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  • Columbidae 

    Columbidae is a bird family consisting of doves and pigeons. It is the only family in the order Columbiformes. These are stout-bodied birds with small heads, relatively short necks and slender bills that in some species feature fleshy ceres. They feed largely on plant matter, feeding on seeds (granivory), fruit (frugivory), and foliage (folivory).

    In colloquial English, the smaller species tend to be called “doves”, and the larger ones “pigeons”,[2] although the distinction is not consistent,[2] and there is no scientific separation between them.[3] Historically, the common names for these birds involve a great deal of variation. The bird most commonly referred to as “pigeon” is the domestic pigeon, descendant of the wild rock dove, which is a common inhabitant of cities as the feral pigeon.

    Columbidae contains 51 genera divided into 353 species.[4] The family occurs worldwide, often in close proximity to humans, but the greatest diversity is in the Indomalayan and Australasian realms. 118 species (34%) are at risk,[4] and 13 are extinct,[5] with the most famous examples being the dodo, a large, flightless, island bird, and the passenger pigeon, that once flocked in the billions.

    Etymology

    Pigeon is a French word that derives from the Latin pīpiō, for a ‘peeping’ chick,[6] while dove is an ultimately Germanic word, possibly referring to the bird’s diving flight.[7] The English dialectal word culver appears to derive from Latin columba.[6] A group of doves has sometimes been called a “dule”, taken from the French word deuil (‘mourning’).[8]

    Origin and evolution

    Columbiformes is one of the most diverse non-passerine clades of neoavians, and its origins are in the Cretaceous[9] and the result of a rapid diversification at the end of the K-Pg boundary.[10] Whole genome analyses have found Columbiformes is the sister clade to the clade Pteroclimesites a clade consisting the orders Pterocliformes (sandgrouses) and Mesitornithiformes (mesites).[11][12][13] The columbiform-pteroclimesitean clade, or Columbimorphae, monophyly has been supported from several studies.[11][12][14][15][16][17][18][19]

    Taxonomy and systematics

    See also: List of Columbidae genera and List of Columbidae species

    The name ‘Columbidae’ for the family was first used by the English zoologist William Elford Leach in a guide to the contents of the British Museum published in 1819.[20][21] However, Illiger in 1811 established an older name for the family group (“Columbini”) and would actually be the proper authority for Columbidae.[22]

    The interrelationships of columbids (between subfamilies) and the ergotaxonomy of them has been debated, with many different interpretations of how they should be classified. As many as five to six families, along with many subfamilies and tribes, have been used in the past including the family Raphidae for the dodo and the Rodrigues solitaire.[23][24][25] A 2024 paper on the systematics and nomenclature of the dodo and the solitaire from Young and colleagues also provided an overview of columbid family-group nomina. They recommended recognizing three subfamilies: Columbinae (New World doves and quail-doves, and columbin doves), Claravinae (American ground-doves), and Raphinae (Old World doves and pigeons including the dodo and solitaire).[22] A 2025 paper on the molecular phylogenetic placement of the Cuban endemic blue-headed quail-dove from Oswald and colleagues found the species to be a sister group to Columbinae, as opposed to being a true columbine or a raphine as previous authors have suggested in the past. These authors recommended that the blue-headed quail-dove should be placed in fourth monotypic subfamily, Starnoenadinae.[26]

    These taxonomic issues are exacerbated by columbids not being well represented in the fossil record,[27] with no truly primitive forms having been found to date.[citation needed] The genus Gerandia has been described from Early Miocene deposits in France, but while it was long believed to be a pigeon,[28] it is now considered a sandgrouse.[29] Fragmentary remains of a probably “ptilinopine” Early Miocene pigeon were found in the Bannockburn Formation of New Zealand and described as Rupephaps;[29] “Columbina” prattae from roughly contemporary deposits of Florida is nowadays tentatively separated in Arenicolumba, but its distinction from Columbina/Scardafella and related genera needs to be more firmly established (e.g. by cladistic analysis).[30] Apart from that, all other fossils belong to extant genera.[31]

    List of genera

    Fossil species of uncertain placement:

    • Genus †Arenicolumba Steadman, 2008
    • Genus †Rupephaps Worthy, Hand, Worthy, Tennyson, & Scofield, 2009 (St. Bathans pigeon, Miocene of New Zealand)

    Subfamily Columbinae (typical pigeons and doves) Illiger, 1811

    Subfamily Starnoenadinae Bonaparte, 1855

    Subfamily Claravinae (American ground doves) Todd, 1913

    Subfamily Raphinae (Old World doves and pigeons) Oudemans, 1917 (1835)

    Description

    Anatomy and physiology

    A landing collared dove (Streptopelia decaocto) displays the contour and flight feathers of its wings.

