The Arctic Tern migrates an astonishing distance - further than any other bird. It spends April-September in the Arctic where it breeds, before travelling some 7,500 miles to Antarctica to enjoy a second summer in the south.

Arctic Terns are fairly long-lived and have been known to reach about 30 years of age.

This is an oceanic bird, found around sea coasts and sometimes inland waterways. It particularly likes rocky cliffs and islands.

The Arctic Tern's most distinctive behaviour is the 7,500 mile journey it makes to and from its Antarctic breeding grounds. Most of the journey is made over the sea, rather than land, and is triggered by changes in day length. Even fledgling terns undergo this long migration, probably aided by their parents. The total distance travelled by an individual bird is around 21,700 miles per year.

Courtship involves a ceremonial 'fish fight' during which the male takes a fish in his mouth and flies over the female. If she is receptive, she joins in with much wailing and screaming. Arctic terns typically mate for life. After courtship and mating, one or two brown, speckled eggs are laid on a rocky or grassy ledge. Both parents incubate the eggs, which hatch after about 22 days. They are fed shrimp, insects and small fish for a period of around 21-28 days, after which the young fledge.

Arctic terns were once hunted for their feathers. Now, their biggest threats are from pollution and egg predators, such as other gulls, foxes, racoons and rats.