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Aug 27 2011

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Pallass Sea-Eagle (Haliaeetus leucoryphus)

Pallass Sea-Eagle

[order] ACCIPITRIFORMES | [family] Accipitridae | [latin] Haliaeetus leucoryphus | [authority] Pallas, 1771 | [UK] Pallass Sea-Eagle | [FR] Aigle pecheur de Pallas | [DE] Binden-Seeadler | [ES] Pigargo de Pallas | [NL] Witbandzeearend

Subspecies

Monotypic species

Genus

Members of the genus Haliaeetus are large to very large eagles, with long, broad wings and medium to short rounded or wedge-shaped tails. The bill is large, strong and compressed. The legs are short and the toes and talons powerfully developed

Physical charateristics

The adult has dull white forehead and lores, becoming golden-brown on the crown, nape and upper back, and dark brown on the lower back, rump and upper-tail coverts. The tail is blackish brown, with one broad white central band. The wing quills are dark brown, the outermost primaries being almost black. The fore neck is off-white, becoming fulvous on pointed breast feathers, and merging into dark brown on lower breast and belly; the under-tail coverts flanks and thighs are still darker. From below, the wing and tail feathers are dark brown, the tail clearly banded. The eyes are yellow; the cere grey; the legs and feet dull white.
Immatures are entirely brown above, the feathers fringed paler, with white on the inner webs of the secondary flight feathers. The tail is dark brown, mottled white towards the base. The throat is fulvous with darker central streaks. The rest of the underside is darker brown, the feathers often tipped paler. The eyes are brown; the cere grey, legs off-white. Tail of immatures may be longer than in adult. Most easily confused with the Golden Eagle (Aquila chrysaetos), which is about the same size. At rest, in adult plumage, the golden-brown head and neck forming a cape extending on to the back and contrasting with the dull brown upper parts, together with the white band on the brown tail are distinctive. In flight it is slimmer and lighter-looking than the Golden Eagle, possibly more like a kite. Adults with white tail bases are paler overall than immature Golden Eagles. Immatures are distinguished from those of the Golden, White-tailed and Bald Eagles (with which it scarcely comes in contact except at the eastern end of the range) by its all-dark tail without the pale base; they are not so dark as young Golden Eagles. In all plumages the bare tarsus distinguishes it from the Golden Eagle. The species is much smaller than the White-tailed Eagle, and has a weaker, dark-coloured bill.

Listen to the sound of Pallass Sea-Eagle

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

Copyright remark: Most sounds derived from xeno-canto


wingspan min.: 200 cm wingspan max.: 250 cm
size min.: 76 cm size max.: 84 cm
incubation min.: 38 days incubation max.: 42 days
fledging min.: 70 days fledging max.: 42 days
broods: 1   eggs min.: 2  
      eggs max.: 4  

Range

Eurasia : Central, also North India. The Pallas’ Sea Eagle breeds in Central Asia from the Kirghiz Steppe east to Manchuria, Tibet and eastern Mongolia; and south to Iraq, northern India and Burma. It winters west to the Crimea, in Iraq, and northern India. It is most likely to be seen on inland waters, although occurring rarely on sea coasts in winter.

Habitat

Unlike White-tailed Eagle, virtually confined to continental lower middle latitudes near large inland seas, lakes, and rivers, but also makes use of smaller lakes, ponds, backwaters, and wetlands up to altitudes sometimes exceeding 4000 m.

Reproduction

The display consists of mutual soaring and calling, without very noticeable aerobatics. In the southern parts of the range nests are built in big trees along the borders of rivers or lakes, and in the north on crags, or on the ground on sand-banks or in reed beds. Sometimes a nest is built by adding to another bird’s nest, and the eagle’s nest is itself sometimes taken over when empty by vultures or large owls. A new nest in a tree, may be four feet across by one foot deep, used year after year and growing larger over the years till it becomes six feet across by three to four feet deep. Nests on the ground may be even bigger. They are made of sticks, reeds, and other material, the largest branches up to three to four feet long and two to three inches thick. The lining is sparse, of grass, occasionally green branches, and oddments. Both sexes bring material, and often stand on the nest together; much material falls to the ground in tree nests. Nest construction or repair takes more than a month in north India, but probably less in the northern part of the range in view of the late arrival of breeding birds. During nest-building one or other of the pair may bring food to the nest.
Between two and four eggs are laid at intervals of two days. They are white, rather coarse and glossless. Incubation begins with the first egg and is mostly the responsibility of the female, though the male does take a small share. Food is brought to the nest by the male during the incubation period and he often perches nearby for long periods. The incubation period of is about 40 days.
When the young first hatch, they are tended by the female. In the early stages the male usually catches prey, while the female remains on the nest and feeds the young; later the female takes a share and the male also helps in feeding the young. The fledging period is about 70-105 days, the latter in north India making, with the 40 days incubation period, a total breeding period of about 140-150 days. Birds breeding further north could not take this long to rear their young, and young are fledged in Turkestan by early July from eggs laid in late March, a combined period of about 100 days. Young from clutches laid in May in Tibet must be able to migrate within a month or so of leaving the nest in late August to September.

