The White-winged Black Tern is one of the smaller terns, and the smallest of the three marsh terns. It is most often seen in its nonbreeding plumage of grey back and tail, whitish underwings and underparts. The bill is black, and the head has a variable black horseshoe over the top of the crown and behind the eye. The legs are pinkish black. Many birds acquire their breeding plumage before departing for Eurasia in autumn. In breeding plumage the bill and legs are red, the head and body black, and the wings are grey with a white shoulder and black wing-linings.
The White-winged Black tern is also known as the White-winged Tern.