The greater spotted eagle (Clanga clanga), also called the spotted eagle, is a large migratory bird of prey in the family Accipitridae.

It is a member of the subfamily Aquilinae, commonly known as "booted eagles". It was once classified as a member of the genus Aquila, but has been reclassified to the distinct genus Clanga, along with the two other species of spotted eagle.

During breeding season, greater spotted eagles are widely distributed across Eastern Europe, parts of Central Europe, central Russia, central Asia and parts of China, along with other isolated areas. During winter, they migrate, primarily to South Asia, Southeast Asia, the Middle East, the upper Mediterranean Basin, and parts of East Africa. Greater spotted eagles favor wetter habitats than most other booted eagles, preferring riparian zones as well as bogs, lakes, ponds, and other bodies of water surrounded by woodland. They breed primarily on floodplains, especially ones that experience high water levels. During winter and migration, they often seek out similar wetland habitats, but have also been observed in dry upland areas such as savanna plateaus.

The eagle is an opportunistic forager, especially during the winter. It will readily scavenge a variety of food sources, including carrion, as well as small mammals (principally rodents), frogs, and a variety of smaller birds (especially water birds), and occasionally reptiles and insects. The eagle is primarily an aerial hunter, gliding from concealed perches over marshes or wet fields to catch prey.

This species builds stick nests in large trees, laying a clutch of one to three eggs. The female of a pair incubates and broods the young while the male hunts and delivers prey. Parents rarely raise more than one fledgling per year. As is common among a few species of raptors, the oldest chick is much larger than its younger siblings, and will often attack and kill the younger siblings.

The greater spotted eagle's range overlaps with the closely related lesser spotted eagle (Clanga pomarina). The two species are known to breed together frequently, forming hybrid offspring, which is detrimental to the population of the rarer greater spotted eagles. The greater spotted eagle is classified as a vulnerable species by the International Union for Conservation of Nature.

Taxonomy and etymology

thumb|left|Adult wintering in [[Oman]]

Greater spotted eagles are members of the Aquilinae, or "booted eagles", subfamily, a monophyletic group within the larger Accipitridae family. All booted eagles have feathers covering their legs. Members of this diverse, wide-ranging family may be found on every continent except Antarctica. Thirty-eight species of booted eagle are recognized.

Booted eagles are often grouped with the genera Buteo and Haliaeetus, and other more heavy-set Accipitridae, but they may be more closely related to the slenderer accipitrine hawks than previously believed. The greater spotted eagle's closest living relative is the lesser spotted eagle. They are believed to have diverged from their most recent common ancestor around the middle Pliocene, approximately 3.6 million years ago (mya). This "proto-spotted eagle" probably lived in the general region of modern-day Afghanistan, and split into northern and southern lineages when both glaciers and deserts advanced in Central Asia at the start of the last ice age. The northern lineage subsequently separated into the greater (eastern) and lesser (western) spotted eagle species of today, probably around the Pliocene–Pleistocene boundary, almost 2 mya.

Spotted eagles were classified as part of the genus Aquila, along with several other mostly large, brownish eagles. Furthermore, a close relationship has been found between the spotted eagles and the black eagle (Ictinaetus malaiensis) native to Asia. The spotted eagles, long-crested eagle, and black eagle may comprise a species complex or clade. The spotted eagles were ultimately reclassified as a distinct genus, Clanga, due to overwhelming genetic evidence and large divergences in morphology and ecology between spotted eagles and their sister taxa. The scientific name Clanga may derive from Ancient Greek (), or its root may be the Greek word (a variant form of ) for "a kind of eagle" as mentioned by Aristotle. The mitochondrial genetic sequences of these species have more than 3% divergence, about twice what is considered the minimum genetic difference to distinguish two species. A third spotted eagle, the Indian spotted eagle (Clanga hastata), was recognized as a distinct species from the similarly sized lesser spotted eagle in 2006.

