BOB HIRSHON (host):
How geese fly high. I’m Bob Hirshon and this is Science Update.
Bar-headed geese migrate across the Himalayas twice a year. To find out how they accomplish this high-altitude journey, University of Bangor biologist Charles Bishop and his team outfitted the birds with heart rate monitors and accelerometers.
CHARLES BISHOP (University of Bangor):
The problem of flying high is that is that the air has become less dense and it’s becoming more difficult to fly. If they were to go up and just fly along at that level, they’re spending an awful lot of time at a very difficult, high energy flight. What we actually discovered was that instead, these birds are regularly going up and then down again within the same flight, and we called this the roller coaster strategy, and this was kind of unexpected.
Bishop’s team reports in the journal Science that even factoring in the costs of climbing back up again, this flight strategy saves the birds energy overall. I’m Bob Hirshon, for AAAS, the science society.
Story by Susanne Bard