Body: Medium-sized water bird not belonging to duck family but found in close association. Sooty gray with somewhat darker head, back and wings. White undertail coverts. Feet with lobed toes and sharp claws. Bill whitish or ivory with red markings. Eyes red. Wings: Overall sooty gray. Secondaries tipped with white. Voice: Quarrelsome high-pitched twittering. In Flight: Dark body contrasts with white bill and undertail coverts. Strong but reluctant flyer.