The mystery of the bird flying out front

摘要

It's a familiar sight: a flock of birds flying overhead in a V-formation, each saving energy by stealing lift from the bird ahead. But what's in it for the bird out front? For northern bald ibises, it's all about taking turns. The leading bird often swaps places with the bird behind it. Bernhard Voelkl at the University of Oxford and his team tagged 14 ibises with high-precision GPS data loggers (PNAS, DOI:10.1073/pnas.1413589112).