, Russia, a part of the species' breeding range 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 Islands,
Russia. Many eagles migrate from breeding grounds to
Korea,
Japan, and
China in winter. Most birds winter south of their breeding range, in the southern
Kuril Islands, Russia, and
Hokkaidō, Japan. Steller's sea eagle is less prone to
vagrancy than the
white-tailed eagle, as it lacks the long-range dispersal typical of juveniles of that species, but vagrant eagles have been found in North America at locations including the
Aleutian Islands,
Pribilof Islands, and
Kodiak Island, as well as a single individual seen in
Texas,
Nova Scotia,
Massachusetts,
Maine, and
Newfoundland, and inland in Asia to as far as
Beijing in China and
Yakutsk in Russia's
Sakha Republic, and south to as far as
Taiwan. The large body size (
see also Bergmann's rule) and distribution of Steller's sea eagle suggests it is a glacial
relict, meaning it evolved in a narrow
subarctic zone of the northeasternmost Asian coasts, which shifted its
latitude according to
ice age cycles, and never occurred anywhere else. Their nests are built on large, rocky outcroppings or at the tops of large trees on the coast and alongside large rivers with mature trees. Habitat with large
Erman's birches (
Betula ermanii) and floodplain forests of
larches,
alders,
willows, and
poplars are preferred. Some eagles, especially those that nest on seacoasts, may not migrate. The timing, duration, and extent of migration depends on ice conditions and food availability. On Kamchatka, eagles overwinter in forests and river valleys near the coast, but are irregularly distributed over the peninsula. Most wintering birds there appear to be residential adults. Steller's sea eagles that do migrate fly south to winter in rivers and wetlands in Japan, but occasionally move to mountainous inland areas as opposed to the seacoast. Each winter, drifting ice on the Sea of Okhotsk drives thousands of eagles south. Ice reaches Hokkaido in late January. Eagle numbers peak in the
Nemuro Strait in late February. On Hokkaido, eagles concentrate in coastal areas and on lakes near the coast, along with substantial numbers of white-tailed eagles. Eagles depart between late March and late April, with adults typically leaving before immatures. Migrants tend to follow seacoasts and are usually observed flying singly. In groups, migrants are typically observed flying apart. On Kamchatka, most migrants are birds in transitional plumages. They are also occasionally seen flying over the northern ocean or perching on sea ice during the winter. Subsequently, a Steller's sea eagle was photographed in Victoria, TX, not long after a winter storm blew into the state. This sighting has been verified by the Texas Bird Records Committee and is presumed to be the same individual as seen in Denali, though the photos are not sufficient to establish this identity. This was the first record of the species in the contiguous United States. The sea eagle was then confirmed in several locations in New Brunswick, Quebec, and Nova Scotia throughout the summer and into November. In December, it was spotted on the Taunton River in Massachusetts and then moved north to the Maine coast (Georgetown, Boothbay, and Pemaquid). More recently, it was seen on the east side on Newfoundland on April 22, 2022. In early 2023, this individual was spotted again in Maine along the shores of Georgetown. Marks on the wing indicate that all these sightings are of the same individual. This bird has been nicknamed "Stella" and garnered significant attention from birders, who boosted the local economy when traveling to see it. Beginning in the spring of 2024 in Newfoundland, a Steller's sea eagle was reported constructing a nest. ==Diet==