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.


Golden eagles usually mate for life. A breeding pair is formed in a courtship display. This courtship includes undulating displays by both in the pair, with the male bird picking up a piece of rock or a small stick, and dropping it only to enter into a steep dive and catch it in mid-air, repeating the maneuver 3 or more times. The female takes a clump of earth and drops and catches it in the same fashion. Golden eagles typically build several eyries within their territory (preferring cliffs) and use them alternately for several years. Their nesting areas are characterized by the extreme regularity of the nest spacing. Mating and egg-laying timing for golden eagle is variable depending on the locality. Copulation normally lasts 10–20 seconds. Mating seems to occur around 40–46 days before the initial egg-laying. The golden eagle chick may be heard from within the egg 15 hours before it begins hatching. After the first chip is broken off of the egg, there is no activity for around 27 hours. Hatching activity accelerates and the shell is broken apart in 35 hours. The chick is completely free in 37 hours.
In the first 10 days, chicks mainly lie down on the nest substrate.   They are capable of preening on their second day but their parents keep them warm until around 20 days.  They grow considerably, weighing around 500 g (1.1 lb).  They also start sitting up more.  Around 20 days of age, the chicks generally start standing, which becomes the main position over the course of the next 40 days. The whitish down continues until around 25 days of age, at which point it is gradually replaced by dark contour feathers that eclipse the down and the birds attain a general piebald appearance. After hatching, 80% of food items and 90% of food biomass is captured and brought to the nest by the adult male. Fledging occurs at 66 to 75 days of age in Idaho and 70 to 81 days in Scotland. The first attempted flight departure after fledging can be abrupt, with the young jumping off and using a series of short, stiff wing-beats to glide downward or being blown out of nest while wing-flapping. 18 to 20 days after first fledging, the young eagles will take their first circling flight, but they cannot gain height as efficiently as their parents until approximately 60 days after fledging. In Cumbria, young golden eagles were first seen hunting large prey 59 days after fledging. 75 to 85 days after fledging, the young were largely independent of parents. Generally, breeding success seems to be greatest where prey is available in abundance.


Golden eagles are fairly long-living birds in natural conditions if they survive their first few years. The survival rate of raptorial birds tends to increase with larger body size, with a 30–50% annual loss of population rate in small falcons/accipiters, a 15–25% loss of population rate in medium-sized hawks (e.g., Buteos or kites) and a 5% or less rate of loss in eagles and vultures. The oldest known wild golden eagle was a bird banded in Sweden which was recovered 32 years later. The longest-lived known wild golden eagle in North America was 31 years and 8 months. The longest-lived known captive golden eagle, a specimen in Europe, survived to 46 years of age. The estimated adult annual survival rate on the Isle of Skye in Scotland is around 97.5%. When this extrapolated into an estimated lifespan this results in 39 and half years as the average for adult golden eagles in this area, which is probably far too high an estimate. Survival rates are usually much lower in juvenile eagles than in adult eagles. In the western Rocky Mountains, 50% of golden eagles banded in the nest died by the time they were 2 and a half years and an estimated 75% died by the time they were 5 years old. Near a wind turbine facility in west-central California, estimated survival rates, based on conventional telemetry of 257 individuals, were 84% for first-year eagles, 79% for 1- to 3-year-olds and adult floaters and 91% for breeders; with no difference in survival rates between sexes. Survival rates may be lower for migrating populations of golden eagles. A 19–34% survival rate was estimated for juvenile eagles from Denali National Park in their first 11 months. The average life expectancy of golden eagles in Germany is 13 years, extrapolated from a reported mere 92.5% survival rate.


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.


In December 2016, the US Fish and Wildlife Service proposed allowing wind-turbine electric generation companies to kill golden eagles without penalty, so long as "companies take steps to minimize the losses". If issued, the permits would last 30 years, six times the current 5-year permits.


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.


The eastern imperial eagle is somewhat varied in hunting techniques but almost exclusively takes its prey on the ground. It is possible some prey, such as fledgling birds, are taken from low perches in ambushes but this is seemingly unverified. They are also known to capture prey in water or from the edge of waterways and may even become waterlogged, especially when capturing birds. Imperial eagles typically still hunt, watching for prey at length from a moderately low perch (usually a tree branch but virtually any perch from rocks to bushes to power poles), then often making a short stoop or dive to the ground once prey is spotted. Alternately, they may make a longer dive onto prey from a low soaring flight, often using any vegetation available to obscure their approach. Some prey are known to be captured on foot, including insects and burrowing mammals, the latter reportedly by waiting by the entrance of the animal’s burrow. Occasionally, this species will pirate foods from other eagles (and other species of bird of prey), especially during winter, and also tandem hunts in pairs as well. The eastern imperial eagle is, like most active predators, an opportunist who exploits any prey they are capable of overpowering. Their prey spectrum is highly varied, including somewhere between 200 and 300 prey species, a total number of prey species only a bit short of the occasionally sympatric common buzzard (Buteo buteo) which may be 500 times more numerous overall. In the nations of Kazakhstan and Hungary alone, the total recorded prey spectrum is 154 and 126 species, respectively. Small to medium-sized mammals are the most regularly selected prey, with a preference for hares, various rodents, especially ground squirrels, hamsters and  voles, as well as insectivores. Furthermore, various birds are taken, at times as much as or more so than mammals, especially the young or fledglings of various medium-sized to larger birds. Birds may locally become the primary foods in some parts of the winter range. Reptiles are taken secondarily in most of the range but can be locally somewhat important and fish and invertebrates, including insects, may be taken rarely.
