Black armpits, white rump and strong white wingbar, legs dark grey. Non-breeding habitat: intertidal mudflats. Feeds as much by night as by day. Forms large communal roosts. Usual call is distinctive loud, far-carrying slurred whistle: 'tlee-oo-ee'.First arrivals in SA in September from northern nesting grounds on lowland Tundra north of tree limit. Young birds remain in south during their first breeding season, thus present all year in SA. On Leisure Isle may occur in Kingfisher Creek area on the mudflats, feeding at low tide.