Arctic Tern Migration: A Complete Guide

Arctic Tern (paradise tern) is a bird that has long been awe-inspiring for its incredible migrations between the northern and southern polar regions. Surprisingly, recent research has shown that these birds fly farther than previously thought.

Arctic terns undergo the longest migration of any animal species on Earth. These superlative birds can travel the distance of the moon and back three times in their lifetime. Let it sink in for a minute!

Scientists are still trying to put all the pieces of the puzzle together, but there are still many unsolved mysteries about their migration. This article describes their incredible journey, giving you a glimpse into the life of one of nature’s most amazing birds.

Read on to learn how, when and why these birds migrate.

A large flock of arctic terns in flight

How do arctic terns migrate?

Arctic terns typically migrate over the open ocean, but they have also been documented migrating over land. Although they often fly low, just over water and crests, they can migrate at altitudes of nearly 10,000 feet.

Arctic terns are made for the air. Weighing only around 4 ounces, these elegant birds have a perfectly streamlined body for both powerful direct flight and effortless long-distance glide.

They’re also smart about their travels, often taking advantage of tailwinds to save energy. They also don’t seem to be in too much of a hurry on their southbound post-breeding journey, often following winding routes through good feeding grounds and weather conditions.

The return flight seemed more urgent, with the birds following an S-shaped course across the Atlantic. The shape of the course is explained by the prevailing winds on either side of the equator.

Arctic terns fly over Shetland Islands, UK

When Do Arctic Terns Migrate?

Arctic terns actively migrate between summer breeding and wintering grounds for approximately four months of the year. Their southward migration usually takes place in the fall and the return trip in the spring.

Arctic tern migration has been studied using tiny instruments called geolocators attached to the birds’ legs. Data collected in this way, along with other observations, help us piece together a picture of their migration timing.

Read on to learn about a typical year in the life of an Arctic tern.

• September to November: The start of autumn marks the beginning of the Arctic tern’s epic southward migration to Antarctic wintering grounds.
• December to March: Terns spend this time of year in their wintering grounds in the Southern Ocean.
• April: This month marks the start of their return to their summer breeding grounds in the Arctic.
• possible: Arctic terns have reached equatorial latitudes, marking the midpoint of their return migration.
• June: By this month, they had reached their northern breeding grounds.
• July to August: These months are busy times for nest building and chick rearing.

A flock of arctic terns hunting in Iceland

Why do arctic terns migrate?

Arctic terns need to migrate every year because the polar winters are too dark for them to hunt. These birds engage in visual predation by diving into the water in search of small fish, crustaceans and insects. A neat solution to this seasonal problem is to follow the sun, as many other migrants do.

The Arctic may provide abundant foraging and safe breeding grounds for arctic terns in summer, but these conditions change dramatically over time. At these latitudes, the length of the day varies greatly, creating summers when the sun never really sets and winters of perpetual darkness!

How far do arctic terns migrate?

Arctic terns migrate annually from the Arctic Circle in the north to the Antarctic in the south and back. That’s about 25,000 miles (40,000 kilometers), but because these birds don’t fly in a straight line, they actually fly farther. Some have been tracked to travel 56,000 miles (90,000 km) in one year!

This is the longest migration of any bird. The actual distance of total migration varies depending on the location of the individual and its breeding site. The birds are also not too rigid about the route they take, and are happy to take a long detour if it means encountering better weather or a food source along the way.

Arctic terns are thought to require around 30,000 kJ or energy to complete their annual migratory journey.

Arctic tern perched on a rock

How long does it take for arctic terns to migrate?

One of the fascinating things about Arctic tern migration is the variation in the routes these birds take. Arctic terns take a much longer distance to migrate south than to return north. Birds usually take about 3 months to reach their wintering grounds in the south, but return to their breeding grounds in about 40 days.

Arctic terns typically migrate at altitudes of 1,000 to 3,000 meters at flight speeds of up to 55 km/h (15 m/s).

Do arctic terns fly non-stop?

Arctic terns do not make the entire journey in one sitting and have been known to stop at rendezvous and places where food resources are plentiful. They may stay for up to a month before continuing their journey.

Migrating takes so much energy, the birds naturally have to eat along the way. Still, they have been recorded traveling as far as 5,000 miles and are always foraging on the go, without spending too much time in any single area.

During their northward migration, Arctic terns can fly more than 500 kilometers a day.

Arctic tern in flight

Do Arctic terns migrate in flocks?

Arctic terns usually migrate in small flocks averaging 6 to 7 birds. However, they have also been recorded as migrating individually or in groups of up to 70 individuals.

Do all Arctic terns migrate?

Although their migration routes and breeding locations do vary, all arctic terns breed at high latitudes in the northern hemisphere’s arctic region and migrate south for the winter.

arctic tern foraging

Where do arctic terns go in winter?

Arctic terns travel south after breeding in the Arctic to escape the harsh northern hemisphere winters. While winter is in full swing, most of these birds are enjoying the long, sunny days in the Antarctic. It’s summer in the southern hemisphere, when birds have easy access to an abundance of small fish and crustaceans as food sources.

Where do arctic terns go in summer?

Arctic terns spend the northern summer in the polar Arctic. This large area includes Alaska, Canada, Greenland, Iceland, Scandinavia, and parts of Russia. Surprisingly, the vast majority of adult terns return to nest near the exact place they were born.

Arctic terns fly farther each year than any other bird

Why Are Arctic Terns Called Migratory Champions?

The Arctic tern is known as the migration champion because it holds the record for the longest annual migration distance of a bird. It’s not a one-time migration either. These tiny birds can live for more than three centuries, making their bodies marvels of endurance.

Thanks to their amazing migrations, arctic terns are able to live and breed in some of the harshest environments on earth, forever following the warmth of summer.

Arctic Tern Migration FAQs

Do arctic terns migrate at night?

Arctic terns migrate at all times of the day, including after dark. In the north, they have been recorded flying high at night, taking advantage of tailwinds to conserve energy. In the Antarctic region, however, very few night flights have been recorded.

How many arctic terns are left?

Research shows that the population of the Arctic tern is about 2 million individuals. They are considered the species of least concern, although their numbers are trending downward.

Where Do Arctic Terns Nest?

Arctic terns are ground-nesting birds. They may be incredible travelers, but they’re not the best nest builders in the bird world. They usually lay their eggs on stony or sandy ground about 350 feet from the water’s edge.

How Long Do Arctic Terns Live?

In terms of size, arctic terns are relatively long-lived birds, and healthy individuals can live for more than 3 years. In fact, the oldest recorded person lived to be at least 34 years old.