    Overall, the anatomy of Columbidae is characterized by short legs, short bills with a fleshy cere, and small heads on large, compact bodies.[32] Like some other birds, the Columbidae have no gall bladders.[33] Some medieval naturalists concluded they have no bile (gall), which in the medieval theory of the four humours explained the allegedly sweet disposition of doves.[34] In fact, however, they do have bile (as Aristotle had earlier realized), which is secreted directly into the gut.[35]

    The wings of most species are large, and have eleven primary feathers;[36] pigeons have strong wing muscles (wing muscles comprise 31–44% of their body weight[37]) and are among the strongest fliers of all birds.[36]

    In a series of experiments in 1975 by Dr. Mark B. Friedman, using doves, their characteristic head bobbing was shown to be due to their natural desire to keep their vision constant.[38] It was shown yet again in a 1978 experiment by Dr. Barrie J. Frost, in which pigeons were placed on treadmills; it was observed that they did not bob their heads, as their surroundings were constant.[39]

    Feathers

    Pigeon feather types, excluding down

    Columbidae have unique body feathers, with the shaft being generally broad, strong, and flattened, tapering to a fine point, abruptly.[36] In general, the aftershaft is absent; however, small ones on some tail and wing feathers may be present.[40] Body feathers have very dense, fluffy bases, are attached loosely into the skin, and drop out easily.[41] Possibly serving as a predator avoidance mechanism,[42] large numbers of feathers fall out in the attacker’s mouth if the bird is snatched, facilitating the bird’s escape. The plumage of the family is variable.[43]

    Granivorous species tend to have dull plumage, with a few exceptions, whereas the frugivorous species have brightly coloured plumage.[44] The genera Chalcophaps, Ptilinopus and Alectroenas include some of the most brightly coloured pigeons. Pigeons and doves may be sexually monochromatic or dichromatic.[45] In addition to bright colours, some pigeon species may have crests or other ornamentation.[46]

    Snow pigeons flying at an altitude of 12,000 feet (3,700 m) above sea level

    Flight

    Many Columbidae are excellent fliers due to the lift provided by their large wings, which results in low wing loading;[47] They are highly maneuverable in flight[48] and have a low aspect ratio due to the width of their wings, allowing for quick flight launches and ability to escape from predators, but at a high energy cost.[49] A few species are long-distance migrants, with some populations of the European turtle dove migrating in excess of 5,000 km between northern Europe in summer and tropical Africa in winter, and the Oriental turtle dove nearly as far in eastern Asia between eastern Siberia and southern China.

    Size

    Pigeons and doves exhibit considerable variation in size, ranging in length from 15 to 75 centimetres (5.9 to 29.5 in), and in weight from 30 g (0.066 lb) to above 2,000 g (4.4 lb).[50] The largest extant species are the crowned pigeons of New Guinea,[51] which are nearly turkey-sized, with lengths of 66–79 cm (2.17–2.59 ft) and weights ranging 1.8–4 kg (4.0–8.8 lb).[52][53][54] One of the largest arboreal species, the Marquesan imperial pigeon with a length of 55 cm (22 in), currently battles extinction.[55][56] The extinct, flightless dodo is the largest columbid to have ever existed, with a height of about 62.6–75 cm (24.6–29.5 in), and a range of suggested weights from 10.2–27.8 kilograms (22–61 lb), although the higher estimates are thought to be based on overweight birds.[57][58][59][60]

    The least massive columbids belong to species in the genus Columbina; the common ground dove (Columbina passerina) and the plain-breasted ground dove (Columbina minuta) which are about the same size as a house sparrow, weighing a little above 22 g (0.78 oz).[44][61][62] The dwarf fruit dove, which may measure as little as 13 cm (5.1 in) long, has a marginally smaller total length than any other species from this family.[44]

    Distribution and habitat

    Pigeons and doves are distributed everywhere on Earth, having adapted to most terrestrial habitats available on the planet, except for the driest areas of the Sahara Desert, Antarctica and its surrounding islands, and the high Arctic.[50] They have colonised most of the world’s oceanic islands, reaching eastern Polynesia and the Chatham Islands in the Pacific, Mauritius, the Seychelles and Réunion in the Indian Ocean, and the Azores in the Atlantic Ocean.

