This distinctive and large duck is reminiscent of a goose and is typically found in coastal wetlands, tidal mudflats, and adjacent grassy fields. Its striking plumage can appear mostly black-and-white from a distance, but up close, the head displays a deep glossy green color, and there’s a broad dark rusty band across the breast. The male features a raised knob at the base of its red bill, while juveniles are generally duller overall with a whitish face and eyering. It is less abundant and more localized further inland around lakes and along rivers. Often observed walking and grazing, sometimes in flocks.