The prey type historically most often associated with the eastern imperial eagle, at least in Europe, has been ground squirrels and hamsters. While these are significant, the primary prey type can vary and often hares or hedgehogs appear to take the primary position in recent studies. The largest European dietary study to date, a multi-year analysis from Hungary, showed that European hare (Lepus europaeus) were the primary foods, making up 27.4% of a total of 8,543 prey items. The second best represented prey in Hungary was the European hamster (Cricetus cricetus), at 12.71% of the diet. Similarly, in Slovakia and the Czech Republic, the European hare was the main prey, comprising 40.2% of 562 prey items and 41.3% of 109 prey items, respectively. The European hamster was the 4th most frequent prey in Slovakia but second most common prey species in the Czech Republic. As presented in the multi-year studies from Hungary, a seeming decline of the European ground squirrel (Spermophilus citellus) population is the cause of their reduced importance in the imperial eagle’s diet, with this species being the primary prey in 1975-1991 (51% of 606 prey items from 1975 to 1985) to contributing almost nothing in 2005-2017. It is possible with reintroductions of the European ground squirrel underway in central Europe, that this prey species may again become more significant in the eastern imperial eagle’s diet again here. In Tyva Republic, the long-tailed ground squirrel (Spermophilus undulatus) still dominates the food of imperial eagles, making up 60.1% of 168 prey items.  In studies of two different areas of Bulgaria, one showed European hares as the main prey (25%) in the Dervent heights and southern white-breasted hedgehog (Erinaceus concolor) (32.5%) in the other, Saker mountain. In East Thrace, Turkey, the same hedgehog was the most important prey, comprising 23.1% of 582 prey items and 21.2% of the prey biomass.
In warmer, southerly areas, the primary prey species seem to generally be smaller. In Georgia, social voles (Microtus socialis) were the primary food, comprising about 15% of 341 prey items. For wintering imperial eagles, the most frequent live prey (though carrion was mainly eaten) was Sundevall's jird (Meriones crassus). Both of these small rodents probably average only about 35 to 60 g (1.2 to 2.1 oz) in body mass. Numerous other small mammals may also be occasionally taken including several species each of hedgehogs, shrews and moles, beyond the common hare, at least 7 other species of lagomorphs, about a dozen species each of murid rodents and cricetid rodents (especially hamsters and voles), 5 species of zokor and assorted dormice and jerboas. Thus, eastern imperial eagles appear to prefer rodents and similar small mammals that are burrow-dwelling and/or partial to ground dwelling in open grass or fields along wooded edges.
Assorted bird species may factor heavily into the diet of eastern imperial eagles. More than 120 bird species are known to be taken by this eagle. European studies reflect the high importance of common pheasants (Phasianus colchicus), in Europe a non-native gamebird (although the imperial eagle also encounters and hunts the species extensively in its native range as well), in their foods. In the aforementioned large Hungarian study, pheasants were the third most frequently taken prey species, making up 12% of the diet. In the Czech Republic, the pheasant ranked third as well. In Slovakia, the pheasant was second only to the hare in frequency, comprising 17.3% of the foods, although exclusively juvenile and hen pheasants (no cocks) were reportedly taken. In Bulgarian studies, the domestic chicken (Gallus gallus domesticus) seems to take the place of pheasants in their diet, making up 10.8% and 20.8% at Saker mountain and Dervent heights and second most frequently taken prey at both, respectively. The largest study of the eastern imperial eagle’s dietary habits known occurred in the vast Naurzum Nature Reserve in Kazakhstan, where 11,079 prey items were reviewed. The prey spectrum was exceptionally diverse here, with no one prey reliably being favored by the imperial eagle pairs, despite an ample colony of yellow ground squirrel (Spermophilus fulvus) and russet ground squirrel (Spermophilus major) being nearby and at least three other species of eagles with nearby nesting sites presenting possible resource competition. Without presenting the metrics, apparently birds were the highest volume prey for the imperial eagles, especially corvids, namely the rook (Corvus frugilegus) and Eurasian magpie (Pica pica), numerous species of duck as well as Eurasian kestrels (Falco tinnunculus) and little bustards (Tetrax tetrax). In East Thrace, Turkey, the second most regularly taken prey species is the yellow-legged gull (Larus michahellis), which comprised more than 12% of the diet by number and 13.8% of the prey biomass. Additionally in East Thrace, a high volume of white storks (Ciconia ciconia) was taken, making up 11.3% of the biomass. In Bulgaria, similar prey were important secondary foods, i.e. Caspian gulls (Larus cachinnans) at 9.78% of the diet in the Saker mountain area, while white stork made up 10.42% of the diet at Dervent heights. A study of wintering eastern imperial eagles in the Bharatpur district of India showed that this species was generally more inactive but also more likely to capture its own food (rather than through scavenging or kleptoparasitism) than 4 assorted other eagle species in the area. Like other eagles here, the imperial eagles most often fed on various water birds, mainly the nestlings of late-nesting painted storks (Ciconia leucocephalus), black-headed ibis (Threskiornis melanocephalus), Oriental darters (Anhinga melanogaster) and a couple of species of cormorant. However, the imperial eagle in particularly here took to regularly hunting various adult water birds especially ducks, geese and large rails and had a mean daily food intake (not mean prey size) of 539 g (1.188 lb). In the Saurashtra region of India, imperial eagles were observed to show a preference for hunting diving water birds, including Eurasian coots (Fulica atra) and diving ducks, which they would hunt in a style reminiscent of the white-tailed eagle, forcing them to dive as they circled over the water and capturing them as they came to the water’s surface to breathe. Numerous pigeons and doves may also be taken fairly often, such as in Slovakia where rock pigeons (Columba livia) were the 3rd most often regular prey at 11.79% of the diet. In general, a picture emerges of the imperial eagle’s dietary preference for relatively large birds with conspicuous behaviour, relatively slow flight, who can be struck on or near the ground and/or have vulnerable nesting sites or conspicuous young, such as gamebirds, waterfowl, other water birds and corvids.
