HOME

TheInfoList



OR:

The eastern imperial eagle (''Aquila heliaca'') is a large bird of prey that breeds in
southeastern Europe Southeast Europe or Southeastern Europe (SEE) is a geographical subregion of Europe, consisting primarily of the Balkans. Sovereign states and territories that are included in the region are Albania, Bosnia and Herzegovina, Bulgaria, Croatia (a ...
and extensively through West and
Central Asia Central Asia, also known as Middle Asia, is a region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes the fo ...
. Most populations are migratory and winter in northeastern
Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
, the
Middle East The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
and
South South is one of the cardinal directions or compass points. The direction is the opposite of north and is perpendicular to both east and west. Etymology The word ''south'' comes from Old English ''sūþ'', from earlier Proto-Germanic ''*sunþa ...
and
East Asia East Asia is the eastern region of Asia, which is defined in both geographical and ethno-cultural terms. The modern states of East Asia include China, Japan, Mongolia, North Korea, South Korea, and Taiwan. China, North Korea, South Korea ...
. Like all
eagle Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, j ...
s, 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.Forsman, D. (1999). ''The raptors of Europe and the Middle East: a handbook of field identification''. London: T & AD Poyser. This is an opportunistic predator that mostly selects smallish
mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur ...
s as prey but also a fairly large proportion of
bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...
s,
reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates ( lizards and snakes) and rhynchocephalia ...
and other prey types, including
carrion Carrion () is the decaying flesh of dead animals, including human flesh. Overview Carrion is an important food source for large carnivores and omnivores in most ecosystems. Examples of carrion-eaters (or scavengers) include crows, vultures ...
. 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 In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate gras ...
. 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 List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biolo ...
ed as Vulnerable since 1994.


Taxonomy

The eastern imperial eagle is a member of the Aquilinae or booted eagles, a rather
monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...
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 Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelag ...
and
Africa Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
(with one in
North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
and a couple in
Australasia Australasia is a region that comprises Australia, New Zealand and some neighbouring islands in the Pacific Ocean. The term is used in a number of different contexts, including geopolitically, physiogeographically, philologically, and ecologic ...
).Lerner, H., Christidis, L., Gamauf, A., Griffiths, C., Haring, E., Huddleston, C.J., Kabra, S., Kocum, A., Krosby, M., Kvaloy, K., Mindell, D., Rasmussen, P., Rov, N., Wadleigh, R., Wink, M. & Gjershaug, J.O. (2017). ''Phylogeny and new taxonomy of the Booted Eagles (Accipitriformes: Aquilinae)''. Zootaxa, 4216(4), 301-320. 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 The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known bird ...
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 The Bonelli's eagle (''Aquila fasciata'') is a large bird of prey. The common name of the bird commemorates the Italian ornithologist and collector Franco Andrea Bonelli. Bonelli is credited with gathering the type specimen, most likely from an ...
(''Aquila fasicata''). The Spanish imperial eagle, which is found in
Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...
and
Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of th ...
, 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 Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overl ...
and molecular characteristics. It is likely that the eastern imperial eagle is the
paraspecies A paraspecies (a paraphyletic species) is a species, living or fossil, that gave rise to one or more daughter species without itself becoming extinct. Geographically widespread species that have given rise to one or more daughter species as periphe ...
for the Spanish imperial eagle and that the imperial eagle complex reached the
Iberian peninsula The Iberian Peninsula (), ** * Aragonese and Occitan: ''Peninsula Iberica'' ** ** * french: Péninsule Ibérique * mwl, Península Eibérica * eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, def ...
sometimes between the late
Pleistocene era The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...
and early
Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...
. The Spanish imperial eagle may be considered an ice age relict due to its isolation.


Description

The eastern imperial eagle is a large
eagle Eagle is the common name for many large birds of prey of the family Accipitridae. Eagles belong to several groups of genera, some of which are closely related. Most of the 68 species of eagle are from Eurasia and Africa. Outside this area, j ...
, but usually falls near the average size of the large-bodied genus '' Aquila''. Adult total length can range from with a typical wingspan of . The average wingspan of a small sample showed males to average while a small sample of females averaged .Brown, Leslie and Amadon, Dean (1986) ''Eagles, Hawks and Falcons of the World''. The Wellfleet Press. . 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.Katzner, T. E., Jackson, D. S., Ivy, J., Bragin, E. A., & DeWoody, A. (2014). ''Variation in offspring sex ratio of a long‐lived sexually dimorphic raptor, the Eastern Imperial Eagle Aquila heliaca''. Ibis, 156(2), 395-403. In terms of body mass, one survey found five males to weigh from and five females to weigh from . The average weight of this sample of imperial eagles was reportedly in the males and in the females.''CRC Handbook of Avian Body Masses, 2nd Edition'' by John B. Dunning Jr. (Editor). CRC Press (2008), . A sample of unknown size showed males to weigh an average while females reportedly weighed an average of .Kirmse, W. (1998). ''Morphometric features characterizing flight properties of palearctic eagles''. Holarctic Birds of Prey. Merida and Berlin: ADENEX and World Working Group on Birds of Prey, 339-348. A further two mature females weighed an average of . Among standard measurements, males may range in wing chord length from , in
tail The tail is the section at the rear end of certain kinds of animals’ bodies; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammal ...
length from and in tarsus length from . Meanwhile, females may range in wing chord length from , in tail length from and in tarsus length from . A sample of imperial eagles ranged in total bill length from . 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 Tar is a dark brown or black viscous liquid of hydrocarbons and free carbon, obtained from a wide variety of organic materials through destructive distillation. Tar can be produced from coal, wood, petroleum, or peat. "a dark brown or black bi ...
-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.Clark, W. S. (1999). ''A field guide to the raptors of Europe, the Middle East, and North Africa''. Oxford University Press, USA.Forsman, D. (2005). ''Eastern Imperial Eagle plumages''. Alula, 11: 146-152. At rest, the wing tips tend to reach the tail tip.Naoroji, R., & Schmitt, N. J. (2007). ''Birds of prey of the Indian subcontinent''. Om Books International. 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.Bijleveld, M. (1974). ''Birds of prey in Europe''. Macmillan International Higher Education. 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.Porter, R. F. (1981). ''Flight identification of European raptors''. A&C Black.Forsman, D. (2016). ''
Flight Identification of Raptors of Europe, North Africa and the Middle East ''Flight Identification of Raptors of Europe, North Africa and the Middle East'' is a 2016 field guide by Dick Forsman, a Finnish ornithologist, with the purpose of helping the reader identify raptors (that is, birds of prey), in flight. It is p ...
''. Bloomsbury Publishing.
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.


Confusion of species

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 The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known bird ...
(''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 in hallux claw length while a male was about , whereas the smallest talon measured for an immature male American golden eagle was . 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 The booted eagle (''Hieraaetus pennatus'', also classified as ''Aquila pennata'') is a medium-sized mostly migratory bird of prey with a wide distribution in the Palearctic and southern Asia, wintering in the tropics of Africa and Asia, with a ...
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 Flight feathers (''Pennae volatus'') are the long, stiff, asymmetrically shaped, but symmetrically paired pennaceous feathers on the wings or tail of a bird; those on the wings are called remiges (), singular remex (), while those on the tail ...
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 similar 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 The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known bird ...
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 Verreaux's eagle (''Aquila verreauxii'') is a large, mostly African, bird of prey. It is also called the black eagle, especially in southern Africa, not to be confused with the Indian black eagle (''Ictinaetus malayensis''), which lives far to ...
(''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 Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...
, 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 The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
(''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.


