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This article is about the bird. For other uses, see Eagle (disambiguation) and Eagles (disambiguation).

Eagle
From left to right, top row first: golden eagle (Aquila chrysaetos), brown snake eagle (Circaetus cinereus), solitary eagle (Buteogallus solitarius), black eagle (Ictinaetus malaiensis) and African fish eagle (Icthyophaga vocifer).
From left to right, top row first: golden eagle (Aquila chrysaetos), brown snake eagle (Circaetus cinereus), solitary eagle (Buteogallus solitarius), black eagle (Ictinaetus malaiensis) and African fish eagle (Icthyophaga vocifer).
Scientific classificationEdit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Accipitriformes
Family: Accipitridae
Species

See text

Eagle is the common name for certain large birds of prey within the family of the Accipitridae. While on a genetic level, only the subfamily Aquilinae comprises "true eagles", many other species are commonly referred to as eagles, such as the bald eagle, and the term generally carries no taxonomic weight. Most of the 68 species of eagles are from Eurasia and Africa.[1] 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 kind of bird of prey large enough to hunt sizeable (about 50 cm long or more overall) vertebrates.

Etymology

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The word "eagle" is borrowed into English from Old French aigle, ultimately from Latin aquila. It is cognate with terms such as French aigle, Portuguese águia and Spanish áquila.[2] Historically, the native English term for eagle was "ern" (Old English: earn), derived from Proto-Germanic *arnuz, and thus cognate with other synonymous words in Germanic languages such as German Aar and Dutch arend, Swedish örn and Gothic 𐌰𐍂𐌰 (ara). The term "ern" or "erne" is still used in Modern English in reference to some larger species of eagle, in particular the fish eagles. While some ornithologists may favor this term as a way to distinguish fish eagles from true eagles, all species of fish eagle (such as the bald eagle and white-tailed eagle) are still commonly referred to as "eagles".

Description

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Eagles are large, powerfully-built birds of prey, with heavy heads and beaks. Even the smallest eagles, such as the booted eagle (Hieraaetus pennatus), 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 their aerodynamic feathers. Most eagles are larger than any other raptors, apart from some vultures. The smallest species of eagle is the Great Nicobar serpent eagle (Spilornis klossi), at 450 g (1 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 wedge-tailed eagle has a visual acuity twice that of a typical human.[3][4][5] 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. Like most diurnal raptors, eagles have little ability to see ultraviolet light.[6] The female of all known species of eagles is larger than the male.[7][8]

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 parents take no action to stop the killing.[9][10] It is said[by whom?] that eagles fly above clouds but this is not true.[citation needed] Eagles fly during storms and glide from the wind's pressure. This saves the bird's energy. 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 Icthyophaga 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 forests. 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.[11]

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 (15 lb) mule deer fawn.[12][13] 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 30 kg (66 lb) and a martial eagle even killed a 37 kg (82 lb) duiker, 7–8 times heavier than the preying eagle.[11]: 67–68 [14] 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):[15]

An Eagle named in honor of Abraham Lincoln and was the mascot of 8th Wisconsin Infantry Regiment, at the time of the U.S. Centennial

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.

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[according to whom?] 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.[11] Eagles in the genus Aquila, found almost exclusively in open country, are noted for their ability to soar, and have relatively long wings for their size.[11]

These lists of the top five eagles are based on weight, length, and wingspan, respectively. Unless otherwise noted by reference, the figures listed are the median reported for each measurement in the guide Raptors of the World[16] in which only measurements that could be personally verified by the authors were listed.[11]

Rank Common name Scientific name Body mass
1 Steller's sea eagle Haliaeetus pelagicus 6.95 kg (15+1⁄4 lb) (Average Weight)[11][1]
2 Harpy eagle Harpia harpyja 6.5 kg (14+1⁄4 lb) (Average Weight)[11][1]
3 Philippine eagle Pithecophaga jefferyi 6.35 kg (14 lb) (Average Weight)[11][1]
4 White-tailed eagle Haliaeetus albicilla 4.8 kg (10+1⁄2 lb) (Average Weight)[1]
5 Martial eagle Polemaetus bellicosus 4.6 kg (10+1⁄4 lb) (Average Weight)[1]
Rank Common name Scientific name Total length
1 Philippine eagle Pithecophaga jefferyi 100 cm (3 ft 3 in)[17]
2 Harpy eagle Harpia harpyja 98.5 cm (3 ft 3 in)
3 Wedge-tailed eagle Aquila audax 95.5 cm (3 ft 2 in)
4 Steller's sea eagle Haliaeetus pelagicus 95 cm (3 ft 1 in)
5 Crowned eagle Stephanoaetus coronatus 87.5 cm (2 ft 10 in)
Rank Common name Scientific name Median wingspan
1 White-tailed eagle Haliaeetus albicilla 218.5 cm (7 ft 2 in)
2 Steller's sea eagle Haliaeetus pelagicus 212.5 cm (7 ft 0 in)
3 Wedge-tailed eagle Aquila audax 210 cm (6 ft 11 in)[18][19]
4 Golden eagle Aquila chrysaetos 207 cm (6 ft 9 in)
5 Martial eagle Polemaetus bellicosus 206.5 cm (6 ft 9 in)

Habitat

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The eagles are generally distributed in all types of habitats and nearly all parts of the world. The birds can be found in northern tundra to tropical rainforests and deserts. In North America, bald eagles and golden eagles are very common.

