The Arctic tern is a tern in the family Laridae. This bird has a circumpolar breeding distribution covering the Arctic and sub-Arctic regions of Europe, Asia, and North America. The species is strongly migratory, seeing two summers each year as it migrates along a convoluted route from its northern breeding grounds to the Antarctic coast for the southern summer and back again about six months later. Recent studies have shown average annual round-trip lengths of about 70,900 km (38,300 nmi) for birds nesting in Iceland and Greenland, and about 48,700 km (26,300 nmi) for birds nesting in the Netherlands, while an individual from the Farne Islands in Northumberland with a light level geolocator tag covered a staggering 96,000 km (52,000 nmi) in ten months from the end of one breeding season to the start of the next. These are by far the longest migrations known in the animal kingdom.
Region
Circumpolar Arctic (breeding) and Southern Ocean/Antarctic (non-breeding)
Typical Environment
Breeds on coastal tundra, rocky shores, islands, and inland lakes across the high Arctic and subarctic of North America, Europe, and Asia. Outside the breeding season it ranges widely over open ocean, concentrating along productive fronts, upwelling zones, and the pack-ice edge of the Southern Ocean. During migration it follows coastlines and open seas through the Atlantic and Pacific, often stopping at estuaries and bays. Colonies are typically near shallow, fish-rich waters and low vegetation or bare ground for nesting.
Altitude Range
Sea level to 1000 m
Climate Zone
Polar
Ease of Keeping
Beginner friendly: 1/5
Arctic terns undertake the longest migrations known, traveling from Arctic breeding grounds to Antarctic waters and back each year, effectively experiencing two summers. They are long-lived for small seabirds and show strong site fidelity to breeding colonies. Adults aggressively defend nests and chicks, often mobbing much larger predators.
An Arctic tern nesting on the Farne Islands, from where the longest migration is recorded
Temperament
social and defensive
Flight Pattern
buoyant and agile, with rapid wingbeats and graceful glides
Social Behavior
Breeds in dense colonies on open ground, forming monogamous pairs. Nests are shallow scrapes, and both adults share incubation and chick-rearing. They vigorously mob intruders and coordinate defense against predators.
Migratory Pattern
Seasonal migrant
Song Description
Calls are sharp, piercing kek-kek and kree-ar notes, often delivered in rapid series during flight. At colonies they give harsh scolding alarms and softer contact calls between mates.