Vocalizations

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 The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known bird ...
, 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 A frog is any member of a diverse and largely Carnivore, carnivorous group of short-bodied, tailless amphibians composing the order (biology), order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-f ...
.Gould, J., & Rutgers, A. (1966). ''Birds of Europe (Vol. 1)''. Methuen. 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.


Distribution and habitat


Breeding range

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 Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...
, eastern
Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
,
Slovakia Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the ...
,
Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Cr ...
, eastern
Croatia , image_flag = Flag of Croatia.svg , image_coat = Coat of arms of Croatia.svg , anthem = " Lijepa naša domovino"("Our Beautiful Homeland") , image_map = , map_caption = , capi ...
,
Serbia Serbia (, ; Serbian: , , ), officially the Republic of Serbia ( Serbian: , , ), is a landlocked country in Southeastern and Central Europe, situated at the crossroads of the Pannonian Basin and the Balkans. It shares land borders with Hu ...
, northeastern
Bosnia and Herzegovina Bosnia and Herzegovina ( sh, / , ), abbreviated BiH () or B&H, sometimes called Bosnia–Herzegovina and often known informally as Bosnia, is a country at the crossroads of south and southeast Europe, located in the Balkans. Bosnia and ...
, Macedonia,
Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedo ...
,
Romania Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...
,
Moldova Moldova ( , ; ), officially the Republic of Moldova ( ro, Republica Moldova), is a landlocked country in Eastern Europe. It is bordered by Romania to the west and Ukraine to the north, east, and south. The unrecognised state of Transnistri ...
and northern, western and much of the eastern part of the
Ukraine Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inva ...
.Michev, T., & Petrov, T. (1979). ''On the distribution of the Imperial Eagle. Aquila heliaca''. 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 North Caucasian Federal District (russian: Се́веро-Кавка́зский федера́льный о́круг, ''Severo-Kavkazsky federalny okrug'') is one of the eight federal districts of Russia. It is located in extreme southern Ru ...
, most of the
Volga The Volga (; russian: Во́лга, a=Ru-Волга.ogg, p=ˈvoɫɡə) is the longest river in Europe. Situated in Russia, it flows through Central Russia to Southern Russia and into the Caspian Sea. The Volga has a length of , and a catch ...
and Ural Federal Districts (excluding the northern parts), and the southern part of
Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part ...
past
Lake Baikal Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the ...
to the Transbaikalia in the landlocked southwest of the
Russian Far East The Russian Far East (russian: Дальний Восток России, r=Dal'niy Vostok Rossii, p=ˈdalʲnʲɪj vɐˈstok rɐˈsʲiɪ) is a region in Northeast Asia. It is the easternmost part of Russia and the Asian continent; and is admin ...
.Karyakin, I. V., Nikolenko, E. N., Levin, A. S., & Kovalenko, A. V. (2011). ''Eastern Imperial Eagle in Russia and Kazakhstan: population status and trends''. Acta zool. bulg., Suppl, 3, 95-104. Out of Russia, their breeding extends south to mostly the northern portions of the following nations:
Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...
,
Armenia Armenia (), , group=pron officially the Republic of Armenia,, is a landlocked country in the Armenian Highlands of Western Asia.The UNbr>classification of world regions places Armenia in Western Asia; the CIA World Factbook , , and ''O ...
,
Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...
,
Turkmenistan Turkmenistan ( or ; tk, Türkmenistan / Түркменистан, ) is a country located in Central Asia, bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the s ...
,
Uzbekistan Uzbekistan (, ; uz, Ozbekiston, italic=yes / , ; russian: Узбекистан), officially the Republic of Uzbekistan ( uz, Ozbekiston Respublikasi, italic=yes / ; russian: Республика Узбекистан), is a doubly landlocked co ...
, much of
Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
, northwestern
China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...
(
Xinjiang Xinjiang, SASM/GNC: ''Xinjang''; zh, c=, p=Xīnjiāng; formerly romanized as Sinkiang (, ), officially the Xinjiang Uygur Autonomous Region (XUAR), is an autonomous region of the People's Republic of China (PRC), located in the northwes ...
) and northern
Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million ...
.Bukreev, A., Boldbataar, S. & Zvonov, B.M. (2010). ''The Imperial Eagle in Mongolia''. Raptors Conservation, 20: 186-194. Isolated populations also persist in northwestern, central and eastern
Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...
,
Cyprus Cyprus ; tr, Kıbrıs (), officially the Republic of Cyprus,, , lit: Republic of Cyprus is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. Its continental position is disputed; while it is ...
, and northern
Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
. As a breeding species, they are probably extirpated from
Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is borde ...
and
Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
.Turan, L. (2005). ''The status of diurnal birds of prey in Turkey''. J. Raptor Res, 39(1), 36-54.


