- Medium-sized duck.
- Very long bill, wider at tip than at base.
- Male with iridescent green head, white chest, and rusty sides.
Male DescriptionBreeding Plumage: Head dark glossy green. Bill black. Back black. Chest white. Flanks and belly chestnut-brown. Eyes yellow.
Eclipse Plumage: Duller. Head and breast brownish black speckled with whitish or tan. Back black with tan feather edges. Flanks light brown. May show indistinct white crescent on face behind bill. Eyes yellow.
Female DescriptionGrayish-brown overall; some feathers have light edging with darker centers. Bill olive-green with yellowish base and edges. Eyes brown.
Immature DescriptionSimilar to adult female.