Description

thumb|left|A juvenile greater spotted eagle wintering in India exhibits the highly distinct fulvescens morph plumage.

thumb|right|Museum specimen of juvenile

The greater spotted eagle is rather large and compact. Normally, it is black-brown with a contrasting yellow beak. This species has a short neck with a large and often shaggy-naped head, a strong beak, and a short gape-line with round nostrils. The wings are broad and long, reaching the tail tip. The tail is relatively short and rounded.

Pale adults, sometimes referred to as Clanga clanga fulvescens, have bicolored plumage. The tail, flight feathers, and greater wing coverts are all blackish, with the body and the rest of the wing coverts appearing light yellow or pale golden buff, sometimes becoming creamy when aged. The buff colour of the fulvescens phenotype is usually contrasted with diffuse dark coloring around the eyes, on the leading edges of wings, and more rarely and sparsely on the chest. Intermediate and other variants are very rare, but include those with a slightly paler body and variable yellowish-brown streaking or mottling on the fore upperwing coverts (which can make them look similar to juvenile lesser spotted eagles), or mottled yellow-brown with a dark-streaked breast and pale-tipped wing coverts (like the juvenile eastern imperial eagle (Aquila heliaca)). These intermediate types may show the typical dark brown to black on the upper body, but in flight display pale mottled grey wing linings, or even normal coloration apart from the contrasting paler underbody. The bare parts change little in color at different ages, with eyes being dark brown, while the beak and feet are yellow in all ages.

In flight, this is a large, dark raptor (often looking bigger than its true size) with a well-protruding head, long wings (which often look shorter due to their broadness), slightly bulging secondaries, and rather squared seven-finger tips, although juvenile wings can look more rounded.

Juveniles on the wing normally appear very dark with liberal spotting above and below, though some juveniles appear with spots restricted to wings, scapulars, and trousers. All juveniles, when seen well, show characteristic white end spots on wing coverts forming two to three wing bars.

Size

thumb|right|Greater spotted eagles are large raptors and medium-sized eagles.

The greater spotted eagle is a medium-sized eagle, but also a large raptor. In wingspan, males have been reported to measure while females can measure . Body mass for males has been reported to range from , while females range from . The shortish tail varies in males and in females. Reportedly, the culmen length can range from .

Vocalizations

The greater spotted eagle is quite noisy when breeding and is often very vocal in winter, especially when in small loose flocks. As with many raptors, the female's tone is lower pitched and hoarser. This species is primarily differentiated from lesser spotted eagles by its structure and proportions, though distant birds may be practically indistinguishable. Typically, the spotting and barring pattern is much stronger in juvenile greater spotted eagles, but this is not always reliable.

The greater spotted eagle on the Indian subcontinent might be confused with Indian spotted eagles. Beyond structural dissimilarities, subadult steppe eagles can be distinguished from paler morph greater spotted eagles by the former's thicker well-spotted quill bars and paler underwing diagonal. Romania, Serbia, and Hungary. A more continuous breeding range begins in Eastern Europe and includes the eastern parts of Estonia, Latvia, and Lithuania, and central Belarus. They are found broadly throughout European Russia, where habitat is favorable up through much of Arkhangelsk Oblast to as far as the lower coasts of the White Sea. They are found across much of Central Russia, with their probable northern limits being in Shuryshkarsky and Pitkyarantsky Districts. They are also found in a broad strip across southern Siberia reaching well into the Amur region. Their range outside Russia includes much of northern Kazakhstan, with isolated breeding areas known in the East Kazakhstan Region and in southern Kazakhstan. Greater spotted eagles also breed in an isolated area reaching from Kyrgyzstan and adjacent areas of Russia down to Xinjiang in China. At times, greater spotted eagles have been known to breed in the Indian subcontinent, reportedly from Gujarat northwards to Punjab, with recorded breeding as far south as Saurashtra and as far north as Maharashtra. However, this may only be historical, and there is almost certainly not a stable breeding population today. They also breed in northern Mongolia, and rather far into Northeastern China and northern North Korea.