Migration and wintering range

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 Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million ...
. In
Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedo ...
, of three post dispersal juveniles, two wandering within the country and only one migrated a long distance to
Israel Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
. 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.Domashevsk,y S.V. (2002). '' bservations of the migration of birds of prey in the Crimea'. Berkut, 11: 112-116. 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 The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
down to
Yemen Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the north and Oman to the northeast and ...
, with pockets of wintering eagles in Israel, northern
Jordan Jordan ( ar, الأردن; tr. ' ), officially the Hashemite Kingdom of Jordan,; tr. ' is a country in Western Asia. It is situated at the crossroads of Asia, Africa, and Europe, within the Levant region, on the East Bank of the Jordan Rive ...
, central
Saudi Arabia Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in Western Asia. It covers the bulk of the Arabian Peninsula, and has a land area of about , making it the fifth-largest country in Asia, the second-largest in the Ara ...
,
Kuwait Kuwait (; ar, الكويت ', or ), officially the State of Kuwait ( ar, دولة الكويت '), is a country in Western Asia. It is situated in the northern edge of Eastern Arabia at the tip of the Persian Gulf, bordering Iraq to Iraq–Ku ...
, northeastern
Iraq Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq ...
and adjacent southwestern
Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
. A radio-tagging study of a few wintering eagles in
Arabia The Arabian Peninsula, (; ar, شِبْهُ الْجَزِيرَةِ الْعَرَبِيَّة, , "Arabian Peninsula" or , , "Island of the Arabs") or Arabia, is a peninsula of Western Asia, situated northeast of Africa on the Arabian Pl ...
found they returned variously to
Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...
in four cases and Kazkhstan and
China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...
in a single case, with a range of ground covered in spring migration of . The eastern imperial eagle winters locally and in quite small numbers in Africa’s
Nile valley The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest riv ...
, mostly being reported in southern
Sudan Sudan ( or ; ar, السودان, as-Sūdān, officially the Republic of the Sudan ( ar, جمهورية السودان, link=no, Jumhūriyyat as-Sūdān), is a country in Northeast Africa. It shares borders with the Central African Republic t ...
, central
Ethiopia Ethiopia, , om, Itiyoophiyaa, so, Itoobiya, ti, ኢትዮጵያ, Ítiyop'iya, aa, Itiyoppiya officially the Federal Democratic Republic of Ethiopia, is a landlocked country in the Horn of Africa. It shares borders with Eritrea to the ...
and northern
Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...
, irregularly down as far as southern
Kenya ) , national_anthem = " Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...
and once even northern
Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...
.Kemp, A., & Kemp, M. (2006). ''Sasol Birds of Prey; New Edition''. Struik. Most migrants to Africa apparently originate in the western part of the breeding range such as
Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...
. Further east, such as the imperial eagles that breed around
Lake Baikal Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the ...
, will generally migrate to
south Asia South Asia is the southern subregion of Asia, which is defined in both geographical and ethno-cultural terms. The region consists of the countries of Afghanistan, Bangladesh, Bhutan, India, Maldives, Nepal, Pakistan, and Sri Lanka.;;;;; ...
. Moderate to quite low numbers are usually noted of this species at migration sites in the
Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 10 ...
. The eastern imperial eagle winters fairly broadly in the
Indian subcontinent The Indian subcontinent is a physiographical region in Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian Ocean from the Himalayas. Geopolitically, it includes the countries of Bangladesh, Bhutan, In ...
, from eastern
Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
, eastward through southern
Nepal Nepal (; ne, नेपाल ), formerly the Federal Democratic Republic of Nepal ( ne, सङ्घीय लोकतान्त्रिक गणतन्त्र नेपाल ), is a landlocked country in South Asia. It is ma ...
to
Bangladesh Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mo ...
and down as far south in
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...
as the states of
Gujarat Gujarat (, ) is a state along the western coast of India. Its coastline of about is the longest in the country, most of which lies on the Kathiawar peninsula. Gujarat is the fifth-largest Indian state by area, covering some ; and the ninth ...
,
Madhya Pradesh Madhya Pradesh (, ; meaning 'central province') is a state in central India. Its capital is Bhopal, and the largest city is Indore, with Jabalpur, Ujjain, Gwalior, Sagar, and Rewa being the other major cities. Madhya Pradesh is the second ...
,
Bihar Bihar (; ) is a state in eastern India. It is the 2nd largest state by population in 2019, 12th largest by area of , and 14th largest by GDP in 2021. Bihar borders Uttar Pradesh to its west, Nepal to the north, the northern part of West ...
and northwestern
Jharkhand Jharkhand (; ; ) is a state in eastern India. The state shares its border with the states of West Bengal to the east, Chhattisgarh to the west, Uttar Pradesh to the northwest, Bihar to the north and Odisha to the south. It has an area of . I ...
. Other semi-regular wintering areas include southern
Bhutan Bhutan (; dz, འབྲུག་ཡུལ་, Druk Yul ), officially the Kingdom of Bhutan,), is a landlocked country in South Asia. It is situated in the Eastern Himalayas, between China in the north and India in the south. A mountainou ...
,
Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...
and north
Indochina Mainland Southeast Asia, also known as the Indochinese Peninsula or Indochina, is the continental portion of Southeast Asia. It lies east of the Indian subcontinent and south of Mainland China and is bordered by the Indian Ocean to the west an ...
(recorded across Chinese border in southwestern
Yunnan Yunnan , () is a landlocked province in the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is Kunming. The province borders the ...
) and spottily in
east China East China () is a geographical and a loosely defined cultural region that covers the eastern coastal area of China. A concept abolished in 1978, for economical purposes the region was defined from 1949 to 1961 by the Chinese Central Governme ...
where wildlands still occur. Occasionally, wintering birds are known to occur in the central
Cambodia Cambodia (; also Kampuchea ; km, កម្ពុជា, UNGEGN: ), officially the Kingdom of Cambodia, is a country located in the southern portion of the Indochinese Peninsula in Southeast Asia, spanning an area of , bordered by Thailand ...
and discontinuously in
Laos Laos (, ''Lāo'' )), officially the Lao People's Democratic Republic ( Lao: ສາທາລະນະລັດ ປະຊາທິປະໄຕ ປະຊາຊົນລາວ, French: République démocratique populaire lao), is a socialist s ...
and
Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making ...
as well as in the
Korean peninsula Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic ...
,
Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the no ...
and southern
Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...
(mostly
Honshu , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island s ...
). Vagrants have been reported in over 20 countries, mainly in Europe, including
Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populou ...
,
Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic countries, Nordic c ...
,
Denmark ) , song = ( en, "King Christian stood by the lofty mast") , song_type = National and royal anthem , image_map = EU-Denmark.svg , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of Denmark , establish ...
,
Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...
and
Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...
.


Habitat

The eastern imperial eagle is distributed as a breeding species largely along the southern edge of the vast
taiga Taiga (; rus, тайга́, p=tɐjˈɡa; relates to Mongolic and Turkic languages), generally referred to in North America as a boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, sp ...
forests. The habitat preferred by the species is often rather open country with
scattered trees Scattered Trees was an American indie rock band from Chicago, Illinois. The band was on the Roll Call/EMI label before their breakup in 2012. Career Scattered Trees began as a solo project for frontman Nate Eiesland, who moved from Brainerd, MN ...
or more enclosed woodlands, as well as around or near
wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes prevailing, especially in t ...
s. The imperial eagle often forages mainly in open areas, extending to beyond typical assorted
grassland A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...
s to wetlands and agricultural areas. In more extensive wooded areas, eastern imperial eagles require glades or
meadow A meadow ( ) is an open habitat, or field, vegetated by grasses, herbs, and other non- woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows may be naturally occurring or arti ...
s in order to executive hunting. The central part of their range as a breeding species occurs in vast areas of
steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate gras ...
and here the species often inhabits forest-steppe mosaics, as well as open woodlands,
river valleys A valley is an elongated low area often running between Hill, hills or Mountain, mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers ...
and even agricultural areas with trees or wooded patches. Lowland areas tend to be preferred, albeit not exclusively.Sanchez-Zapata, J. A., Carrete, M., Gravilov, A., Sklyarenko, S., Ceballos, O., Donazar, J. A., & Hiraldo, F. (2003). ''Land use changes and raptor conservation in steppe habitats of Eastern Kazakhstan''. Biological Conservation, 111(1), 71-77.Fefelov, I. V. (2004). ''Observations on the nesting of Imperial Eagle Aquila heliaca in the Kuitun-Zima steppe area, Baikal region, Russia''. Forktail., (20), 145. In
Turkestan Turkestan, also spelled Turkistan ( fa, ترکستان, Torkestân, lit=Land of the Turks), is a historical region in Central Asia corresponding to the regions of Transoxiana and Xinjiang. Overview Known as Turan to the Persians, western Turk ...
and Kazakhstan, they may extend their breeding habitat into
semi-desert A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi ...
. True
desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...
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
mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher ...
s and montane steppe and
meadow A meadow ( ) is an open habitat, or field, vegetated by grasses, herbs, and other non- woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows may be naturally occurring or arti ...
land. In Europe at least, this is due to human pressures, which caused them to abandon open lowlands, timbered
plain In geography, a plain is a flat expanse of land that generally does not change much in elevation, and is primarily treeless. Plains occur as lowlands along valleys or at the base of mountains, as coastal plains, and as plateaus or uplands ...
s and river-fringed forests for forested, precipitous uplands. A slow repopulation of their preferred lowlands reported since 1990s in
Slovakia Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the ...
and
Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Cr ...
.Horváth, M., Szitta, T., Fatér, I., Kovács, A., Demeter, I., Firmánszky, G., & Bagyura, J. (2011). ''Population dynamics of the Eastern Imperial Eagle (Aquila heliaca) in Hungary between 2001 and 2009''. Acta Zoologica Bulgarica Suppl, 3, 61-70. Often, eastern imperial eagles winter in more open habitats such as nearly continuous
grassland A grassland is an area where the vegetation is dominated by grasses ( Poaceae). However, sedge ( Cyperaceae) and rush ( Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur na ...
, plains,
semi-desert A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi ...
and cultivation with scattered trees as well as various
marsh A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found ...
es,
lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...
s and other
wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes prevailing, especially in t ...
s. The species resides mainly from sea level to , locally to , and has been recorded on passage at in Asia.