Distribution

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Groups

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Eagles are often informally divided into four groups.[a][22]

The snake eagles are placed in the subfamily Circaetinae. The fish eagles, booted eagles, and harpy eagles have traditionally been placed in the subfamily Buteoninae together with the buzzard-hawks (buteonine hawks) and harriers. Some authors may treat these groups as tribes of the Buteoninae; Lerner & Mindell[23] proposed separating the eagle groups into their own subfamilies of Accipitridae.

Fish eagles

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Fish eagles (or sea eagles) take fish as a large part of their diets, either fresh or as carrion.

Some authors include Gypohierax angolensis, the "vulturine fish eagle" (also called the palm-nut vulture) in this group.[22] However, genetic analyses indicate it is related to a grouping of Neophron–Gypaetus–Eutriorchis (Egyptian vulture, bearded vulture (lammergeier), and Madagascar serpent eagle).[24]

The fish eagles have a close genetic relationship with Haliastur and Milvus; the whole group is only distantly related to the Buteo group.[24]

Fish eagles exist in every continent throughout the world, except for South America.[25]

Although fish eagles can be found in many different places around the world, they have been classified as "Near Threatened". Reasons such as overfishing, pollution, habitat destruction, and the use of pesticides have contributed to the species' rapid population drop.[26]

Booted eagles

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Booted eagles or "true eagles"[22][27] have feathered tarsi (lower legs).

Tribe Aquililae or proposed subfamily Aquilinae. Genera: Aquila, Hieraaetus; Spizaetus, Oroaetus, Spizastur; Nisaetus;[24] Ictinaetus, Lophoaetus; Polemaetus; and Stephanoaetus.[22][27]

See comments under eagle species for changes to the composition of these genera.

Snake eagles

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Most snake or serpent eagles, as the name suggests, primarily prey on snakes.

  • Subfamily Circaetinae. Genera: Circaetus, Spilornis, Dryotriorchis, Terathopius.[22]
  • Eutriorchis (subfamily Gypaetinae or Circaetinae).

Despite filling the niche of a snake eagle, genetic studies suggest that the Madagascar serpent eagle (Eutriorchis) is not related to them.[24]

Over several decades, a great deal of research has been done on the  Snake-eagle's diet, which is mainly made up of reptiles, especially snakes. When it comes to catching snakes, it is generally accepted that the bird exhibits generalist feeding behavior, which means it does not hunt down specific types of snakes but rather feeds on them depending on their availability in the wild.[28]

Harpy eagles

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Harpy eagles[22] or "giant forest eagles"[21] 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, they are not all related: the solitary eagles are related to the black hawks and the Philippine eagle to the snake eagles.

Species

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Martial eagle in Namibia
Philippine eagle (Pithecophaga jefferyi) in Southern Philippines
Wedge-tailed eagle in Australia
Eastern imperial eagle in Israel

Major new research into eagle taxonomy suggests that the important genera Aquila and Hieraaetus are not composed of nearest relatives, and it is likely that a reclassification of these genera will soon take place, with some species being moved to Lophaetus or Ictinaetus.[23]

Family Accipitridae

Main article: Accipitridae
Short-toed snake eagle in flight

In culture

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Eagles, a Chinese Ming period painting; Located at the National Palace Museum

Etymology

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The modern English term for the bird is derived from Latin: aquila by way of French: aigle. The origin of aquila is unknown, but it is believed to possibly derive from aquilus (meaning dark-colored, swarthy, or blackish) as a reference to the plumage of eagles.

Old English used the term earn, related to Scandinavia's ørn/örn. It is similar to other Indo-European terms for "bird" or "eagle", including Greek: ὄρνις (ornís), Russian: орёл (orël), and Welsh: eryr.

In the southern part of Finland, near the Gulf of Finland, is the town of Kotka, which literally means "eagle", while the town of L'Aquila in the central part of Italy literally means "the eagle".

