Explained: Why do flocks of birds fly in 'V' formation?

You must have noticed large flocks of birds spanning across the sky moving in a particular formation resembling quite like V shape.

Well if you wonder that's no big deal, you must know that the truth is far away from it. In fact, such movement of these winged species is a very fascinating phenomenon called the V formation.

Also known as the Echelon formation, it is mostly seen among migratory birds who travel over long distances.

But why do birds create V formation - 

Well speaking in simple terms, you should know that when a bird flies, the tip of both its wings develop a rotating vortex which is a spinning spiral of air flowing around the ends of the wings of the bird.

As a result, the air right behind the bird gets pushed downwards, while the air off the sides gets pushed upwards. This creates specific changes in the flow of air either in upward or downward direction.

Now what happens is that once a bird flies behind and to the right, or behind and to the left of another bird, it gets considerable support of air lift, without using much effort of its own. So birds flying behind the leader of the flock diagonally may not need to flap their wings as many times as they can just glide along.

But the most important necessity to this whole process is the timing at which the trailing birds flap their wings.

The timing explained - 

When the front bird flaps its wings, the bird in the rear needs to adjust its own flapping time to match the moving zone of the free lift coming from the wings of the front bird. In this way, birds are able to extract maximum benefit while putting in least effort out of this pattern.

Another interesting fact to note here is that there is no constant leader of a flock, because birds may take turns to remain at the front.