Cracking the mysteries of bird migration

日期:2019-03-02 08:09:15 作者:颜缳瑷 阅读:

By Bob Holmes 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. Until recently, the idea that we could chart a small bird’s migration in such detail was unthinkable. Now, however, biologists are developing tracking technologies that are leading to a revolution in their understanding of migration. Suddenly they have the power to answer questions they could barely guess at before. They are beginning to learn not just where the birds are going, but also the timetables of their migratory flights and their airspeeds and energy costs. These new techniques are also helping to explain the biology that underpins the uncanny navigational abilities of migratory birds. The new-found opportunities have biologists brimming with anticipation. “Every new instrument you put out is a major breakthrough,” says Martin Wikelski from the Max Planck Institute for Ornithology in Radolfzell, Germany. “I think we’re entering a new,