    Columbid species may be arboreal, terrestrial, or semi-terrestrial. They inhabit savanna, grassland, shrubland, desert, temperate woodland and forest, tropical rainforests, mangrove forest, and even the barren sands and gravels of atolls.[63]

    Some species have large natural ranges. The eared dove ranges across the entirety of South America from Colombia to Tierra del Fuego,[64] the Eurasian collared dove has a massive (if discontinuous) distribution from Britain across Europe, the Middle East, India, Pakistan and China,[65] and the laughing dove across most of sub-Saharan Africa, as well as India, Pakistan, and the Middle East.[66]

    When including human-mediated introductions, the largest range of any species is that of the rock dove, also known as the common pigeon.[67] This species had a large natural distribution from Britain and Ireland to northern Africa, across Europe, Arabia, Central Asia, India, the Himalayas and up into China and Mongolia.[67] The range of the species increased dramatically upon domestication, as the species went feral in cities around the world.[67] The common pigeon is currently resident across most of North America, and has established itself in cities and urban areas in South America, sub-Saharan Africa, Southeast Asia, Japan, Australia, and New Zealand.[67] A 2020 study found that the east coast of the United States includes two pigeon genetic megacities, in New York and Boston, and observes that the birds do not mix together.[68]

    As well as the rock dove, several other species of pigeon have become established outside of their natural range after escaping captivity, and other species have increased their natural ranges due to habitat changes caused by human activity.[44]

    Other species of Columbidae have tiny, restricted distributions, usually seen on small islands, such as the whistling dove, which is endemic to the tiny Kadavu Island in Fiji,[69] the Caroline ground dove, restricted to two islands, Truk and Pohnpei in the Caroline Islands,[70] and the Grenada dove, which is only found on the island of Grenada in the Caribbean.[71]

    Some continental species also have tiny distributions, such as the black-banded fruit dove, which is restricted to a small area of the Arnhem Land of Australia,[72] the Somali pigeon, found only in a tiny area of northern Somalia,[73] and Moreno’s ground dove, endemic to the area around Salta and Tucuman in northern Argentina.[44]

    Behaviour

    Feeding

    White-bellied green pigeon (Treron sieboldii) feeding on fruit

    Seeds and fruit form the major component of the diets of pigeons and doves,[50][74] and the family can be loosely divided between seed-eating (granivorous) species, and fruit-and-mast-eating (frugivorous) species, though many species consume both.[75]

    The granivorous species typically feed on seed found on the ground, whereas the frugivorous species are more arboreal, tending to feed in trees.[75] The morphological adaptations used to distinguish between the two groups include granivores tending to having thick walls in their gizzards, intestines, and esophagi, with the frugivores evolved with thin walls,[50] and the fruit-eating species have short intestines, as opposed to the seed eaters having longer intestines.[76] Frugivores are capable of clinging to branches and even hang upside down to reach fruit.[44][75]

    In addition to fruit and seeds, a number of other food items are taken by many species. Some, particularly the ground doves and quail-doves, eat a large number of prey items such as insects and worms.[75] One species, the atoll fruit dove, is specialised in taking insect and reptile prey.[75] Snails, moths, and other insects are taken by white-crowned pigeons, orange fruit doves, and ruddy ground doves.[44] Flowers are also taken by some species.[4]

    Urban feral pigeons, descendants of domestic rock doves (Columbia livia), reside in urban environments, disturbing their natural feeding habits. They depend on human activities and interactions to obtain food, causing them to forage for spilled food or food provided by humans.[77]

    Spotted dove (Spilopelia chinensis) on its nest, with one unhatched egg and one hatchling

    Reproduction

    Doves and pigeons build relatively flimsy nests, often using sticks, other vegetable matter, and other debris, which may be placed on trees, on rocky ledges, or on the ground, depending on species. The female may either build the nest, with material gathered by the male, or the male builds the nest by himself. A few species nest colonially, others nest in aggregation.[4]

    Most lay a clutch of one or (usually) two white eggs at a time which take 11-30 days to hatch (larger species have longer incubation times). Both parents care for the young; unlike most birds, both sexes of doves and pigeons produce “crop milk” to feed their young. This fluid is secreted by a sloughing of epithelial cells from the lining of the crop.[4]

    Unfledged baby doves and pigeons are called squabs and are generally able to fly by five weeks old. These fledglings, with their immature squeaking voices, are called squeakers once they are weaned,[78] and leave the nest after 25–32 days.

