The breeding season is from July to December through much of range, in New Guinea apparently from May on. They have a distinct tendency that lay earlier in the more northerly part of the range. For instance, in northeastern Australia laying has been recorded in January and February and in Tasmania in September. In western Australia, breeding depends on food and during drought periods there may be no nesting for up to 4 years. Adult wedge-tailed eagles are usually solitary or occur in pairs but immatures are more gregarious. 10–15 May rest or soar together or even hunt together and up to 40 recorded at carcasses. Mated adults perform mutual soaring, undulating dives, and tandem flights with rolling and foot-touching. The female may appear to ignore or more often turn over and present claws when a male is displaying. As possibly part of courtship feedings on pairs have taken place away from the nest and sharing of a cache of food may occur. Allopreening occurs occasionally between pairs but is seldom observed, although at times has been considered a “regular” part of the courtship process. Contrary to historical accounts, wedge-tailed eagles seldom engage in an elaborate courtship display and will instead generally try to conserve energy, instead devoting their energy for the upcoming trying breeding season along with territorial exclusions of conspecifics and obtaining food. Mating tends to occur on a bare branch or dead tree in the nest area, and may continue into the nestling period. Contrary to old accounts, the species does not mate in flight. In the pre-laying phase, mating was recorded to be preceded or accompanied by loud, slow yelping, but in the nestling period, the pair alighted together and the male mounted without preliminaries and a silent copulation lasted for one minute.


Territories are established with aerial displays, which can include high circling by one or both of pair, sometimes interspersed with flight rolls and talon presenting. Most of the time, wedge-tailed eagles typically respect pair boundaries and can limit territorial behaviour to mild aerial flights, with the intruders usually giving the ground to incumbents. Violence is usually avoided but sometimes the most heated territorial disputes can escalate to deaths. Sometimes the displaying eagle may engage in a steep dive on part closed wings followed by an upwards swoop, later may escalate into spectacular sky dance with undulations; they may too loop-the-loop. Cartwheeling is typically rare but in one case, three immatures mock dived at each other, two birds interlocked and cartwheeled several times before breaking away. No cartwheeling or talon grappling has been reported between members of a mated pair, but occasionally reported as used against intruding eagles. Aerial displays may go on for a while normally early in the breeding season, between 3 months and 3 weeks prior to egg laying. Territorial attacks by male wedge-tailed eagles may be against any encountered intruding eagles, including both male and female intruders, while female eagles engage in less territorial attacks and when they do, it is exclusively against other females. Territorial aggression can extend towards hang gliders and aircraft, advances noisily, bill open and talons extended until flying just above and behind or slightly ahead of pilot then swoops repeatedly after making contact with the hang-glider. A core of some 1 km (0.62 mi) radius around the nest is most fervently defended. Foraging ranges from nest may be up to about 20 km² (7.7 sq mi). Foraging ranges on breeding home ranges may be around 50 km² (19 sq mi) for males and 20 km² (7.7 sq mi) for females in arid central western Australia. Range sizes of pair members vary greatly based on topography, habitat and prey access. Several reported densities of 3–6 pairs per 100 km² (39 sq mi), others of 7–12 pairs per 100 km² (39 sq mi). When rabbits were in plague type numbers, pairs may nest as close 700 m (2,300 ft) apart and 4 others no more than 2 km (1.2 mi) from those two pairs. In semi-arid areas of New South Wales near Menindee densities were found to be about a pair per 53 km² (20 sq mi), 10–12 pairs in good years, 3 in drought years. Not far from that in Mutawintji National Park density was around a pair per 3 to 9 km² (1.2 to 3.5 sq mi). Much higher densities in this semi-arid zone of western New South Wales, with a pair per 3 to 9 km² (1.2 to 3.5 sq mi), against around a pair per 40 to 48 km² (15 to 19 sq mi) in other arid zones. In Western Australia, arid areas had a nearest neighbor distance of 5.32 km (3.31 mi) while those nesting in mesic areas had a distance of 4.88 km (3.03 mi). At Fowlers Gap, there were 9–10 pairs per 390 km² (150 sq mi). Near Canberra, around 37 pairs were reported in an area of 1,000 km² (390 sq mi), including some unusually as close as 130 m (430 ft) to paved roads and as close as 260 m (850 ft) from suburban spots. This contrasts strongly with 36 years prior, when few nests were near human-altered areas and the amount of pairs in the same area was about 32. In the Fleurieu Peninsula in South Australia during the early to mid 2000s, there was a pair per 53 km² (20 sq mi), active nest sites were 6.6 km (4.1 mi) apart, while the average home range around the nest is 34 km² (13 sq mi) roughly. Resurvey efforts a dozen years later in Fleurieu Peninsula found a more populous population, resulting in a home range estimated at 32.1 km² (12.4 sq mi) with some active nests as close as 1.5 km (0.93 mi) apart. In the Perth area, it was projected that the mean home range was about 36 km² (14 sq mi). Meanwhile, in southern Victoria the nearest neighbor distance of breeding pairs was 4.7 km (2.9 mi) while mean territory size was calculated at 17.6 km² (6.8 sq mi).


Both sexes may participate in building the nest but the female takes the greater share, often standing in the middle and building outwards. Often wedge-tailed eagles build alternative nest, up to 2 to 3 per territory, though when undisturbed uses the same general site repeatedly. In Tasmania, territories held a mean of 1.4 nests. The nest is usually either substantial or massive. The nest is a structure of sticks ranging 70 to 100 cm (2.3 to 3.3 ft) across and 30 to 80 cm (12 to 31 in) deep when first build but with repeated additions up to 2.5 m (8.2 ft) across and nearly 4 m (13 ft) deep. The interior nest cup is commonly around 30 to 40 cm (12 to 16 in) across about 10 cm (3.9 in) deep. Four studies found the diameter of nests to average from as little as 1.1 m (3.6 ft) and as much as 1.9 m (6.2 ft) and in depth from as little as 1 m (3.3 ft) to as much as 1.3 m (4.3 ft). Generally speaking in woodland or forest edge areas, nests tend to be larger, while those in sparser, more arid areas tend to have characteristically smaller nests, as they have lesser access to nest building materials. Good sized nests can weigh well over 400 kg (880 lb). Nests are usually lined with green leaves and twigs, a common practice in accipitrids. Infrequently, they may use an old nest built by another accipitrid, namely whistling kites (Haliastur sphenurus) and white-bellied sea eagles, with the earlier's nests apparently added to in order to enlargen it. Ideally the nest is located at 12 to 30 m (39 to 98 ft) above the ground on a lateral branch or main fork of lone or forest tree; in taller trees, nests can be as much as 75 m (246 ft) high to the opposite extreme down in lower ground or even on rocks or ground trees are scarce. In a few studies different areas of New South Wales, the mean nest height was from 5.2 to 21.7 m (17 to 71 ft) and were often relatively close to human development. Two results in southern Victoria found mean nest heights to be 12.6 and 18.1 m (41 and 59 ft). In often particularly arid Western Australia, mean nest heights were reportedly lower, averaging at 6.5 and 15.5 m (21 and 51 ft). Detailed study in Western Australia found nest heights were higher in Mediterranean scrubland at 4 to 16 m (13 to 52 ft) against 2 to 6 m (6.6 to 19.7 ft) in the arid zone, but nest height seemed to not have bearing on occupancy or success, territoriality kept the population regulated within the habitats. Occasionally they may nest in dwarf trees at as low as 1 to 2 m (3.3 to 6.6 ft).
Favoured nesting trees include many Eucalyptus and Casuarina species, as well as Corymbia, Callitris and Syncarpia glomulifera while in inland areas more often Acacia, Flindersia as well as Hakea leucoptera and Grevillea striata. The amount of Eucalyptus tree species used by wedge-tailed eagles is extremely diverse and ultimately the species seem to have no strong overall preferences regarding tree species, more importantly seeking a given tree of ample height and considerable broadness. Furthermore, nest trees are often on slightly elevated ground above the mean ground level, presumably in order to offer a more commanding view of the surrounding environment.  Additionally, trees with fewer lower branches may be preferred. Nests are seldom on dead trees, usually this occurs where there is an absence of leafy ones. While Australian nests can be in quite varied surroundings, Tasmanian nests are almost exclusively within well forested areas. Forest type nests tend to have a sparse, open understory and woodlands or nearby glades often are considered perhaps more attractive to the species. In desert-type areas, they may nest on a hill or a rise, and in addition sometimes cliff ledges, or among rocks, and even on ground in both islands and desert-like areas, preferably in areas difficult for or inaccessible to humans. Additionally they've been known to nest on power pylons and telegraph poles. Other smaller animals may nest among the sticks at the base of active wedge-tailed eagle nests such as finches, pardalotes and even possums (which more so than the small birds are presumably vulnerable to the eagles if caught in the open), perhaps gaining some protection from the presence of the eagles. This is a not unknown phenomenon in many bird assemblages for small birds to gain incidental protection from strong raptors. Other species, such as Pacific black ducks (Anas superciliosa), falcons and owls, may also benefit by utilizing unused nests for their own breeding purposes, although typically only the falcons usually use them with relative regularity.