European studies of the eastern imperial eagle’s diet rarely reflect prey outside of the main preferred classes of mammals and birds, however studies from somewhat outside Europe show respectable numbers of reptiles may be taken. In Georgia, reptiles amounted to 29.62% of the food, comprised largely either of Caucasian agama (Paralaudakia caucasia) or other unidentified smallish lizards. A larger class of reptiles were regular secondary prey in East Thrace in Turkey, namely Greek tortoise (Testudo graeca) and Hermann's tortoise (Testudo hermanni), with tortoises altogether comprising 11.1% of the diet by number and 13.7% of the prey biomass. Tortoises can be significant in the diet elsewhere as well, especially in more arid climes. Although snakes do not seem to be typically quantitatively important, eastern imperial eagles have no problem occasionally subduing large snakes, such as Aesculapian snakes (Zamenis longissimus), or very aggressive venomous snakes, such as Russell's viper (Daboia russelii) (the latter taken in their wintering Indian quarters). In Hungary, very small numbers of invertebrates (mostly insects such as ground beetles) and fish were found amongst the foods of imperial eagles. Carrion is eaten through the year by eastern imperial eagles, but most heavily during winter. For example, in the wintering population of Jordan, 53.7% of the dietary intake of the species was made up of carrion. However, in some breeding populations, apparently the eagles can come to rely on dead or already injured prey inadvertently provided by humans, largely due to intensive agricultural practices, as was the case in the Czech Republic. In one area of Slovakia, although imperial eagles also hunted, the adult eagles routinely practiced kleptoparasitism while nesting, regularly robbing other species of raptorial bird of their fresh catches. Almost any mammal or bird will be readily eaten when dead or dying by imperial eagles, with at least 10 species of ungulate known to be consumed thusly and providing an ample source of meat.
The size of prey taken by eastern imperial eagles can be fairly variable, though is not generally as impressively varying as the golden eagle’s prey sizes. Most live prey taken by eastern imperial eagles weighs less than 2 kg (4.4 lb). According to Watson (2010), the prey of imperial eagles is fairly evenly spread from 63 g (2.2 oz) up to 2,000 g (4.4 lb), with a peak focus (at around 25%) on prey weighing 500 and 1,000 g (1.1 and 2.2 lb) and a mean estimated prey size of 565 g (1.246 lb). Many of the prey species taken by imperial eagles are relatively large as adults such as European hares and bobak marmots (Marmota bobac), which were the second most often taken mammalian prey species in Kazakhstan, but generally, these eagles take juvenile specimens of both hares and marmots rather than prime adults. The mean weight of European hares and bobak marmots taken in Kazakhstan was estimated at 1.5 kg (3.3 lb) and 1.4 kg (3.1 lb), in both cases no less than a third of the average adult weight attainable by the species. In contrast, the smallest staple prey in Kazakhstan were small rodents (i.e. mice, voles) that weighed an estimated 30 g (1.1 oz). Similarly, the upper size of hare typically taken in Slovakia was estimated at 1.4 kg (3.1 lb). In Hungary, staple prey size was estimated at between 250 g (8.8 oz) and 2.5 kg (5.5 lb). However, the eastern imperial eagle is capable of taking large, impressive prey as well. In some cases, they are capable of taking adult hares, including the typical European hares but also other species such as mountain hare (Lepus timidus) and the Tolai hare (Lepus tolai). They have taken adults of numerous larger water birds averaging over the expected prey weight of 2 kg (4.4 lb), although (at least for wading birds such as stork) nestlings are most often preyed upon, including greylag goose (Anser anser), greater white-fronted goose (Anser albifrons), bean goose (Anser fabalis), bar-headed goose (Anser indicus), knob-billed duck (Sarkidiornis melanotos), common crane (Grus grus), great cormorant (Phalacrocorax carbo), white stork and black stork (Ciconia nigra). Eastern imperial eagles also attack the young of ungulates at times, reportedly neonatal and mildly older calves and lambs of similar size to the eagles themselves, including species such as argali (Ovis ammon), roe deer (Capreolus capreolus), Arabian sand gazelle (Gazella marica) and goitered gazelle (Gazella subgutturosa). At the opposite end of the scale in vertebrate prey, imperial eagles are known to take mammals down to the size of the 7 g (0.25 oz) Eurasian harvest mouse (Micromys minutus) and birds down to the size of the 21.4 g (0.75 oz) Eurasian tree sparrow (Passer montanus). In Kazakhstan, the estimated size of all prey taken varied from approximately 2 g (0.071 oz) for a locust to 5 kg (11 lb) for the largest bird prey (i.e. cranes and geese) and 5.7 kg (13 lb) for the largest mammals taken (i.e. adult marmots and domestic lambs (Ovis aries)). It is known that eastern imperial eagles will also prey upon great bustards (Otis tarda), though the female is possibly taken as she is about as large as a crane or large goose, it is unlikely that the eagle can take the much larger adult males of this huge ground bird, since imperial eagles apparently even avoids adult male birds of much smaller species such as pheasants.
