile golden eagles usually attain full independence in the fall, after which they wander widely until establishing a territory for themselves in four to five years.
Once widespread across the northern continents of the world, it has disappeared from many areas which are now more heavily populated by humans. Despite being extirpated from or uncommon in some of its former range, the species is still widespread, being present in sizeable stretches of Eurasia, North America and parts of North Africa. It is the largest and least populous of the five species of true accipitrid to occur as a breeding species in both the Palearctic and the Nearctic.
For centuries, this species has been one of the most highly regarded birds used in falconry. Due to its hunting prowess, the golden eagle is regarded with great mystic reverence in some ancient, tribal cultures. It is one of the most extensively studied species of raptor in the world in some parts of its range, such as the Western United States and the Western Palearctic.
Fish eagles
Sea eagles or fish eagles take fish as a large part of their diets, either fresh or as carrion. Three species pairs exist: white-tailed and bald eagles, Sanford's and white-bellied sea eagles and the African and Madagascan fish eagles; each of these consists of a white- and a tan-headed species.
White-bellied sea eagle
The white-bellied sea eagle (Haliaeetus leucogaster), also known as the white-breasted sea eagle, is a large diurnal bird of prey in the family Accipitridae. Originally described by Johann Friedrich Gmelin in 1788, it is closely related to Sanford's sea eagle of the Solomon Islands, and the two are considered a superspecies. A distinctive bird, the adult white-bellied sea eagle has a white head, breast, under-wing coverts and tail. The upper parts are grey and the black under-wing flight feathers contrast with the white coverts. The tail is short and wedge-shaped as in all Haliaeetus species. Like many raptors, the female is slightly larger than the male, and can measure up to 35 inches long with a wingspan of up to 7.2 feet, weighing 9.9 lbs. Immature birds have brown plumage, which is gradually replaced by white until the age of five or six years. The call is a loud goose-like honking.
Resident from India and Sri Lanka through Southeast Asia to Australia on coasts and major waterways, the white-bellied sea eagle breeds and hunts near water, and fish form around half of its diet. Opportunistic, it consumes carrion and a wide variety of animals. Although rated as Least Concern globally, it has declined in parts of southeast Asia such as Thailand and southeastern Australia. It is ranked as Threatened in Victoria and Vulnerable in South Australia and Tasmania. Human disturbance to its habitat is the main threat, both from direct human activity near nests which impacts breeding success and from removal of suitable trees for nesting. The white-bellied sea eagle is revered by indigenous people in many parts of Australia and is the subject of various folk tales throughout its range.
Booted eagle
Booted eagles are eagles that have fully feathered tarsi. That is, their legs are covered with feathers down to the feet. Most other accipitrids have bare lower legs, scaled rather than feathered.
They may be treated as an informal group, as distinct from "fish eagles," "snake eagles" and "giant forest eagles. "They may also be treated as a formal taxon, either as a tribe (Aquililae) or subfamily (Aquilinae).
The booted eagles, sea eagles, harpy eagles and buteonine hawks are heavily built birds that have traditionally been classified together in the large subfamily Buteoninae. In 2005, Heather Lerner and David Mindell proposed separating the eagles into their own subfamilies Aquilinae, Haliaeetinae, and Harpiinae, leaving only the buteo–buteogallus clade in a more restricted Buteoninae.
Included in the booted eagles are the genera Aquila, Hieraaetus and Clanga; all species described as "hawk eagles" including the genera Spizaetus and Nisaetus; as well as assorted monotypical genera such as Oroaetus, Lophaetus, Stephanoaetus, Polemaetus, Lophotriorchis and Ictinaetus.
Snake eagles
These are mainly birds which specialize in feeding on snakes and other reptiles, which is the reason most are named as "snake-eagles" or "serpent-eagles." The exceptions are the bateleur, a more generalized hunter, and the Philippine eagle, which preys on mammals and birds.
All but one of the subfamily are restricted to warmer parts of the Old World: Spilornis and Pithecophaga in south Asia, the others in Africa. The short-toed eagle Circaetus gallicus migrates between temperate Eurasia and Africa, as well as being resident in India.
They have hooked beaks for tearing flesh from their prey, strong legs and powerful talons. They also have extremely keen eyesight to enable them to spot potential prey from a distance.
Species include Short-toed snake eagle, Beaudouin's snake eagle, Black-chested snake eagle, Brown snake eagle, Southern banded snake eagle, Western banded snake eagle, Congo serpent eagle, Crested serpent eagle, Bawean serpent eagle, Great Nicobar serpent eagle, Mountain serpent eagle,Sulawesi serpent eagle, Philippine serpent eagle, Andaman serpent eagle, Madagascan serpent eagle, Bateleur and Philippine eagle.
Harpy eagles
Harpy eagles or "giant forest eagles" are large eagles that inhabit tropical forests. The group contains two to six species, depending on the author. Although these birds occupy similar niches, and have traditionally been grouped together, they are not all related; the solitary eagles are related to the black-hawks and the Philippine eagle to the snake eagles.
Species include harpy eagle, crested eagle, Papuan eagle, Philippine eagle, chaco eagle and solitary eagle.
Religion and folklore
In ancient Sumerian mythology, the mythical king Etana was said to have been carried into heaven by an eagle. Classical writers such as Lucan and Pliny the Elder claimed that the eagle was able to look directly at the sun, and that they forced their fledglings to do the same. Those that blinked would be cast from the nest. This belief persisted until the Medieval era.
The eagle is the patron animal of the ancient Greek god Zeus. In particular, Zeus was said to have taken the form of an eagle in order to abduct Ganymede, and there are numerous artistic depictions of the eagle Zeus bearing Ganymede aloft, from classical times up to the present.
Psalm 103 in Greek, Latin and English mentions renewing one's youth "as the eagle," although the Hebrew word נשר apparently means vulture. Augustine of Hippo or Saint Augustine gives a curious explanation of this in his commentary on the Psalms.
The eagle is a common form in the Anglican tradition, often used to support the Bible because of the symbolism of spreading the gospel over the world. Additional symbolic meanings for "eagle" include the pronouncements to the Israelites in Exodus 19:4; Psalms 103:5 and Isaiah 40:31. The United States eagle feather law stipulates that only individuals of certifiable Native American ancestry enrolled in a federally recognized tribe are legally authorized to obtain eagle feathers for religious or spiritual reasons. In Canada, the poaching of eagle feathers for the booming U.S. market has sometimes resulted in the arrests of First Nations person for the crime.
The Moche people of ancient Peru worshiped the eagle and often depicted eagles in their art.
Heraldry
Eagles are an exceptionally common symbol in heraldry, being considered the "King of Birds" in contrast to the lion, the "King of Beasts." Whereas the lion e.g., England usually represents a kingdom, the eagle is symbolic for an empire. They are particularly popular in Germanic countries such as Austria, due to their association with the Holy Roman Empire. The eagle of the Holy Roman Empire was two-headed, supposedly representing the two divisions, East and West, of the old Roman Empire. This motif, derived from the Byzantine or Eastern Roman Empire was also adopted by the Russian Empire and is still featured in the Flag of Albania. The Roman eagle was preceded by the eagle of Ptolemaic Egypt and the Achaemenid Empire. In the coat of arms of Kotka, Finland, the eagle is depicted carrying an anchor and the caduceus — staff carried by Hermes in Greek mythology — on its feet.
Heraldic eagles are most often found displayed i.e., with their wings and legs extended. They can also occur close i.e., with their wings folded or rising i.e., about to take flight. The heads, wings and legs of eagles can also be found independently.
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