Clutch size is usually just one or two but sometimes to 4. About 80% of nests where eagles have managed to lay eggs contain two eggs. Mean clutch size is apparently somewhat higher in the western part of the range. The female lays multi-egg clutches by some 3 days or so apart. The eggs are buff or white in colour, often appearing heavily blotched all over with purple-brown, red-brown or lavender, or more sparsely spotted with reddish brown. The amount of spotting is quite variable on eggs even within a single clutch, some being heavily marked, others hardly at all, and at times concentrated on the pointier end of the egg. When freshly laid, the eggs are glossy but they become more matte and brittle with age. Eggs may range in height from 66 to 79.3 mm (2.60 to 3.12 in), averaging 73 mm (2.9 in) in a sample of 54, by 55 to 63.5 mm (2.17 to 2.50 in), averaging 58.8 mm (2.31 in). Each egg normally weighs about 120 to 150 g (4.2 to 5.3 oz), the equivalent to about three chicken eggs or about 3% of the female eagle's body weight, 10% when the clutch number is 3, which is typical for an Aquila eagle but a small percentage relative to smaller raptors. The larger eagles of Tasmania lay larger eggs on average reportedly. Wedge-tailed eagles sometimes lay runt eggs in nests in normal nests, in a condition apparently unique for Australian raptors, and these reportedly never hatch. If a clutch is lost or stolen early in incubation, some pairs have been documented to replace it, being able to do so about a month later. The incubation stage lasts for 42–48 days. The female of the pair either primarily or entirely incubates on her own and, like many eagles, she is a tight sitter.  However, the male will incubate at times as well, at least up to an hour at a time. In New South Wales, the male was found to incubate for 16–20% of daylight during which the nest was unguarded for 3–13% of the day. In some cases, male incubation may vary from 1–6% of daylight to as much as 38% of daylight with shifts in extreme lasting up to 6 hours. Male primarily delivers prey to the nest during incubation (not prior), up about to the stage where the eaglet(s) can be left unattended.
The chicks are covered in white down up at first and are expectedly semi-altricial. At about 12 days or so, a slightly greyer down develops and this ultimately becomes the woolly undercoat for the contour feathers. Within a couple days later, the black quills of the primaries often start to emerge, and can start to stand and move around the nest. At 28 days, the eaglets are showing their upper wing coverts increasingly through the down. At 35 days of age, some darker feathers are appearing on areas such as the breast, belly, mantle, back and head; mostly these are evident as a few dark rufous feathers poking through the head down while at this age they show a short buff-tipped tail. They are partially feathered up to 37 days and nearly completely feathered by 49 days. At around 37 days, they can attempt to tear food from carcass in the nests without much success. From 50 days onwards, the eaglet(s) play a good deal, pouncing on sticks and degree around the nest. Around this age, they are markedly almost full feathered but for the wing and tail, neither of which has reached its full length, and they may have a few wisps of down about their crown or neck. Weight increases are from about 1.17 kg (2.6 lb) at 15 days with a notably increase in robustness to 2.6 kg (5.7 lb) at 29 days, to 3.2 kg (7.1 lb) at 49 days, making more rapid feathering growth thereafter primarily while body size growth slows considerably. Sibling aggression tends to begin at when around when the eaglets are two weeks of age, as in many birds of prey, the younger sibling(s) in wedge-tailed eagles are not infrequently runts. Unlike related eagles, there is some evidence that higher parental attendance limits instances of aggression, whereas in other eagles this occurs often in the parent's presence. In all eagles, the parent eagles make no attempt to intercede when runting or aggression between siblings occurs. Siblicide occurs occasionally in this species and it is considered a “facultative cainist” rather than an obligate one, meaning siblicide occurs occasionally and as conditions dictate as opposed to some eagles where it occurs almost invariably. Reportedly, in Tasmania, a study reported that all but 2% of recorded nests managed to produce two fledglings, implying extremely low rates of siblicide in this race. The female broods attentively at first but then decreases after the second or third week and then ceases brooding almost entirely by 30 days, even at night. For 40 or more days, the female continues to assist the young with feeding, typically from the male's prey deliveries though the female may resume hunting after nest attendance drops. Potential predators such as goannas are struck when found to be approaching the nest, although the eagles usually abandon the nest when a human approaches. Repeated intrusions and noisy disturbances may have a net negative effect such as on Tasmanian wedge-tailed eagles, as these factors often lead to nest failure. In one case in South Australia, the removal of a dead tree in the vicinity of a wedge-tailed eagle nest resulted in full abandonment of the nest by the parents. The female may too continue to bring green leaves to a late stages, doing so more often in a spell of wet weather. During times of plenty, caches can sometimes form around the nest, with much prey left partially or entirely uneaten. Upon leaving the nest at 11 to 12 weeks of age, the young eagles are not strong fliers for another 20 days or so, but can competent flying can be by about 90 days of ages, though full feather development is not until 120 days. Fledgling occurs at 67 to 95 days, typically being less than 90 days and averaging roughly around 79 days. Dependence lasts up to 4 to 6 months after fledging, with the juvenile eagles which overstay rarely known to be an occasionally fatal danger to the subsequent chick hatched to their parents. During the later periods of fledgling, interactions are restricted to brief prey deliveries and the parent eagles stop feeding the young eagle(s), forcing to go forage elsewhere for foods. A study of post-fledgling dispersal found in one case that a young eagle covered only a 4.22 km² (1.63 sq mi) range, with a maximum covered in a week of 3.28 km (2.04 mi). Most recoveries in one banding study were distributed under 300 km (190 mi) from their original banding site, mostly as fledgling age juveniles, but some meandered up to 821 km (510 mi) away. After dispersal, young eagles are floaters up until their 4th or 5th year, typically avoiding the territories of adults and searching out feeding opportunities. Up to two-thirds of young wedge-tailed eagles may die some time between fledgling and when they are 3–5 years but adults often have quite low mortality rates and can live the better part of a half century. First breeding is typically at 6 or 7 years old. Lifespans of wedge-tailed eagles in the wild are poorly known, with the maximum recorded in one banding study being merely 9 years, quite a paltry age compared to other large eagles, and it is quite conceivable that eagles who survive to maturity not infrequently live around twice that long or more. In captivity, the species has been known to live to around 40 years of age.


In the 1990s, it was estimated broadly that the global population was somewhere between 10,001 and 1,000,000 individuals. As of 2009, Birdlife International listed the total population as only 100,000 mature individuals, possibly conservative and admittedly from poor supporting data. As of that analysis, Birdlife considers the overall population of wedge-tailed eagles to be “possibly increasing”. Generally, the wedge-tailed eagle appears to be quite stable in population. Although wedge-tailed eagles are often scarcer than those large distribution suggests, their total distribution covers more than 10.5 million square kilometers and the population is quite likely within hundreds of thousands. Thinning of forest cover, mostly inadvertent provisioning of carrion food sources and, particularly, rabbit introductions may have aided the species, and it may actually be commoner now than before European colonization. Though protected, sometimes wedge-tailed eagles are shot or trapped or killed by poison carcasses set out by farmers many of whom consider it a serious sheep killer. Historically, the wedge-tailed eagle was subject to persecution levels to rival any other eagle in the world. The heavy persecution began in the closing decades of the 19th century, due largely to the establishment of large-scale sheep farming in Australia. One Queensland station claimed to have poisoned 1060 eagles over 8 months in 1903. Laws passed from 1909 to 1925 made it mandatory for landowners and farmers to kill eagles as vermin with enforcement determined by a given region's minister or vermin board, resulting in even more sweeping efforts to destroy the species. Steel-jawed rabbit traps were set around carcasses and Heligoland traps could sometimes trap several eagles at once, beyond sustained shooting and poisoning efforts. Between the years 1958 and 1967, 120,000 bounties were paid in merely the states of Queensland and Western Australia on wedge-tailed eagles killed, meaning an average 13,000 were killed each year. Even by 1967 to 1976, likely intentional human killings accounted for 54% of wedge-tailed eagle mortalities in Western Australia, with an estimated 30,000 killed in the year of 1969 throughout Australia. Strong legal protections started in Western Australia in the 1950s increasingly so to the 1970s or later elsewhere, now it is protected and subject to limited persecution throughout. Despite reduced persecution, as of the 1980s, 54% of recovered eagles by the 1980s were killed by human persecution. Despite such stunningly high rates of persecution, the wedge-tailed eagle was remarkably resilient to the haphazard persecution inflicted by humans in a way many other Australian wildlife, especially the regionally endemic mammals, and even other eagles elsewhere often are not.
Often the species is less intentionally harmed via human disturbance via land development particularly intensifying agricultural and modern settlements, which can in turn lead to clearing of mature trees, disturbances at the nest and decline of native prey species, all of which have a net negative effect on the wedge-tailed eagles. Eggshell thickness was not significantly decreased by the use of DDT likely due likely to the largely mammal-based diet of the species, whereas raptors which consume birds or fish are disproportionately effected by DDT. On occasional, the species is still subject to illegal shootings and poisonings, however persecution of the species is significantly less prevalent in recent decades. Occasionally but not commonly, they are killed by sodium fluoroacetate poisons long used to “control” Australian wildlife, but now generally directed at invasive species such as rabbits, feral pigs and foxes. A list of the main persistent threats in the 21st century to wedge-tailed eagles consists of: destruction of habitat, including logging, developments including urbanization, wind farm collisions and the disturbance and destruction associated with their construction, increasing density rural human populations, illegal persecution in sheep farm areas, drowning in open tanks in dry pastoral zones, roadkills (especially while foraging for roadkill carrion), collisions with fences, powerlines and airplanes, regular electrocutions, poisoning from rabbit baits and other baits and exposure to lead and other bullet fragments which may be responsible for some eagle debilitations and deaths. Within the Fleurieu Peninsula, some 1.74 eagles on average are claimed by wind farm turbine collisions. Conservation needs may differ in different habitats, i.e. in more coastal temperate areas, the eagle is reported to have difficulty nesting when hillsides have been cleared of trees, meanwhile inland, they have lesser need of trees in elevated locations because they are more often assisted by thermals. However, they cannot generally persist where leafy trees are clearcut. Surprising resilience even to drought was found recently in the wedge-tailed eagles in the Australian Capital Territory where pair occupancy remained consistent through drought for wedge-tailed eagles but not for little eagles, but this is may have more to do with the wedge-tails more successful uncoupling from a dependence on declining rabbits as prey than the little eagle. Of 84 eagle deaths or debilitating injuries, 52% were attributable to collisions or electrocutions, 15.5% due to persecution, 11% due to natural causes and 15% were due to unknown causes.