Dietary biology

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 Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
.Horváth, M., Solti, B., Fatér, I., Juhász, T., Haraszthy, L., Szitta, T., Bállok, Z. & Pásztory-Kovács, S. (2018). ''Temporal changes in the diet composition of the Eastern Imperial Eagle (Aquila heliaca) in Hungary''. Ornis Hungarica, 26(1), 1-26. 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
insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...
s 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 The common buzzard (''Buteo buteo'') is a medium-to-large bird of prey which has a large range. A member of the genus '' Buteo'', it is a member of the family Accipitridae. The species lives in most of Europe and extends its breeding range acr ...
(''Buteo buteo'') which may be 500 times more numerous overall.Katzner, T. E., Bragin, E. A., Knick, S. T., & Smith, A. T. (2006). ''Spatial structure in the diet of imperial eagles Aquila heliaca in Kazakhstan''. Journal of Avian Biology, 37(6), 594-600. In the nations of
Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
and
Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Cr ...
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
hare Hares and jackrabbits are mammals belonging to the genus ''Lepus''. They are herbivores, and live solitarily or in pairs. They nest in slight depressions called forms, and their young are able to fend for themselves shortly after birth. The g ...
s, various
rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...
s, especially ground squirrels, hamsters and
vole Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of lo ...
s, 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.
Reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates ( lizards and snakes) and rhynchocephalia ...
s are taken secondarily in most of the range but can be locally somewhat important and
fish Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...
and
invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...
s, including
insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...
s, 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
hare Hares and jackrabbits are mammals belonging to the genus ''Lepus''. They are herbivores, and live solitarily or in pairs. They nest in slight depressions called forms, and their young are able to fend for themselves shortly after birth. The g ...
s or hedgehogs appear to take the primary position in recent studies. The largest European dietary study to date, a multi-year analysis from
Hungary Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Cr ...
, 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 The European hamster (''Cricetus cricetus''), also known as the Eurasian hamster, black-bellied hamster or common hamster, is the monotypic, only species of hamster in the genus ''Cricetus''. It is native to grassland and similar habitats in a ...
(''Cricetus cricetus''), at 12.71% of the diet. Similarly, in
Slovakia Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the ...
and the
Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
, 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.Chavko, J., Danko, Š., Obuch, J., & Mihók, J. (2007). ''The food of the Imperial Eagle (Aquila heliaca) in Slovakia''. Slovak Raptor Journal, 1, 1-18.Horal, D. (2011). ''Eastern imperial eagle (Aquila heliaca) in the Czech Republic''. Acta Zoologica Bulgarica, 63, 55-59. 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.Haraszthy, L., Bagyura, J., Szitta, T., Petrovics, Z., & Viszló, L. (1996). ''Biology, status and conservation of the Imperial Eagle Aquila heliaca in Hungary''. Eagle Studies, 425-427. It is possible with reintroductions of the European ground squirrel underway in
central Europe Central Europe is an area of Europe between Western Europe and Eastern Europe, based on a common historical, social and cultural identity. The Thirty Years' War (1618–1648) between Catholicism and Protestantism significantly shaped the a ...
, 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.Karyakin, I.V. (2010). ''The Imperial Eagle is a Vanishing Species in the Tyva Republic, Russia''. Raptor Conservation, 20: 177-185. In studies of two different areas of
Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedo ...
, 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.Marin, S. A., Ivanov, I. I., Georgiev, D. G., & Boev, Z. N. (2004). ''On the food of the imperial eagle Aquila heliaca on Sakar Mountain and Dervent Heights, Bulgaria''. Raptors Worldwide, 589-592. In
East Thrace East Thrace or Eastern Thrace ( tr, Doğu Trakya or simply ''Trakya''; el, Ανατολική Θράκη, ''Anatoliki Thraki''; bg, Източна Тракия, ''Iztochna Trakiya''), also known as Turkish Thrace or European Turkey, is the pa ...
,
Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...
, the same hedgehog was the most important prey, comprising 23.1% of 582 prey items and 21.2% of the prey biomass.Demerdzhiev, D., Dobrev, D., Stoychev, S., Terziev, N., Spasov, S., & Boev, Z. (2014). ''Distribution, abundance, breeding parameters, threats and prey preferences of the eastern imperial eagle (Aquila heliaca) in European Turkey''. Slovak Raptor Journal, 8 (1). In warmer, southerly areas, the primary prey species seem to generally be smaller. In
Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...
, social voles (''Microtus socialis'') were the primary food, comprising about 15% of 341 prey items.Abuladze, A. (1996). ''Ecology of the imperial eagle Aquila heliaca in Georgia''. Eagle Studies, 447-457. For wintering imperial eagles, the most frequent live prey (though carrion was mainly eaten) was Sundevall's jird (''Meriones crassus'').Al Hasani, I. K., Azar, J. F., Nishimura, K., Amr, Z. S., & Katzner, T. E. (2012). ''Distribution, diet and winter ecology of the Imperial Eagle Aquila heliaca in Jordan''. VERTEBRATE ZOOLOGY, 62(2), 273-280. Both of these small rodents probably average only about in body mass. Numerous other small mammals may also be occasionally taken including several species each of hedgehogs,
shrew Shrews (family Soricidae) are small mole-like mammals classified in the order Eulipotyphla. True shrews are not to be confused with treeshrews, otter shrews, elephant shrews, West Indies shrews, or marsupial shrews, which belong to differ ...
s 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
vole Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of lo ...
s), 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.Zhelev, P. V., Gradev, G. Z., Ivanov, I. I., & Georgiev, D. G. (2009). ''Data on the Trophic Spectrum of Young Imperial Eagles (Aquila heliaca Savigny, 1809) in South Bulgaria''. Ecologia Balkanica, 1. 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 pheasant The common pheasant (''Phasianus colchicus'') is a bird in the pheasant family ( Phasianidae). The genus name comes from Latin ''phasianus'', "pheasant". The species name ''colchicus'' is Latin for "of Colchis" (modern day Georgia), a countr ...
s (''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 Naurzum State Nature Reserve ( kk, Наурызым мемлекеттік табиғи қорығы, ) is a nature reserve in Kostanay Region, Kazakhstan. It is part of the UNESCO heritage site Saryarka — Steppe and Lakes of Northern Kazakhstan. ...
in
Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
, 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 The yellow ground squirrel (''Spermophilus fulvus'') is a large and sturdy ground squirrel species native to Afghanistan, China, Iran, Kazakhstan, Turkmenistan, Uzbekistan and Russia. It inhabits sandy steppes with Artemisia, glasswort an ...
(''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 The Eurasian magpie or common magpie (''Pica pica'') is a resident breeding bird throughout the northern part of the Eurasian continent. It is one of several birds in the crow family (corvids) designated magpies, and belongs to the Holarctic ...
(''Pica pica''), numerous species of
duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form ...
as well as
Eurasian kestrel The common kestrel (''Falco tinnunculus'') is a bird of prey species belonging to the kestrel group of the falcon family Falconidae. It is also known as the European kestrel, Eurasian kestrel, or Old World kestrel. In the United Kingdom, where no ...
s (''Falco tinnunculus'') and little bustards (''Tetrax tetrax'').Katzner, T. E., Bragin, E. A., Knick, S. T., & Smith, A. T. (2005). ''Relationship between demographics and diet specificity of Imperial Eagles Aquila heliaca in Kazakhstan''. Ibis, 147(3), 576-586. In
East Thrace East Thrace or Eastern Thrace ( tr, Doğu Trakya or simply ''Trakya''; el, Ανατολική Θράκη, ''Anatoliki Thraki''; bg, Източна Тракия, ''Iztochna Trakiya''), also known as Turkish Thrace or European Turkey, is the pa ...
, 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 stork The white stork (''Ciconia ciconia'') is a large bird in the stork family, Ciconiidae. Its plumage is mainly white, with black on the bird's wings. Adults have long red legs and long pointed red beaks, and measure on average from beak tip to e ...
s (''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 Bharatpur District is a district in Rajasthan state in western India. The town of Bharatpur is the District Headquarters, Division Headquarters and Headquarters of Bharatpur Police Range of Rajasthan Police. Bharatpur District is a part o ...
of
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...
showed that this species was generally more inactive but also more likely to capture its own food (rather than through scavenging or
kleptoparasitism Kleptoparasitism (etymologically, parasitism by theft) is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, which can mean when ...
) 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 Phalacrocoracidae is a family of approximately 40 species of aquatic birds commonly known as cormorants and shags. Several different classifications of the family have been proposed, but in 2021 the IOC adopted a consensus taxonomy of seven ge ...
. However, the imperial eagle in particularly here took to regularly hunting various adult water birds especially
