The Arctic Tern (Sterna paradisaea ) is a seabird of the tern family Sternidae. This bird has a circumpolar distribution breeding abundantly in arctic and sub-arctic regions of Europe, Asia and North America as far south as Brittany and Massachusetts. It is strongly migratory, wintering in the Antarctic. This 12,000 mile journey ensures that this bird sees more daylight than any other creature on the planet.
This species breeds in colonies on coasts, islands and occasionally inland on tundra near water. It lays up to four eggs. Like all white terns, it is fiercely defensive of its nest and young and will attack humans and other large predators, usually attacking the back of the head. Although it is too small to cause serious injury, it is capable of drawing blood, a distinction from the Common Tern, which has a blunter bill.
Like all Sterna terns, Arctic Tern feeds by plunge-diving for fish, usually from saline environments. It often dives from a "stepped-hover". The offering of fish by the male to the female is part of the courtship display.
This is a medium-sized tern, most readily confused within its range with the similar Common Tern Sterna hirundo and Roseate Tern Sterna dougalli .
Unlike the others, its thin sharp bill is entirely dark red, as are its short legs. Its upperwings are uniformly grey. Its long tail extends beyond the wingtips on the standing bird, unlike Common Tern, but is shorter than that of Roseate Tern. It is not as pale as Roseate Tern, and has longer wings.
In winter, the forehead and underparts are white. Juvenile Arctic Terns lack the extensive ginger colouration of young Common Terns and the scaly appearance of juvenile Roseate Terns.
The call is a clear piping, like Common Tern.