The golden eagle (Aquila chrysaetos) is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of prey in the Northern Hemisphere. 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 large, sharp talons to hunt 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 200 km² (77 sq mi). 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 Holarctic, it has disappeared from many areas that are 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. Because of 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.


There are six extant subspecies of golden eagle that differ slightly in size and plumage. Individuals of any of the subspecies are somewhat variable and the differences between the subspecies are clinal, especially in terms of body size. Other than these characteristics, there is little variation across the range of the species. Some recent studies have gone so far as to propose that only two subspecies be recognized based on genetic markers: Aquila chrysaetos chrysaetos (including A. c. homeyeri) and A. c. canadensis (including A. c. japonica, A. c. daphanea and A. c. kamtschatica).
 Aquila chrysaetos chrysaetos (Linnaeus, 1758) – sometimes referred to as the European golden eagle. This is the nominate subspecies. This subspecies is found almost throughout Europe, including the British Isles (mainly in Scotland), the majority of Scandinavia, southern and northernmost France, Italy and Austria. In Eastern Europe, it is found from Estonia to Romania, Greece, Serbia and Bulgaria in southeastern Europe. It is also distributed through European Russia, reportedly reaching its eastern limit around the Yenisei River in Russia, also ranging south at a similar longitude into western Kazakhstan and northern Iran. Male wing length is from 56.5 to 67 cm (22.2 to 26.4 in), averaging 62 cm (24 in), and female wing length is from 61.5 to 71.2 cm (24.2 to 28.0 in), averaging 67 cm (26 in). Males weigh from 2.8 to 4.6 kg (6.2 to 10.1 lb), averaging 3.69 kg (8.1 lb), and females weigh from 3.8 to 6.7 kg (8.4 to 14.8 lb), averaging 5.17 kg (11.4 lb). The male of this subspecies has a wingspan of 1.89 to 2.15 m (6 ft 2 in to 7 ft 1 in), with an average of 2.02 m (6 ft 8 in), with the female's typical wingspan range is 2.12 to 2.2 m (6 ft 11 in to 7 ft 3 in), with an average of 2.16 m (7 ft 1 in). This is a medium-sized subspecies and is the palest. As opposed to golden eagles found further east in Eurasia, the adults of this subspecies are a tawny golden-brown on the upperside. The nape patch is often gleaming golden in color and the feathers here are exceptionally long.
 Aquila chrysaetos homeyeri Severtzov, 1888 – commonly known as the Iberian golden eagle. This subspecies occurs in almost the entirety of the Iberian peninsula as well as the island of Crete, though it is absent from the rest of continental Europe. It also ranges in North Africa in a narrow sub-coastal strip from Morocco to Tunisia. A completely isolated population of golden eagles is found in Ethiopia's Bale Mountains, at the southern limit of the species' range worldwide. Although this latter population has not been formally assigned to a subspecies, there is a high probability that it belongs with A. c. homeyeri. This subspecies also ranges in much of Asia Minor, mainly Turkey, spottily through the Middle East and the Arabian Peninsula into northern Yemen and Oman to its eastern limits throughout the Caucasus, much of Iran and north to southwestern Kazakhstan. Male wing length is from 55 to 64.3 cm (21.7 to 25.3 in), averaging 59 cm (23 in), and female wing length is from 60 to 70.5 cm (23.6 to 27.8 in), averaging 64 cm (25 in). Weight is from 2.9 to 6 kg (6.4 to 13.2 lb) with no known reports of average masses. This subspecies is slightly smaller and darker plumaged than the nominate subspecies, but it is not as dark as the golden eagles found further to the east. The forehead and crown are dark brownish, with the nape patch being short-feathered and a relatively light rusty color.
 Aquila chrysaetos daphanea Severtzov, 1888 – known variously as the Asian golden eagle, Himalayan golden eagle or berkut. This subspecies is distributed in central Kazakhstan, eastern Iran, and the easternmost Caucasus, distributed to Manchuria and central China and along the Himalayas from northern Pakistan to Bhutan and discontinuing in northeastern Myanmar (rarely ranging over into northernmost India). This subspecies is the largest on average. Male wing length is from 60 to 68 cm (24 to 27 in), averaging 64 cm (25 in), and female wing length is from 66 to 72 cm (26 to 28 in), averaging 70 cm (28 in). No range of body weights are known, but males will weigh approximately 4.05 kg (8.9 lb) and females 6.35 kg (14.0 lb). Although the wingspan of this subspecies reportedly averages 2.21 m (7 ft 3 in), some individuals can have much longer wings. One female berkut had an authenticated wingspan of 2.81 m (9 ft 3 in), although she was a captive specimen. It is generally the second-darkest subspecies, being blackish on the back. The forehead and crown are dark with a blackish cap near the end of the crown. The feathers of the nape and top-neck are rich brown-red. The nape feathers are slightly shorter than in the nominate subspecies and are similar in length to A. c. homeyeri.
 Aquila chrysaetos japonica Severtzov, 1888 – commonly known as the Japanese golden eagle. This subspecies is found in northern Japan (the islands of Honshu, Hokkaido and discontinuously in Kyushu) and undefined parts of Korea. Male wing length is from 58 to 59.5 cm (22.8 to 23.4 in), averaging 59 cm (23 in), and female wing length is from 62 to 64.5 cm (24.4 to 25.4 in), averaging 63 cm (25 in). No range of body weights are known, but males will weigh approximately 2.5 kg (5.5 lb) and females 3.25 kg (7.2 lb). This is, by far, the smallest-bodied subspecies. It is also the darkest, with even adults being a slaty-grayish black on the back and crown and juveniles being similar, but with darker black plumage contrasting with brownish color and white scaling on the wings, flank and tail. This subspecies has bright rufous nape feathers that are quite loose and long. Adult Japanese golden eagles often maintain extensive white mottling on the inner-webs of the tail that tend to be more typical of juvenile eagles in other subspecies.
 Aquila chrysaetos canadensis (Linnaeus, 1758) – commonly known as the North American golden eagle. Occupies the species' entire range in North America, which comprises the great majority of Alaska, western Canada, Western United States and Mexico. The species is found breeding occasionally in all Canadian provinces but for Nova Scotia. It is currently absent in the Eastern United States as breeding species east of a line from North Dakota down through westernmost Nebraska and Oklahoma to West Texas. The southern limits of its range are in central Mexico, from the Guadalajara area in the west to the Tampico area in the east; it is the "Mexican eagle" featured on the coat of arms of Mexico. It is the subspecies with the largest breeding range and is probably the most numerous subspecies, especially if A. c. kamtschatica is included. Male wing length is from 59.1 to 64 cm (23.3 to 25.2 in), averaging 61 cm (24 in), and female wing length is from 60.1 to 67.4 cm (23.7 to 26.5 in), averaging 65 cm (26 in). The average wingspan in both sexes is about 2.04 m (6 ft 8 in). Males weigh from 2.5 to 4.47 kg (5.5 to 9.9 lb), averaging 3.48 kg (7.7 lb), and females typically weigh from 3.6 to 6.4 kg (7.9 to 14.1 lb), averaging 4.91 kg (10.8 lb). The subspecies does not appear to follow Bergmann's rule (the rule that widely distributed organisms are larger-bodied further away from the Equator), as specimens of both sexes from Idaho had a mean weight of 4.22 kg (9.3 lb) and where slightly heavier than those from Alaska, with a mean weight of 3.76 kg (8.3 lb). It is medium-sized, being generally intermediate in size between the nominate and A. c. homeyeri, but with much overlap. It is blackish to dark brown on the back. The long feathers of the nape and top-neck are rusty-reddish and slightly narrower and darker than in the nominate subspecies.
 Aquila chrysaetos kamtschatica Severtzov, 1888 – sometimes referred to as the Siberian golden eagle or the Kamchatkan golden eagle. This subspecies ranges from Western Siberia (where overlap with A. c. chrysaetos is probable), across most of Russia, including the Altay (spilling over into Northern Mongolia), to the Kamchatka Peninsula and the Anadyrsky District. This subspecies is often included in A. c. canadensis. Male wing length is from 61.8 to 70.5 cm (24.3 to 27.8 in), averaging 64 cm (25 in), and female wing length is from 65 to 72 cm (26 to 28 in), averaging 69 cm (27 in). No weights are known in this subspecies. The coloration of these eagles is almost exactly the same as in A. c. canadensis. The main difference is that this subspecies is much larger in size, being nearly the equal of A. c. daphanea if going on wing-length.
The larger Middle Pleistocene golden eagles of France (and possibly elsewhere) are referred to a paleosubspecies Aquila chrysaetos bonifacti, and the huge specimens of the Late Pleistocene of Liko Cave (Crete) have been named Aquila chrysaetos simurgh (Weesie, 1988). Similarly, an ancestral golden eagle, with a heavier, broader skull, larger wings and shorter legs when compared to modern birds, has been found in the La Brea Tar Pits of southern California.


