Northern Prairie Wildlife Research Center
Body: Medium-sized duck, 1 3/4 - 2 1/4 pounds, 17-20 inches long. Black back contrasts with white belly. Iridescent green head. Eyes gold. Round white spot on cheek. Bill short and black. Feet yellow-orange. Wings: Coverts and speculum form white patch; remainder of wing black. Voice: Piercing speer. In Flight: White on body. Dark head. White on trailing edge of underwings. Fast wingbeat causes distinct whistling sound.
Ranging from dull gray appearance to blotchy near-winter coloration. Head brownish green. White spot in front of eyes blotched with brown. Eyes, bill, wings and feet same as in winter.
Body: Mottled gray over back, chest and sides. Throat and belly white. Brown head lacks white cheek-spot. Bill short and black, occasionally with orangish tip. Feet yellow-orange. Wings: Dark with lesser and middle coverts gray; inner greater coverts and secondaries white. Voice: Low quack.