This species is prone to vagrancy, and has been reported in several countries in Europe including the Netherlands, Great Britain, Gibraltar, and the Czech Republic. Its regular breeding range no longer extends as far westwards as Germany, but birds are still occasionally seen there with a few records per decade. Young birds also disperse widely; the Staatliches Museum für Tierkunde Dresden has a specimen (C 21845) shot in November 1914 near Bernsdorf in Saxony. It is a juvenile, and though its exact age cannot be determined, it is heavily spotted and probably less than 20 months old.

Additionally, vagrancy has been reported in Africa, including in Morocco, Algeria, Tunisia, Libya, Cameroon, Chad, Kenya, Tanzania, Zambia, and Botswana. It is sometimes documented in central and east Afghanistan. They also may also be found in East Asia across the southern part of the Russian Far East, eastern China, and occasionally in Southeast Asia from Myanmar and Thailand down through the Malay Peninsula. Occasionally, greater spotted eagles are documented even in Indonesia (i.e. Sumatra).

Wintering range

Dedicated wintering areas tend to be more limited and isolated than their range during migration. Small pockets may exist in southwestern Spain and bordering Portugal, South France, northeastern Italy, western Greece (where it is sometimes considered the most common wintering eagle), small areas of southern Bulgaria, eastern Romania, and southern Moldova. Other wintering areas including northeastern Egypt, southern Sudan and adjacent South Sudan, north-central Ethiopia, and scattered areas of the Middle East including northern Israel, Kuwait, and central Syria. More continuously, they are found through much of the southern coastal Arabian Peninsula, including broadly along the Red Sea coast in Saudi Arabia, west and southern Yemen, southern Oman, coastal United Arab Emirates, and eastern Saudi Arabia. Furthermore, they winter in southeastern Turkey, Azerbaijan, southeastern Georgia, eastern Iraq, broadly in western, northern and eastern Iran, southern Turkmenistan, western Afghanistan, and far western Pakistan. They are also found discontinuously in eastern Pakistan, northern India, Bangladesh, southern Bhutan, and into northwestern Myanmar. In India, the winter range is through the Indo-Gangetic Plain to Bihar, Jharkhand, West Bengal to Assam (including the North Cachar hills), and northeastern hill states extending south through central India. They were once reasonably common in the Malabar and Carnatic coasts but likely only before a hundred years ago. After another gap, they are found in much of southern and central Myanmar, central and southern Thailand, southern Laos, the northern tip of Vietnam, discontinuously in southeastern Vietnam and much of Cambodia, and southern coastal Malaysia. In China, wintering greater spotted eagles range from Jiangsu and Anhui continuously down to northern Guangdong across to Taiwan, and rarely in Korea.

Habitat

thumb|left|A greater spotted eagle in [[Karumady, Kerala, India. This species is often at home in wetland-type habitats.]]

Greater spotted eagles are found in open wet forests and forest edges, often adjoining marshes, swampy patches, bogs, or wet meadows, as well as river-valley woodlands and floodplain forests.

Although typically scarce while breeding in areas modified by heavy human development, they have been seen hunting over cultivated land in Estonia and migrating over lowland farms in the Czech Republic. One seen wintering in Ankara, Turkey, was in an upland forest area. In the Mediterranean Basin, a study found that the preferred habitats of wintering greater spotted eagles were salt marshes and coastal lagoons with freshwater areas. In Arabia, they are largely found now in manmade habitats—such as sewage farms, reservoirs, and agricultural land—since the native mangrove and Phragmites reed-beds that once lined the coastal bays have been almost entirely eliminated. In southern Iran, they are usually found in mangrove areas. A key habitat in Iraq is the Mesopotamian Marshes. Wintering habitats in Israel are the wettest available valleys and damp open zones, chiefly cultivated fields and fishponds near patches of trees, with similar habitats used in Oman. They migrate between late August to October, occasionally lasting into November. The return flight typically starts in early February, peaking in March and ending in April. However, migration has been documented well into May, near the Bosphorus in Turkey. On average, migration peaks earlier in the eastern end of their range, such as in Bhutan, where the largest numbers are seen in late February. They migrate around two weeks later than lesser spotted eagles and return earlier than that species as well. At known migration stopovers, lesser spotted eagles almost always outnumber greater spotted eagles.

