Meet World’s Longest Traveller: This tiny 100-gram bird, light as a feather, circles the Earth twice each year

Imagine taking a flight that circles the Earth twice every year. For the Arctic Tern, that is simply a way of life. This small seabird, weighing less than a bar of chocolate, makes one of the longest journeys in the animal world, flying nearly 70,000 kilometres annually between the Arctic and Antarctic.

How Far Does the Arctic Tern Travel?
According to research by the British Antarctic Survey and the National Geographic Society, Arctic terns record more flight mileage than any other known animal. The bird nests in the Arctic during the northern summer and then heads south to the Antarctic to enjoy another round of sunshine.  When the summer in the south comes to an end, it heads north once more, having done a round trip around the whole Earth.

In its 30-year lifespan, one Arctic Tern alone travels over 2.4 million kilometres. That's three journeys to the Moon and an absolute endurance hero of the air.

How Do Scientists Track Their Migration?
Scientists employed geolocators that were lightweight to trace the long flights of the birds. The results indicated that Arctic terns do not cover distances in a straight line but take curved paths that are optimised for wind. These routes enable them to glide for extensive distances with little effort, saving energy over oceans and continents.