    Status and conservation

    While many species of pigeons and doves have benefited from human activities and have increased their ranges, many other species have declined in numbers and some have become threatened or even succumbed to extinction.[79] Among the ten species to have become extinct since 1600 (the conventional date for estimating modern extinctions) are two of the most famous extinct species, the dodo and the passenger pigeon.[79][4]

    The passenger pigeon was exceptional for a number of reasons. In modern times, it is the only pigeon species that was not an island species to have become extinct[79] even though it was once the most numerous species of bird on Earth.[citation needed] Its former numbers are difficult to estimate, but one ornithologist, Alexander Wilson, estimated one flock he observed contained over two billion birds.[80] The decline of the species was abrupt; in 1871, a breeding colony was estimated to contain over a hundred million birds, yet the last individual in the species was dead by 1914.[81] Although habitat loss was a contributing factor, the species is thought to have been massively over-hunted, being used as food for slaves and, later, the poor, in the United States throughout the 19th century.[citation needed]

    The Socorro dove (Zenaida graysoni) is extinct in the wild.

    The dodo, and its extinction, was more typical of the extinctions of pigeons in general. Like many species that colonise remote islands with few predators, it lost much of its predator avoidance behaviour, along with its ability to fly.[82] The arrival of people, along with a suite of other introduced species such as rats, pigs, and cats, quickly spelled the end for this species and many other island species that have become extinct.[82]

    118 columbid species are at risk (34% of the total), with 48 species NT, 40 VU, 18 EN, 11 CR, and 1 EW.[4] Most of these are tropical and live on islands. All of the species are threatened by introduced predators, habitat loss, hunting, or a combination of these factors.[82] In some cases, they may be extinct in the wild, as is the Socorro dove of Socorro Island, Mexico, last seen in the wild in 1972, driven to extinction by habitat loss and introduced feral cats.[83] In some areas, a lack of knowledge means the true status of a species is unknown (DD); the Negros fruit dove has not been seen since 1953,[84] and may or may not be extinct, and the Polynesian ground dove is classified as critically endangered, as whether it survives or not on remote islands in the far west of the Pacific Ocean is unknown.[85]

    Various conservation techniques are employed to prevent these extinctions, including laws and regulations to control hunting pressure, the establishment of protected areas to prevent further habitat loss, the establishment of captive populations for reintroduction back into the wild (ex situ conservation), and the translocation of individuals to suitable habitats to create additional populations.[82][86]

    Domestication

    Main article: Domestic pigeon

    The domestic pigeon (Columba livia domestica) is a descendant of the rock dove (Columba livia) that underwent domestication, with studies suggesting domestication as early as 10 thousand years ago. Domestic pigeons have long been a part of human culture; doves were important symbols of the goddesses Innana, Asherah, and Aphrodite, and revered by the early Christian, Islamic and Jewish religions. Domestication of pigeons led to significant use of homing pigeons for communication, including war pigeons, such as the 32 pigeons who were awarded the Dickin Medal for “brave service” to their country, in World War II.

    The ringneck dove is a smaller species of domestic columbid that was kept as a source of food. As a result of selection for tame individuals who would not escape their cages, they lack a survival instinct and cannot survive release.[87]

  • Eagle 

    Eagle is the common name for the golden eagle, bald eagle, and other birds of prey in the family of the Accipitridae. Eagles belong to several groups of genera, some of which are closely related. True eagles comprise the genus Aquila. 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

    [edit]

    The word “eagle” is borrowed into English from Anglo-Norman: eagle and Middle French: aigle, both derived ultimately from Latin: aquila (“eagle”). It is cognate with terms such as French: aigle, Portuguese: águia and Spanish: águila.[2] It is broadly synonymous with the less common English term “erne” or “earn”, deriving from Middle English: ern, from Old English: earn, in which it acts as the usual word for the bird. The Old English term is turn derived from Proto-Germanic: *arnaz and is cognate with other synonymous words in Germanic languages such as Swedish: örn, German: Aar and Gothic: ara. Through the Proto-Indo-European root, it is further related to words such as ὄρνις (“bird”) and Lithuanian: erelis (“eagle”). Although “erne” can be used to refer to any eagle, it is most commonly used for the golden eagle or sea-eagle.[3][4]

    Description

    [edit]

    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.[5][6][7] 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.[8] The female of all known species of eagles is larger than the male.[9][10]

    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.[11][12] 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.[13]

    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.[14][15] 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.[13][16] 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):[17]

    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.[13] 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.[13]

    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[18] in which only measurements that could be personally verified by the authors were listed.[13]