Adults of both sexes have similar plumage and are primarily dark brown, with some grey on the inner wing and tail, and a paler, typically golden colour on the back of the crown and nape that gives the species its common name.  Unlike other Aquila species, where the tarsal feathers are typically similar in colour to the rest of the plumage, the tarsal feathers of golden eagles tend to be paler, ranging from light golden to white. In addition, some full-grown birds (especially in North America) have white "epaulettes" on the upper part of each scapular feather tract. The bill is dark at the tip, fading to a lighter horn colour, with a yellow cere. As in many accipitrids, the bare portion of the feet is yellow. There are subtle differences in colouration among subspecies, described below.
Juvenile golden eagles are similar to adults but tend to be darker, appearing black on the back especially in East Asia. They have a less faded colour. Young birds are white for about two-thirds of their tail length, ending with a broad, black band. Occasionally, juvenile eagles have white patches on the remiges at the bases of the inner primaries and the outer secondaries, forming a crescent marking on the wings which tends to be divided by darker feathers. Rarely, juvenile birds may have only traces of white on the tail. Compared to the relatively consistently white tail, the white patches on the wing are extremely variable; some juveniles have almost no white visible. Juveniles of less than 12 months of age tend to have the most white in their plumage. By their second summer, the white underwing coverts are usually replaced by a characteristic rusty brown colour. By the third summer, the upper-wing coverts are largely replaced by dark brown feathers, although not all feathers moult at once which leaves many juvenile birds with a grizzled pattern. The tail follows a similar pattern of maturation to the wings. Due to the variability between individuals, juvenile eagles cannot be reliably aged by sight alone. Many golden eagles still have white on the tail during their first attempt at nesting. The final adult plumage is not fully attained until the birds are between 5 and a half and 6 and a half years old.


While many accipitrids are not known for their strong voices, golden eagles have a particular tendency for silence, even while breeding. That being said, some vocalization has been recorded, usually centering around the nesting period. The voice of the golden eagle is considered weak, high, and shrill, has been called "quite pathetic" and "puppy-like", and seems incongruous with the formidable size and nature of the species. Most known vocalisations seem to function as contact calls between eagles, sometimes adults to their offspring, occasionally territorial birds to intruders and rarely between a breeding pair. In western Montana, nine distinct calls were noted: a chirp, a seeir, a pssa, a skonk, a cluck, a wonk, a honk and a hiss.


Golden eagles are sometimes considered the best fliers among eagles and perhaps among all raptorial birds. They are equipped with broad, long wings with somewhat finger-like indentations on the tips of the wing. Golden eagles are unique among their genus in that they often fly in a slight dihedral, which means the wings are often held in a slight, upturned V-shape. When they need to flap, golden eagles appear at their most laboured, but this is less common than soaring or gliding––. Flapping flight usually consists of 6–8 deep wing-beats, interspersed with 2–3 second glides. While soaring, the wings and tail are held in one plane with the primary tips often spread. A typical, unhurried soaring speed in golden eagles is around 45–52 kilometres per hour (28–32 mph). When hunting or displaying, the golden eagle can glide very fast, reaching speeds of up to 190 kilometres per hour (120 mph). When stooping (diving) in the direction of prey or during territorial displays, the eagle holds its legs up against its tail, and holds its wings tight and partially closed against its body. When diving after prey, a golden eagle can reach 240 to 320 kilometres per hour (150 to 200 mph). Although less agile and manoeuvrable, the golden eagle is apparently quite the equal and possibly even the superior of the peregrine falcon's stooping and gliding speeds. This makes the golden eagle one of the two fastest living animals. Although most flight in golden eagles has a clear purpose (e.g., territoriality, hunting), some flights, such as those by solitary birds or between well-established breeding pairs, seem to be play.


Golden eagles are fairly adaptable in habitat but often reside in areas with a few shared ecological characteristics. They are best suited to hunting in open or semi-open areas and search them out year-around. Native vegetation seems to be attractive to them and they typically avoid developed areas of any type from urban to agricultural as well as heavily forested regions. In desolate areas (e.g., the southern Yukon), they can occur regularly at roadkills and garbage dumps. The largest numbers of golden eagles are found in mountainous regions today, with many eagles doing a majority of their hunting and nesting on rock formations. However, they are not solely tied to high elevations and can breed in lowlands if the local habitats are suitable. Below are more detailed descriptions of habitats occupied by golden eagles in both continents where they occur.


In the Arctic fringe of Eurasia, golden eagles occur along the edge of the tundra and the taiga from the Kola peninsula to Anadyr in eastern Siberia, nesting in forests and hunting over nearby arctic heathland. Typical vegetation is stunted, fragmented larch woodland merging into low birch-willow scrub and various heathland. In the rocky, wet, windy maritime climate of Scotland, Ireland, and western Scandinavia, the golden eagle dwells in mountains. These areas include upland grasslands, blanket bog, and sub-Arctic heaths but also fragmented woodland and woodland edge, including boreal forests. In Western Europe, golden eagle habitat is dominated by open, rough grassland, heath and bogs, and rocky ridges, spurs, crags, scree, slopes and grand plateaux. In Sweden, Finland, the Baltic States, Belarus and almost the entire distribution in Russia all the way to the Pacific Ocean, golden eagles occur sparsely in lowland taiga forest. These areas are dominated by stands of evergreens such as pine, larch and spruce, occasionally supplemented by birch and alder stands in southern Scandinavia and the Baltic States. This is largely marginal country for golden eagles and they occur where tree cover is thin and abuts open habitat. Golden eagle taiga habitat usually consists of extensive peatland formations caused by poorly drained soils. In central Europe, golden eagles today occur almost exclusively in the major mountain ranges, such as the Pyrenees, Alps, Carpathians, and the Caucasus. Here, the species nests near the tree line and hunt subalpine and alpine pastures, grassland and heath above. Golden eagles also occur in moderately mountainous habitat along the Mediterranean Sea, from the Iberian Peninsula and the Atlas Mountains in Morocco, to Greece, Turkey and Iraq. This area is characterized by low mountains, Mediterranean maquis vegetation, and sub-temperate open woodland. The local pine-oak vegetation, with a variety of Sclerophyllous shrubs are well-adapted to prolonged summer droughts. From Turkey and the southern Caspian Sea to the foothills of the Hindu Kush Mountains in Afghanistan, the typical golden eagle habitat is temperate desert-like mountain ranges surrounded by steppe landscapes interspersed with forest. Here the climate is colder and more continental than around the Mediterranean. Golden eagles occupy the alpine ranges from the Altai Mountains and the Pamir Mountains to Tibet, in the great Himalayan massif, and Xinjiang, China, where they occupy the Tien Shan range. In these mountain ranges, the species often lives at very high elevations, living above tree line at more than 2,500 m (8,200 ft), often nesting in rocky scree and hunting in adjacent meadows. In Tibet, golden eagles inhabit high ridges and passes in the Lhasa River watershed, where they regularly join groups of soaring Himalayan vultures (Gyps himalayensis). One golden eagle was recorded circling at 6,190 m (20,310 ft) above sea-level in Khumbu in May 1975. In the mountains of Japan and Korea, the golden eagle occupies deciduous scrub woodland and carpet-like stands of Siberian dwarf pine (Pinus pumila) that merge into grasslands and alpine heathland. The golden eagle occurs in mountains from the Adrar Plateau in Mauritania to northern Yemen and Oman where the desert habitat is largely bereft of vegetation but offers many rocky plateaus to support both the eagles and their prey. In Israel, their habitat is mainly rocky slopes and wide wadi areas, chiefly in desert and to a lesser extent in semi-desert and Mediterranean climates, extending to open areas. In Northeastern Africa, the habitat is often of a sparse, desert-like character and is quite similar to the habitat in Middle East and the Arabian peninsula. In Ethiopia's Bale Mountains, where the vegetation is more lush and the climate is clearly less arid than in Northeastern Africa, the golden eagle occupies verdant mountains.