The sculpture of eagle at the top of the fountain at Plac Orła Białego in Szczecin, Poland

In Britain before 1678, eagle referred specifically to the golden eagle, with the other native species, the white-tailed eagle, being known as erne. The modern name "golden eagle" for aquila chrysaetos was introduced by the naturalist John Ray.[29]

The village of Eagle in Lincolnshire, England, has nothing to do with the bird; its name is derived from the Old English words for "oak" and "wood" (compare Oakley).[30]

Religion and spirituality

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Representation of an eagle at Rio Carnival, 2014
Garuda, the vahana (mount) of Vishnu, depicted with an eagle's beak and wings

In the ancient Sumerian mythology, the mythical king Etana was said to have been carried into heaven by an eagle.[31] 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.[32]

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 (see illustrations in the Ganymede (mythology) page.)[33]

Eagles appear metaphorically in many translations of the Old Testament. God is spoken of as carrying Israel on "eagles' wings" in Exodus 19:4, Isaiah 40:31 compares those who wait on the Lord to flying eagles, and Psalm 103 mentions renewing one's youth "as the eagle". In explaining this rejuvenation, Augustine of Hippo says in his commentary on the Psalms that eagles' beaks overgrow as they age and that they break them against rocks to restore them.[34] The translation, however, is uncertain: the word in the Hebrew, נשר, can also be translated vulture,[35] and is listed alongside specific kinds of vulture in Leviticus' discussion of unclean animals.

The eagle is also often used in Christian iconography to represent the Gospel of John,[36] and eagle-shaped lecterns are common in Anglican and some Roman Catholic churches.[37] The eagle was believed to be able to look directly into the sun in the same way that the Gospel of John looks directly at Jesus' divinity, and the great distances the eagle flies represent the spread of the gospel to the ends of the earth.

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.[38] 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.[39]

The Moche people of ancient Peru worshiped the eagle and often depicted eagles in their art.[40] The golden eagle was sacred to the Aztec god Huitzilopochtli while the harpy eagle was sacred to Quetzalcoatl.[41]

Heraldry

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Main article: Eagle (heraldry)
Coat of arms of Austria.
Coat of arms of Kotka, Finland
Coat of arms of the United States

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 authority, the eagle is the symbol of power. 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 (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 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.

Eagles symbolize strength, courage, and independence and are commonly found in the heraldry of many nations across the world. Albania, Andorra, Armenia, Austria, Dagestan, Egypt, Germany, Ghana, Indonesia, Iraq, Jordan, Kazakhstan, Mexico, Montenegro, Nigeria, the Philippines, Poland, Palestine, Panama, Russia, Romania, Serbia, South Sudan, Somaliland, Syria, the United States of America, Yemen, Zambia, and Zimbabwe are the nations whose coats of arms feature an eagle. The eagle's continuing significance and worldwide appeal as a forceful symbol in national identity and imagery is demonstrated by its widespread usage.[42]

Notes

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References

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Revisions and contributorsEdit on WikipediaRead on Wikipedia

Eagle

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from Grokipedia
Eagle is the common name for more than 60 species of large in the family , distinguished by their powerful build, exceptional eyesight, strong talons, and used to capture and tear apart vertebrate prey. The term "eagle" does not represent a but rather a functional category applied to large capable of hunting sizable vertebrates, with most of these species occurring in Eurasia and Africa. , including eagles, are characterized by broad wings, sharp talons on strong legs and feet, and a cere—a waxy membrane covering the base of the upper bill—along with large eyes shaded by a supraorbital ridge that contributes to their intense appearance and . Their eyesight is particularly remarkable, enabling some to detect small prey such as or from distances exceeding 400 meters. Eagles typically exhibit reversed sexual size dimorphism, with females larger than males, and many species take several years to attain through multiple . These birds occupy diverse habitats worldwide except Antarctica, ranging from open landscapes suited to soaring flight to forested areas, though they often prefer locations with trees or cliffs for nesting. They are generally , building large and laying clutches that vary by species, with lasting 28 to 60 days. Many eagle species are , moving between . Among the most notable is the extinct Haast's eagle (Hieraaetus moorei) from New Zealand, recognized as the largest eagle known to have existed, with estimates of up to 15 kilograms in weight and a hunting style distinct from other ; it persisted until about 600 years ago. Eagles play significant ecological roles as in many ecosystems and hold cultural importance in various societies, though numerous species face conservation challenges including .