    RankCommon nameScientific nameBody mass
    1Philippine eaglePithecophaga jefferyi8.3 kg (18+1⁄4 lb) (Average Weight)
    2Steller’s sea eagleHaliaeetus pelagicus7.4 kg (16+1⁄4 lb) (Average Weight)
    3Harpy eagleHarpia harpyja6.35 kg (14 lb) (Average Weight)
    4White-tailed eagleHaliaeetus albicilla4.8 kg (10+1⁄2 lb) (Average Weight) [19]
    5Martial eaglePolemaetus bellicosus4.6 kg (10+1⁄4 lb)[19] (Average Weight)
    RankCommon nameScientific nameTotal length
    1Philippine eaglePithecophaga jefferyi100 cm (3 ft 3 in)[20]
    2Harpy eagleHarpia harpyja98.5 cm (3 ft 3 in)
    3Wedge-tailed eagleAquila audax95.5 cm (3 ft 2 in)
    4Steller’s sea eagleHaliaeetus pelagicus95 cm (3 ft 1 in)
    5Crowned eagleStephanoaetus coronatus87.5 cm (2 ft 10 in)
    RankCommon nameScientific nameMedian wingspan
    1White-tailed eagleHaliaeetus albicilla218.5 cm (7 ft 2 in)
    2Steller’s sea eagleHaliaeetus pelagicus212.5 cm (7 ft 0 in)
    3Wedge-tailed eagleAquila audax210 cm (6 ft 11 in)[21][22]
    4Golden eagleAquila chrysaetos207 cm (6 ft 9 in)
    5Martial eaglePolemaetus bellicosus206.5 cm (6 ft 9 in)

    In northwestern Chihuahua, Mexico, the Golden Eagle’s diet during the breeding seasons (2014–2016) predominantly consisted of black-tailed jackrabbits (Lepus californicus), accounting for approximately 72% of prey items and around 86% of total biomass consumed.[23]

    Habitat

    [edit]

    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

    [edit]

    Groups

    [edit]

    Eagles are often informally divided into four groups.[a][26]

    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[27] proposed separating the eagle groups into their own subfamilies of Accipitridae.

    Fish eagles

    [edit]

    Sea eagles or fish eagles take fish as a large part of their diets, either fresh or as carrion.

    Proposed subfamily Haliaeetinae. Genera: Haliaeetus, Icthyophaga.

    Some authors include Gypohierax angolensis, the “vulturine fish eagle” (also called the palm-nut vulture) in this group.[26] However, genetic analyses indicate it is related to a grouping of Neophron–Gypaetus–Eutriorchis (Egyptian vulture, bearded vulture (lammergeier), and Madagascar serpent eagle).[28]

    The fish eagles have a close genetic relationship with Haliastur and Milvus; the whole group is only distantly related to the Buteo group.[28]

    Fish eagles exist in every continent throughout the world, except for South America.[29]

    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.[30]

    Booted eagles

    [edit]

    The booted eagle is a group of eagle that typically migrates across the Sahara Desert to Europe. It usually reaches Europe around the beginning of March and leaves by the end of September. It’s interesting to note that these types of eagles usually mate with the same partner and return to the same areas years later. Female booted eagles usually lay 1-4 eggs, which promptly hatch after 37 to 40 days. Researchers estimate that there are between 3600 and 6900 pairs of booted eagles in Europe, which are mostly situated in the Iberian Peninsula.[31]

    For the species Hieraaetus pennatus (Aquila pennata), see booted eagle.

    Main article: Booted eagles

    Booted eagle in flight

    Booted eagles or “true eagles”[26][32] have feathered tarsi (lower legs).

    Tribe Aquililae or proposed subfamily Aquilinae. Genera: Aquila, Hieraaetus; Spizaetus, Oroaetus, Spizastur; Nisaetus;[28] Ictinaetus, Lophoaetus; Polemaetus; and Stephanoaetus.[26][32]

    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.[26]
    • 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.[28]

    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.[33]

    Harpy eagles

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    Harpy eagles[26] or “giant forest eagles”[25] 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.[27]

    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.[34]

    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).[35]

    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.[36] 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.[37]

    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.)[38]

    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.[39] The translation, however, is uncertain: the word in the Hebrew, נשר, can also be translated vulture,[40] 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,[41] and eagle-shaped lecterns are common in Anglican and some Roman Catholic churches.[42] 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.[43] 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.[44]

    The Moche people of ancient Peru worshiped the eagle and often depicted eagles in their art.[45] The golden eagle was sacred to the Aztec god Huitzilopochtli while the harpy eagle was sacred to Quetzalcoatl.[46]

    Heraldry

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    Main article: Eagle (heraldry)

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    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, Philippines, Poland, Palestine, Panama, Russia, Romania, Serbia, South Sudan, Somaliland, 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.[47]