Eastern imperial eagles select broadly overlapping prey with mammalian carnivorans but also fairly regularly attack these as prey. Foxes are widely known in the foods of imperial eagles but at times at visited as carrion. Most attacks on red foxes (Vulpes vulpes) are on juvenile, other than perhaps small females, adults at average weights of up to 6 to 10 kg (13 to 22 lb) in some areas are probably too large for this eagle to overpower. However attacks and successful predation has been committed on adult corsac foxes (Vulpes corsac) as well as probably bengal foxes (Vulpes bengalensis). Beyond small weasels, which are probably no issue for large eagles to attack, larger mustelids may too be attacked including European (Mustela putorius) and steppe polecats (Mustela eversmanii) and stone martens (Martes foina). Small or kitten domestic cats (Felis catus) are sometimes prey for eastern imperial eagles and juvenile Pallas's cats (Otocolobus manul) may too be vulnerable to this eagle.


The eastern imperial eagle is a powerful bird of prey but frequently overlaps in range with multiple other eagle species and that may require them to share both habitats and prey. The golden eagle is generally a larger, more powerful bird. It is also more tends to be a bolder, more aggressive predator than the imperial eagle and may be able to attack much larger prey. While the mean prey body mass relative to the eagle’s weight is probably similar between the two species, an estimated 15% of golden eagle prey will weigh over 5 kg (11 lb). In its very extensive range, the golden eagle’s distribution includes nearly all areas occupied by breeding eastern imperial eagles. Furthermore, there is considerable overlap in prey species selected by these species. There is a natural partitioning between the two Aquila species and that comes in the form of habitat preferences. The golden eagle takes to, usually but not always, rocky and uneven terrain, so favors mountainous areas with alpine meadows to access for prey. This is quite different from the eastern imperial eagle preference for flat or somewhat rolling interface between wood stands and fields at low elevations. However, in some areas, especially eastern Europe, eastern imperial eagles have been driven to higher elevations and more montane habitats that are typically the haunts of golden eagles by persecution, habitat destruction and other interferences by humans, usually with mixed to minor success as the golden species is scarce at best locally and unlikely to produce competition. There is surprisingly little information on conflicts between these two eagle species. In the Naurzum Nature Reserve of Kazakhstan the golden and eastern imperial eagle, and to some extent also both white-tailed eagles and steppe eagles, were recorded nesting with a fairly close proximity to each other. The eagle species here would even use nests built by the other species and seemed to have similar or broadly overlapping food habits, but no interspecies conflicts were detected. On the contrary, in the Altai Republic, it appears that golden and eastern imperial eagles are considered to fill a largely similar ecological niche in abutting areas and do compete for nesting sites. In some cases in Europe, golden and eastern imperial eagles will engage in a territorial display if prompted against one another.
Of a similar distribution to eastern imperial eagles, both in their mid-Eurasian breeding ground and southerly Indo-African wintering grounds, are the steppe eagle and the greater spotted eagle. There is a fair amount of habitat partitioning between the three species, however, with the steppe eagle preferring flat, often almost treeless steppe while the greater spotted eagle prefers more densely wooded and wetter habitats generally than imperial eagles such as taiga bogs. Diet however can overlap considerably, especially with steppe eagles as both it and the imperial species are largely attracted to colonies of ground squirrels in Central Asia. While steppe eagles occur much more broadly in Africa during winter and a similarly narrow extent in the Indian subcontinent as eastern imperials, greater spotted eagles are similarly as rare as imperial eagles in Africa but spread farther in Asia than either the steppe or imperial species. In all three species, by winter they are attracted to more open habitats ranging from savanna to wetlands and even semi-desert. The ecology of wintering eastern imperials was studied at length in Bharatpur district of India in contrast to the steppe and greater spotted eagle as well as the resident Indian spotted eagle and shorter-distance migrant Pallas's fish eagle. It was found that the feeding opportunities sought were largely similar (nestling water birds were often favored) by all five eagle species and that a hierarchy was formed, though each species competed most regularly with others of their own species. The eastern imperial eagle was, by and large, dominant in correspondence to its slightly larger size than the other booted eagles and rivaled the similarly-sized Pallas's fish eagle as the top avian predator in this raptor community. The steppe eagle, despite being only scarcely smaller than an imperial eagle, was usually subordinate to imperial eagles and had a much lower estimated average daily food intake, 141 g (5.0 oz) against an average of 539 g (1.188 lb) for the imperial. However, the mean daily intake of Pallas's fish eagle was slightly higher still at 623 g (1.373 lb) and the fish eagle would perch slightly higher than the imperials as well. In one case, a flock of 9 steppe eagles was able to pirate a freshly caught coot from an imperial eagle. The imperial was the most inactive forager here, having spent 36% of observed hours foraging, against 45% for steppe eagles, 46% for Pallas's fish eagle, 49% for greater spotted eagle and 65% for Indian spotted eagle. Other studies on the interactions of eastern imperial eagles also support that it is dominant during winter over similar species such as steppe and the spotted eagles at competitive feeding spots. In the Korean peninsula, similarly as in the Indian subcontinent, wintering eastern imperial eagles (though rare) can reportedly be seen more than singly concentrated where there are ample numbers of water birds along with other large eagles. Next to nothing is known about the ecology of the rare, seldom-observed wintering population of eastern imperial eagles in east Africa but it is claimed to usually be seen in the company of “other brown eagles”.
