HONG KONG: Amazing formation flying skills of migrating birds unraveled: ‘V’shape and timing of flaps ensures flock is aerodynamic.
Being the leader in a V-formation of migrating birds is hard work, which is why birds in the formation “share the pain” inherent in that role by taking turns, researchers have found.
After a period of leading the flock, the lead bird can save energy by turning the job over to another bird and then moving back in the formation to follow in the wake of another bird, international researchers led by scientists at Oxford University in England have discovered.
The findings are the first conclusive evidence for “turn taking” reciprocal cooperative behavior in birds, the scientists report in the Proceedings of the National Academy of Sciences.
The researchers followed a flock of juvenile Northern bald ibis birds as they migrated from Austria to Italy.
The birds had been raised to be “human imprinted” so they would follow their handlers flying in powered parachutes, with each bird carrying a tiny data logger that allowed researchers to track the position of individual birds within the V-formation.
Individual birds were seen changing position frequently within the flock, they said, dividing their time between leading the formation and taking advantage of the updraft provided by the flapping of another bird’s wings, where they can save an estimated 10 to 14 percent of their energy output.
“Our study shows that the ‘building blocks’ of reciprocal cooperative behavior can be very simple: ibis often travel in pairs, with one bird leading and a ‘wingman’ benefiting by following in the leader’s updraft,” says lead author Bernhard Voelkl of Oxford’s Department of Zoology.
