Largest duck in N. Hemisphere. In Alaska, nest close to ocean around tundra ponds. In Maine and Maritimes, nest on small coastal islands. Population probably around 150,000. Slow reproducers- breed at 3 years, ave.
Gulls inadvertantly help protect eider nests.
BUT then prey on class 1 ducklings. Nest in May on Penobscot Bay, June on Hudson Bay, late June in high arctic. Eider down is an important economic resource in some areas, and is salvaged after nesting is over. Averages 1 oz. In winter, do not necessrily migrate very far, but simply shift to open coastal bays.