Researchers have found new evidence to support the longstanding theory that birds fly in a V formation to conserve energy during long flights. In accordance with the current theories on aerodynamics, birds use the formation to minimize the consumption of energy during flight.
The current theory implies that birds use the lift provided by the lead birds in a V formation. Lead researcher Dr. Steven Portugal, a postdoctoral researcher at Royal Veterinary College in England, headed the recent study involving the rare and endangered northern bald ibis.
The current theory on birds flying in a V formation was put forward as early as 1989 in a study conducted by researchers from the Technical University of Braunschweig, Germany. The theory was further elaborated in a separate study published in 1994 by scientists from the Department of Zoology of the Aberdeen University in Scotland. Both studies came to a conclusion that birds use the V-formation to reduce the energy needed to traverse long distances in flight.
The most recent study, published in the online journal Nature, used technologies that were unavailable during the earlier studies to confirm the theories. GPS tracking units were attached to a group of northern bald ibises to collect data on their flights. Moreover, a microlight aircraft also followed the birds closely to gather video footage of the flying birds.
The data collected during the flights indicate that the birds have a way of knowing where to position themselves to take advantage of the additional lift provided by birds in the front of the formation.
"They're seemingly very aware of where the other birds are in the flock and they put themselves in the best position possible," says Dr. Portugal. "This can give a bit of a free ride for the bird that's following. So the other bird wants to put its own wingtip in the upwash of the bird in front."
An upwash is an upward flow of air that is created by a moving airfoil, in this case, a bird's wing. The upwash provides the additional lift that birds take advantage of using the V formation.
The new study provides solid proof regarding the veracity of the earlier studies. The data collected by Portugal and his team also provides important insights in ornithology and animal behavior.
