All About Arctic Terns - Arctic Tern Facts & Information
Arctic Tern Species
With long tail streamers, a streamlined shape, black cap and a white forehead, (Breeding birds also have a red bill) these marine birds are sometimes known as the 'sea swallow' and are a long distance migrant that come all the way from antarctic wintering grounds.
Arctic terns, along with the common tern and other tern species, are celebrated for their extraordinary migrations, symbolising endurance and resilience, and are a subject of interest and admiration for bird watchers and scientists alike.
The Arctic Tern is a coastal bird, but can sometimes be seen inland during migration as they pass over the North Sea, taking breaks at lakes and reservoirs. They thrive on a healthy marine environment, and some colonies have been affected by the loss of marine life.
A bird study showed that Arctic Tern numbers increased by 50% between 1969 to 1970 but decreased by 31% by 2000.
These common terns are social birds, foraging in groups and creating nesting sites in colonies. Similar to other tern species, they primarily feed on small fish and invertebrates, which they catch by plunge-diving into the water.
How Far do the Arctic Tern Population Migrate?
After spending the northern hemisphere winter in the Antarctic, they embark on a long migration northward to reach their breeding grounds in the UK and other parts of the Arctic and sub-Arctic regions.
This journey is one of the longest migrations in the animal kingdom, with Arctic terns traveling approximately 44,000 miles (71,000 kilometers) round-trip each year.
Arctic Tern Diet
Arctic terns primarily have a diet consisting of mainly fish. They are adept hunters, often seen catching their prey by plunge-diving into the water. These agile birds forage both in coastal areas and around pack ice, where small fish are abundant.
Like most terns, Arctic terns supplement their diet with invertebrates, but their primary food source remains small fish, which are crucial for their energy needs during long migrations.
Their foraging efficiency and diet are comparable to most terns, allowing them to thrive in diverse marine environments.
Arctic Tern Lifespan
Arctic terns are known for their impressive lifespan, often living up to 20-30 years. This longevity is remarkable, especially considering the extreme distances they migrate annually between their breeding grounds in the Arctic and their wintering grounds in the Antarctic.
Over their lifetime, an Arctic tern can travel the equivalent distance to the moon and back three times, highlighting their endurance and resilience.
Where Do Arctic Terns Live
In the UK, Arctic Terns are primarily coastal birds and spend their time near sandy and rocky shores.
Sometimes they will venture out to islands off shore as these provide extra safety from predation when nesting.
During migration, they tend to be near pack ice regions as these provide ample food.
Major colonies in the UK are found on Farne Islands in Northumberland.
Breeding Seabirds
Arctic Terns breed in the UK, they arrive from late April to Early May and nest in May to June.
Synchronised flying and calling are all part of the courtship process for these birds. They might also preen each others feathers as a sign of affection during breeding season and males may offer small fish to the females.
Arctic Terns do not build elaborate nests. Instead, they lay their eggs in simple ground scrapes or shallow depressions, often lined with bits of seaweed or grasses to provide some cushioning.
Nests are usually located on sandy or rocky shores, coastal grasslands, or heath lands, often on offshore islands to reduce predation risks.
There are typically 1 to 3 eggs in a clutch and both parents share incubation, which lasts around 24 days. Parents are highly protective of their nests, and may be quite aggressive to potential threats.
Both parents feed the chicks, primarily with small fish. They regurgitate food for the chicks and provide warmth and protection. Chicks are initially downy and flightless. They fledge, or learn to fly, about 21-24 days after hatching.
Arctic Breeding Grounds, in the UK
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Farne Islands, Northumberland
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Isle of May, Firth of Forth
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Shetland Islands
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Orkney Islands
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Inner and Outer Hebrides
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Coquet Island, Northumberland
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Anglesey, North Wales
Five Facts about the Arctic Tern
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The Arctic Tern holds the record for the longest migration of any bird species. It travels about 44,000 miles (71,000 kilometers) annually between its breeding grounds in the Arctic and its wintering grounds in the Antarctic. This incredible journey means that Arctic Terns experience two summers per year!
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Over its lifetime, an Arctic Tern can cover the equivalent distance to the moon and back three times. Their remarkable endurance and long lifespan contribute to this astounding mileage.
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Arctic Terns are known for their impressive courtship displays. During mating season, pairs perform synchronised aerial acrobatics and mutual calling. Males often present small fish to females as part of their courtship ritual.
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When nesting, Arctic Terns become very protective and aggressive. They dive at and peck intruders, including humans, to defend their nests and chicks. Their dive-bombing behaviour can be quite startling to unsuspecting visitors.
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Despite their small size, Arctic Terns have an astonishing ability to navigate across the globe. They use a combination of environmental cues, such as the position of the sun, stars, and the Earth's magnetic field, to guide them on their epic migrations. Their navigation skills are among the most sophisticated in the animal kingdom.