Feeding habits

Fish form the main part of the diet, often taken dead or stranded. When available, carrion, also young and sick or disabled adults of water birds such as duck or coots. It has been known to kill a pelican and a crane. It rarely takes fully active birds or fish, but can decimate the young in colonies of water birds. This is a sluggish, scavenging bird, given to perching for long periods on trees or crags, and often very bold around camps or places where fish are landed. It takes more carrion or dead fish rather than catching live prey for itself. It can, however, snatch live fish from the water surface, and it takes young duck and the young of storks and other such birds. It frequently pursues other large raptors, including Ospreys, in the hope of obtaining what they have caught, but will not contest a carcase with Himalayan Griffon Vultures. In north India in winter it catches fish more than in its breeding areas – it catches fish by snatching them from the surface in the manner of the African Fish Eagle, rather than by plunging into the water like an Osprey.

Video Pallass Sea-Eagle

httpv://www.youtube.com/watch?v=wwNmVcE9yrA

copyright: J. del Hoyo


Conservation

This species has a small, declining population as a result of widespread loss, degradation and disturbance of wetlands and breeding sites throughout its range. It therefore qualifies as Vulnerable.
The extralimital range of the species lies in Kazakhstan, Tajikistan, Uzbekistan, Iran and Afghanistan, the last two of which it visits as a non-breeding visitor (to the Seistan swamps, south Caspian Sea and the Persian Gulf). Breeding has not been confirmed in Tajikistan, but passage and non-breeding visitors occur at water bodies in the south of the country and the Pamis mountains. Similarly, no nests are known in Uzbekistan, but breeding is considered probable on the eastern Aral Sea and in the Amudar’ya valley where there are (or were until recently) frequent sightings, although some of these probably refer to non-breeders or birds moving north after breeding in India. In Turkmenistan, too, records are considered to relate to dispersing non-breeders. In Kazakhstan Pallas’s Fish-eagle formerly summered regularly and in some numbers in the Volga_Ural steppes and it is generally more regular in the west of the country, over half of c.50 records during 1970_1995, including five in the breeding season, coming from the area between the Volga, Ural and Emba rivers.
There are further widespread reports of birds in summer from the north of the country (e.g. Turgay depression, Kurgal’dzhino) as well as the south and south-east. One was collected in the southern Altay in 1966, but none there in the period 1978_1986. There are few breeding records in Kazakhstan, where the range apparently once extended from the north-east shores of the Caspian Sea (last bred 1947) east to the Aral Sea, Syrdar’ya river and Balkhash lake_Ili river area. A nest was found even further east at Lake Markakol’ (Altay) in 1876. After dramatic declines in these areas, observations suggested breeding may have taken place on or near the Ili river in the 1980s: in the Ili valley close to the Malaysary mountains, two adults were recorded in May 1985, single birds in June 1985 and May 1986; some 100 km further east in the valley (near the Kalkany mountains), single birds were seen in July and August, and two displaying birds in August 1989. Stragglers have occurred elsewhere from Ukraine, Crimea, and the Sea of Azov to eastern Caucasus, but it is now only an accidental visitor to these regions. Similarly, it was once a regular winter visitor to Iraq in small numbers, but this no longer appears to be the case. It has occurred further west into several European countries as a vagrant, although there appear to be no recent records. The population is likely to be <10,000 mature individuals.
Pallass Sea-Eagle status Vulnerable

Migration

Little known; evidently migratory or partially migratory in regions of climatic extremes, mainly resident or dispersive elsewhere. Few individuals over-winter in northern parts of breeding range where rivers freeze; and normally ranges south to Iran (south Caspian, Seistan, Persian Gulf), Afghanistan (Seistan), and probably to Indian subcontinent where presumed presence masked by large winter-breeding local populations. Breeds India October-February, then disappears from lowlands for hottest months large numbers of non-breeding summer visitors (June-July) on plateau lakes of west Tibet may be linked to this exodus.
Autumn dispersal USSR begins October in central Kazakhstan. Spring return to some extent dependent on thawing of rivers; reappears Syr-Dar’ya river in February and begins breeding there March, but northward movement continues April-May and these presumed immatures. In the warmer parts of its range, such as in north India and north Burma, it is resident, but on the high Asian plateau and in Central Asian steppes it is a migrant, departing in September-October and returning late in the year, March to mid-May, to breed. On migration it travels in small groups of five to seven individuals, but may collect in larger numbers in favourable feeding places. It is more gregarious than most of the genus, and it is only in winter that it is likely to appear on any sea coast, and then only on the landlocked Black and Caspian Seas.

Distribution map

Pallass Sea-Eagle distribution range map

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