The biomes occupied by golden eagles are roughly concurrent with those of Eurasia. In western and northern Alaska and northern Canada to the Ungava Peninsula in Quebec, the eagles occupy the Arctic fringe of North America (the species does not range into the true high Arctic tundra), where open canopy gives way to dwarf-shrub heathland with cottongrass and tussock tundra. In land-locked areas of the sub-Arctic, golden eagles are by far the largest raptor. From the Alaska Range to Washington and Oregon, it is often found in high mountains above the tree line or on bluffs and cliffs along river valleys below the tree line. In Washington state, golden eagles can be found in clear-cut sections of otherwise dense coniferous forest zones with relatively little annual precipitation. From east of the Canadian Rocky Mountains to the mountains of Labrador, the golden eagle is found in small numbers in boreal forest peatlands and similar mixed woodland areas. In the foothills of the Rocky Mountains in the United States are plains and prairies where golden eagles are widespread, especially where there is a low human presence. Here, grassland on low rolling hills and flat plains are typical, interrupted only by cottonwood stands around river valleys and wetlands where the eagles may build their nests. Golden eagles also occupy the desert-like Great Basin from southern Idaho to northern Arizona and New Mexico. In this habitat, trees are generally absent other than junipers with vegetation being dominated by sagebrush (Artemisia) and other low shrub species. Although the vegetation varies a bit more, similar habitat is occupied by golden eagles in Mexico. However, golden eagles are typically absent in North America from true deserts, like the Sonora Desert, where annual precipitation is less than 20 cm (7.9 in). Golden eagles occupy the mountains and coastal areas of California and Baja California in Mexico where hot, dry summers and moist winters are typical. The golden eagles here often nest in chaparral and oak woodland, oak savanna and grassland amongst low rolling hill typified by diverse vegetation. In the Eastern United States, the species once bred widely in the Appalachian Plateau near burns, open marshes, meadows, bogs and lakes. In Eastern North America, the species still breeds on the Gaspe Peninsula, Quebec. Until 1999, a pair of golden eagles were still known to nest in Maine but they are now believed to be absent as a breeding bird from the Eastern United States. The golden eagles who breed in eastern Canada winter on montane grass and heath fields in the Appalachian Plateau region, especially in Pennsylvania, New York, West Virginia, Maryland and Virginia. Most sightings in the Eastern United States recently are concentrated within or along southwestern border of the Appalachian Plateau (30% of records) and within the Coastal Plain physiographic region (33% of records).
Though they do regularly nest in the marsh-like peatland of the boreal forest, golden eagles are not generally associated with wetlands and, in fact, they can be found near some of the most arid spots on earth. In the wintering population of Eastern United States, however, they are often associated with steep river valleys, reservoirs, and marshes in inland areas as well as estuarine marshlands, barrier islands, managed wetlands, sounds, and mouths of major river systems in coastal areas. These wetlands are attractive due to a dominance of open vegetation, large concentrations of prey, and the general absence of human disturbance. In the midwestern United States, they are not uncommon during winter near reservoirs and wildlife refuges that provide foraging opportunities at waterfowl concentrations.


Golden eagles usually hunt during daylight hours, but were recorded hunting from one hour before sunrise to one hour after sunset during the breeding season in southwestern Idaho. The hunting success rate of golden eagles was calculated in Idaho, showing that, out of 115 hunting attempts, 20% were successful in procuring prey. A fully-grown golden eagle requires about 230 to 250 g (8.1 to 8.8 oz) of food per day but in the life of most eagles there are cycles of feast and famine, and eagles have been known to go without food for up to a week and then gorge on up to 900 g (2.0 lb) at one sitting.
The diet of golden eagles is composed primarily of small mammals such as rabbits, hares, ground squirrels, prairie dogs, and marmots. They also eat other birds (usually of medium size, such as gamebirds), reptiles, and fish in smaller numbers. Golden eagles occasionally capture large prey, including seals, ungulates, coyotes, and badgers. They have also been known to capture large flying birds such as geese or cranes. They have also been known to prey on other raptors, including owls and falcons.


Despite the dramatic ways in which they attain food and interact with raptors of their own and other species, the daily life of golden eagles is often rather uneventful. In Idaho, adult male golden eagles were observed to sit awake on a perch for an average of 78% of daylight, whereas adult females sat on nest or perched for an average of 85% of the day. During the peak of summer in Utah, hunting and territorial flights occurred mostly between 9:00 and 11:00 am and 4:00 and 6:00 pm, with the remaining 15 or so hours of daylight spent perching or resting. When conditions are heavily anticyclonic, there is less soaring during the day. During winter in Scotland, golden eagles soar frequently in order to scan the environment for carrion. In the more wooded environments of Norway during autumn and winter, much less aerial activity is reported, since the eagles tend to avoid detection by actively contour-hunting rather than looking for carrion. Golden eagles are believed to sleep through much of the night. Although usually highly solitary outside of the bond between breeding pairs, exceptionally cold weather in winter may cause eagles to put their usual guard down and perch together. The largest known congregation of golden eagles was observed on an extremely cold winter's night in eastern Idaho when 124 individuals were observed perched closely along a line of 85 power poles.


Most populations of golden eagles are sedentary, but the species is actually a partial migrant. Golden eagles are very hardy species, being well adapted to cold climates, however they cannot abide declining available food sources in the northern stretches of their range. Eagles raised at latitudes greater than 60° N are usually migratory, though a short migration may be untaken by those who breed or hatch at about 50° N. During migration, they often use soaring-gliding flight, rather than powered flight. In Finland, most banded juveniles move between 1,000 and 2,000 km (620 and 1,240 mi) due south, whereas adults stay locally through winter. Further east, conditions are too harsh for even wintering territorial adults. Golden eagles that breed from the Kola peninsula to Anadyr in the Russian Far East migrate south to winter on the Russian and Mongolian steppes, and the North China Plains. The flat, relatively open landscapes in these regions hold relatively few resident breeding golden eagles. Similarly the entire population of golden eagles from northern and central Alaska and northern Canada migrates south. At Mount Lorette in Alberta, approximately 4,000 golden eagles may pass during the fall, the largest recorded migration of golden eagles on earth. Here the mountain ranges are relatively moderate and consistent, thus being reliable for thermals and updrafts which made long-distance migrating feasible. Birds hatched in Denali National Park in Alaska traveled from 818 to 4,815 km (508 to 2,992 mi) to their winter ranges in western North America. These western migrants may winter anywhere from southern Alberta and Montana to New Mexico and Arizona and from inland California to Nebraska. Adults who bred in northeastern Hudson Bay area of Canada reached their wintering grounds, which range from central Michigan to southern Pennsylvania to northeastern Alabama, in 26 to 40 days, with arrival dates from November to early December. The departure dates from wintering grounds are variable. In southwestern Canada, they leave their wintering grounds by 6 April to 8 May (the mean being 21 April); in southwestern Idaho, wintering birds leave from 20 March to 13 April (mean of 29 March); and in the Southwestern United States, wintering birds may depart by early March. Elsewhere in the species' breeding range, golden eagles (i.e., those who breed in the contiguous Western United States, all of Europe but for Northern Scandinavia, North Africa and all of Asia but for Northern Russia) are non-migratory and tend to remain within striking distance of their breeding territories throughout the year. In Scotland, among all recovered, banded golden eagles (36 out of 1000, the rest mostly died or disappeared) the average distance between ringing and recovery was 44 km (27 mi), averaging 63 km (39 mi) in juveniles and 36 km (22 mi) in older birds. In the dry Southwestern United States, golden eagles tend to move to higher elevations once the breeding season is complete. In North Africa, populations breeding at lower latitudes, like Morocco, are mostly sedentary, although some occasionally disperse after breeding to areas outside of the normal breeding range.


