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The Arctic Tern (Sterna paradisaea): Champion of Migration

An Arctic Tern in graceful flight over the water.
The Arctic Tern is a master of the air, famous for having the longest migration of any animal on Earth.

The Perpetual Summer Seeker

The Arctic Tern (Sterna paradisaea) is a medium-sized seabird renowned for its incredible long-distance migration. Nicknamed the "sea swallow" for its long tail streamers and graceful flight, this bird experiences two summers each year, flying from its breeding grounds in the Arctic to the oceans of Antarctica and back again. This phenomenal journey ensures it sees more daylight than any other creature on the planet. Over a lifetime that can exceed 30 years, an Arctic Tern may travel 1.5 million miles (2.4 million km), equivalent to more than three round trips to the moon.

Identifying the Arctic Tern

The Arctic Tern is a slender, elegant bird with key features that change slightly with the season. It is often confused with the Common Tern, but several details can help distinguish them.

  • >Breeding Plumage (Summer): In summer, it has a full black cap, much like a Black Headed Gull, a blood-red bill with no black tip, and short, dark red legs. Its body is pale grey, with white cheeks that contrast with the black cap. The long, forked tail streamers often extend beyond the wingtips when the bird is perched.
  • Non-Breeding Plumage (Winter): In winter, the bill and legs turn black. The forehead becomes white, and the black cap is reduced.
  • In Flight: Its wings are narrow and appear translucent. The flight is buoyant and graceful, often involving hovering before a dive.

Call of the Traveler

The call of the Arctic Tern is a harsh, grating "kee-arr" or "ti-ri", often heard in its noisy breeding colonies. It is typically more nasal and raspy than the call of the Common Tern.

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Arctic Tern Scientific Dimensions and Records

Characteristic Male Female Record / Average
Length 33 – 39 cm (approx. 13-15 in) 33 – 39 cm (approx. 13-15 in) 33 – 39 cm (including tail streamers)
Weight 86 – 127 g (approx. 3.0-4.5 oz) 86 – 127 g (approx. 3.0-4.5 oz) Average 100-120 g
Wingspan 76 – 85 cm (approx. 30-33 in) 76 – 85 cm (approx. 30-33 in) 76 – 85 cm (average)
Flight speed Up to 40 km/h (approx. 25 mph) cruise, faster when diving Up to 40 km/h (approx. 25 mph) cruise, faster when diving Efficient long-distance flier
Life expectancy 20 – 30 years (wild) 20 – 30 years (wild) Oldest recorded: 34 years

These figures highlight the Arctic Tern's modest size yet incredible endurance, which enables its unparalleled migratory feats across the globe.

Our Ornithologist's Advice

By the Les-Oiseaux.com team, published on July 16, 2025

My advice: To truly appreciate the Arctic Tern, focus on its purpose-driven behavior. During the breeding season (May-August in the northern hemisphere), find a coastal colony and watch from a respectful distance. You'll witness not just their aggressive defense of the nest—they will dive-bomb any intruder, including humans—but also their tender courtship rituals. Look for males offering fish to females, a key part of forming their lifelong bond. This fierce, energetic defense and dedicated parenting, all fueled by the need to succeed before undertaking the planet's longest journey, is the essence of the Arctic Tern.

Arctic Tern vs. Common Tern: A Tricky ID

Distinguishing the Arctic Tern from the very similar Common Tern (*Sterna hirundo*) is a classic birdwatching challenge. Here are the key differences to look for in breeding adults:

Arctic Tern

Portrait of an Arctic Tern showing its solid red bill.

Structure: More slender and dainty, with a smaller, rounded head. Bill: Shorter, and a solid blood-red color with no black tip. Legs: Very short and dark red. Plumage: Paler, more uniform grey. Tail: Longer tail streamers, often projecting beyond the wingtips at rest.

Common Tern

Portrait of a Common Tern showing its reddish-orange bill with a black tip.

Structure: Appears larger and bulkier. Bill: Longer, reddish-orange, and crucially, has a black tip. Legs: Longer and a brighter orange-red color. Plumage: Can appear a duskier grey, less uniform than the Arctic Tern. Tail: Shorter tail streamers, which do not extend beyond the wingtips at rest.

Habitat and Distribution

The Arctic Tern is known for its impressive breeding range, nesting in colonies throughout the Arctic and sub-Arctic regions of Europe, Asia, and North America. These birds favor treeless coastal spots, like rocky or sandy islands and beaches. Once the breeding season wraps up, they embark on an incredible migration, spending the summer months in the southern hemisphere at sea, often close to the Antarctic pack ice.

Distribution Map

The map below shows the incredible global range of the Arctic Tern, from its northern breeding grounds to its Antarctic wintering areas and the vast migratory routes in between.

Diet and Plunge-Diving

The diet of the Arctic Tern consists mainly of small fish like sand lances, herring, and cod, as well as crustaceans and insects. They are skilled hunters, hovering gracefully above the water before plunge-diving to catch their prey just below the surface. They are also known to snatch insects from the air.

Nesting on the Edge of the World

Arctic Terns are colonial nesters, forming monogamous pair bonds that often last for life. They typically start breeding at 3-4 years old. The nest is a simple scrape on the ground, located on open, sandy or shingle beaches, or rocky islands. The female lays one to three eggs, which are incubated by both parents for about 21-23 days. The parents are fiercely protective, aggressively dive-bombing any perceived threats. The young chicks can fly about three to four weeks after hatching.

Frequently Asked Questions (FAQ)

How long is the Arctic Tern's migration?

The Arctic Tern holds the record for the longest migration of any animal. It flies from its Arctic breeding grounds to the Antarctic and back each year, covering an average round-trip distance of about 44,000 miles (70,900 km), with some tracked individuals flying over 59,000 miles (96,000 km). Over its lifetime, a single bird may fly 1.5 million miles (2.4 million km).

Does the Arctic Tern see more daylight than any other animal?

Yes. Because it migrates from the continuous daylight of the Arctic summer to the perpetual light of the Antarctic summer, the Arctic Tern experiences more daylight each year than any other animal on the planet.

How long do Arctic Terns live?

Arctic Terns are remarkably long-lived for their size. They often live for more than 20 years, and the oldest recorded individual was at least 34 years old.