As its preferred habitat seldom overlaps with larger eagles such as golden eagles and white-tailed eagles, the eastern imperial eagle is usually the top avian predator in its breeding grounds. In particular, smaller raptors with largely overlapping diets (i.e. ground squirrels, hamsters, voles & lagomorphs) and habitat preferences such as saker falcons (Falco cherrug) and long-legged buzzards (Buteo rufinus) are often at a disadvantage in direct competition with the eagle species. In Slovakia, some pairs of imperial eagle were reported to kleptoparasitize other raptors as a matter of routine. Here, four species consisting of saker falcons, western marsh harrier (Circus aeruginosus), black-winged kite (Elanus caeruleus) and Eurasian sparrowhawk (Accipiter nisus) as well as red foxes were all robbed of their catches with a remarkable degree of success by imperial eagles. The eagles so heavily depleted the falcons catches that the falcons’ nesting attempts failed. A still swifter falcon than the saker, the peregrine falcon (Falco peregrinus) was observed successfully robbing imperial eagles and a few other raptorial birds several times when the species nested near each other in the lower Sakmara river of Russia (although in one case, a juvenile peregrine was killed by the golden eagle it was attempting to rob). Interestingly, many of the imperial eagles kills that were robbed by the peregrines were other species of bird of prey. In Tartarstan, Russia it was found that eastern imperial eagles have begun nesting in atypical habitats and locations, namely the old nests of white-tailed eagles in isolated trees amongst open wetlands and old nests of greater spotted eagle in densely wooded bogs. Despite the remaining presence of both other eagle species in the area, competition is probably not the driver for the imperial eagle altering its nesting habits but instead it is likely due to the heavy human-caused depletion of the imperial eagles preferred prey of ground squirrels and hamsters in the area, with the wetland-located nests putting them close to currently reliable alternate primary foods, mainly water birds.
The eastern imperial eagle may be characterized as an occasional and opportunistic predator of other birds of prey. The following raptorial birds have been known to fall prey this eagle: the lesser spotted eagle (Clanga pomarina), European honey buzzard (Pernis apivorus), black kite (Milvus migrans), hen harrier (Circus cyaneus), Montagu's harrier (Circus pygargus), western marsh harrier, Eurasian sparrowhawk, northern goshawk (Accipiter gentilis), common buzzard (Buteo buteo), long-legged buzzard, rough-legged buzzard (Buteo lagopus), Ural owl (Strix uralensis), tawny owl (Strix alucco), little owl (Athene noctua), long-eared owl (Asio otus), short-eared owl (Asio flammeus), Eurasian hobby (Falco subbuteo), common kestrel (Falco tinnunculus), lesser kestrel (Falco naumanni), merlin (Falco columbarius), red-footed falcon (Falco vespertinus), saker falcon and peregrine falcon. Although it may be classed properly as an apex predator, eastern imperial eagles have fallen prey to other birds of prey on rare occasions. An instance of predation was reportedly committed by a white-tailed eagle. Furthermore, imperial eagles may be vulnerable at their nest to nighttime ambushes by Eurasian eagle-owls (Bubo bubo).


The eastern imperial eagle is a fairly solitary bird, with rarely more than a pair occurring, although some small gatherings recorded at waterholes or food during migrant or winter. Pairs on the breeding grounds engage in aerial displays with loud calling and extensive high circling, which like most of accipitrids is likely for the purposes territorial proclamation to other eagles of their species. The display is often interspersed with mock dives and talon showing. One or both members of a pair may participate in the aerial display. If an interloper does not leave during the first part of the display, the territorial skirmish then may become physical and it sometimes leads to cartwheeling with interlocked talons, falling until they nearly hit the ground. Despite the fairly impressive display, it is generally of slightly shorter duration than the similar one done by golden eagles. In East Thrace, Turkey, the mean nearest nest distance between actively breeding pairs was 10.44 km (6.49 mi). In the Irkutsk Oblast near Lake Baikal, the mean distance of the central area of nests (each pair had more than one nest on territory) was 17 km (11 mi). The breeding season lasts from late March to September throughout the range but in their former range in Pakistan (where it is now extirpated as a breeder) was said to extend from November to April. The pair constructs a very large nest of sticks, which may average up to 1.2 to 1.5 m (3 ft 11 in to 4 ft 11 in) across and 60 to 70 cm (24 to 28 in) in depth. However, nests for the species have been recorded to measure up to 2.4 m (7 ft 10 in) or more across and 1.8 to 2 m (5 ft 11 in to 6 ft 7 in) deep. Nests can outmatch in size those even of larger species such as golden eagles. Nests are frequently lined with various materials, including twigs, grass, fur, debris and greenery. Usually eastern imperial eagles build their nest in tall trees but recorded down to as low as 2 m (6.6 ft) in low scrub or, rarely, on cliff or ground (later as recorded in the Sayan mountains of Kazakhstan). Nest sites have been found anywhere from in the depth of a forest to forest edge to a solitary tree that may be visible for miles in open plains. Nesting sites in both Turkey and Georgia were consistently under 450 m (1,480 ft) elevation. In Georgia, denser mixed forests with openings were favored alternately with more arid, isolated stands of juniper (Juniperus ssp.) and pistachio (Pistacia vera); in Turkey, poplar (Populus ssp.) (44%) and oak (Quercus ssp.) (40%) were favored. In extensive Russian studies, 78% of nests were in conifers when compared with Kazakhstan where deciduous trees are more prevalent, however in the latter country conifers are still used where they are found. Unusual nest sites in agricultural land of Slovakia include one next to a railroad and another next to a busy road. The eastern imperial eagle has also been recorded as nesting on electric poles and towers in Russia and Kazakhstan. In several cases they aggressively took over the nests from steppe eagles that were previously nesting on the electric towers. Often one nest is used but sometimes a 2nd or 3rd is constructed by the imperial eagle pair may exist on a home range.
