Thursday, October 15, 2015


Steller's sea eagle (Haliaeetus pelagicus is a large bird of prey in the family Accipitridae found in coastal northeastern Asia and mainly preys on fish and water birds. On average, it is the heaviest eagle in the world, at about 5 to 9 kg (11 to 20 lb), but may be below the harpy eagle (Harpia harpyja) and Philippine eagle (Pithecophaga jefferyi) in some standard measurements. This bird is named after the German naturalist Georg Wilhelm Steller.This species was first described as Aquila pelagica by Peter Simon Pallas, in either 1811 or 1826 depending on the source. Subsequently, many generic and specific names have been variously spelled, e.g., Haliaetus pelagicusHaliaetos pelagicaFaico leucopterusFaico imperatorThalassaetus pelagicusThalassaetus macrurusHaliaeetus macrurus, and most recently Thallasoaetus pelagicus. Besides its normal common name, the species has sometimes been referred to as the Pacific eagle or white-shouldered eagle. In Russian, the eagle has been called morskoi orel (sea eagle), pestryi morskoi orel (mottled sea eagle) or beloplechii orlan (white-shouldered eagle). In Japanese, it is called 0-washi (large eagle or great eagle).

Steller's sea eagle is the biggest bird in the genus Haliaeetus and is one of the largest raptorsoverall. Females may vary in weigh from 6,195 to 9,500 g (13.658 to 20.944 lb), while males being rather lighter with a weight range from 4,900 to 6,800 g (10.8 to 15.0 lb).The average weight is variable, possibly due to seasonal variation in food access or general condition of eagles, but has been reported from as high as a mean mass of 7,757 g (17.101 lb) to a median estimate weight of 6,250 g (13.78 lb), excluding expired eagles that were poisoned by lead and endured precipitous weight loss by the occasion of their deaths.

At its average weight, the Steller's seems to outweigh the average harpy by approximately 500 g (1.1 lb) and the average Philippine eagles by more than 1,000 g (2.2 lb). Steller's sea eagle can range in total length from 85 to 105 cm (2 ft 9 in to 3 ft 5 in), apparently males average about 89 cm (2 ft 11 in) in length, while females average about 100 cm (3 ft 3 in), marginally shorter on average than the harpy eagle and about 65 mm (2.6 in) shorter than the Philippine eagle. The wingspan is from 1.95 to 2.5 m (6 ft 5 in to 8 ft 2 in) and the wing chord measurement is 560 to 680 mm (22 to 27 in).The sea eagle's wingspan is one of the largest of any living eagle, at an median of 2.13 m (7 ft 0 in) per Ferugson and Lees (2001) or a median of 2.2 m (7 ft 3 in) per Saito (2009). Closest are the closely related white-tailed eagle (Haliaeetus albicilla), at reported median wingspans of 2.1 and 2.18 m (6 ft 11 in and 7 ft 2 in) and the unrelated wedge-tailed eagle (Aquila audax), at reported average wingspans of 2.04 and 2.23 m (6 ft 8 in and 7 ft 4 in); nonetheless, both other eagles are rather smaller in overall size, particularly body mass.

As in most Haliaeetus eagles, the tarsus and tail are relatively short compared to other very large eagles at 95–100 mm (3.7–3.9 in) and 320–390 mm (13–15 in) in length, respectively, the Philippine eagle besting it by up to 40 mm (1.6 in) and 110 mm (4.3 in) apparently. In all sea and fish eagles, the toes are relatively short and stout, with the bottom of the foot covered in spiracles and the talons being relatively shorter and more strongly curved than in comparably sized eagles found in forests and fields, such as the "booted eagle" group (i.e. Aquila) or "harpy eagles", all of these specializations developed in the aid of capturing fish rather than medium-sized mammals and large birds, although clearly these are not excluded from capture. As in all fish and sea eagles, as well as the majority of the world's fish-eating raptors, Steller's sea eagle has spiracles, which are bumpy waves all along the bottom of their feet, which allow them to hold fish that may otherwise slip out of their grasp.The feet are very powerful despite not bearing talons as long as those of a harpy eagle. In one case, a wildlife veteranian was badly injured when a female eagle grabbed his arm and embedded her talons, piercing through to the other side of his arm. Perhaps the most noted physical feature of Steller's sea eagle, other than its overall great size, is its extremely large billand prominent head. The skull is around 14.6 cm (5.7 in) in total length, the culmen Steller's sea eagle's bill is probably the largest of any living eagle, just surpassing to the Philippine eagle with a sole known culmen measurement (from a mature female) of 72.2 mm (2.84 in), and are similar in robustness (if slightly shorter in culmen length) to those of the largest accipitrids, the Old World vultures.

he mature Steller's sea eagle is dark brown to black over the majority of its body, with strongly contrasting white on the lesser and median upper-wing coverts, underwing coverts, thighs, under-tail coverts and tail. Their wedge-shaped, white tails are relatively longer than those of the white-tailed eagle. The bold, pied coloration of adults may play some part in social hierarchies with other eagles of their own species during the nonbreeding season, although this has not been extensively studied. The eyes, the bill, and the feet of adults are all yellow in colouration. Two subspecies have been named: The relatively widespread nominate H. p. pelagicus and the virtually unknown H. p. niger. Korea. Last seen in 1968 and long believed to be extinct, a female matching H. p. niger in appearance was born in captivity in 2001. Both its parent were "normal" in appearance, indicating that H. p. niger is an extremely rare morph rather than a valid subspecies, as had been suggested earlier.
 The latter name was given to the population which lacked white feathers except for the tail and supposedly was resident all year in
The first down plumage of new nestlings is silky white, though they soon turn a smoky brown-grey. As in other sea eagles, remiges and retrices of the first-year plumage are longer than adults. Juvenile plumage is largely a uniform dark brown with occasional grey-brown streaking about the head and the neck, white feather bases, and light mottling on the retrices. The tail of the immature eagle is white with black mottling basally.The young Steller's sea eagle has a dark brown iris, whitish legs and blackish-brown beak. Through at least three intermediate plumages, mottling in the tail decreases, body and wing feathering acquires a bronze cast, and the eye and bill lighten in colour. Definitive plumage is probably reached in the fifth year of life, based on fragmentary data from captives. First and intermediate plumages are difficult to distinguish from those of the white-tailed eagle, which occurs in the entire breeding range of the Steller's.

Steller's sea eagles are not extensively known for their voices, but are known to make a deep barking cry, ra-ra-ra-raurau, in aggressive interactions. Their call is similar to the white-tailed eagles but deeper. During the display at the beginning of the breeding season, they have been heard to make calls to each that sound like very loud, deep-voiced gulls.The relationships of Steller's sea eagle are not completely resolved. data tentatively suggest that this species's ancestors diverged early in the colonization of the Holarctic by sea eagles.
Steller's sea eagle breeds on the Kamchatka Peninsula, the coastal area around the Sea of Okhotsk, the lower reaches of the Amur River and on northern Sakhalin and the Shantar IslandRussia. The majority of birds winter farther south, in the southern Kuril IslandsRussia and HokkaidōJapan. That being said, Steller's sea eagle is less vagrat than the white-tailed eagle, usually lacking the long-range dispersal common in juveniles of that species. Vagrant eagles have been found in North America, at locations including the Pribilof Islands and Kodiak Island, inland to as far as Peking in China and Yakutsk in Russia's Sakha Republic, and south to as far as Taiwan, but these are considered to be individual eagles that have strayed far from the species' typical range.

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