- Medium-sized diving duck.
- Mostly black-and-white plumage, varying throughout year.
- Black wings in all plumages.
- Male has long central tail feathers and often a pink band near tip of black bill.
Male DescriptionSummer plumage: Black head, chest, and wings. Gray face patch surrounding eyes. Upper back feathers long, and buffy with black centers. Central tail feathers very long.
Winter plumage: White head and neck. Gray patch around the eyes. Large black spot extending from cheek down sides of neck. Black band across lower neck and breast. Back black. Long, gray upper back feathers. Long, black central tail feathers. Eyes dull yellow-brown.
Female DescriptionSummer plumage: Mostly dark head and neck, with white around eyes, extending in a thin line toward the ear. Back and breast are variably brown or gray. Eyes brown.
Winter plumage: White head and neck. Round dark brown cheek patch. White belly. Variably brownish gray crown, breast, and back.
Immature DescriptionJuvenile has dark brown head, white or pale brownish gray face, white belly, and brownish gray upperparts, breast, and upper belly. Immature resembles adult of same sex.