The mother eastern imperial eagle lays 2 to 3 eggs at intervals of 2 or more days. The average clutch size in Georgia was 2.09. In the Czech Republic, the average clutch size was 2.27. 81 nests from Russia had a mean clutch size of 2.1. Exceptional clutch sizes of up to four eggs have been recorded in Kazakhstan. The eggs are a dull buffish white colour overall and are sparsely marked with grey, purplish or, occasionally, brown spots. A sample of 150 eggs were found to have measured from 63 to 82.5 mm (2.48 to 3.25 in) in height by 52.5 to 62.5 mm (2.07 to 2.46 in), with an average of 73.3 mm × 56.5 mm (2.89 in × 2.22 in). In Georgia, the average dimensions of eggs was measured in a sample of 20 as 72.3 mm × 57.5 mm (2.85 in × 2.26 in) with a mean weight of 136.8 g (4.83 oz). As was recorded in 13 cases in Slovakia, if eggs are lost early into incubation, around March or April, a replacement clutch may be laid, though always the parent eagles used an alternate nest when this occurred. In southeast Europe egg laying peaks at about mid-February to March while in central Asia, it is in first half of April shifting late April further north. The incubation starts with the 1st egg, with males only infrequently taking a shift. The incubation stage lasts for 43 days. In Bulgaria, two females were recorded to do 90.8-94.1% of the incubating. The eaglets hatch at intervals of several days, with one usually being distinctly larger than the rest. However, cases of siblicide are infrequent compared to the golden eagle and, when not interrupted by human interference, prey population crashes and nest collapses, nest frequently bear two fledglings. At 14 days of age, the first feathers through down, while feathers on the back starting at 21 days. Feathers cover the down by 35–40 days but sometimes the down persists about head and neck for up to 45 days. Feathering is complete at 55 days and first flight attempts by 60 days onward. Mostly the female broods the young and male captures prey in this species (as is often the case in booted eagles in which males rarely engage in direct brooding). From when the young are 40 days onward, the female eastern imperial eagle typically resumes hunting and takes to a perch nearby. Male does not appear to bring prey directly to the nest instead to nearby branch for female to dismantle. One or two large prey items last 1–2 days but small prey may require up to 5-6 daily prey deliveries. Fledgling may variously occur at anywhere from 63 to 77 days. After leaving the nest the young linger near it for 2–3 days. Breeding success was once considerable in Russia at about 1.5 young per pair.


Breeding success is somewhat variable in the eastern imperial eagle. In the Czech Republic the 1-3 pairs found to be nesting in 1998-2009 had an average number of 1.53 fledglings. In the Hungarian population, it was recorded that from fewer than one fledgling per pair that average had increased to 1.15 fledglings per pair in 2001-2009. In 2011 in Bulgaria, with a gradual increase of the population to 20 occupied territories, success rate was shown to be about 1 fledgling per pair. By 2014, productivity was reported as averaging similarly at 1.03 fledgling per pair in Bulgaria. In Austria, the average number of fledglings per successful pair was 1.63. Of 27 breeding Austrian breeding attempts, 22 were successful. In East Thrace, Turkey, the breeding success was estimated at 1.01 fledglings per pair. Pairs living in the Marmara region were more productive than those in the Dervent heights (1.05 vs 0.91). Breeding success in Hungary reportedly was driven largely by the  age of the nesting pair, with mature adults more likely to show adaptability to changes in habitat and prey, and secondarily to habitat composition. In particular, nesting success tends to higher in lowland areas against higher elevation nests.  Post-dispersal in Bulgaria, the most significant cause of juvenile mortality per radio-tagging studies was shown to be electrocution (59% of the mortalities), followed by poisoning and shooting. The radio-tracking studies of Bulgarian juveniles showed survival rates were 59.1% in the 1st year of life, 83.3% for the 2nd year, 80% for the 3rd year. Furthermore, 50% of the mortalities of the Bulgarian juveniles occurred in Bulgaria while 43% occurred after they’d migrated to Turkey. Electrocution by collision with power lines are likely major causes of mortality almost throughout the range. Furthermore, other deadly collisions with manmade objects, including automobiles and wind turbines, are also a persistent threat. Like other birds of prey, eastern imperial eagles are occasionally vulnerable to Haematozoa, helminths and viruses as well as maggot infection in a wound by blowflies. Studies to determine if there’s a skewered sex ratio of offspring for eastern imperial eagles in Kazakhstan and secondarily in Serbia determined that the ratio of males to females was nearly equal and stable. For example pairs in the Naurzum Nature Reserve showed during study to produce 123 males and 116 females from 1998-2004. Further study in Kazakhstan showed that adult survivorship was about 84%, which is somewhat low for long-lived raptor, but nonetheless reproductive rate shown to be sufficient to maintain a stable breeding population. While breeding success in areas such as Naurzum reserve may be successful, in non-pristine habitats of Kazakhstan the breeding population may not necessarily be self-sustaining. In Bulgaria, estimates of adult survivorship were from 75 to 94%. Against the overall stability of Kazakhstani imperial eagles and the gradual increased success of European nesting eagles, a rapidly declining population has been noted with alarm, in nearly at the species’ eastern limits as breeder in Lake Baikal. Here fledgling success has decreased from roughly 71% to about 52%.


The eastern imperial eagle has declined greatly through history. At one time, people of eastern Europe and adjacent parts of Russia used to admire and even revere this eagle as a "sacred bird". It was widely referred to as the "cross-bearing eagle" (because of the shape of the white spots on its wings). According to folklore, the imperial eagle was able to divert the hailstorm clouds from the area it inhabited, and it was thus able to save farmers' crops. Therefore, the monarchy of Austria-Hungary once chose the imperial eagle to be its heraldic animal. Despite the historic reverence for the species, it was not spared the negative and hostile view of all birds of prey that arose throughout Europe and its colonies in the 17th century onwards, and the resulting persecution of essentially all birds of prey, including the eastern imperial eagle. However, almost certainly the leading cause of this species' decline was the practice of felling old trees on field boundaries that were the nest sites for the eagle. Among other reasons for its decline were the depletion (both incidental and intentional) of prey species and the incidental consumption by the eagles of poison baits, left out to eliminate wolves. As with other eagles in Eurasia, the Industrial revolution allowed access to poisons and firearms, which made the killing of eagles far easier and hastened their decline. Towards the end of the 19th century, 1824 nests were recorded in Bulgaria, but by 1979 only 5 to 12 pairs remained in the country. Similarly, from a population once numbering in the thousands, the Hungarian population of imperial eagles was driven down to only 10-15 pairs by 1975-1980. In Greece, the eastern imperial eagle was extirpated altogether as a breeding species. While the declines further east in the species range have been less studied, more or less the same threats likely persist throughout the range. Some reserves in central Russia and Kazakhstan have retained semi-stable populations, due in no small part to their isolation. However, the eastern imperial eagle has also been extirpated as a breeding species from Pakistan and Afghanistan.
