English: This is a medium-sized tern with dark grey upperparts, white underparts, a forked tail with long flexible streamers, and long pointed wings. The bill is yellow and the legs red. It has a black cap in breeding plumage as seen in this shot. In the winter the cap is greyish white, flecked and streaked with black, there is a dark mask through the eye, and the tip of the bill becomes dusky.