Arctic tern

Photograph by Joel Sartore, National Geographic Photo Ark
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Famous for their record-setting migration—the longest of any animal in the world—Arctic terns are projected to lose 20 to 50 percent of their habitat due to climate change.

Photograph by Joel Sartore, National Geographic Photo Ark
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Famous for their record-setting migration—the longest of any animal in the world—Arctic terns are projected to lose 20 to 50 percent of their habitat due to climate change.


About the Arctic tern

Arctic terns hold the record for the longest migration of any animal in the world, annually making the journey from the Arctic Circle to the Antarctic Circle. One particularly committed tern made the trip in nearly 60,000 miles, or more than twice the circumference of the planet. Terns rack up all those miles by meandering across oceans and continents rather than flying directly north or south.

These small seabirds were born to fly long distances. Arctic terns are so lightweight—with small bodies, short legs, and narrow wings—that they can glide through the skies on a breeze. Their beaks and feet are bright red, and their bodies are covered in gray and white feathers with a cap of black feathers on their heads.

Habitat

Arctic terns can be found just about everywhere as their travels take them to every ocean and every continent. They breed on the coasts and tundra of Arctic and subarctic regions of Europe, Asia, and North America, then follow the sun and fair weather on their yearly journey to the Antarctic Circle—a trip that takes a couple of months. Arctic terns migrate in groups known as colonies.

Diet and behavior

Arctic terns are also incredibly efficient at catching and eating prey, which is yet another reason why they can fly so far in such a short time. These seabirds hover in the air as they look for their food—mostly fish, but also insects and crustaceans—on the surface below. Then they plunge into the water to scoop up the prey, which they can even eat while gliding.

Courtship for these monogamous birds also takes place in flight. Their mating ritual begins with a “fish flight,” which is when a male Arctic tern swoops over a migratory camp carrying a fish in its mouth while making screaming sounds. On the ground, the bird struts a little before offering its prey to a female. In June and July, tern couples nest on rocky or sandy beaches where the female lays two or three eggs.

Threats to survival

Climate change is one of the major threats to Arctic terns. According to the International Union for Conservation of Nature—which has put Arctic terns on its Red List of Threatened Species—these birds are projected to lose 20 to 50 percent of their habitat due to the temperature changes linked to climate change. Increasing sea temperatures are driving away their prey, while also causing deadly storms and knocking breeding schedules off-kilter.

Arctic terns also face the potential loss of their habitat to drilling in places like Alaska’s Arctic National Wildlife Refuge, one of their preferred places to rest during their long migration.

Finally, rats, hedgehogs, and the invasive American mink have all been known to attack the nests of Arctic terns.

Conservation

Researchers across the world are working to gather more data about the plight and patterns of Arctic terns in order to help protect them—including in Iceland, which has seen diminishing Arctic tern colonies along the country’s coast. Meanwhile, the removal of the American mink from the terns’ typical habitats has helped protect their offspring.