A chunky, unmistakable waterbird. Adults are dark grey with a bright white bill and matching forehead shield, while younger birds show a paler breast and a duller bill that whitens as they mature. When seen on land, its large feet with lobed toes are obvious. It frequents freshwater and brackish marshes, lake edges, and rivers, and is occasionally found on saltwater. During the breeding season pairs defend territories fiercely, but outside this time large flocks can gather, sometimes numbering in the hundreds. It is distinctive across most of its range, though in some regions it should be compared with the similar Red-knobbed Coot. Its calls are varied, including high squeaks, squawks, and shorter clipped notes.