Greater spotted eagles who breed in Europe may migrate to southern France (especially Camargue), Spain, Italy, and sometimes Sweden. Western breeding birds also regularly end up in North Africa, with a few in Morocco, Egypt, the Nile Valley, Sudan, Ethiopia, and occasionally points further south. Birds from various origin sites may end up in the Middle East (mainly Arabia), South Asia (from Pakistan, most often Punjab and Sind, northern India, and Nepal), east to Indochina, the Malay Peninsula, and southern and eastern China. The flight speeds of migrating eagles of the species was documented as in the Baikal region, with peak movements times from noon to 6:00 PM. At Lake Baikal, 96% of migrating greater spotted eagles were observed to be adults, an imbalance that concerned researchers. The largest (modern?) counts were 86 and 74 at Suez, Egypt, in autumn and spring, respectively, with smaller numbers recorded crossing into Africa at Bab-el-Mandeb, although a maximum of 85 has been recorded in northern Israel in autumn.

A wintering greater spotted eagle in southwest Saudi Arabia (from a Western Siberia breeding area) was found to utilize an average home range in winter of , which contracted 24% before it migrated in the spring, taking from late February to late April to migrate over . Wintertime territory in Spain was found to be smaller, at .

The southernmost migration record of a greater spotted eagle was one that traveled from the Biebrza National Park in Poland to Zambia in southern Africa. Several other purportedly greater spotted eagles were tracked to several areas of Africa, but nearly half were actually hybrids with lesser spotted eagles and were migrating in more typical fashion and location to that species.

Greater spotted eagles hunt mainly on the wing, quartering over relatively open ground (somewhat like a harrier) or soaring high above and dropping or diving steeply when prey is spotted. The hunting success rates of greater spotted eagles seem rather high—the aforementioned 34% for much of the breeding season is much higher than the hunting success rates of golden eagles (Aquila chrysaetos) (around 20%), lesser spotted eagles (24%), and Bonelli's eagles (Aquila fasciata) (28.5%) at comparable times.

It is sometimes stated that they tend to take prey mostly up to only . The mean prey sizes are roughly similar to those of larger steppe eagles and somewhat higher than those of lesser spotted eagles, which tend to focus on prey weighing under (around 60% of diet); however, the typical prey of most Aquila eagles tended to be slightly higher (eastern imperial eagle) to considerably higher (golden eagle) in weight than the typical prey of greater spotted eagles. At a nest in Estonia, of 105 visually identified prey items, Microtus species and further unidentified rodents comprised some 63% by number but only 28% by biomass, while birds formed only 19% by number but 56% by biomass; 45% of avian prey species were medium-sized, such as hazel grouse, grey partridge, northern lapwing, and hooded crow.

Over 8 years of study in Natural Park of El Fondo in the Spanish province of Alicante, almost entirely large prey was taken, with few to no small rodents (such as voles). Among the 100 prey items found, the main prey were common moorhen (23.1% by number, 15.2% in biomass), common teal (8.97%, 6.44%), black rat (7.69%, 3.01%), and unidentified Rattus (7.69%, 2.76%). Other notable regular prey were black-headed gull, Eurasian coots, and northern lapwing. Large prey, which made up much of the biomass, were common carp (18.9% of biomass), grey heron (11.7%), and European rabbit (9%).

At nests in Western Russia, a mean total of 53% of the diet was found to be small mammals and 45% was birds.

