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Aug 27 2011

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Black Eagle (Ictinaetus malayensis)

Black Eagle

[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Ictinaetus malayensis | [authority] Temminck, 1822 | [UK] Black Eagle | [FR] Aigle noir | [DE] Malaienadler | [ES] Aguila milana | [NL] Indische Zwarte Arend

Subspecies

Monotypic species

Genus

Members of the genus Ictinaetus are large, but lightly built eagles with small beaks. They have very long wings and a long tail. The legs are feathered, and the talons long, but only slightly curved. The outer digit is quite short. These characteristics of the feet are probably adaptations for taking nestling birds from tree-top nests. There is a slight crest, formed by the pointed feathers of the crown. The adult is mostly black; the immature more buff.
This genus is probably a specialised booted eagle, but there is some evidence, that it is closely related to the kites, although that would make the feathered tarsi difficult to explain. The genus contains one species in tropical Asia.

Physical charateristics

The entire plumage of the adult is black to dark chocolate brown, paler on secondaries and scapulars.A small amount of white sometimes forms a patch on the upper tail coverts. The tail and wing quills have grey bands on the inner webs,and there is, in flight, a white patch at the carpal joint formed by the white bases of the primary flight feathers. The eyes brown, the cere and feet yellow.
Immatures are dark sepia brown above, the feathers of crown and nape and some on the back are tipped with buff. The upper tail coverts are banded with sepia and buff making a pale bar across the base of the tail. The sides of the head are golden-brown. The rest of the under side as far as the tail coverts is rufous to golden brown, with black streaks on the breast, and with some black bars on the tail coverts. The under-wing coverts are buff. The wing and tail quills are less clearly banded than in the adult. The eyes are brown, the feet and cere yellow.
The primary feathers of this species are very long, reaching beyond the tip of the tail when folded. They are strongly curved and are quite flexible. The feet are also weak, the claws less sharply curved than most eagles.

Listen to the sound of Black Eagle

[audio:http://www.planetofbirds.com/MASTER/ACCIPITRIFORMES/Accipitridae/sounds/Black Eagle.mp3]

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 164 cm wingspan max.: 178 cm
size min.: 67 cm size max.: 81 cm
incubation min.: 0 days incubation max.: 0 days
fledging min.: 0 days fledging max.: 0 days
broods: 1   eggs min.: 1  
      eggs max.: 2  

Range

Oriental Region : widespread. The Indian Black Eagle is found in hilly, forested or wooded country in India, Sri Lanka, Myanmar (Burma) and Malaysia.

Habitat

This eagle inhabits wooded mountainous country, from near sea level to about 9,000 feet. It soars in a unique manner, moving at a very slow pace, with the wings held out at full stretch and above the back, the primaries widely separated and projecting some distance from the wing-tips. While circling very slowly over forests, it will also glide over grassy hillsides like a harrier very slowly, but without beating its wings. It is able to fly at a very slow pace, and to circle in and out of small clearings in the forest, just above the tree-tops. It sometimes flies into the mouths of caves and takes either bats or swiftlets with ease. At other times it can be seen soaring high above the mountain slopes, when it seems to have very large wings in relation to its body area.
The long and soft primaries must be an adaptation to assist the very slow flight, which help the bird in its detailed search of forest and grassy hillside for birds’ nests, the contents of which are one of its chief foods. The flexibility and length of the primaries permit exceptionally wide separation at their tips, which is a useful adaptation enabling the bird to maintain very low flying speeds. When seizing a bird’s nest it drops from flight on to the tree-tops, or drops suddenly on small animals on grassy hillsides.

Reproduction

The Indian Black Eagle carries out a spectacular plunging display, high over its mountain habitat, in which the wings are folded so that their tips touch the tip of the tail, producing a heart-shaped silhouette. It plunges down at great speed, then throws up again. This display is like that of Ayre’s Hawk-eagle (Hieraaetus dubius) and the African Mountain Buzzard (Buteo oreophilus), but unlike any kite. Pairs also chase one another among the forest trees, passing with great skill between the trunks, not unlike some kites. It also performs typical undulating displays.
The nest is built high up in a big tree, often one overgrown with creepers. It is a substantial structure – four feet across by one-and-a-half to two feet deep – made of small sticks, and lined with green leaves. Pairs often have two nests about a mile apart. Nest repair begins two to three months before egg-laying.
One egg is laid (two occasionally) – laying dates vary by latitude between November and May, but mostly during the cold dry season. The breeding season in India is long and irregular, and may be more so in the true tropical rain forest.
No details of the incubation behaviour and fledging period are available.

Feeding habits

The main part of the diet of the Indian Black Eagle is birds’ eggs and young, taken in the tree-tops. It also takes ground prey, including mammals up to the size of a large rat, and the eggs and young of ground birds. It occasionally takes in flight small to medium-sized birds, bats, and swiftlets.
The talons, much less sharply curved than in most raptors, are an advantage when taking whole birds’ nests, from which the eagle consumes the contents at a later time

Video Black Eagle

httpv://www.youtube.com/watch?v=vZFnP6GewJU

copyright: Josep del Hoyo


Conservation

This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size may be moderately small to large, but it is not believed to approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
Black Eagle status Least Concern

Migration

Sedentary

Distribution map

Black Eagle distribution range map

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