Scientific Name: Sterna paradisaea
Description: The Arctic tern is a small bird with narrow wings and short legs. Their coloration varies depending on age and season. Newborns are gray or brown. Adults are gray to white in color during the breeding season. Their beak and legs are red, and a black patch covers the head and forehead. During the non-breeding season, the legs and beak are black and the black patch of color on the head shrinks.
Size: Wingspan is between 25 and 30 inches, and length averages 11 to 16 inches.
Diet: When feeding, Arctic terns hover in midair before plunging into the water to catch fish or crustaceans. Occasionally the Arctic tern steals food from other birds by flying at them and startling them into dropping their catch. They also capture insects.
Typical Lifespan: Reproductive maturity is reached at 3 to 4 years. At least one individual is known to have lived 34 years.
Habitat: Breeding grounds range in type from boreal forests, islands, tundra, and rocky beaches. After migration, the birds winter on pack ice. During this time, they undergo a molt and lose most of their feathers. Sometimes the feathers are lost more quickly than they can be replaced and the individual is flightless for a time.
Range: During the summer breeding season, Arctic terns nest by the shore as far south as New England and Washington State. Their migration route follows the west coast all the way to Tierra del Fuego, the southernmost point of South America. Arctic terns can also be seen along the east coast of South America, Western Europe, Iceland, Australia, New Zealand, and on Pacific islands. Their winter habitat extends to the northernmost points of Antarctica.
Life History and Reproduction: Arctic terns have the longest yearly migration of any animal in terms of distance between the start and end points. They travel from their Arctic breeding grounds to Antarctica and back—a distance of at least 25,000 miles—every year! Arctic terns often return to the same area they were hatched to breed. They are ground-nesting species, and both parents rear the young. Hatchlings stay with the parents for about three months before they venture off on their own.
Fun Fact: The sooty shearwater may rival the Arctic tern for the title of longest migrator. Electronic tagging of sooty shearwaters revealed that they travel nearly 40,000 miles every year moving between New Zealand and the North Pacific. The exact distance of the migration of Arctic terns isn’t known, but they may travel a similar or greater distance than the sooty shearwater.
Conservation Status: Appears to be stable, but population trends are difficult to observe because of the birds’ remote range. Climate change may pose a threat since Arctic terns rely on Arctic and Antarctic ecosystems which are now changing.
Seattle Audubon Society Bird Web
The Cornell Lab of Ornithology
The IUCN Red List of Threatened Species
National Geographic Society – “Longest Animal Migration Measured, Bird Flies 40,000 Miles a Year”