322 non-carrion prey items were found for greater spotted eagles in the Belaya River, 59% of which were mammals. The diet was largely European water vole at 32.6%, followed by smaller voles and mice. It was found that the Belaya eagles ate a large balances of reptile prey (19.5%)—in fact, 15% of all vertebrate prey were European adders. The eagles took average sized snakes but were not seen to prey on small snakes, nor to take many particularly large snakes; they were often seen grasping snakes about the head. In Belaya, only 6.5% of the diet was birds, mainly significant only in the Oka Nature Reserve. The eagles of the region also occasionally partook in carrion feeding, including moose carcasses.

In a compilation study from the Volga region, Ural Mountains, and Western Siberia, 74.7% of the eagle's diet was mammalian, of 482 prey items. Its main prey species was the European water vole at an average of 32.4% of diet (28.1–36.8%), followed by common vole averaging 11.4% (0–17%), tundra vole at 6.2% (1.9–16.9%), and birds at 16%, most importantly Eurasian coots and Podiceps grebes followed by rooks.

thumb|right|Water birds such as [[common moorhens are a common component of the diet of greater spotted eagles in almost any season.]]

Their diet is generally more erratically known in non-European wintering areas. Like many other raptors of similar region, migrating greater spotted eagles typically fast until they reach their wintering terminus point.

In the Indian subcontinent as a whole, greater spotted eagles are known to freely scavenge carrion, as well as feed on frogs (especially Indus valley bullfrogs), chameleons, Calotes lizards, snakes, rodents, and small mammals. A general aptitude in the region has been reported for avian prey—largely larger rails such as moorhens, Eurasian coots and gray-headed swamphens—as well as waterfowl and (mostly young) storks, herons and egrets; however, upland birds such as rufous treepies, Eurasian collared doves, and Indian rollers also seem to be included. Though rare at large carrion, greater spotted eagles in the Indian subcontinent seem to be attracted to terrapins maimed or partially eaten by Pallas's fish eagles, Egyptian vultures, and red-headed vultures.

thumb|A [[drongo mobs a wintering greater spotted eagles, which are predators of birds of various sizes.]]

Anecdotal evidence of the diet of wintering greater spotted eagles was attained in the central plains of Thailand. Here they were seen to eat dead fish in drained ponds as well as to actively hunt and to pirate food from other raptors. They were seen to prey on domestic ducks that became separated from their large farm flocks, as well as to feed on dead lesser whistling ducks found to be killed by poisons meant to kill snails. Sometimes the greater spotted eagle will attack or scavenge on cranes, though many attempted attacks are reportedly unsuccessful. Scavenging on common crane (Grus grus) carcass and failed predation attempt on adult demoiselle crane (Grus virgo) have been reported. the eagles were also considered a potential threat to the young of red-crowned cranes(Grus japonensis), which are known to furiously defend their chicks.

Outside of avian prey, mammals have been taken ranging from Eurasian harvest mouse and common shrew, weighing no more than , up to the European hare, potentially weighing up to . Sometimes greater spotted eagles may prey upon around a half dozen species of mustelids, mostly assorted weasels and stoats but also including larger species such as minks and martens.

Interspecific predatory relationships

Greater spotted eagles often overlap broadly with a number of similar eagle species in both its breeding and wintering regions. As such, the lesser spotted eagle tends to nest in slightly drier environments, usually somewhat away from wetlands and floodplains, adapting rather more readily to patchwork areas where human development has occurred. More similar in central distribution are larger eagles such as the eastern imperial eagle (Aquila heliaca) and steppe eagle (Aquila nipalensis). However, the greater spotted eagle is clearly partitioned from the other eagles by its favoring of wet and partially wooded habitats and the prey found therein. The eastern imperial eagle also nests in woods, but usually in upland areas, and favors both social and solitary terrestrial mammals and birds, including hares, hamsters, ground squirrels, and hedgehogs as well as pheasants, corvids, and other mid-sized birds. Meanwhile, the steppe eagle favours typically rather dry and very open habitats in the steppe, usually nesting on a rise or outcrop in the flat, sparse habitat, and much favours ground squirrels, supplemented by other small terrestrial species such as pikas, voles, and zokors. Habitat usually keeps these eagles separated from the greater spotted eagle while nesting; however, in winter quarters such as India, the Mediterranean Basin, and the Middle East, considerable convergence does occur.

