Flocks Of Birds Are Chaos In Flight, Study Suggests

NEW ORLEANS - When birds of a feather flock together, they may look graceful and ordered in flight, but that's probably just an illusion.

Bird clusters are leaderless, and their flight patterns very much resemble computer models of chaos, Frank Heppner, a University of Rhode Island zoology professor, said at a recent meeting of the American Association for the Advancement of Science.

Scientists long have wondered how flocks of birds can fly in coordinated patterns - soaring, diving and turning to the left or right with deftness in formation.

``Do flocks have leaders?'' Heppner asked. ``Human experience would suggest that they do.''

But in some elegant studies using two cameras photographing flocks in flight three times a second, Heppner found birds actually shift positions as the flock moves along.

His study focused on birds flying in clusters rather than in lines such as V formations. Cluster formations are more popular with small birds such as starlings.

``Birds that are in front at one point will be at the back a few minutes later,'' Heppner said. ``So, unless there are birds with radio sets to communicate orders from the rear of the flock, it appears the flocks are without leaders.''

To test this idea, Heppner collaborated with mathematicians to write a computer model providing a few simple rules of behavior.

Simulated birds in this model liked to fly near each other but not so near as to crash together. Also, they liked to travel at about the same speed and were attracted to a common roosting area.

With just these three rules and one random factor to simulate wind, a computer model produces flight patterns that look remarkably like flocks of birds in flight.

``We're not saying this is the way birds do it,'' Heppner said, ``but we're saying this could be the way birds do it.''

Further studies of actual birds on the wing should provide the answers, he said.