Description

Morphology and anatomy

Eagles exhibit a robust tailored for as large , with key in the , , talons, , and supporting their hunting prowess. The wings of most eagles are broad and relatively long relative to body size, featuring a low to medium wing-loading that favors soaring flight over long distances and at high altitudes. The often have separated or , which generate additional lift and propulsion, as seen in the , enabling efficient with minimal flapping. In contrast, some smaller forest-dwelling related to eagles have shorter wings suited for maneuverability among trees, though large soaring eagles typically prioritize broad, slotted configurations for open-country hunting. The is sharply hooked with cutting edges (tomia) that enable tearing of flesh. Its outer layer, the rhamphotheca, consists of keratin—a hard, fibrous protein similar to that in human fingernails—and grows continuously throughout life, requiring natural wear or manual coping in captivity to prevent overgrowth. This structure supports the powerful grip and processing of prey. are highly curved, needle-sharp, and exceptionally strong, consisting of a bony core encased in a keratin sheath. Eagles possess an , with the (first digit) facing backward and the other three forward, optimized for perching and firmly grasping prey. include that lock the toes in place, resisting extension and allowing sustained, powerful grip even during struggle or transport of heavy prey. The includes powerful that drive the talons' crushing and holding force, while the breast () muscles support , particularly the initial powerful strokes and sustained soaring. Many bones, including the , , and , are pneumatized with , reducing overall skeletal weight while maintaining strength—an essential adaptation for . The respiratory system features extensive integrated with these , enabling efficient oxygen delivery during high-altitude soaring, with some eagles possessing a keratinized operculum in the nares to regulate airflow during rapid or prolonged flight.

Size and weight variation

Eagles exhibit substantial variation in body size across species, with total lengths ranging from about 45 cm in smaller serpent eagles to over 100 cm in the largest forms, wingspans from roughly 1 m to more than 2.5 m, and body masses from under 1 kg to 7–9 kg in the heaviest living representatives. Most eagle species display reverse sexual size dimorphism, where females are noticeably larger than males, often by 20–40% in body mass. This pattern is evident in the (), with female weights ranging from 3.94 to 6.125 kg compared to smaller males, and wing lengths up to 10% greater in females. In the (Haliaeetus leucocephalus), weights range from 3 to 6.3 kg, with females typically heavier and larger overall. Among living eagles, the heaviest include species such as the and , with maximum masses up to about 9–10 kg and wingspans reaching 2.4 m or more. The stands out for its large wingspan of up to 2.2 m. The extinct Haast's eagle (Hieraaetus moorei) of New Zealand was the largest known eagle, with estimated body masses of 10–15 kg and wingspans of 2–3 m, making it 30–40% heavier than the largest extant eagles such as the (as estimated in some studies). Size differences contribute to functional groupings among eagles, with (genus ) and booted eagles (genus Aquila) generally among the largest and most powerful, while groups such as serpent eagles (Spilornis) and snake eagles () are typically smaller and lighter.

Vision and sensory adaptations

Eagles, like other , possess highly specialized that support exceptional detection of distant prey. Their is among the highest in the animal kingdom, facilitated by large eyes with long , high in the , and dual foveal structures in each eye. These adaptations allow for sharp, detailed vision over long distances, with behavioral measurements in the () showing maximum of 132–143 cycles per degree, approximately twice that of humans. The of eagles and other features two : a deep central (nasal) fovea for high-resolution lateral vision and a shallower temporal fovea for frontal vision. These foveae exhibit elevated —several times higher than in humans—and displaced that minimize light scattering, enhancing sharpness. The central fovea typically provides the greatest , while the temporal fovea aids in binocular coordination during close-range tasks. Eagles achieve through four types of , sensitive to violet, blue, green, and red wavelengths, though ocular media transmittance limits ultraviolet detection in . This system supports enhanced color discrimination, potentially aiding in prey identification against varied backgrounds. Forward-facing eye placement creates binocular overlap, enabling precise essential for judging distances to prey. The , a highly vascular, pigmented structure unique to , projects into the and supplies nutrients to the avascular , sustaining its high metabolic activity and supporting sustained visual performance.

Taxonomy and phylogeny

Classification and non-monophyly

The common name "eagle" refers to a functional grouping of large predatory birds within the family , rather than a . reveal that eagles are , with different lineages arising independently across the Accipitridae tree and sharing such as powerful build, strong talons, and exceptional vision suited to hunting large prey. encompasses , kites, eagles, and , and is distinct from the families ( and caracaras) and (), which represent separate evolutionary lineages of diurnal raptors. Within , eagles are traditionally assigned to several subfamilies based on morphology and ecology, though molecular evidence has refined these groupings. Key clades include booted eagles (), characterized by feathered legs; (Haliaeetinae), adapted for fishing; harpy eagles (), robust forest hunters; and serpent eagles (), specialized for reptile prey. Analyses of mitochondrial and nuclear sequences support for booted eagles (Aquilinae) and sea eagles (Haliaeetinae). More recent phylogenomic studies using ultraconserved elements confirm monophyly for booted eagles, sea eagles, and harpy eagles (Harpiinae, comprising four genera: Harpia, Morphnus, Harpyopsis, and Macheiramphus), while placing the () within Circaetinae. These findings demonstrate that the "eagle" label reflects ecological similarity and large body size rather than shared ancestry.

