- An average Arctic tern weighs 100grammes
- Each bird can live up to 34years
- The birds make 44,000 return journey yearly
- The birds fly in a large ‘S’ shape between north and south pole
- Tracking devices attached to the terns’ legs allowed scientists to monitor their movements
A sea bird, the Arctic Tern makes an equivalence of three round trips to the moon in its life, scientists have found. The bird is popular for its long-distance migrations between the North and South Poles annually to escape harsh winter.
Within its lifespan, the bird makes a return journey of about 44,000 miles from pole to pole in a migration, flying between its breeding grounds in Greenland in the north and the Weddell Sea on the shores of Antarctica in the far south.
Though a sea bird, the Arctic Tern spends most of its time in summer, making it almost a tropical bird.
According to a monitored report via www.independent.co.uk, small tracking devices attached to the terns’ legs have allowed scientists to monitor their movements.
Scientists from the British Antarctic Survey found that the birds do not immediately head south from Greenland, but first spend almost a month at sea, in the middle of the North Atlantic, before continuing down the coast of north-west Africa.
Half of the migrating birds stop around the Cape Verde Islands, in West Africa while the rest crossed the Atlantic to follow a parallel route down the east coast of South America, scientists found.
All the terns studied escaped the northern winter by flying to Antarctic waters, where it is summer at that time of year. On the return trip, they again did not take the shortest route, but traced a giant ‘S’ shape.
To conserve energy, the birds make use of the diversions through West Africa, taking advantage of prevailing global wind systems, according to Carsten Egevang, from the Greenland Institute of Natural Resources.
“They paused in their southward migration to spend time in highly productive waters in the middle of the Atlantic Ocean,” he said. “Clearly, Arctic terns have learned to ‘fuel up’ before crossing areas of ocean with limited foraging options.”
Arctic terns feed from the water while on the wing and can live up to 34 years. When the scientists added up the total distance each bird flew during its lifetime they found it equaled three round trips to the Moon – or more than 1.25 million miles.