Birds
Steller's Sea Eagle
Haliaeetus pelagicus · also called stellers sea eagle, steller's sea eagle
The Steller’s sea eagle is the heaviest eagle alive, built around a massive orange bill made for tearing into salmon along the icy coasts of the Russian Far East. In winter, thousands gather on drifting sea ice off Japan, one of the great wildlife spectacles of the north Pacific.
Overview
Steller’s sea eagles breed along the coastal Russian Far East, wintering on pack ice around Hokkaido, Japan. Females reach up to 9 kg and a 2.4 m wingspan, the heaviest eagle species in the world, built around an unusually massive orange bill for tearing into salmon.
Following the salmon
Their movements track the seasonal salmon runs, gathering where fish are abundant, and building some of the largest stick nests of any bird.
A single vulnerable stronghold
With only a few thousand individuals worldwide, confined largely to one breeding region, the species is exposed to logging, declining salmon stocks, and lead poisoning from scavenged carcasses.
Status
The Steller’s sea eagle is Vulnerable and decreasing.
Steller's Sea Eagle: common questions
How does the Steller's sea eagle compare in size to the bald eagle?
It is considerably larger and heavier than the bald eagle, generally recognised as the heaviest eagle species in the world by average body mass, with large females reaching around 9 kilograms compared to a typical bald eagle female of roughly 5 kilograms, meaning the Steller's sea eagle can weigh nearly twice as much. Its wingspan, at over 2.4 metres in large females, also exceeds that of the bald eagle, and its notably larger, deeper, more massive bill gives it an even more imposing appearance up close. Both species belong to the same genus, Haliaeetus, and share a broadly similar fish-based diet and coastal habitat preference.
Why does the Steller's sea eagle have such a huge bill?
Its unusually large, deep, bright orange-yellow bill is proportionally bigger than that of almost any other eagle species, and this size closely matches its diet, since it feeds heavily on large, tough-skinned fish such as salmon that require considerable force and leverage to tear open and process. A bigger, stronger bill allows the eagle to handle bulkier prey items more efficiently than a smaller-billed eagle could, and the bright colouring likely also plays a role in visual signalling between individuals, since bill colour and condition in many raptors can reflect health and age.
Where does the Steller's sea eagle spend the winter?
A substantial portion of the world population migrates south each year from breeding grounds along the coasts and rivers of the Russian Far East to spend the winter around the Sea of Okhotsk and the northern Japanese island of Hokkaido, where the birds famously gather on drifting sea ice to scavenge fish carcasses and hunt near open leads in the ice. This winter concentration on Hokkaido's pack ice has made the location one of the most reliable and popular places in the world for birdwatchers and photographers to see large numbers of Steller's sea eagles together at close range.
Why is the Steller's sea eagle considered Vulnerable?
Its total population is estimated at only a few thousand individuals worldwide, and several converging pressures continue to reduce it, including logging and industrial development along the rivers where it breeds and where salmon spawn, declining wild salmon stocks from overfishing and habitat degradation, and lead poisoning caused by eating carcasses of animals shot with lead ammunition, which has been documented as a significant cause of death in wintering birds on Hokkaido. Its restricted, largely single breeding region also makes the overall population more vulnerable to any localised environmental disaster than a more widely distributed eagle species would be.