Major genera and living species

The major of living eagles encompass several groups within the family , with notable diversity in form and ecology. The genus Aquila (true or booted eagles) contains approximately 11 species, characterized by and robust builds suited to hunting medium to large prey. Representative species include the (), widely distributed across the and known for its powerful flight and predatory prowess, the (Aquila adalberti), a threatened endemic, the (), and the (). The genus ( and ) comprises 8 species adapted to aquatic environments with strong bills for catching fish and . Key examples are the (Haliaeetus leucocephalus), iconic in , the (), widespread in Eurasia, the (), one of the largest raptors, the (), and the (). The genus (snake eagles) includes 6 species specialized in hunting reptiles, particularly snakes, often hovering while searching for prey. Representative species are the (), common in Europe and Asia, the (), the black-chested snake eagle (Circaetus pectoralis), Beaudouin's snake eagle (Circaetus beaudouini), and banded snake eagles. The genus Spilornis (serpent eagles) has 7 species, mostly tropical Asian, distinguished by crests and reptile-hunting habits. Examples include the (), widespread and variable, the (), and island endemics like the Kinabalu serpent eagle (Spilornis kinabaluensis). Other significant genera include Ichthyophaga (2 fish eagle species, such as the ), (around 5 smaller hawk-eagle species), and (about 4 hawk-eagle species), alongside like Stephanoaetus (, , a powerful African forest predator) and Polemaetus (, , Africa's largest eagle). These illustrate the functional diversity among eagles, though the grouping is not strictly .

Extinct species and fossil record

The of eagles (large ) dates back to at least the , with early representatives of the genus Aquila documented in Australia. Aquila bullockensis, known from a distal humeral fragment recovered from the Camfield Beds at Bullock Creek in the , represents the oldest record of Aquila in Australia and one of the earliest in the genus globally, dated to approximately 11–5 million years ago. This species is morphologically distinct from extant Aquila in features such as a flatter tuberculum supracondylare ventrale and a deeper sulcus scapulotricipitalis, highlighting early diversity within true eagles. The and Holocene epochs witnessed several large and giant forms, often exhibiting in isolated ecosystems. In , —a giant accipitrid with a wingspan of up to 3 meters and powerful talons spanning 30 cm—lived from around 700,000 to 50,000 years ago, with fossils recovered from sites including Mairs Cave in the , Cooper Creek in the , , and Wellington Caves. This species, closely related to and the , preyed on and coexisted with the extant , illustrating a once-diverse Australian raptor fauna disrupted by later . Other notable extinct giant eagles include moorei (Haast's eagle) from New Zealand, the largest known eagle species with a wingspan of 2–3 m and weight of 10–15 kg, known from to late Holocene fossils and extinct shortly after human arrival around the . Ancient DNA evidence places it within the Hieraaetus clade, with rapid size evolution occurring in the early to mid-Pleistocene. Similar gigantism appears in forms such as Titanohierax gloveralleni, a large hawk (estimated 7.3 kg) from Pleistocene deposits in the Bahamas. These examples demonstrate how isolated environments fostered exceptionally large raptors in the eagle lineage.

Distribution and habitat

Geographic range

Eagles exhibit a global distribution that is heavily concentrated in the , with the highest species diversity in Eurasia and , where most of the more than 60 recognized species occur. This region serves as the primary center of diversity for the group, encompassing a wide array of large adapted to varied environments across , , and the . Outside of Eurasia and , eagle diversity is markedly lower: only two species are resident in (the and ), nine species occur in Central and South America, and three species are found in . Eagles are entirely absent from Antarctica and most oceanic islands. hosts resident populations of two eagle species: the (Haliaeetus vociferoides) and the (). New Zealand once hosted the extinct Haast's eagle, the largest known eagle species and a former unique to that isolated ecosystem.

Preferred ecosystems and habitat types

Eagles, as a within the , occupy diverse ecosystems worldwide, ranging from open landscapes to dense forests and aquatic environments, with habitat preferences often tied to hunting strategies and prey availability. Open-country species, such as the (), favor semi-open and open habitats including , , , , , and mountainous regions with rocky ridges, sparse vegetation, and rugged terrain. These environments allow for extended soaring flight and unobstructed views for locating prey across vast areas. Forest-interior species, including the () and various hawk-eagles (Nisaetus spp.), specialize in and dense wooded habitats, typically occupying in . These species thrive in structurally complex, that support arboreal prey and provide concealment and nesting sites. , such as the () and related species, primarily inhabit coastal and , including shorelines, , islands, large rivers, lakes, , and , often with adjacent forested or for perching and nesting. These habitats provide reliable access to fish and other aquatic prey. Altitudinal ranges vary widely among eagles, from sea-level coastal zones to high elevations exceeding 1,700 meters in , with some species showing to lower altitudes or different in response to prey availability or weather conditions.