All three eagles are well-established to be rather unpicky opportunists and scavengers during winter. They freely come to human refuse (favoring livestock carcass dumps), scavenge unclaimed carrion, rob other birds of prey of their catches, kill the young of prey such as water birds, find insect swarms or emergences (the steppe eagle more so than the others), and follow grass fires. Of these three, the steppe eagle tends to be least actively predatory in winter, the eastern imperial eagle tends to be the most likely to continue to live-hunt (and perch most extensively), and the greater spotted eagle somewhere in the intermediate behavioral zone. The greater spotted is the least likely of the three to visit carrion or carcass dumps; but, on the Indian subcontinent, they all heavily share food sources such as nestling water birds.

thumb|left|Greater spotted eagle in Israel

While scavenging, greater spotted eagles tend not to come to carrion if Old World vultures are present.

More infrequently, greater spotted eagles will target other raptors as prey, including black kites, booted eagles, western marsh harriers, and common buzzards, as well as some owls, like long-eared and short-eared owls. Additionally, they are considered a potential predator of small nestlings of the Eurasian griffon vulture.

Greater spotted eagles themselves have few well-documented predators. Furthermore, European pine martens are known to feed on nestlings of greater spotted eagles. Furthermore, in well-suited Russian habitats, nests were said (at least historically) to be found every of riverside, with fairly consistent pair reuse in following years. In Poland, birch (such as downy birch) appear popular in use. From a sample of 83 nests in the Volga–Ural area, the average nest height was .

Development of young

thumb|Egg of greater spotted eagle (Collection [[Museum Wiesbaden)]]

In Russia, greater spotted eagles reportedly seldom lay eggs until May, but sometimes as early as late April, with similar (if mildly earlier) laying times farther west.

The incubation stage lasts 42–44 days per most sources, but in southern Belarus, an incubation stage of only 39 days was documented. Incubation begins with the first egg. Meanwhile, in the Volga–Ural and Western Siberia areas, the mean brood sizes were 1.24 and 1.42, respectively. However, this species raises two fledglings at least somewhat more commonly than the lesser spotted eagle. Out of 50 nests in the Oka Nature Reserve, though, only one pair managed to produce two fledglings in a year.

In an experiment in a nest in Poland, a younger sibling was taken out of the nest to save it. At the time, the younger eaglet weighed and the older sibling weighed . After being taken out of the nest, the younger eaglet was raised with minimal interactions, to avoid imprinting, beyond feeding in captivity by humans. The eaglet shared a cage with an eastern imperial eagle and a lesser spotted eagle, both of which were indifferent towards it, and did not in any way care for or feed it. At the point of fledging, the eaglet was successfully reintroduced to its own parent's nest, fledged, and attained independence.

Dependence on the parents lasts 30 days more after fledging. Most were gone from Poland by the end of September. Juveniles were seen to wander elsewhere in Poland during autumn before finally migrating. Hybridization is now known to occur extensively. Hybrids occurs in the entire overlapping range of the two species, which is some . Interbreeding is mostly determined via conjecture in European Russia, which is roughly the eastern limit of the lesser spotted eagle's range and thus where hybridization possibly occurred most recently.

Hybrids between the two species often show a nape patch (absent in pure greater spotted eagles), an intermediate amount of spotting about the wings, and typically a larger body size than pure lesser spotted eagles. Despite their intermediate characteristics and larger size than lesser spotteds, the hybridization of the species is thought to be an indication of the abandonment of greater spotted eagle territories and the replacement of them by the more adaptive and populous lesser spotted eagles, as was indicated in an Estonian study. Lesser spotted eagles were estimated to number around 1,000 breeding pairs in Lithuania, with an estimated 37 or so of these containing one mate that was a greater spotted eagle. Furthermore, the Polish data indicated that the hybrids favoured the habitats of lesser spotted eagles, farther away from the wetter habitats of the greater spotted eagle and often nearer human development, with a local 50% reduction of pure greater spotted eagle pairs and 30% increase in hybrid pairs.

