April 10, 2009

Study Sheds Light On Mystery Of Bird Flight

Persistent scientists using high-speed film have revealed one of the secrets of flight in birds and bees. 

The researchers discovered that when birds, bats or insects make a turn, all they have to do is return to flapping their wings normally again and they straighten right out. 

The findings surprised scientists who previously believed turning and stopping a more complex process.

Tyson L. Hedrick of the University of North Carolina, the study's lead researcher, compared the phenomenon to sitting on a desk chair and turning left in a three-step process: initiate the turn by pushing with one foot, turn, then stop by pushing with the other foot.

However, it's a simpler, one-step process for flying animals: launch a turn and then merely flap normally to end it and fly away, Hedrick said.

"We didn't expect things to fall out this neatly," he said in an interview with the Associated Press.

The process is the same for animals of all sizes, he added.

"It's sort of unusual" to discover a general rule that covers six orders of magnitude in size, he said, adding that the study could aid in the development of robotic flying machines.

However, this research centers on just one type of maneuver, a turn, known in aviation as yaw.  Pitch and roll must also be considered.

"We picked basically the simplest turn you can imagine to make comparison," Hedrick said.

More complex maneuvers do make the situation more complex.

"That is clearly the next step," he said.

Bret W. Tobalske of the University of Montana, who was not involved in the study, welcomed the findings.

"The results will inform all future research into maneuvering flight in animals and biomimetic flying robots," he told the AP.

"Now that technology has developed to the point where detailed measurements of flapping maneuvers have become feasible, a world of comparative research is opening," Tobalske wrote in a commentary about the study, which was published Friday in the journal Science.

The National Science Foundation funded the research.


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