Fly by wire - Clever tracking technology is finally letting us crack the mysteries of bird migration

Description

On 17 March 2007, the bar-tailed godwit known to science as E7 spread her wings and took flight, leaving the northern shores of New Zealand behind her. For the next eight days and nights she flew non-stop, 10,000 kilometres northwards to the coast of China's Yellow Sea. Five weeks later, after a brief break for refuelling, E7 continued on her way. She headed east, then took a sharp left turn in the featureless mid-Pacific, before arriving six days later at her breeding ground in Alaska. By late August, she was off again, this time on a non-stop journey of nearly 12,000 kilometres - the longest continuous bird flight on record - that ended just 13 kilometres from where she had started.