Habitat alterations to the environment by humans are thought in general to be partially beneficial to lesser spotted eagles and normally harmful to greater spotted eagles.

Status and conservation

thumb|left|Wintering greater spotted eagle in [[Israel]]

Despite maintaining a fairly vast breeding range—covering at least 9 million square kilometres in a band from the Baltic Sea in Europe eastward to the Pacific Ocean with minor outposts in the Indian subcontinent—this eagle occurs at extremely low densities. Greater spotted eagles are considered extripated as a breeding species from Hungary, Romania, Bulgaria, Czech Republic (where they may have never consistently bred), and Slovakia, as well as Israel where they last bred in the 1960s. Meanwhile, the Finland breeding population is also likely almost gone. The number of greater spotted eagles in Estonia declined 14% merely from 2004 to 2010, with declines having been detected for some time there. Belarus has as many as 150–200 breeding pairs (with confirmed counts of somewhat over 100) and is considered the most important breeding area known outside of Russia. The species' range has shrunk in the Russian Far East, where it was once widely found but is now restricted to below the middle Amur river, along the Ussuri river, and south Primorsky Krai, although anecdotal information suggests that it is still somewhat common in the whole Western Siberian lowlands from the Ural Mountains to the middle Ob River. In Armenia, it is considered one of the two rarest of the nation's 30 raptor species, along with the eastern imperial eagle. Wintering numbers of greater spotted eagles in the Mediterranean Basin were found to total about 300–400 individuals, with a bit under 34% of these in Israel, just under 32% in Greece, 16% in Turkey, somewhat smaller numbers in Romania and Spain, and tiny numbers in Southeastern Europe, Montenegro, and France.

Detrimental wetland management processes have additionally affected the species on their wintering grounds, where in Saudi Arabia at least, the effect has been offset by the species adapting to man-made bodies of water (unlike in winter, though, there is no evidence that they adapt well to man-made areas during breeding). The amount of usable manmade habitat has shrunk in Thailand with a change to dry season rice field cropping and the creeping presence of urbanization, along with probable rodenticide usage and other poisonings, likely harming the number of the species able to winter there. Poisonings were known to be a serious cause of mortality in a Shanxi reserve in China, where the eagles were seen to hunt down sickly or dying common pheasants that had been poisoned and then subsequently dying themselves, this becoming the primary local source of mortality.

In the Malay Peninsula, subsequent to a brief increase of the species from the 1960s to the 1980s due to environmental changes favorable to avian scavengers, a crash in numbers down to almost none was thought to be quite likely due to pesticide and other poison usage. The working groups have managed to undertake conservation efforts in Belarus, Estonia, and Ukraine—the core breeding areas left in Europe for the species—and have successfully instituted restrictions on forestry activities near nesting sites during the breeding season. An international project under the title "Above the borders: conservation of Greater Spotted Eagles at breeding and wintering areas, and on its flyway" has been established to improve conditions at the breeding sites and increase the abundance of the greater spotted eagle.

The building of artificial nest platforms did not seem to greatly aid greater spotted eagles in Nizhny Novgorod—unlike other raptors such as the osprey, the white-tailed eagle, and the golden eagle—as only one pair of greater spotted eagles were recorded to use a platform as a nest. In an exceptional positive note, it was found the European population of greater spotted eagle, as studied via microsatellites, retains quite high genetic diversity, meaning that there is no eminent threat of a genetic bottleneck for the species.

References

  • Greater spotted eagle Photographs, text and map at Oiseaux.net
  • Securing the population of Aquila clanga in Poland: preparation of the National Action Plan and primary site conservation at LIFE public database.
  • Above the borders: conservation of Greater Spotted Eagles at breeding and wintering areas, and on its flyway at LIFE public database and project website.