duck Duck is the common name for numerous species of waterfowl in the family Anatidae. Ducks are generally smaller and shorter-necked than swans and geese, which are members of the same family. Divided among several subfamilies, they are a form ...
s, geese and large rails and had a mean daily food intake (not mean prey size) of .Prakash, V. (1988). ''The general ecology of raptors in Keoladeo National Park, Bharatpur'' (Doctoral dissertation, Ph.D. thesis. Bombay University, Mumbai, India). In the Saurashtra region of
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...
, 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 The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
, forcing them to dive as they circled over the water and capturing them as they came to the water’s surface to breathe.Dharmakuarsinhji, K.S. (1955). ''Birds of Saurashtra''. Dil Bahar. Numerous pigeons and doves may also be taken fairly often, such as in
Slovakia Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the ...
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 Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae, the largest family, which ...
, 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
reptile Reptiles, as most commonly defined are the animals in the class Reptilia ( ), a paraphyletic grouping comprising all sauropsids except birds. Living reptiles comprise turtles, crocodilians, squamates ( lizards and snakes) and rhynchocephalia ...
s may be taken. In
Georgia Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...
, 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 Hermann's tortoise (''Testudo hermanni'') is a species of tortoise. Two subspecies are known: the western Hermann's tortoise (''T. h. hermanni'' ) and the eastern Hermann's tortoise (''T. h. boettgeri'' ). Sometimes mentioned as a subspecies ...
(''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
snake Snakes are elongated, limbless, carnivorous reptiles of the suborder Serpentes . Like all other squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales. Many species of snakes have skulls with several more ...
s 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 Hungary ( hu, Magyarország ) is a landlocked country in Central Europe. Spanning of the Carpathian Basin, it is bordered by Slovakia to the north, Ukraine to the northeast, Romania to the east and southeast, Serbia to the south, Cr ...
, very small numbers of
invertebrate Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...
s (mostly
insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pa ...
s such as
ground beetle Ground beetles are a large, cosmopolitan family of beetles, the Carabidae, with more than 40,000 species worldwide, around 2,000 of which are found in North America and 2,700 in Europe. As of 2015, it is one of the 10 most species-rich animal f ...
s) and
fish Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as we ...
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 Jordan ( ar, الأردن; tr. ' ), officially the Hashemite Kingdom of Jordan,; tr. ' is a country in Western Asia. It is situated at the crossroads of Asia, Africa, and Europe, within the Levant region, on the East Bank of the Jordan Rive ...
, 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 The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
. In one area of
Slovakia Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the ...
, although imperial eagles also hunted, the adult eagles routinely practiced
kleptoparasitism Kleptoparasitism (etymologically, parasitism by theft) is a form of feeding in which one animal deliberately takes food from another. The strategy is evolutionarily stable when stealing is less costly than direct feeding, which can mean when ...
while nesting, regularly robbing other species of raptorial bird of their fresh catches.Danko, Š. (2007). ''Kleptoparasitism by raptors, focusing on the Imperial Eagle (Aquila heliaca)''. Slovak raptor journal, 1, 29-33. Almost any mammal or bird will be readily eaten when dead or dying by imperial eagles, with at least 10 species of
ungulate Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, ...
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 . According to Watson (2010), the prey of imperial eagles is fairly evenly spread from up to , with a peak focus (at around 25%) on prey weighing and a mean estimated prey size of . 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 and , 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 . Similarly, the upper size of hare typically taken in Slovakia was estimated at . In Hungary, staple prey size was estimated at between and . 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 The mountain hare (''Lepus timidus''), also known as blue hare, tundra hare, variable hare, white hare, snow hare, alpine hare, and Irish hare, is a Palearctic hare that is largely adapted to polar and mountainous habitats. Evolution The mount ...
(''Lepus timidus'') and the
Tolai hare The tolai hare (''Lepus tolai'') is a species of hare native to Central Asia, Mongolia, and Northern and Central China. It inhabits semi-desert, steppes, rocky habitats, and forest meadows. It is relatively common, even in areas with heavy huma ...
(''Lepus tolai'').Ryabtsev, V. V. (1984). ''Ecology and conservation of Imperial Eagle (Aquila heliaca) in Pre-Baikal region''. Leningrad State University Newsletter, 9: 20-27. They have taken adults of numerous larger water birds averaging over the expected prey weight of , 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 The bean goose (''Anser fabalis'' or ''Anser serrirostris'') is a goose that breeds in northern Europe and Eurosiberia. It has two distinct varieties, one inhabiting taiga habitats and one inhabiting tundra. These are recognised as separate s ...
(''Anser fabalis''), bar-headed goose (''Anser indicus''), knob-billed duck (''Sarkidiornis melanotos''), common crane (''Grus grus''),
great cormorant The great cormorant (''Phalacrocorax carbo''), known as the black shag in New Zealand and formerly also known as the great black cormorant across the Northern Hemisphere, the black cormorant in Australia, and the large cormorant in India, is a w ...
(''Phalacrocorax carbo''),
white stork The white stork (''Ciconia ciconia'') is a large bird in the stork family, Ciconiidae. Its plumage is mainly white, with black on the bird's wings. Adults have long red legs and long pointed red beaks, and measure on average from beak tip to e ...
and black stork (''Ciconia nigra'').Karyakin, I., Nikolenko, E., Vazhov, S., & Bekmansurov, R. (2009). ''Imperial Eagle in the Altai Mountains: Results of the Research in 2009, Russia''. Raptors Conservation, (16). Eastern imperial eagles also attack the young of
ungulate Ungulates ( ) are members of the diverse clade Ungulata which primarily consists of large mammals with hooves. These include odd-toed ungulates such as horses, rhinoceroses, and tapirs; and even-toed ungulates such as cattle, pigs, giraffes, ...
s 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 The roe deer (''Capreolus capreolus''), also known as the roe, western roe deer, or European roe, is a species of deer. The male of the species is sometimes referred to as a roebuck. The roe is a small deer, reddish and grey-brown, and well-adapt ...
(''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
Eurasian harvest mouse The harvest mouse (''Micromys minutus'') is a small rodent native to Europe and Asia. It is typically found in fields of cereal crops, such as wheat and oats, in reed beds and in other tall ground vegetation, such as long grass and hedgerows. It ...
(''Micromys minutus'') and birds down to the size of the
Eurasian tree sparrow The Eurasian tree sparrow (''Passer montanus'') is a passerine bird in the sparrow family with a rich chestnut crown and nape, and a black patch on each pure white cheek. The sexes are similarly plumaged, and young birds are a duller version ...
(''Passer montanus''). In Kazakhstan, the estimated size of all prey taken varied from approximately for a locust to for the largest bird prey (i.e.
cranes Crane or cranes may refer to: Common meanings * Crane (bird), a large, long-necked bird * Crane (machine), industrial machinery for lifting ** Crane (rail), a crane suited for use on railroads People and fictional characters * Crane (surname ...
and geese) and 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 fox The red fox (''Vulpes vulpes'') is the largest of the true foxes and one of the most widely distributed members of the Order (biology), order Carnivora, being present across the entire Northern Hemisphere including most of North America, Europe ...
es (''Vulpes vulpes'') are on juvenile, other than perhaps small females, adults at average weights of up to 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'').Ellis, D. H., Tsengeg, P., Whitlock, P., & Ellis, M. H. (2000). ''Predators as prey at a Golden Eagle Aquila chrysaetos eyrie in Mongolia''. Ibis, 142(1), 141-142. Beyond small
weasel Weasels are mammals of the genus ''Mustela'' of the family Mustelidae. The genus ''Mustela'' includes the least weasels, polecats, stoats, ferrets and European mink. Members of this genus are small, active predators, with long and slend ...
s, which are probably no issue for large eagles to attack, larger
mustelid The Mustelidae (; from Latin ''mustela'', weasel) are a family of carnivorous mammals, including weasels, badgers, otters, ferrets, martens, minks and wolverines, among others. Mustelids () are a diverse group and form the largest family in t ...
s may too be attacked including European (''Mustela putorius'') and
steppe polecat The steppe polecat (''Mustela eversmanii''), also known as the white or masked polecat, is a species of mustelid native to Central and Eastern Europe and Central Asia. It is listed as Least Concern on the IUCN Red List because of its wide dis ...
s (''Mustela eversmanii'') and stone martens (''Martes foina''). Small or kitten
domestic cat The cat (''Felis catus'') is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members o ...
s (''Felis catus'') are sometimes prey for eastern imperial eagles and juvenile Pallas's cats (''Otocolobus manul'') may too be vulnerable to this eagle.