Behavior and ecology

Hunting techniques and prey capture

Eagles employ diverse hunting techniques to locate and capture , with methods varying by species, habitat, and prey availability. A prominent strategy involves soaring flight, where eagles circle on or glide at height to survey large areas for movement below, leveraging their to identify targets from afar. Upon detection, many species initiate a stoop—a steep, high-speed dive with wings partially folded to minimize and maximize velocity—allowing a rapid, forceful descent to surprise and strike prey. Alternative approaches include perch-hunting, in which an eagle remains stationary on an elevated vantage such as a tree, cliff, or pole to scan for prey before launching a direct attack, and low-level contour hunting, where the bird flies close to the ground to flush or ambush hidden animals. Some species also use prolonged low soaring or quartering flight to pursue prey across open terrain. Prey capture is typically executed foot-first, with the eagle extending its powerful legs forward at the moment of impact to seize the target. The strongly curved close with substantial force to pierce flesh, deliver a crushing grip, and secure the prey, often killing or immobilizing it immediately; the is then used to tear and consume the catch. This talon-based grasping mechanism enables eagles to handle prey that may be large relative to their body size. Cooperative hunting is uncommon but documented in certain species, notably , where mated pairs coordinate efforts—one individual flushing prey from cover while the other intercepts and captures it from a different angle.

Diet and feeding

Eagles in the family are predominantly , feeding primarily on such as , , , , and . Most species are opportunistic predators, consuming whatever prey is most abundant, accessible, and easy to capture. occurs in several groups. Serpent eagles, such as the (), feed mainly on , including tree snakes and often venomous species, though they also take , , , small mammals, birds, , and invertebrates like and earthworms. , including those in genera such as , rely heavily on fish but supplement with other vertebrates. (), by contrast, focus on medium-sized mammals such as rabbits, , , and , along with medium-sized birds, and occasionally larger prey like . forms an important supplementary food source for many eagles, with occurring year-round and increasing during periods of prey scarcity, such as winter in . , the theft of prey or food from other animals, is documented in several species and enhances feeding efficiency by allowing eagles to obtain food without hunting. Prey size varies widely but typically ranges from small to animals of intermediate size relative to the eagle's body mass, with some species capable of taking prey up to several kilograms, occasionally comparable to or exceeding the eagle's own weight in exceptional cases. Uneaten portions of prey are often cached for later consumption, particularly during . Daily food intake generally represents 10–25% of body weight, varying with species size and environmental conditions.

Breeding, nesting, and parental care

Eagles are generally , with established often unless one partner dies. Courtship involves elaborate aerial displays, including mutual high soaring, steep dives, and—in species such as the —talon-locking cartwheels during which the pair spirals downward before separating near the ground. Pairs build large nests, called eyries, primarily from , lined with finer materials such as grass, , , or . Nests are typically placed on , tall trees, or occasionally on the ground in open areas, with locations chosen for accessibility, visibility, and proximity to prey. These structures are often reused and expanded year after year, with pairs adding material during and between , sometimes resulting in nests several meters wide and deep. Clutch size is typically one to three , laid at intervals of several days, though some species may produce up to four in exceptional cases or skip breeding in years of poor prey availability. Eggs are usually white to pale with variable brown markings. is shared by both parents and lasts 34–45 days in many species (such as Bald and Golden Eagles), though longer in others (such as the , around 53-56 days), with the female often taking the larger share. Following hatching, the young are , covered in down, and dependent on . The female typically broods the chicks closely at first while the male provides most prey, though both adults hunt and deliver food as the chicks grow. occurs after 45–98 days in the nest in many species (such as Bald and Golden Eagles), though significantly longer in others (such as the , 4.5-6 months), with on parents continuing for weeks or months as juveniles learn to hunt. In species that lay multiple eggs, (also called cainism) is common, particularly in food-limited conditions: the oldest or strongest chick often attacks and kills its younger siblings to reduce competition for parental resources, ensuring higher survival probability for at least one offspring. This behavior is well-documented in and several other large .

Migration and territoriality

Many eagle species exhibit a mix of resident and , often depending on , food availability, and climate. Species or populations in and regions tend to be resident, remaining in stable year-round, while those in or northern areas frequently undertake to exploit resources or avoid harsh conditions. For example, northern migrate south when lakes and rivers freeze, with complex patterns varying by age and breeding location, whereas southern populations often remain resident. similarly show both resident and migratory strategies, with some individuals staying local year-round and others moving seasonally along ridges and . are particularly pronounced in certain species. , for instance, undertake extensive journeys from breeding grounds in to wintering areas in South Asia, often involving crossings of major barriers such as the Himalayas. Eagles are generally , defending or territories against conspecifics through flight displays and other behaviors. Home range sizes vary with and season; in , these can span 20 to 33 km² in some western North American populations. Juvenile eagles typically disperse from natal areas after , traveling varying distances to establish independence and reduce competition. In , such can reach maximum distances of approximately 1500 km from the natal site. Dispersal patterns often involve exploratory movements, with juveniles sometimes farther than adults in partially migratory species.