Territoriality is believed to be the primary cause of interactions and confrontations between non-paired golden eagles. Golden eagles maintain some of the largest known home ranges (or territories) of any bird species but there is much variation of home range size across the range, possibly dictated by food abundance and habitat preference. Home ranges in most of the range can vary from 20 to 200 km² (7.7 to 77.2 sq mi). In San Diego County in California, the home ranges varied from 49 to 137 km² (19 to 53 sq mi), with an average of 93 km² (36 sq mi). However, some home ranges have been much smaller, such as in southwestern Idaho where, possibly due to an abundance of jackrabbits, home ranges as small as 4.85 km² (1.87 sq mi) are maintained. The smallest known home ranges on record for golden eagles are in the Bale Mountains of Ethiopia, where they range from 1.5 to 9 km² (0.58 to 3.47 sq mi). 46% of undulating displays in Montana occurred shortly after the juvenile eagles left their parents range, suggesting that some residents defend and maintain territories year-round. Elsewhere it is stated that home ranges are less strictly maintained during winter but hunting grounds are basically exclusive. In Israel and Scotland, aggressive encounters peaked from winter until just before egg-laying and were less common during the nesting season. Threat displays include undulating flight and aggressive direct flapping flight with exaggerated downstrokes. Most displays by mature golden eagles (67% for males and 76% for females) occur, rather than around the nest, at the edge of their home ranges. In Western Norway, most recorded undulating flight displays occur during the pre-laying period in late winter/early spring. Display flights seem to be triggered by the presence of other golden eagles. The use of display flights has a clear benefit in that it lessens the need for physical confrontations, which can be fatal. Usually, non-breeding birds are treated aggressively by the golden eagle maintaining their home range, normally being chased to the apparent limit of the range but with no actual physical contact. The territorial flight of the adult golden eagle is sometimes preceded or followed by intense bouts of undulating displays. The invader often responds by rolling over and presenting talons to the aggressor. Rarely, the two eagles will lock talons and tumble through the air; sometimes fall several revolutions and in some cases even tumble to the ground before releasing their grip. In some parts of the Alps, the golden eagle population has reached the saturation point in appropriate habitat and apparently violent confrontations are more common than in other parts of the range. Golden eagles may express their aggression via body language while perched, typically the adult female when confronted by an intruding eagle: the head and body are upright, feathers on head and neck are erect; the wings may be slightly spread and beak open; often accompanied by intense gaze. They then often engage in a similar posture with wings spread wide and oriented toward the threat; sometimes rocking back on tail and even flopping over onto the back with talons extended upward as defense. Such behavior may be accompanied by wing slap against the threatening intruder. When approached by an intruder, the defending eagle turns away, partially spreads tail, lowers head, and remains still; adults on the nest may lower head and "freeze" when approached by a person or a helicopter. Females in Israel displayed more than males and mostly against interspecific intruders; males apparently displayed primarily as part of courtship. Five of 7 aggressive encounters at carcasses during winter in Norway were won by females; in 15 of 21 conflicts, the younger bird dominated an older conspecific. However, obvious juvenile eagles (apparent to the adult eagles due to the amount of white on their wings and tail) are sometimes allowed to penetrate deeply into a pair's home range and all parties commonly ignore each other. In North Dakota, it was verified that parent eagles were not aggressive towards their own young after the nesting period and some juveniles stayed on their parents territory until their 2nd spring and then left by their own accord.


Natural sources of mortality are largely reported in anecdotes. On rare occasions, golden eagles have been killed by competing predators or by hunting mammalian carnivores, including the aforementioned wolverine, snow leopard, cougar, brown bear and white-tailed eagle attacks. Most competitive attacks resulting in death probably occur at the talons of other golden eagles. Nestlings and fledglings are more likely to be killed by another predator than free-flying juveniles and adults. It has been suspected that golden eagle nests may be predated more frequently by other predators (especially birds, which are often the only other large animals that can access a golden eagle nest without the assistance of man-made climbing equipment) in areas where golden eagles are regularly disturbed at the nest by humans. Jeff Watson believed that common raven occasionally eats golden eagle eggs but only in situations where the parent eagles have abandoned their nesting attempt. However, there are no confirmed accounts of predation by other bird species on golden eagle nests. Occasionally, golden eagles may be killed by their prey in self-defense. There is an account of a golden eagle dying from the quills of a North American porcupine (Erethizon dorsatum) it had attempted to hunt. On the Isle of Rùm in Scotland, there are a few cases of red deer trampling golden eagles to death, probably the result of a doe having intercepted a bird that was trying to kill a fawn.  Although usually well out-matched by the predator, occasionally other large birds can put up a formidable fight against a golden eagle. An attempted capture of a great blue heron by a golden eagle resulted in the death of both birds from wounds sustained in the ensuing fight.  There is at least one case in Scotland of a golden eagle dying after being "oiled" by a northern fulmar, a bird whose primary defense against predators is to disgorge an oily secretion which may inhibit the predator's ability to fly.  Of natural sources of death, starvation is probably under-reported. 11 of 16 dead juvenile eagles which had hatched in Denali National Park had died of starvation.  Of 36 deaths of golden eagles in Idaho, 55% were possibly attributable to natural causes, specifically 8 (26%) from unknown trauma, 3 (10%) from disease and 6 (19%) from unknown causes.  Of 266 golden eagle deaths in Spain, only 6% were from unknown causes that could not be directly attributed to human activities.  Avian cholera caused by bacteria (Pasteurella multocida) infects eagles that eat waterfowl that have died from the disease. The protozoan Trichomonas sp. caused the deaths of four fledglings in a study of wild golden eagles in Idaho. Several further diseases that contribute to golden eagle deaths have been examined in Japan. A captive eagle died from two malignant tumors – one in the liver and one in the kidney.


Human beings have been fascinated by the golden eagle as early as the beginning of recorded history. Most early-recorded cultures regarded the golden eagle with reverence. In pre-Hispanic Mesoamerica, the eagle was a major Mexica (Aztec) symbol: the tribal and sun god, Huitzilopochtli, had told his people that when they saw the sun (i.e., Huitzilopochtli) in the form of an eagle perched on a cactus whose fruit was red and shaped like a human heart, there they should build their city, Tenochtitlan. The scene—shown on a well-known sculpture, in early manuscripts, and on the present-day Mexican flag—surely had astronomical and geomantic, as well as mythological meaning.
It was only after the Industrial Revolution, when sport-hunting became widespread and commercial stock farming became internationally common, that humans started to widely regard golden eagles as a threat to their livelihoods. This period also brought about the firearm and industrialized poisons, which made it easy for humans to kill the evasive and powerful birds.
In 2017 the French Army trained golden eagles to catch drones. The golden eagle is officially Utah's state bird of prey.


At one time, the golden eagle lived in a great majority of temperate Europe, North Asia, North America, North Africa, and Japan. Although widespread and quite secure in some areas, in many parts of the range golden eagles have experienced sharp population declines and have even been extirpated from some areas. The number of golden eagles from around the range is estimated to be between 170,000 and 250,000 while the estimates of breeding pairs are from 60,000 to 100,000.  It has the largest known range of any member of its family, with a range estimated at 140 million square kilometers. If its taxonomic order is considered, it is the second most wide-ranging species after only the osprey (Pandion haliaetus). Few other eagle species are as numerous, though some species like the tawny eagle, wedge-tailed eagle and bald eagle have total estimated populations of a similar size to the golden eagle's despite their more restricted distributions.  The world's most populous eagle may be the African fish eagle (Haliaeetus vocifer), which has a stable total population estimated at 300,000 and is found solely in Africa. On a global scale, the golden eagle is not considered threatened by the IUCN.


The eastern imperial eagle (Aquila heliaca) is a large bird of prey that breeds in southeastern Europe and extensively through West and Central Asia. Most populations are migratory and winter in northeastern Africa, the Middle East and South and East Asia. Like all eagles, the eastern imperial eagle is a member of the family Accipitridae. Furthermore, its well feathered legs mark it as a member of the subfamily Aquilinae. It is a large, dark-colored eagle, with a resemblance to other members of the genus Aquila but it is usually the darkest species in its range. This is an opportunistic predator that mostly selects smallish mammals as prey but also a fairly large proportion of birds, reptile and other prey types, including carrion. Compared to other Aquila eagles, it has a strong preference for the interface of tall woods with plains and other open, relatively flat habitats, including the wooded mosaics of the steppe. Normally, nests are located in large, mature trees and the parents raise around one or two fledglings. The global population is small and declining due to persecution, loss of habitat and prey. It has therefore been IUCN Red Listed as Vulnerable since 1994.


