ttps:////»https://www.w3.org/TR/REC-html40/loose.dtd»>
Because that way they save energy. The strategy is very smart and produces a fundamental economy for migratory birds that need to travel long distances. This is a question of aerodynamics: when the bird at the head of the flock flaps its wings, overcoming air resistance, a vacuum is formed behind it, helping the others to glide for longer and with less effort. Observing such a formation in the sky, you will notice that the animal that goes in front beats its wings much more intensely than the ones that follow. And there’s more: in order not to tire the leader, they take turns in that front position. Scientists have long suspected that aerodynamics benefited the V formation, but they were only able to prove this effect recently, thanks to studies conducted by biologist Henri Weimerskirch at the National Center for Scientific Research in Villiers, France.
He found that the heart rate of pelicans flying in a V was lower than when they were on land. This was possible thanks to the installation of small cardiac monitors on the backs of the birds, trained to chase the light of an aircraft. Monitoring has shown that pelicans following the leader save up to 14% of energy.