The Eider Duck (Somateria mollissima) is a large sea duck renowned for its striking plumage, with males displaying a bold black-and-white pattern and females a mottled brown for camouflage. Commonly found in coastal waters, including Faxaflói Bay in Iceland, Eider Ducks are year-round residents in these cold, nutrient-rich environments. They primarily feed on mollusks and crustaceans, using their specialized bills to dive and forage along the seabed. Eiders are also famous for their soft down, which they pluck from their own bodies to insulate nests. Faxaflói Bay provides crucial habitat for these ducks, offering both feeding and nesting opportunities. Monitoring Eider populations in this region aids in understanding marine ecosystem health and the impacts of changing ocean conditions on coastal wildlife.