Arctic Tern - Distribution and Migration

Distribution and Migration

The Arctic Tern has a worldwide, circumpolar breeding distribution which is continuous; there are no recognized subspecies. It can be found in coastal regions in cooler temperate parts of North America and Eurasia during the northern summer. While wintering during the southern summer, it can be found at sea, reaching the southern edge of the Antarctic ice.

The Arctic Tern is famous for its migration; it flies from its Arctic breeding grounds to the Antarctic and back again each year. This 19,000 km (12,000 mi) journey each way ensures that this bird sees two summers per year and more daylight than any other creature on the planet. One example of this bird's remarkable long-distance flying abilities involves an Arctic Tern ringed as an unfledged chick on the Farne Islands, Northumberland, UK, in the northern summer of 1982, which reached Melbourne, Australia, in October 1982, a sea journey of over 22,000 km (14,000 mi) in just three months from fledging. Another example is that of a chick ringed in Labrador, Canada, on 23 July 1928. It was found in South Africa four months later.

Research using tracking devices attached to the birds was published in January 2010 and showed that the above examples are in fact not unusual for the species; eleven Arctic Terns that bred in Greenland or Iceland each covered 70,900 km on average in a year, with a maximum of 81,600 km. The difference from previous estimates was because the birds were found to take a meandering course to take advantage of prevailing winds. The average Arctic Tern lives about twenty years, and will travel about 2.4 million km (1.5 million mi).

Arctic Terns usually migrate far offshore. Consequently, they are rarely seen from land outside the breeding season.