The Real Reason Birds Fly In A V-Formation

Look! Up in the air! Its a bird! Its a plane! No, its a bird. Hey there flappy birds, Jules here for Dnews! Youve probably seen birds migrating, or
just making short trips for feeding, and youve probably noticed that birds tend to fly in
a V-shape. Theres usually one bird up at the front
leading the way, and each successive bird lines up back and to the right or left of
the bird in front of it. There are other basic shapes, such as J-formations,
and inverted versions of both, and these groups are actually types of echelon formations,
meaning that they line up linearly.

V-formations have been used extensively, not
just by birds, but by military generals. From the earliest days of war, allegedly stemming
back to when the Thebans were fighting the Spartans in 4th century BC, all the way to
today, the formation is used in sea battles and aerial warfare. Birds, planes, boats, and people all have
similar reasons for doing this. Lining up in a V gives each member a clear
line of sight ahead of them.

In some cases, it also takes less energy to
travel in this formation. See, when a bird flaps its wings, a vortex
of air directly behind it is pushed downward, called downwash. The air further back and to the sides responds
by pushing up, called upwash. Any bird situated in another birds upwash
has to expend less energy to stay aloft, since theyre already being pushed upwards, and
a V-formation situates each member back and to the side, directly in its neighbors
upwash.

In 2001, researchers at the French National
Center for Scientific Research put heart-rate monitors on pelicans flying in V-shapes, and
they found that the ones farther back had slower heart rates and did not have to flap
their wings as often to stay afloat. In fact, there was an 11-14% total energy
savings for the birds. Another study from the Proceedings of the
National Academy of Sciences also found that the flock also tries to makes sure that the
bird up front doesnt get too tired. Since it doesnt receive any benefits from
the communal upwash.

The leader bird rotates among the flock, although
scientists still arent sure if there is a hierarchy of who gets to be the leader. Of course, all this mess could be avoided
if we taught birds how to order plane tickets. One bird, the arctic tern, flies roughly 56,000
miles round-trip and is able to sleep while in flight. But how does the tern, and plenty of other
birds pull off the ability to sleep mid-air? Find out in this video.

And do you have any animal questions for us? Ask us in the comments, don't forget to subscribe,
and come back here for more DNews every day..