flock of birds LO21823

John Paul Fullerton (j-fullerton@tamu.edu)
Thu, 03 Jun 1999 12:10:58 -0700

Replying to LO21791 --

Leo Minnigh wrote:
> Arthur mentioned the simple rules that Craig Reynolds has used in his
> computer program. Craig was also facinated by the flock of birds which
> made the strangest caprioles above the cemetery in Culver City. In 1987 he
> formulated his three basic rules for his Boid computerprogram:
> >1. It tried to maintain a minimum distance from other objects in the
> >environment, including other boids.
> >
> >2. It tried to match velocities with boids in its neighbourhood.
> >
> >3. It tried to move toward the perceived centre of mass of boids in its
> >neighbourhood.

> There were some hesitations against the simple rules:
> a. Do animals 'know' these rules? Are they realy following these rules?

One day, after rain, I noticed what seemed like an unusual number of birds
on power or telephone lines. The thought came to mind that it might be
about the dryest place for them to be sitting.

On one line the birds were sitting a fairly uniform distance from one
another (with perhaps less than the space for a bird between them). At
times when another bird landed and joined the group, there was a ripple
down the line as the birds repositioned themselves with the same amount of
space between them.

Maybe that behavior offers another viewpoint on group behavior.
Repositioning on the line probably takes more time than repositioning
while in flight.

Have a nice day
John Paul Fullerton


John Paul Fullerton <j-fullerton@tamu.edu>

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