This is an adult. This spectacular, immense eagle breeds in the Russian Far-East with the majority wintering in northern Japan. Here at Lake Sunset, wintering eagles are baited and they come into the ice to feed providing good photo opportunities. However, this season the numbers were lower than usual and we only saw a few. This iconic species is the largest sea-eagle and one of the heaviest of all raptors in the world, weighing up to 20 pounds. It has a relatively small declining population of about 5,000 individuals and is thus classified as Vulnerable by IUCN. Threats include habitat degradation, pollution, poisoning by lead shot, and over-fishing. An extremely rare dark morph, lacking the white wing patches and leggings has been documented by Kaiser (2011). Canon PowerShot SX60.
References:
BirdLife International (2019) Species factsheet: Haliaeetus pelagicus. Downloaded from http://www.birdlife.org on 18/05/2019
Kaiser, M. (2011) A living specimen of the dark form of Steller’s Sea Eagle, Haliaeetus pelagicus (“niger”) in captivity. J Ornithol 152: 207. https://doi.org/10.1007/s10336-010-0580-2
Meyburg, B.U., Kirwan, G.M. & Christie, D.A. (2019). Steller's Sea-eagle (Haliaeetus pelagicus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/52988 on 19 May 2019).