Wednesday, April 1, 2009

Nature Factoid


Have you ever noticed that when you see a bunch of birds in the sky flying in a "V" formation, there is always one line of birds that is longer than the other one. There is actually a reason for that. Do you want to know why? See below.


























Because there are more birds in that line.



1 comment:

Jin said...

I had to find out why:

Flying in a V formation aids the birds in covering long distances efficiently. All the birds except the first are flying in the upwash from the wingtip vortices of the bird ahead. The birds in the formation take turns flying first. A little upwash assists the bird to support its own weight in flight in the same way a glider can climb or maintain height indefinitely in rising air. In V formation of 25 members, each bird can achieve a reduction of induced drag by up to 65% and as a result increase their range by 71%[1]. The birds flying at the tips and at the front are rotated in a timely cyclical fashion to spread flight fatigue equally among the flock members. The formation also makes communication easier and allows the birds to maintain visual contact with each other.

Often one side of the V formation extends beyond the other side, creating a lopsided effect. Despite comical answers, such as "more birds," the reason may actually be as simple. Each bird likely figures out where it will fit in, just as humans choose which vehicle to follow on a six-lane highway. On a long trip, a multitude of factors determines which lane we choose to drive in, and it is probably not much different for a goose that must fly a thousand miles.