Steller's Sea Eagles, Kamchatka, Russia

Stellers' Sea-eagle is the biggest bird in the Genus Haliaeetus and is one of the largest raptors overall. The typical size range is 86.5 to 105 centimetres (34.1 to 41 in) long and the wingspan is 203 to 241 centimetres (80 to 95 in). On average, females weigh from 6.8 to 9 kilograms (15 to 20 lb; 1.07 to 1.4 st), while males are considerably lighter with a weight range from 4.9 to 6 kilograms (11 to 13 lb; 0.77 to 0.94 st). An unverified record exists of a huge female, who apparently gorged on salmon, having weighed 12.7 kilograms (28 lb; 2.00 st). Two subspecies have been named: the nominate pelagicus, and the Korean Sea-eagle, Haliaeetus pelagicus niger. The latter name was given to the Korean population which was apparently resident all year and lacked white feathers except for the tail. Its validity is disputed; it may have been a morph and not a genetically distinct population. In any case, the Korean population of this species is extinct since the 1950s due to habitat loss and hunting.
The relationships of Steller's Sea-eagle are not completely resolved. mtDNA cytochrome b sequence data tentatively suggests that this species's ancestors diverged early in the colonization of the Holarctic by sea eagles. This is strongly supported by morphological traits such as the yellow eyes, beak, and talons shared by this species and the other northern sea-eagles, the White-tailed and Bald Eagles, and biogeography.