Greater Spotted Eagle

The greater spotted eagle, occasionally just called the spotted eagle, is a large bird of prey. Its feathered legs indicate it as a member of the subfamily Aquilinae, also known as the “booted eagles”.

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. The overall effect of the broad wings and short tail can give them an almost vulture-like silhouette. The feet are large, and the feathers covering the legs are less compactly arranged than on lesser spotted eagles.

Greater spotted eagles tend to perch in the open. Most perches are on treetops at a forest edge, or more isolated vantage points such as a bush, utility pole, or steep riverbank. It is not uncommon for greater spotted eagles to forage from the ground, or rest there in a somewhat hunched posture.

The upperwing covert feathers are often a shade paler than the rest, though these eagles generally appear uniformly dark with two contrasting features: a pale beak and a narrow white U above the tail, though the latter is usually concealed at rest. The species is sexually dimorphic or even polymorphic. Pale and intermediate phenotypes are rare, although they can be slightly more common in eastern ranges.

Birds that breed in the Volga–Ural area are slightly larger and more muted in plumage characteristics. Slightly smaller individuals seem to be prevalent farther west in Europe. There appears to be a near 5% size difference in favor of Indian wintering birds over Middle Eastern ones.

Vocalizations

The greater spotted eagle is quite noisy when breeding and is often very vocal in winter, especially when in small loose flocks.[4] The most common call, often heard during intraspecies conflicts, is a soft, one-syllable, penetrating, high-pitched, urgent whistle, variously transcribed as kyack, kluh, tyuck, or dyip. The call is not unlike that of lesser spotted eagles but is slightly deeper and more ringing. The calls are higher pitched than steppe eagles' and much higher pitched than those of the eastern imperial eagles (Aquila heliaca), the latter having a guttural call somewhat reminiscent of a frog. Additionally, a similar three-syllable bark is seemingly used to warn off intruders at a feeding site, sometimes considered a harsh chrr-chrr-chaa-chaa, kyak-yak-yak, and kyew-kyew-kyew. The cumulative effect of the repeated call has been compared to that of a "small hound". As with many raptors, the female’s tone is lower pitched and hoarser. One individual greater spotted eagle recorded over two days was found to utter an unusual ringing call that sounded remarkably similar to the first two syllables of the typical call of the crested serpent eagle (Spilornis cheela).

Distribution and habitat

This raptor breeds primarily in the Palearctic and the Indomalayan regions. It also breeds in central and southeastern Europe; however, it is highly restricted to small, non-contiguous pockets in Poland, Belarus, Ukraine, 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. An uncertain number of breeding birds spill over into the edge of eastern Finland. 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.

Nests

The species builds a large stick nest which may measure 70–110 cm across and up to 100 cm deep. Nests appear significantly smaller in the Indian subcontinent, at around 60 cm across—shorter than the eagle’s own total length—and merely 5–15 cm deep.

Unusually, these eagles tend to build nests using fresh branches with foliage or green conifer needles still attached.

Habitat

Greater Spotted Eagles eat frogs, snakes and lizards, waterfowl, fish, insects, carrion, and small mammals up to the size of hares.

They hunt in flight, from a perch, or on the ground. They also steal food from other raptors, including other Greater Spotted Eagles and Milvus migrans (Black Kites).

Conservation Status

It is classified as vulnerable to extinction by the IUCN. As of 2000, the world population of this eagle was estimated at less than 4,000 breeding pairs. The primary threats are habit degradation and habitat loss, as well as human disturbance during the mating season. Aquila clanga is currently listed as Vulnerable by BirdLife International.