Smallest diving duck, the Bufflehead, is easily distinguished from other ducks. The male has a white underside and a dark back that appears black, but upon closer inspection, is actually a deep iridescent greenish-purple. At the back of the black head is a wedge of white. This mark distinguishes the Bufflehead from the larger goldeneyes, which have white in front of their eyes. The smaller female is a drab, brownish, dusty-black with white ear- and wing-patches.