Interspecies predatory relationships

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 The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known bird ...
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 . 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.Katzner, T. E., Bragin, E. A., Knick, S. T., & Smith, A. T. (2003). ''Coexistence in a multispecies assemblage of eagles in central Asia''. The Condor, 105(3), 538-551.Vazhov, S. V. (2012). ''Some Features of the Ecological Niches of Raptors in the Russian Part of the Altai Foothills''. Raptors Conservation, (25). 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.Katzner, T. E., Bragin, E. A., & Milner-Gulland, E. J. (2006). ''Modelling populations of long-lived birds of prey for conservation: a study of imperial eagles (Aquila heliaca) in Kazakhstan''. Biological Conservation, 132(3), 322-335.MARTI, C. D., & KORPIMÁKI, E. (2012). ''TROPHIC STRUCTURE OF RAPTOR COMMUNITIES: A THREE-CONTINENT''. Current Ornithology, 10, 47. 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 Naurzum State Nature Reserve ( kk, Наурызым мемлекеттік табиғи қорығы, ) is a nature reserve in Kostanay Region, Kazakhstan. It is part of the UNESCO heritage site Saryarka — Steppe and Lakes of Northern Kazakhstan. ...
of
Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
the golden and eastern imperial eagle, and to some extent also both
white-tailed eagle The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
s 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 The Altai Republic (; russian: Респу́блика Алта́й, Respublika Altay, ; Altai: , ''Altay Respublika''), also known as Gorno-Altai Republic, and colloquially, and primarily referred to in Russian to distinguish from the neighbour ...
, it appears that golden and eastern imperial eagles are considered to fill a largely similar
ecological niche In ecology, a niche is the match of a species to a specific environmental condition. Three variants of ecological niche are described by It describes how an organism or population responds to the distribution of resources and competitors (for ...
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 In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate gras ...
while the greater spotted eagle prefers more densely wooded and wetter habitats generally than imperial eagles such as
taiga Taiga (; rus, тайга́, p=tɐjˈɡa; relates to Mongolic and Turkic languages), generally referred to in North America as a boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, sp ...
bog A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and muskeg; a ...
s. 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 Central Asia, also known as Middle Asia, is a region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes the fo ...
. While steppe eagles occur much more broadly in Africa during winter and a similarly narrow extent in the
Indian subcontinent The Indian subcontinent is a physiographical region in Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian Ocean from the Himalayas. Geopolitically, it includes the countries of Bangladesh, Bhutan, In ...
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 A savanna or savannah is a mixed woodland- grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground ...
to
wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (Anoxic waters, anoxic) processes prevailing, especially in t ...
s and even
semi-desert A semi-arid climate, semi-desert climate, or steppe climate is a dry climate sub-type. It is located on regions that receive precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi ...
. The ecology of wintering eastern imperials was studied at length in
Bharatpur district Bharatpur District is a district in Rajasthan state in western India. The town of Bharatpur is the District Headquarters, Division Headquarters and Headquarters of Bharatpur Police Range of Rajasthan Police. Bharatpur District is a part o ...
of
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...
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, against an average of for the imperial. However, the mean daily intake of Pallas's fish eagle was slightly higher still at 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 Coots are medium-sized water birds that are members of the rail family, Rallidae. They constitute the genus ''Fulica'', the name being the Latin term for "coot". Coots have predominantly black plumage, and—unlike many rails—they are usually ...
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 Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic ...
, 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 East Africa, Eastern Africa, or East of Africa, is the eastern subregion of the African continent. In the United Nations Statistics Division scheme of geographic regions, 10-11-(16*) territories make up Eastern Africa: Due to the historica ...
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 eagle The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
s, 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,
vole Voles are small rodents that are relatives of lemmings and hamsters, but with a stouter body; a longer, hairy tail; a slightly rounder head; smaller eyes and ears; and differently formed molars (high-crowned with angular cusps instead of lo ...
s & 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 Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the ...
, 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 The Eurasian sparrowhawk (''Accipiter nisus''), also known as the northern sparrowhawk or simply the sparrowhawk, is a small bird of prey in the family Accipitridae. Adult male Eurasian sparrowhawks have bluish grey upperparts and orange-barr ...
(''Accipiter nisus'') as well as
red fox The red fox (''Vulpes vulpes'') is the largest of the true foxes and one of the most widely distributed members of the Order (biology), order Carnivora, being present across the entire Northern Hemisphere including most of North America, Europe ...
es 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 The peregrine falcon (''Falco peregrinus''), also known as the peregrine, and historically as the duck hawk in North America, is a cosmopolitan bird of prey (raptor) in the family Falconidae. A large, crow-sized falcon, it has a blue-grey bac ...
(''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 Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...
(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.Moshkin, A. (2009). ''Kleptoparasitism-One of Hunting Technique of the Peregrine Falcon that Became Common under Condition of the Increase in its Number in the Southern Ural Mountains, Russia''. Raptors Conservation, (17). In Tatarstan,
Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...
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.Bekmansurov, R. H., Karyakin, I. V., & Shnayder, E. P. (2015). ''On Eastern Imperial Eagle (Aquila heliaca) breeding in atypical habitat under competitive conditions with other eagle species''. Slovak Raptor Journal, 9(1), 95-104. 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 The hen harrier (''Circus cyaneus'') is a bird of prey. It breeds in Eurasia. The term "hen harrier" refers to its former habit of preying on free-ranging fowl. It migrates to more southerly areas in winter. Eurasian birds move to southern Eur ...
(''Circus cyaneus''), Montagu's harrier (''Circus pygargus''), western marsh harrier,
Eurasian sparrowhawk The Eurasian sparrowhawk (''Accipiter nisus''), also known as the northern sparrowhawk or simply the sparrowhawk, is a small bird of prey in the family Accipitridae. Adult male Eurasian sparrowhawks have bluish grey upperparts and orange-barr ...
,
northern goshawk The northern goshawk (; ''Accipiter gentilis'') is a species of medium-large raptor in the family Accipitridae, a family which also includes other extant diurnal raptors, such as eagles, buzzards and harriers. As a species in the genus '' Acci ...
(''Accipiter gentilis''),
common buzzard The common buzzard (''Buteo buteo'') is a medium-to-large bird of prey which has a large range. A member of the genus '' Buteo'', it is a member of the family Accipitridae. The species lives in most of Europe and extends its breeding range acr ...
(''Buteo buteo''), long-legged buzzard, rough-legged buzzard (''Buteo lagopus''), Ural owl (''Strix uralensis''), tawny owl (''Strix alucco''),
little owl The little owl (''Athene noctua''), also known as the owl of Athena or owl of Minerva, is a bird that inhabits much of the temperate and warmer parts of Europe, the Palearctic east to Korea, and North Africa. It was introduced into Britain at ...
(''Athene noctua''), long-eared owl (''Asio otus''),
short-eared owl The short-eared owl (''Asio flammeus'') is a widespread grassland species in the family Strigidae. Owls belonging to genus ''Asio'' are known as the eared owls, as they have tufts of feathers resembling mammalian ears. These "ear" tufts may or ...
(''Asio flammeus''), Eurasian hobby (''Falco subbuteo''), common kestrel (''Falco tinnunculus''), lesser kestrel (''Falco naumanni''),
merlin Merlin ( cy, Myrddin, kw, Marzhin, br, Merzhin) is a mythical figure prominently featured in the legend of King Arthur and best known as a mage, with several other main roles. His usual depiction, based on an amalgamation of historic and leg ...
(''Falco columbarius''),
red-footed falcon The red-footed falcon (''Falco vespertinus''), formerly the western red-footed falcon, is a bird of prey. It belongs to the family Falconidae, the falcons. This bird is found in eastern Europe and Asia although its numbers are dwindling rapidly ...
(''Falco vespertinus''), saker falcon and
peregrine falcon The peregrine falcon (''Falco peregrinus''), also known as the peregrine, and historically as the duck hawk in North America, is a cosmopolitan bird of prey (raptor) in the family Falconidae. A large, crow-sized falcon, it has a blue-grey bac ...
.Korepov, M.V. & Borodin, O.V. (2013). ''The Imperial Eagle (Aquila heliaca) is a natural symbol of the Ulyanovsk region''. - Ulyanovsk: Volga Research Center.— 120 p.Adamian, M. S., & Klem, D. (1999). ''Handbook of the Birds of Armenia''. American University of Armenia. 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 The white-tailed eagle (''Haliaeetus albicilla'') is a very large species of sea eagle widely distributed across temperate Eurasia. Like all eagles, it is a member of the family Accipitridae (or accipitrids) which includes other diurnal raptors ...
.Palmer, R. S. (Ed.). (1988). ''Handbook of North American Birds Volume VI: Diurnal Raptors (Part 1)''. Yale University Press. Furthermore, imperial eagles may be vulnerable at their nest to nighttime ambushes by Eurasian eagle-owls (''Bubo bubo'').


