A new study published in the journal Nature has found evidence to suggest that birds adopt a V formation while in flight to improve aerodynamics and conserve energy.
An international team led by Steven Portugal of the Royal Veterinary College in London did a study with 14 endangered wading birds from Europe called ibises and watched them migrate between Austria and Italy.
They fitted data loggers to a flock of those birds that were being trained to migrate by following a microlight. They were accustomed to wearing harnesses, which made a handy place to hang the sensors, and they met their foster parents at the end of every flight, allowing easy access to the instruments. As a result, it was discovered that the birds flew in the optimal position – gaining lift from the bird in front by remaining close to its wingtip.
A previous research conducted in the year of 2001investigated the V-shape formation adopted by pelicans and was the first real clue to the energy-saving purpose of V formations. The authors determined that those pelicans situated at the front had higher heart rates, relative to those flying at the rear. On this basis, scientists made the logical deduction that the birds at the front expended more energy.
However, this latest study differs, as scientists recorded the position, speed and headings, as well as all wing flaps of every bird in he flock. It showed that the ibises altered their wingbeat patterns based on the style of formation: birds flying in a V formation timed their movements differently to those flying in a single file line, just as they need to for maximum efficiency.
Lead researcher Dr. Steven Portugal explained: “They’re seemingly very aware of where the other birds are in the flock and they put themselves in the best possible position.”
Creative Director at the Smithsonian Eric Schulze recently talked about this phenomenon, explaining that a particular bird will waste a lower amount of energy by flying slightly behind and above the bird at the head of the V formation. He compares this aerodynamic strategy to that of a cyclist in a bike race; cyclists tend to ride behind one another to save energy.
Birds are trying ti make the most of the upward-moving air generated by the bird in front. This so-called “upwash” is created as a bird flies forward; whether it is gliding or flapping, it pushes air downward beneath its wings, says the BBC News.
“Downwash is bad,” explained Dr. Portugal. “Birds don’t want to be in another bird’s downwash as it’s pushing them down.”
But as the air squeezes around the outside of the wings, it creates upwash at the wingtips.
Even though the findings don’t show directly that the birds are saving energy, they almost certainly are, says Geoff Spedding, chairman of the aerospace and mechanical engineering department at the University of Southern California, who was not involved with the study.
He and Breuer praise the new research for finally confirming theories that have languished without evidence for decades.
“We’ve been wondering for years whether flapping birds can save energy by following each other in the right way,” Mr. Spedding. “This work answers that question, and the answer is yes.”
The research could even have implications for the aviation industry. Airlines are dedicating time and money to determine how birds use updraft to their advantage, in the hope that they can use this knowledge to their advantage, notes the Liberty Voice.