Today, dedicated conservationists and biologists are working extensively to remediate and reverse the decline of eastern imperial eagle. The species was uplisted to Vulnerable in 1994 and global protection initiatives were begun around this time. By 1996, it was estimated that there were 363-604 pairs in all of Europe (including European Russia). After a couple of decades of recovery efforts, by 2000-2010, the number of breeding pairs in Europe was estimated at up to 1800-2200, a significant increase. Peak numbers in Europe may fall along the European Green Belt. The strongest increases were in Hungary where from 10-15 pairs in the late 1970s an estimated total of 105 nesting pairs by the late 2000s. Conversions and conservation of lowland wildlands, has allowed the numbers of pairs using less ideal mountainous habitat decrease from 50% to 15% of breeding imperials, as they’ve shifted to more ideal lowland habitat. The nation’s imperial eagle population has been continuously protected and monitored since 1975. Further efforts in Hungary were the mitigation of human-eagle conflicts through education in Hungary as poisoning (whether these eagles are the main target or not) continues, as well as general coordination with landowners and agricultural interests as the eastern imperial eagles are often required to forage in such areas. Other increases or returns to former parts of their range include have been noted in the Morava region of southwestern Slovakia as well as some parts of the Czech Republic, Serbia and Austria. However, overall 85% of the population in the Carpathian mountains region that forms the bulk of the land in eastern Europe was restricted to the Great Hungarian Plain, and were isolated from other populations. In Slovakia, the gap in the distribution in the Carpathian basin has led to concern about genetic isolation. Upon review, the genetic isolation of the two Slovakian populations was determined to be "marginally significant". The number of pairs of eastern imperial eagles increased in Bulgaria from 20 in 2009 to 24 in 2013. Among the efforts untaken to restore the Bulgarian populations were mitigating hazardous electrical poles, 608 were insulated within eagle territories, while also 483 supplemental feedings were given to 14 pairs from October to March. In Turkey, the number of imperial eagle pairs in recent estimates during the 21st century was widely placed at 35-150 pairs, probably closer to the higher number as there is evidence for there being 30-50 pairs in the East Thrace region alone.
In some areas of western Russia and in Kazakhstan, the eastern imperial eagle has maintained the nearest thing to a population stronghold. In 2011, the total estimated number of pairs was estimated at 3000-3500 in Russia and 3500-4000 in Kazakhstan. Though only 1534 breeding territories found firsthand, only some parts of the range were surveyed. According to Russian and Kazakh studies, cattle grazing in taiga forest edge appeared to benefit imperial eagles since they encourage habitat for prey, especially ground squirrels. In Kazakhstan moister conditions, possibly correlated with climate change seems to have increased populations of yellow ground squirrels and 2nd growth trees which both are likely to have caused a localized increase there. In Naurzum Nature Reserve alone nearly 300 imperial eagles may congregate in winter, making it a “critical refugium” for this species. On the other hand, precipitous decline has been detected in the Lake Baikal region of Russia and the species may be on its way to local extinction there. In the 1950s, imperial eagle pairs in the Baikal area numbered 250-300 strong. A strong decline was already noted by the mid-1980s when 150-200 pairs remained. However, the reduction hastened even more to merely 70 pairs in 1999. The Baikal imperial eagles during monitoring from 1950 to 1999 showed no overall changes in habitat or pair occupancy. In the 1998-1999 period, fledgling success was also found to drop considerably. Satellite study of migrating birds from Lake Baikal at migration stopovers and winter sites was reviewed but only 4 eagles were studied so results could not clearly determine whether depletions were mostly occurring at this time rather than during breeding. The reason for the sharp declines of the Baikal imperial eagles are not fully understood but are likely correlated with habitat destruction and human land use changes followed by pesticide use and other toxic threats through bioaccumulation. Reductions have also been reported in the lower Ural mountains region of Russia with largely similar threats but it is not known what the exact rate of reduction is here. Although gone from Pakistan as a breeding species, it continues to be a key wintering site as around 150 eagles are estimated to winter in Pakistan.


The  steppe eagle (Aquila nipalensis) is a large bird of prey. Like all eagles, it belongs to the family Accipitridae. The steppe eagle's well-feathered legs illustrate it to be a member of the subfamily Aquilinae, also known as the "booted eagles". This species was once considered to be closely related to the non-migratory tawny eagle (Aquila rapax) and the two forms have previously been treated as conspecific. They were split based on pronounced differences in morphology and anatomy; two molecular studies, each based on a very small number of genes, indicate that the species are distinct but disagree over how closely related they are.
