An eider is a large sea duck that lives in the cold northern waters of the Arctic and North Atlantic. These remarkable birds are famous for the incredibly soft, warm down feathers they use to line their nests.

For centuries, people have collected eider down (carefully taken from nests after the ducklings hatch) to make the warmest, lightest quilts and jackets imaginable. The word eiderdown originally meant the fluffy insulation from eider nests, though today it often refers to any puffy comforter. True eider down is still prized as one of the finest natural insulations in the world.

Eiders are tough, hardy birds perfectly adapted to harsh Arctic conditions. They dive deep underwater to catch mollusks and crustaceans, and they can survive in waters so cold that most other ducks would freeze. The males have striking black and white plumage, while females are mottled brown, providing camouflage while nesting.