The eastern imperial eagle is a member of the Aquilinae or booted eagles, a rather monophyletic subfamily of the accipitrid family. At least 38 species are currently housed in the subfamily, all with signature well-feathered tarsi. This species is a member of the genus Aquila, which are mostly large, fairly dark colored eagles distributed largely through the more open habitats of Eurasia and Africa (with one in North America and a couple in Australasia). Studies on DNA have indicated that the imperial eagle is part of a subgroup with other moderately sized Aquila such as the steppe eagle (Aquila nipalensis) and the tawny eagle (Aquila rapax). Despite the  outward resemblance to the imperial eagle, the 4 species in the golden eagle subgroup appear to rather more closely related to the dissimilarly smallish and pale-bellied sister species, African hawk eagle (Aquila spilogaster) and Bonelli's eagle (Aquila fasicata). The Spanish imperial eagle, which is found in Spain and Portugal, was formerly lumped with this species, the name imperial eagle having been previously used in both circumstances. However, the two are now regarded as separate species due to significant differences in morphology, ecology and molecular characteristics. It is likely that the eastern imperial eagle is the paraspecies for the Spanish imperial eagle and that the imperial eagle complex reached the Iberian peninsula sometimes between the late Pleistocene era and early Holocene. The Spanish imperial eagle may be considered an ice age relict due to its isolation.


The eastern imperial eagle is a large eagle, but usually falls near the average size of the large-bodied genus Aquila. Adult total length can range from 68 to 90 cm (27 to 35 in) with a typical wingspan of 1.76 to 2.2 m (5 ft 9 in to 7 ft 3 in). The average wingspan of a small sample showed males to average 1.95 m (6 ft 5 in) while a small sample of females averaged 2.07 m (6 ft 9 in). Although otherwise outwardly similar, the species displays reverse sexual dimorphism as do most birds of prey, in which males are usually smaller than the females. For the eastern imperial eagle, females are up to 10% larger linearly and 40% heavier in body mass in some cases. In terms of body mass, one survey found five males to weigh from 2.45 to 2.72 kg (5.4 to 6.0 lb) and  five females to weigh from 3.26 to 4.54 kg (7.2 to 10.0 lb). The average weight of this sample of imperial eagles was reportedly 2.62 kg (5.8 lb) in the males and 3.9 kg (8.6 lb) in the females. A sample of unknown size showed males to weigh an average 2.88 kg (6.3 lb) while females reportedly weighed an average of 3.38 kg (7.5 lb). A further two mature females weighed an average of 3.56 kg (7.8 lb). Among standard measurements, males may range in wing chord length from 540 to 622 mm (21.3 to 24.5 in), in tail length from 260 to 308 mm (10.2 to 12.1 in) and in tarsus length from 91 to 98 mm (3.6 to 3.9 in). Meanwhile, females may range in wing chord length from 565 to 665 mm (22.2 to 26.2 in), in tail length from 270 to 330 mm (11 to 13 in) and in tarsus length from 97 to 107 mm (3.8 to 4.2 in). A sample of imperial eagles ranged in total bill length from 65.7 to 76.5 mm (2.59 to 3.01 in).
In general, compared to other species in their taxonomic group, the eastern imperial eagle has a relatively long and thick neck, a big head and bill (with a gape line level with middle of eye), a longish square tipped tail, somewhat long and well-feathered legs and strong feet. The species tends to perch in a fairly upright position often on rather exposed tree branch or low mound, rock, haystack or similar convenient site. For an Aquila eagle, it is seemingly relatively less shy and bolder in the presence of humans. The adult plumage is largely a tar-like blackish-brown but for a well-demarcated and highly contrasting creamy to golden buff colour about the crown, hindneck and neck sides. Furthermore, adults have bold white spots on their shoulder braces, which are usually fairly conspicuous on perched birds. The adult’s tail is narrowly dark barred over a greyish ground colour and has a broad black subterminal band, while a white tail tip sometimes manifest in adults that are freshly molted. The undertail coverts are sometimes indistinctly paler, rust to creamy, combined with grey tail base to give the appearance of a paler rear end. At rest, the wing tips tend to reach the tail tip. The juvenile eastern imperial eagle is mostly pale tawny-buff to sandy yellow with fairly heavy dark brown streaks from the throat down to the breast, mantle, scapulars and forewing coverts. The juvenile’s scapulars and forewing coverts also have sometimes noticeable white tipped feathers while the median coverts are perceptibly browner and greater coverts blackish both with broad creamy-yellow tips forming clear wing bars. The flight feathers and tail on juveniles are often blackish and tipped whitish, however the white parts on the lower back to tail coverts are only lightly streaked in the centre and often not visible when perched. Below the streaked breast, the remainder of the juvenile’s underparts are plain pale buff. By the 2nd year, the brown streaking on the underside fades to a plainer sandy hue and the pale bars also start to fade on wings. Especially later into the 2nd year into the 3rd year, some young eastern imperial-eagles show an erratic blotching of blackish-brown feathers below. By about the 4th winter, as the birds enter their subadult plumage, the forefront of the eagle is often a rather patchy mix of sandy and darker adult-like feathers. During slow annual molts, the dark feathers expand initially from the throat and upper breast outward. Late into the subadult stage, the birds also start to develop a pale crown and nape but usually the rear body still more juvenile-like, such as the pale rump-band and crissum despite the otherwise darkening tail and wing feathers. The full adult plumage is attained at 5–6 years of age but some subadults are already breeding before this.
In flight, the eastern imperial eagle is a large raptor that has for an Aquila a very projecting neck and "huge" head and bill. The long wings may appear fairly broad when compared to other, smaller raptors, but are relatively narrow with even parallel edges when compared to other Aquila eagles. Their flight style is relatively heavy but steady with deep powerful beats but they are not uncommonly clumsy at first takeoff. They tend to soar with forward pressed but rather flat wings, the outer wing feathers may sometimes curve up but as a rule they do not fly with a V as do some other Aquila. The species may also hold their wings flat while engaging in a glide but as it accelerates they may arch wings back. In flight, the adult from above shows dark brown with small white braces, greyish tail with fine dark bars and a very broad, blackish subterminal band. The adult is essentially all dark colored when seen from below relieved only by some very dusky grey flight feathers on the primaries (against the black wing tips), a grey crissum and thinly barred grey tail base. However, these features may be only obvious in good light and at reasonable distances. In flight, the juvenile is largely pale buff with brown streaking. The lower back, rump, tail coverts and leg feathers are all whitish cream in colour which contrasts noticeably with their white-tipped blackish greater coverts, primary coverts and quills. On their mantle, juveniles manifest two white wing bars above and a narrow whitish lower trailing edge. Meanwhile, the juvenile’s inner primaries are much paler creamy-buff hue than their other flight feathers. The dusky brown wing linings of the juvenile plumage, when compared to the darker ones of adults, show more extensive coarse patterning. Some birds by 2nd to 3rd year are so worn in their flight feathers as to appear almost unstreaked sandy while, from the 3rd year on, darker feathers start to appear below with various untidy variations.


