Question: Why do birds fly in a V shape?

Rupert Marshall answered on 16 Mar 2017:

It saves energy to fly in a V shape. Although birds take turns to lead the formation, swapping over after a while so they can save energy, if this was the only reason then they could just fly in a straight line behind each other – like if the blows against you on a windy day it can be difficult to walk but if you’re behind someone else it’s easier.
But when birds flap their wings theirs a whoosh of air from the wingtips. Flying in a V means the bird behind gets an extra bit of whoosh under its wing from the bird in front – if it times its flapping right. And they do. Every little helps when you’re flying high for hundreds of miles.