Relationship with humans

Cultural and symbolic significance

Eagles have long served as powerful symbols across cultures, embodying strength, courage, freedom, , and divine or spiritual authority due to their majestic flight, , and commanding presence. In , including influences from , the eagle functioned as a divine symbol of authority and power from the Bronze Age onward. It was associated with before becoming an attribute of major gods such as Zeus in and in , often depicted in to signify divine protection and military success. Among Native American tribes, eagles are revered as medicine birds possessing exceptional magical powers and playing central roles in religious ceremonies. They frequently act as messengers between humans and , serve as directional guardians in some , and symbolize courage, leadership, and honor; , in particular, are earned as marks of distinction among and used in , rituals, and clan symbolism across groups such as the , , and . The , with origins in the Bronze Age Near East, emerged as a prominent emblem in the by the 10th–11th centuries, where it represented imperial dominion over both East and West, as well as the unity of church and state under the . The motif later spread widely in , signifying sovereignty and dual authority. In contemporary national symbolism, the represents the United States, appearing on the since 1782 to signify strength, independence, and a preference for peace. The , meanwhile, is a national symbol or official bird for countries including Mexico, Albania, Austria, Germany, and Kazakhstan. Across these traditions, the eagle consistently conveys themes of elevated perspective, leadership, and transcendent power.

Use in falconry and hunting

The use of eagles in is primarily associated with the traditional practice of hunting with () in , particularly among in Kazakhstan, , and the of western . Hunters, known as berkutchi, train these powerful birds—most often females, valued for their larger size, strength, and aggression—to capture prey from horseback in mountainous terrain. are typically captured as eaglets from nests or trapped as subadult juveniles during , with training beginning in late summer or autumn to prepare for the winter hunting season (late October to mid-February). The process is intensive and passed down through generations, involving hooding the bird (tomaga) to keep it calm, hand-feeding from a to build trust, and from increasing distances until the eagle reliably returns to the hunter and captures live prey on command. Eagles are fed every few days to maintain and are often kept in the home or on a . The partnership emphasizes mutual respect, with eagles typically released back into the wild after several years (ranging from one to ten) once they reach maturity or the hunter deems it appropriate. Hunting focuses on medium-sized mammals, primarily (such as and ) for their pelts and , though are occasionally targeted in some regions. The is released to pursue flushed prey, seizing it with talons, after which the hunter retrieves the pelt while allowing the bird to eat the meat. Hunts require coordination, often involving additional people to drive game. In contemporary times, this practice is sustained through annual in and similar events in Kazakhstan and , which showcase the and attract tourism while helping preserve the tradition amid modernization. was inscribed on , underscoring its cultural significance. However, ethical debates have arisen over increasing commercialization, including the buying and selling of eagles for tourism, longer holding periods, and potential strain on wild populations from these shifts away from traditional sustainable practices. Some communities and conservation efforts now collaborate to promote and monitor impacts on eagles and prey.

Conservation status and threats

Many eagle species in the family face varying degrees of conservation concern, with classifications ranging from to . Common species such as the (Haliaeetus leucocephalus) and () are currently listed as , with some populations showing increases following historical recoveries. In contrast, forest-dependent species like the () are classified as with declining populations, while others such as the () and () appear on threatened lists due to restricted ranges and ongoing pressures. Major threats include and , particularly in for species like the and , as well as human-related mortality factors. Lead poisoning from ingested ammunition fragments in poses a significant risk to scavenging eagles such as bald and golden eagles, contributing to chronic health impacts and mortality. Electrocution on power lines, , and direct persecution (including shooting) further threaten many species, especially migratory or open-country eagles. Conservation successes include the 's recovery in , where banning , habitat protection, captive breeding, and reintroduction programs led to its removal from the protections. Several eagle species receive protection under international agreements, including the , which regulates trade in many (e.g., bald and under ), and the , which supports action plans for migratory species such as the .