The eastern imperial eagle is typically smaller, being more slender and less bulky and powerful in appearance despite its proportionately larger head and longer neck, than the golden eagle (Aquila chrysaetos). In some parts of the range, the female imperial eagle probably averages similar size and body mass to the smaller male golden eagle. However, apparently the species can be reliably distinguished by the size of its hallux claw (the enlarged rear talon that accipitrids used as a killing apparatus) which is consistently larger in the golden species. Two female eastern imperial eagles measured 38 and 43 mm (1.5 and 1.7 in) in hallux claw length while a male was about 35.5 mm (1.40 in), whereas the smallest talon measured for an immature male American golden eagle was 44.9 mm (1.77 in). Nonetheless, besides its wider ranging golden cousin, this species is typically the largest, with the largest extremities (i.e. tarsal, tail and bill length) and most powerful booted eagle species in the majority of its range (apart from its rare African winter range) when compared to similar eagles such as others in the genera Aquila and Clanga. Usually, the plumage of the adult eastern imperial eagle is very distinctive. It is considerably darker than other adult Aquila eagles in central Eurasia. Furthermore, all other Eurasian eagles in their range lack the white spots on the wing mantle and greyish under-tail. Given reasonable views, the juvenile imperial eagle is no less distinctive, with its unique tawny-buff covered in brownish streaking, a colour combination not seen in other species. From a distance, the juvenile may give the impression of a dark mantle and chest band with very pale rear body and a blackish tail and remiges against strikingly pale primary wedges. Adults do however strongly resemble their considerably extralimital cousins, the Spanish imperial eagle, but the eastern species has more restricted white on the shoulder and has a slightly more brownish hue in the dark underside feathers, while juvenile Spanish imperials are richly tawny in colour rather than pale buffy and lack brownish streaking on the body. The Spanish species is similar in size and proportions to the eastern imperial but is marginally heavier on average and has an even more protruding head and neck.
The subadult eastern imperial eagle may be confused with older immature greater spotted eagles (Clanga clanga) but the latter is less contrastingly patterned, without a paler shawl and has greater covert band below (despite the rare hint of one on some imperials) and densely bared flight feathers. Adult greater spotted eagles have similar underwing contrast as juvenile eastern imperial eagles but, beyond plumage characteristics, are distinct for their much smaller head, slightly smaller overall size and more compact frame with a relatively broader and shorter wings. More similiar to the juvenile eastern imperial eagle is the fulvescens morph of the greater spotted eagle which is fairly rare (more so in the west) but is similarly or even as pale buffy. However this spotted eagle morph lacks the brownish streaks below of the juvenile imperial and further has contrasting much darker feathering on the wing coverts (heavily spotted in juvenile greater spotteds) and mantle as well as sometimes the facial feathers, and can further be distinguished by the same aforementioned differences in form. Indian spotted eagles (Clanga hastata) tend to show paler lesser under-wing coverts like juvenile eastern imperial eagles but are considerably smaller and differ in all other proportions and plumage features. Although at times described as “very similar”, the eastern imperial eagles are fairly easily told from the golden eagle by being much darker with less broad wings that are held much flatter. The golden eagle, unlike imperial eagles, tends to fly with its wings pointed upwards and have a gradual tapering wing shape (somewhat narrower at the base, broader at the primaries). In golden eagles, the tail generally appears narrower and squarer in shape. At closer range, the pale area on the back of the head and neck in eastern imperial eagle may be suggestive to some of the golden eagle’s golden nape but is always much paler and chalkier in colour, as well as more strongly contrasted by the otherwise dark feathers and is more extensive. Against the somewhat similarly sized but more compact juvenile steppe eagle (Aquila nipalensis), the juvenile eastern imperial eagle does not show a white band on underwing like the steppe. More obviously, the steppe eagle lacks the paler overall colours and contrasting brownish streaking of juvenile imperials. Feather wear can make the wing shape of the two resemble the other but the larger head and less compact frame of the imperial species render its flight profile distinctive. The only darker large booted eagle encountered by the eastern imperial eagle, in its African winter quarters, is the jet-black Verreaux's eagle (Aquila verreauxii) which is more suggestive in size and proportions of the golden eagle. An unlikely source of confusion, the Verreaux's differs in almost all plumage characteristics and has far more tapered wings that pinch in at the base and, like the golden eagle, tends to fly in a fairly strong dihedral. In Asia, its proportions and size may be suggestive of the perhaps even rarer Pallas's fish eagle (Haliaeetus leucoryphus) and the two can potentially be mistaken in strongly backlit conditions which obscure their obviously distinct plumages. The large headed and flat winged shape of the imperial eagle may too suggest in silhouette the white-tailed eagle (Haliaeetus albicilla) but that species is usually rather larger bodied and even larger headed with much broader wings and a proportionately shorter tail. Cinereous vulture (Aegypius monachus), being similarly dusky overall below, have been suggested as confusion species, but are much larger than imperial eagles with differing proportions (far broader wings, proportionately smaller head and shorter tail) and lack any of the contrasting pale parts of the imperial eagle’s plumage.


The eastern imperial eagle is quite vocal on their breeding ground but tends to be silent or nearly so elsewhere. The main call of the species is a deep, harsh bark owk owk, gok gok or kraw-kraw. The call tends to be repeated rapidly up to 8-10 times. Their call is perceptibly deeper and harsher than that of the golden eagle, somewhat incongruously also being more resonant and commanding. Sometimes when extending to a prolonged version, its call is sometimes considered reminiscent of the croak of a large frog. The eastern imperial eagle most frequently calls during their aerial displays. In extreme cases, the call may be repeated up to 13 times during an aerial display. Furthermore, they may repeat the call from a perch. Females may also call when a male arrives with prey. Alarm calls recorded for the species include a soft ko-gok, wk wk wk, uttered in response to a distant intruder, a closer approach also may cause a harder gek call by the mother. A rising and falling trill has been additionally recorded in captivity is also probably an alarm call.


The eastern imperial eagle is found as far west as east-central and southeastern Europe. The European part of its breeding range includes eastern Austria, eastern Czech Republic, Slovakia, Hungary, eastern Croatia, Serbia, northeastern Bosnia and Herzegovina, Macedonia, Bulgaria, Romania, Moldova and northern, western and much of the eastern part of the Ukraine. The species distribution continues across central Russia, where it is found through most of the Central Federal District, essentially all of the North Caucasian Federal District, most of the Volga and Ural Federal Districts (excluding the northern parts), and the southern part of Siberia past Lake Baikal to the Transbaikalia in the landlocked southwest of the Russian Far East. Out of Russia, their breeding extends south to mostly the northern portions of the following nations: Georgia, Armenia, Azerbaijan, Turkmenistan, Uzbekistan, much of Kazakhstan, northwestern China (Xinjiang) and northern Mongolia. Isolated populations also persist in northwestern, central and eastern Turkey, Cyprus, and northern Iran. As a breeding species, they are probably extirpated from Afghanistan and Pakistan.


Unlike the Spanish imperial eagle, the eastern imperial eagle is fairly strongly migratory in most of its range, though a variable amount of residency or very local wandering during winter in the western and southern parts of its range may lend it to be described as a partial migrant. The species has been recorded overwintering as far north as Mongolia. In Bulgaria, of three post dispersal juveniles, two wandering within the country and only one migrated a long distance to Israel. Migratory movements occur during fall any time from September to November and in spring anytime from February to May, shifting earlier in the fall and later in spring the farther north that the eagles breed. Differentiating the large areas use merely for passage migration or vagrancy from regular wintering grounds can be difficult. Though typically seen in very small numbers at main raptor migration sites the species may occur as a passage migrant through much of the Middle East down to Yemen, with pockets of wintering eagles in Israel, northern Jordan, central Saudi Arabia, Kuwait, northeastern Iraq and adjacent southwestern Iran. A radio-tagging study of a few wintering eagles in Arabia found they returned variously to Russia in four cases and Kazkhstan and China in a single case, with a range of ground covered in spring migration of 3,900 to 5,000 km (2,400 to 3,100 mi). The eastern imperial eagle winters locally and in quite small numbers in Africa’s Nile valley, mostly being reported in southern Sudan, central Ethiopia and northern Kenya, irregularly down as far as southern Kenya and once even northern Tanzania. Most migrants to Africa apparently originate in the western part of the breeding range such as Europe. Further east, such as the imperial eagles that breed around Lake Baikal, will generally migrate to south Asia. Moderate to quite low numbers are usually noted of this species at migration sites in the Himalayas. The eastern imperial eagle winters fairly broadly in the Indian subcontinent, from eastern Pakistan, eastward through southern Nepal to Bangladesh and down as far south in India as the states of Gujarat, Madhya Pradesh, Bihar and northwestern Jharkhand. Other semi-regular wintering areas include southern Bhutan, Thailand and north Indochina (recorded across Chinese border in southwestern Yunnan) and spottily in east China where wildlands still occur. Occasionally, wintering birds are known to occur in the central Cambodia and discontinuously in Laos and Vietnam as well as in the Korean peninsula, Taiwan and southern Japan (mostly Honshu). Vagrants have been reported in over 20 countries, mainly in Europe, including Poland, Sweden, Denmark, Germany and Italy.


The eastern imperial eagle is distributed as a breeding species largely along the southern edge of the vast taiga forests. The habitat preferred by the species is often rather open country with scattered trees or more enclosed woodlands, as well as around or near wetlands. The imperial eagle often forages mainly in open areas, extending to beyond typical assorted grasslands to wetlands and agricultural areas. In more extensive wooded areas, eastern imperial eagles require glades or meadows in order to executive hunting. The central part of their range as a breeding species occurs in vast areas of steppe and here the species often inhabits forest-steppe mosaics, as well as open woodlands, river valleys and even agricultural areas with trees or wooded patches. Lowland areas tend to be preferred, albeit not exclusively. In Turkestan and Kazakhstan, they may extend their breeding habitat into semi-desert. True desert is used during winter so long as foods are available. Largely where golden eagles are absent, the species has been reported to range into secondary habitats such as forested lower mountains and montane steppe and meadowland. In Europe at least, this is due to human pressures, which caused them to abandon open lowlands, timbered plains and river-fringed forests for forested, precipitous uplands. A slow repopulation of their preferred lowlands reported since 1990s in Slovakia and Hungary. Often, eastern imperial eagles winter in more open habitats such as nearly continuous grassland, plains, semi-desert and cultivation with scattered trees as well as various marshes, lakes and other wetlands. The species resides mainly from sea level to 1,300 m (4,300 ft), locally to 1,800 m (5,900 ft), and has been recorded on passage at 3,900 m (12,800 ft) in Asia.