The steppe eagle is in many ways a peculiar species of eagle. It is a specialized predator of ground squirrels on the breeding ground, also taking other rather small mammals and other prey, doing so more often when ground squirrels are less consistently found. In rather treeless areas of the steppe habitats, these eagles tend to nest on a slightly rise, often on or near an outcrop, but may even the flat, wide-open ground, in a rather flat nest. They are the only eagle to nest primarily on the ground. Usually one to three eggs are laid and, in successful nests, one to two young eagles fledge. The steppe eagle undertakes a massive migration from essentially its entire breeding range, moving en masse past major migration flyways, especially those of the Middle East, Red Sea and the Himalayas. In winter, though less closely studied than during breeding, the steppe eagle is remarkable for its sluggish and almost passive feeding ecology, focusing on insect swarms, landfills, carrion and the semi-altricial young of assorted animals, lacking the bold and predatory demeanor of their cousin species. Although still seen by the thousands at migration sites in larger numbers than other migrating eagles of these areas, the steppe eagle's entire population has declined precipitously. The threats to this species consist of increasing steppe fires and pests around the nests (both probably increased by the warming climate) which can cause a large volume of nest failures. Rivaling these factors, declines are being exacerbated by disturbance and persecution via humans, as well  trampling of nests by livestock. Free-flying steppe eagles are also being killed in alarmingly large numbers, especially in the stronghold nation for breeding of Kazakhstan, by electrocutions on dangerous electricial wires and pylons. Due to these and other reasons, the decline of the species is thought to be considerably in excess of 50%. Therefore, the species is considered to be endangered by the IUCN. The steppe eagle appears on the flag of Kazakhstan and is the national bird of both Kazakhstan and Egypt.


British naturalist Brian Houghton Hodgson described the steppe eagle in 1833. Aquila is Latin for "eagle" while nipalensis means "from Nepal" based on the location where the type specimen was collected presumably while migrating. Samuel G. Gmelin however described a species of eagle from Tanais where they were found sitting on ancient mounds or graves of nomads. He called it Aquila mogilnik, the species name "mogilnik" meaning burial in Russian. This was included in the 13th edition of Systema Naturae by his cousin J.F. Gmelin in 1788. The identity of this bird was however confused with A. heliaca but research in 2019 suggests that A. mogilnik can reliably be identified and that it would have been a valid senior name for A. nipalensis had it not been declared as a nomen dubium, a doubtful name by Ernst Hartert in 1914. The lack of usage of the name in literature now makes the name nomen oblitum, a valid senior name lost by disuse. The steppe eagle is a member of the booted eagle subfamily within the Accipitridae family. The booted eagle clan are monophyletic and study of karyotypes has indicated that they likely have few to no close external relations within the overall extant accipitrid family. The booted eagle subfamily all have feathers covering their legs and may be found to some extent on every continent that contains accipitrids. The genus Aquila has been thought to traditionally composed of by large and fairly dark eagles that generally habituate to various open habitats. However, a significant division was determined to exist between superficially similar eagles such as the golden eagle (Aquila chrysaetos) and its three extant and similar-looking close cousins, as well as three very different smaller and pale-bellied eagles (the Bonelli's, African hawk- and Cassin's hawk-eagles) and the species complex which contains the steppe eagle. There is a similar genetic disparity with the golden eagle for the steppe eagle as with the spotted eagles which have been deemed distinct enough to form a separate genus, Clanga. The steppe eagle genetically clusters closely to the tawny eagle as well as, albeit more distantly, with the eastern (Aquila heliaca) and Spanish imperial eagles (Aquila adalberti). However, the loci evidenced in the Aquila genera have been found to be relatively homogenous, with general studies of isoenzymes showing their genes as about ten times less distanced than certain owl genera.
The steppe eagle has historically been considered conspecific with the tawny eagle, even until as recently as 1991. The latter species resides year-round in the African and Asian areas often used seasonally as wintering grounds by steppe eagle. The species were ultimately separated on the grounds of the differences in morphology, disparate coloring, distinct life histories and behaviours. Testing of genetic materials has reinforced the species distinction of the steppe and tawny eagles. Genetically, the steppe eagle is thought to be basal to related species such as the tawny and imperial eagles. A fossil species, Aquila nipaloides, has been found in Italy, Corsica, Sardinia and France and was hypothesized to most closely related to the steppe eagle based on osteology of the ramus (although did evidence some differences in leg morphology). Despite being even more strongly distinctive from the steppe eagle than the tawny eagle, the eastern imperial eagle has been seen to hybridize with the steppe eagles in the wild, once in Turkey and at least three times in Kazakhstan. Each hybrid with imperial eagles has been known to involve pairs of subadult or juvenile eagles and all known hybrid pairings were between male steppe eagles (or apparent steppe-imperial hybrids themselves) mated to female imperial eagles. Some of these hybrid pairs also produced seemingly healthy young with roughly intermediate characteristics.
The steppe eagle has been generally considered to contain two subspecies. One was the nominate subspecies, A. n. nipalensis, which breeds in the eastern portions of the range (perhaps from the East Kazakhstan Region to all points east) while the western breeding population, found in most of Kazakhstan and European Russia, was considered as the subspecies, A. n. orientalis. The separation of two subspecies was largely based on size, with the eastern population being larger and much heavier than the western eagles. The more eastern birds tend to be a shade darker and a have a more extensive nape patch, as well as having a more conspicuously deep gape-line. However, both western and Russian researchers have since made a convincing advocacy that the steppe eagle is actually a monotypical species. It was found that both previously claimed subspecies appear to broadly overlap in the breeding range and become indistinguishable at the Kazakh-Russian meeting point. The primary differences, i.e. in size and mildly in colour, can be explained as clinal variations due to the environment. The breeding populations of the eastern and western eagles are insufficiently allopatric and too extensively engage in introgression to be properly regarded as full subspecies. Erroneously, a checklist once included the former subspecies of A. n. orientalis as being part of the subspecies of tawny eagle from Asia, A. r. vindhiana, an error that was later corrected.