Breeding

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 eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known bird ...
s. In
East Thrace East Thrace or Eastern Thrace ( tr, Doğu Trakya or simply ''Trakya''; el, Ανατολική Θράκη, ''Anatoliki Thraki''; bg, Източна Тракия, ''Iztochna Trakiya''), also known as Turkish Thrace or European Turkey, is the pa ...
,
Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...
, the mean nearest nest distance between actively breeding pairs was .Demerdzhiev, D., Stoychev, S., Terziev, N., & Angelov, I. (2011). ''Status of the Eastern Imperial Eagle (Aquila heliaca) in the European part of Turkey''. Acta zoologica Bulgarica Supplementum, 3, 87-93. In the
Irkutsk Oblast Irkutsk Oblast (russian: Ирку́тская о́бласть, Irkutskaya oblast; bua, Эрхүү можо, Erkhüü mojo) is a federal subject of Russia (an oblast), located in southeastern Siberia in the basins of the Angara, Lena, and N ...
near
Lake Baikal Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the ...
, the mean distance of the central area of nests (each pair had more than one nest on territory) was . The breeding season lasts from late March to September throughout the range but in their former range in
Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
(where it is now extirpated as a breeder) was said to extend from November to April.Khan, A. A., Khan, R., Ullah, A., Ali, M., Mahmood, J. A., & Sheikh, K. M. (1996). ''Conservation perspectives of the Imperial Aquila heliaca and Steppe Eagle Aquila nipalensis in Pakistan''. Eagle Studies World Walking Group on Birds of Prey (WWGBP) Berlin, London & Paris. The pair constructs a very large nest of sticks, which may average up to across and in depth. However, nests for the species have been recorded to measure up to or more across and 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 in low scrub or, rarely, on cliff or ground (later as recorded in the
Sayan mountains The Sayan Mountains (russian: Саяны ''Sajany''; mn, Соёны нуруу, ''Soyonï nurû''; otk, 𐰚𐰇𐰏𐰢𐰤, Kögmen) are a mountain range in southern Siberia, Russia ( Buryatia, Irkutsk Oblast, Krasnoyarsk Krai, Tuva Repu ...
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 elevation. In Georgia, denser mixed forests with openings were favored alternately with more arid, isolated stands of
juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arc ...
(''Juniperus ssp''.) and
pistachio The pistachio (, ''Pistacia vera''), a member of the cashew family, is a small tree originating from Central Asia and the Middle East. The tree produces seeds that are widely consumed as food. ''Pistacia vera'' is often confused with other spe ...
(''Pistacia vera''); in Turkey, poplar (''Populus ssp''.) (44%) and oak (''Quercus ssp''.) (40%) were favored. In extensive Russian studies, 78% of nests were in
conifer Conifers are a group of cone-bearing seed plants, a subset of gymnosperms. Scientifically, they make up the division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single extant class, Pinopsida. All ext ...
s 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 Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the ...
include one next to a
railroad Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a prep ...
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 Georgia most commonly refers to: * Georgia (country), a country in the Caucasus region of Eurasia * Georgia (U.S. state), a state in the Southeast United States Georgia may also refer to: Places Historical states and entities * Related to the ...
was 2.09. In the
Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
, 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 in height by , with an average of . In Georgia, the average dimensions of eggs was measured in a sample of 20 as with a mean weight of . As was recorded in 13 cases in
Slovakia Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the ...
, 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 Central Asia, also known as Middle Asia, is a region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes the fo ...
, 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 Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedo ...
, two females were recorded to do 90.8-94.1% of the incubating.Dobrev, D. D. (2009). ''Some Aspects of the Nest Etology of the Eastern Imperial Eagle (Aquila heliaca)(Aves: Accipitridae) in Sakar Mountain''. Ecologia Balkanica, 1. 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 and survivorship