Notable species

Haast's eagle (extinct)

Haast's eagle (Hieraaetus moorei), also known historically as Harpagornis moorei, was an extinct giant eagle endemic to New Zealand's and recognized as the largest known eagle species. It possessed a robust with an estimated of up to 3 m and body mass ranging from 10–18 kg, with females larger than males and reaching up to 17.8 kg. Its included talons up to 75 mm long and a up to 130 mm long, enabling it to grasp and kill large prey effectively. Haast's eagle primarily preyed on , large flightless birds that could exceed 200 kg in weight, such as species in the genus . It hunted by swooping from perches to seize prey with powerful talons and deliver fatal skull-crushing blows with its beak, then fed on soft organs and viscera in a manner akin to . As the only documented eagle to function as an in its ecosystem, Haast's eagle occupied the top trophic level in prehistoric New Zealand's , in the absence of . Evidence of human coexistence includes Māori oral traditions referring to the bird as "pouakai" or "hokioi" and describing it as capable of attacking humans or children, along with cave drawings depicting large eagle-like birds and Haast's eagle bones found worked into tools in , indicating possible hunting by . The species went extinct approximately 500–600 years ago, during the 14th–15th centuries, coinciding with the extinction of due to overhunting by and associated from forest burning, which eliminated its primary prey base.

Steller's sea eagle

() is a massive native to , recognized as the heaviest living eagle species with adult females averaging around 9 kg and males approximately 6 kg, and body lengths ranging from 85 to 105 cm. It features a dark brown to black body contrasting with white shoulders, thighs, tail, and forehead, along with a large yellow and talons. The species has a restricted distribution centered on , breeding along sea coasts and major rivers with mature trees on the , coastal areas around the , the , , and the Shantar Islands, at elevations from sea level to about 100 m. It is a full migrant, with most individuals wintering in the and , , and smaller numbers remaining in or along the northern and Okhotsk coasts, with occasional vagrants reaching , , and beyond. is highly , specializing in fish such as and trout, which it captures alive or scavenges along rivers and coasts, particularly during , supplemented by other marine fish, , , and when prey is scarce. It employs perching, aerial hunting, or wading in shallow water to seize prey with its powerful talons. The global population is estimated at 4,600–7,000 individuals, including 3,600–4,670 mature birds and 1,830–1,900 breeding pairs, and is declining due to and industrial development in breeding areas, lead poisoning from ingested ammunition in wintering grounds, of , pollution, climate change effects on breeding success, and nest predation by in some regions. The species is classified as on the .

Harpy eagle

The () is the largest and most powerful eagle in the Americas. Females typically reach body lengths of 3 to 3.5 feet (about 1 meter), wingspans of up to 6.5 feet (2 meters), and weights of 13 to 20 pounds (6–9 kg), with males smaller. This species is specially adapted to life in dense , where its powerful build and talons—measuring up to 4–5 inches—enable it to capture and subdue large arboreal prey. The inhabits undisturbed across Central and South America, from southern Mexico to northern Argentina, with preferred habitat consisting of large expanses of pristine forest featuring emergent canopy layers and tall nesting trees. It is most commonly found in areas of continuous canopy cover at low elevations, though it can persist in some modified landscapes provided sufficient prey, nesting sites, and protection remain. The largest known breeding population in occurs in , , near the border with Colombia. As a forest-specialist , the primarily hunts arboreal mammals such as and , including , along with other prey like opossums and ; it occasionally takes larger birds, , or ground-dwelling mammals when available. It captures prey by gliding silently beneath the or perching nearby before launching powerful attacks, often lifting animals weighing up to 20 pounds. The species occurs at low population densities due to its dependence on extensive forest tracts and large , making it highly vulnerable to deforestation. It is classified as on the , with from logging, agriculture, and infrastructure development as the primary threat to its survival across its range.

Golden eagle

The () is the most widespread and intensively studied of all eagle species, renowned for its powerful build, speed, and adaptability as a . It occupies a distribution across the , ranging from (primarily the western half, from Alaska to ) through Europe, , and . The species favors open and semi-open habitats—including tundra, , , mountainous terrain, and —typically from sea level to elevations exceeding 3,600 meters, with nesting sites often on or in large trees. exhibit a versatile diet, preying primarily on such as rabbits and , along with , , , and other small mammals; they also take birds, reptiles, and occasionally larger prey including , , , cranes, and domestic livestock. In , particularly among in 's and in Kazakhstan, (often females, which are larger and more effective hunters) are employed in traditional falconry to capture medium-sized game such as foxes, hares, and Pallas’s cats, a practice with origins over 2,500 years old and inscribed on in 2010. This form of forms a core element of , typically transmitted from father to son, and is celebrated through annual that reinforce community bonds and transmit the tradition. The also carries broader cultural significance, serving as a national symbol in countries including Kazakhstan, Mexico, Albania, and others. Global population estimates range from around 170,000 individuals (based on 2004 data), with the species ranked secure () and listed as overall, though regional trends show stability in many areas and declines in parts of western North America and elsewhere due to habitat changes, human disturbance, and mortality from infrastructure. includes legal protections, infrastructure modifications to reduce electrocution risks on power lines, and ongoing monitoring of vital rates and threats.

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