A migration is the seasonal movement of a group of animals from one place to another. Which animal holds the record for longest migration? The arctic tern. These birds have a wingspan of about 75 cm (30 in). Wingspan is the distance from one wing tip to the other. They fly up to 96,000 km, or almost 60,000 miles, per year! Arctic terns live up to 30 years. In a tern’s lifetime, it could fly over 2,800,000 km! That’s like an astronaut going from the Earth to the Moon and back three times, which no astronaut has done yet.
Where are the terns going? They fly from the Arctic to Antarctica and back every year. They spend the summer producing and raising offspring in the Arctic, then begin their journey to Antarctica in late August or early September.
It takes them a few months to reach Antarctica, where they spend the summer again. Remember that Antarctica is in the southern hemisphere, and summer in the southern hemisphere is from December to March. The birds take off for the Arctic again in April, reaching their breeding grounds by May or June.
Just like any long-distance traveler, the terns make stops along the way. As they fly south, one stop is in the North Atlantic Ocean. The water here is full of fish and other marine life that terns feed on. This gives them the energy they need to keep flying toward Antarctica. Once the birds reach Antarctica, they spend the summer feeding on fish and krill, which are shrimp-like organisms that live in the ocean. When the birds are ready to fly north, they take advantage of the wind to travel faster. The flight north takes less time than the flight south.
How do scientists know so many details about arctic tern migration? They put small trackers on some birds; the trackers weigh about as much as a raisin and are placed on a bird’s leg.
What Do You Think? Why is it important for birds to have places to stop during migration?
Photo Credit: (t)hakoar/iStock/Getty Images, (b)F.Demonsant/Shutterstock
