Why do birds fly in "V" formation?

clarod

it to do with aerodynamics http://news.softpedia.com/news/Why-Do-Birds-Fly-in-V-Formation-52785.shtml Jan 18 09, 7:19 AM

BRY2K

Here's a bit more detailed data: Scientists who have studied formation flight believe that birds fly in this way for two reasons. The first reason is that the shape of the formation reduces the drag force that each bird experiences compared to if it were flying alone. This decrease in drag occurs thanks to the formation of wingtip vortices described in previous articles. These vortices are generally undesirable because they create a downwash that increases the induced drag on a wing in flight. However, this downwash is also accompanied by an upwash that can be beneficial to a second wing flying behind and slightly above the first. A bird flying in one of these upwash regions essentially gains free lift so that it can fly at a lower angle of attack. As angle of attack is reduced, the induced drag is also lowered so that the bird does not need to flap its wings as hard or as often to generate the thrust needed for forward flight. Flapping the wings less often means that the bird's muscles do not work as hard and its heart rate drops. As a result, the bird does not tire as quickly and is able to fly farther. Researchers explored this theory by monitoring pelican heartbeats during flight. Examination of the data showed that the heart rates of pelicans flying in formation were much lower than that of a bird flying alone. Other studies have estimated that a flock of 25 birds in formation can fly as much as 70% further than a solo bird using the same amount of energy. http://www.aerospaceweb.org/question/nature/q0237.shtml Jan 18 09, 9:38 AM