153712 Arctic Tern Sterna paradisaea L 35cm. Graceful seabird with buoyant flight. Plunge-dives for fish. Sexes are similar. Adult has grey upperparts, black cap, and pale underparts, palest on cheeks, darkest on belly. Has uniformly red bill, short, red legs and long tail streamers. In flight from below, flight feathers look translucent, with narrow, dark trailing edge to primaries. Juvenile has white underparts, incomplete dark cap and scaly grey upperparts. In flight from above, has dark leading edge, and white trailing edge, to inner wing. Legs and bill are dull. Voice Utters harsh krt-krt-krt call near nest. Status Locally common summer visitor and passage migrant. Colonial nester, always near coasts; commonest in N.