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 Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedo ...
, 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.Demerdzhiev, D., Stoychev, S., Dobrev, D., Spasov, S., & Terziev, N. (2014). ''Conservation measures undertaken to improve the population status of eastern imperial eagle (Aquila heliaca) in Bulgaria''. Slovak Raptor Journal, 8(1), 27-39.Demerdzhiev, D., Gradev, G., Stoychev, S., Ivanov, I., Petrov, T., & Marin, S. (2011). ''Increase of the population of the eastern imperial eagle (Aquila heliaca) in Bulgaria''. Acta zoologica Bulgarica Supplementum, 3, 41-54. In Austria, the average number of fledglings per successful pair was 1.63. Of 27 breeding Austrian breeding attempts, 22 were successful.Wichmann, G. (2011). ''The situation of the eastern imperial eagle Aquila heliaca in Austria''. Acta Zoologica Bulgarica Supplement. In
East Thrace East Thrace or Eastern Thrace ( tr, Doğu Trakya or simply ''Trakya''; el, Ανατολική Θράκη, ''Anatoliki Thraki''; bg, Източна Тракия, ''Iztochna Trakiya''), also known as Turkish Thrace or European Turkey, is the pa ...
,
Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...
, the breeding success was estimated at 1.01 fledglings per pair. Pairs living in the
Marmara region The Marmara Region ( Turkish: ''Marmara Bölgesi'') is a geographical region of Turkey. Located in northwestern Turkey, it is bordered by Greece and the Aegean Sea to the west, Bulgaria and the Black Sea to the north, the Black Sea Region to t ...
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.Stoychev, S., Demerdzhiev, D., Spasov, S., Dobrev, D., & Meyburg, B. U. (2014). ''Survival rate and mortality of juvenile and immature eastern imperial eagles (Aquila heliaca) from Bulgaria studied by satellite telemetry''. Slovak Raptor Journal, 8(1), 53-60. 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 A car or automobile is a motor vehicle with wheels. Most definitions of ''cars'' say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people instead of goods. The year 1886 is regarded ...
and
wind turbine A wind turbine is a device that converts the kinetic energy of wind into electrical energy. Hundreds of thousands of large turbines, in installations known as wind farms, now generate over 650 gigawatts of power, with 60 GW added each year. ...
s, are also a persistent threat. Like other birds of prey, eastern imperial eagles are occasionally vulnerable to Haematozoa,
helminth Parasitic worms, also known as helminths, are large macroparasites; adults can generally be seen with the naked eye. Many are intestinal worms that are soil-transmitted and infect the gastrointestinal tract. Other parasitic worms such as ...
s and viruses as well as maggot infection in a wound by
blowflies The Calliphoridae (commonly known as blow flies, blow-flies, carrion flies, bluebottles, greenbottles, or cluster flies) are a family of insects in the order Diptera, with almost 1,900 known species. The maggot larvae, often used as fishing ...
. 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 Naurzum State Nature Reserve ( kk, Наурызым мемлекеттік табиғи қорығы, ) is a nature reserve in Kostanay Region, Kazakhstan. It is part of the UNESCO heritage site Saryarka — Steppe and Lakes of Northern Kazakhstan. ...
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 Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the ...
. Here fledgling success has decreased from roughly 71% to about 52%.Ryabtsev, V. V., & Katzner, T. E. (2007). ''Severe declines of Eastern Imperial Eagle Aquila heliaca populations in the Baikal region, Russia: a modern and historical perspective''. Bird Conservation International, 17(3), 197-209.


Status

The eastern imperial eagle has declined greatly through history. At one time, people of
eastern Europe Eastern Europe is a subregion of the European continent. As a largely ambiguous term, it has a wide range of geopolitical, geographical, ethnic, cultural, and socio-economic connotations. The vast majority of the region is covered by Russia, whi ...
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).Petrov, T., Iankov, P., Darakchiev, A., Nikolov, K., Michev, T., Profirov, L., & Milchev, B. (1996). ''Status of the Imperial Eagle Aquila heliaca in Bulgaria in the period between 1890 and 1993''. Eagle Studies, 429–433. 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 Austria-Hungary, often referred to as the Austro-Hungarian Empire,, the Dual Monarchy, or Austria, was a constitutional monarchy and great power in Central Europe between 1867 and 1918. It was formed with the Austro-Hungarian Compromise of ...
once chose the imperial eagle to be its
heraldic Heraldry is a discipline relating to the design, display and study of armorial bearings (known as armory), as well as related disciplines, such as vexillology, together with the study of ceremony, rank and pedigree. Armory, the best-known branc ...
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 The wolf (''Canis lupus''; : wolves), also known as the gray wolf or grey wolf, is a large canine native to Eurasia and North America. More than thirty subspecies of ''Canis lupus'' have been recognized, and gray wolves, as popularly un ...
. As with other eagles in Eurasia, the
Industrial revolution The Industrial Revolution was the transition to new manufacturing processes in Great Britain, continental Europe, and the United States, that occurred during the period from around 1760 to about 1820–1840. This transition included going f ...
allowed access to
poison Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...
s and
firearm A firearm is any type of gun designed to be readily carried and used by an individual. The term is legally defined further in different countries (see Legal definitions). The first firearms originated in 10th-century China, when bamboo tubes ...
s, which made the killing of eagles far easier and hastened their decline.Belik, V.P. & Galushin, V.M. (2002). ''Population structure of the Inperial mperialEagle range in northern Eurasia''. in Yosef R; Miller ML; Pepler D. Raptors in the new millennium. Pages 200. 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 Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders wi ...
, 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 Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
and
Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan,; prs, امارت اسلامی افغانستان is a landlocked country located at the crossroads of Central Asia and South Asia. Referred to as the Heart of Asia, it is borde ...
. 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 European Russia (russian: Европейская Россия, russian: европейская часть России, label=none) is the western and most populated part of Russia. It is geographically situated in Europe, as opposed to the cou ...
). 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 Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the ...
as well as some parts of the
Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
,
Serbia Serbia (, ; Serbian: , , ), officially the Republic of Serbia ( Serbian: , , ), is a landlocked country in Southeastern and Central Europe, situated at the crossroads of the Pannonian Basin and the Balkans. It shares land borders with Hu ...
and
Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...
. However, overall 85% of the population in the
Carpathian mountains The Carpathian Mountains or Carpathians () are a range of mountains forming an arc across Central Europe. Roughly long, it is the third-longest European mountain range after the Urals at and the Scandinavian Mountains at . The range stretche ...
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 East Thrace or Eastern Thrace ( tr, Doğu Trakya or simply ''Trakya''; el, Ανατολική Θράκη, ''Anatoliki Thraki''; bg, Източна Тракия, ''Iztochna Trakiya''), also known as Turkish Thrace or European Turkey, is the pa ...
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 Taiga (; rus, тайга́, p=tɐjˈɡa; relates to Mongolic and Turkic languages), generally referred to in North America as a boreal forest or snow forest, is a biome characterized by coniferous forests consisting mostly of pines, sp ...
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 In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to ...
seems to have increased populations of
yellow ground squirrel The yellow ground squirrel (''Spermophilus fulvus'') is a large and sturdy ground squirrel species native to Afghanistan, China, Iran, Kazakhstan, Turkmenistan, Uzbekistan and Russia. It inhabits sandy steppes with Artemisia, glasswort an ...
s and 2nd growth trees which both are likely to have caused a localized increase there. In
Naurzum Nature Reserve Naurzum State Nature Reserve ( kk, Наурызым мемлекеттік табиғи қорығы, ) is a nature reserve in Kostanay Region, Kazakhstan. It is part of the UNESCO heritage site Saryarka — Steppe and Lakes of Northern Kazakhstan. ...
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 Lake Baikal (, russian: Oзеро Байкал, Ozero Baykal ); mn, Байгал нуур, Baigal nuur) is a rift lake in Russia. It is situated in southern Siberia, between the federal subjects of Irkutsk Oblast to the northwest and the ...
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 The Ural Mountains ( ; rus, Ура́льские го́ры, r=Uralskiye gory, p=ʊˈralʲskʲɪjə ˈɡorɨ; ba, Урал тауҙары) or simply the Urals, are a mountain range that runs approximately from north to south through western ...
region of Russia with largely similar threats but it is not known what the exact rate of reduction is here.Korovin, V.A. (2005). ''Peculiarities of the ecology of the Imperial Eagle Aquila heliaca and problems of its conservation in the Trans-Uralia steppes''. Russkiy Ornitologicheskiy Zhurnal, 14: 644-646. Although gone from
Pakistan Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
as a breeding species, it continues to be a key wintering site as around 150 eagles are estimated to winter in Pakistan.


References


External links

* * * * * * {{DEFAULTSORT:eagle, imperial, eastern eastern imperial eagle eastern imperial eagle Birds of prey of Eurasia Birds of East Africa National symbols of Austria-Hungary eastern imperial eagle