The Common Eider is a large diving duck with a distinctive sloping forehead, black body, and white breast and back. It has a black crown and a greenish olive bill with an olive green wash on the back and sides of the neck. It is most common as a winter visitor but also breeds locally in small but growing numbers. Common Eiders feed near rocky shores, diving for mollusks and crustaceans. Large flocks are found all along the Vineyard Sound shoreline in Falmouth with large concentrations in Woods Hole. This male Common Eider was seen near the Menauhant Yacht Club in East Falmouth.