Formation-flying birds swap places to share out lift

Birds that benefit from each other's aerodynamic lift take turns to do the harder work out front – a rare example of reciprocal altruism

















from New Scientist - Online news http://feeds.newscientist.com/c/749/f/10897/s/42f6baee/sc/36/l/0L0Snewscientist0N0Carticle0Cdn268950Eformationflying0Ebirds0Eswap0Eplaces0Eto0Eshare0Eout0Elift0Bhtml0Dcmpid0FRSS0QNSNS0Q20A120EGLOBAL0Qonline0Enews/story01.htm