Tiny Sea Bird Lighter Than iPhone Makes Longest Annual Migration

Arctic tern
An Arctic tern dives down to protect its nest on Inner Farne, England, on June 24, 2011. The tiny species has clocked up the longest migration ever recorded with a meandering journey to Antarctica and back. Dan Kitwood/Getty

A tiny sea bird has made the longest known annual migration, flying from Northumberland, England, to Antarctica and back.

The Arctic tern, which weighs less than an iPhone, covered 96,000km (59,650 miles) in its journey to its winter home in the Weddell Sea before returning to the Farne Islands.

Last year, 29 birds were fitted with geolocators by researchers as part of a study carried out by scientists at Newcastle University for BBC's Springwatch program. They have now returned to the islands to breed after an incredible journey.

The previous record had been held by an Arctic tern that covered 91,000km (56,545 miles) on its flight from the Netherlands.

"It's really quite humbling to see these tiny birds return when you consider the huge distances they've had to travel and how they've battled to survive," said Richard Bevan, part of the tracking team at Newcastle University.

The birds survive the vast journey by dipping down to the sea surface to catch fish and other food as they travel. "They live in the fast lane all the time, constantly on the move," said Bevan. "They have to flap all the time. It is an incredibly energetic lifestyle."