Arctic Tern

The Arctic tern, Sterna paradisaea, is a medium-sized bird with a remarkable circumpolar breeding distribution that spans the Arctic and sub-Arctic regions. It is a member of the family Laridae, with a length ranging from 28 to 39 centimeters and a wingspan of 65 to 75 centimeters. The plumage is predominantly grey and white, accented with a red or orange beak and feet, a white forehead, and a black nape and crown streaked with white. The mantle is grey, and the deeply forked tail is whitish with grey outer webs.

Identification Tips

Adult Arctic terns can be identified by their grey upperparts, white cheeks, and black cap. The beak and legs are a vibrant red, and the tail is notably forked. In flight, the white leading edge of the wing is a key characteristic. Juveniles differ with their black bill and legs, and their wings have a "scaly" appearance with dark feather tips.

Habitat

The Arctic tern breeds in coastal areas, on islands, and occasionally inland near water in tundra regions. It prefers open habitats free from predation where it can nest on the ground.

Distribution

This species has a worldwide circumpolar breeding distribution, with no recognized subspecies. It is found in cooler temperate parts of North America and Eurasia during the northern summer and spends the southern summer at sea, reaching the northern edge of the Antarctic ice.

Behaviour

The Arctic tern is highly migratory, undertaking a convoluted route from its northern breeding grounds to the Antarctic coast and back, covering astonishing distances. It is known for its aggressive defense of its nest and young, willing to attack humans and predators. The species is also long-lived, with individuals reaching up to thirty years of age.

Song & Calls

The Arctic tern has a variety of calls, with the alarm call and the advertising call being the most common. Its call is more nasal and rasping compared to similar species like the common tern.

Breeding

Arctic terns typically begin breeding around their third or fourth year and are known to mate for life. They exhibit elaborate courtship displays and lay one to three eggs per clutch. Both parents share incubation duties, and the young fledge after 21 to 24 days.

Similar Species

The Arctic tern can be confused with the common and roseate terns. However, it has a longer tail, a mono-coloured bill, and a slightly different profile and colouring. Its call also helps distinguish it from these similar species.

Diet and Feeding

The diet mainly consists of fish and small marine invertebrates. Arctic terns are adept at plunge-diving and may also feed on insects while breeding.

Conservation status

The Arctic tern is classified as Least Concern by the IUCN, with an estimated population of two million individuals. While the overall population trend is unknown, past exploitation has reduced numbers in the southern parts of its range. Conservation efforts are in place to monitor and protect this species.

Cultural depictions

The Arctic tern has been featured on postage stamps of various countries and territories, reflecting its cultural significance and widespread recognition.