Last week it was my luck and great pleasure to stand by the side of a
country road in deepening dusk, and watch perhaps 200 birds wheel and
gyre for 3 1/2 minutes. They formed a wildly malleable globe, elongating
on any axis at random, while moving on another axis. There was no
single leader. Several times a bird would break out in a new direction,
and his near neighbors follow, forming a pointed protuberance which
however soon sank back into the mass. Real direction change seemed to
be more of a mass decision, with all turning nearly together, and the
lack of perfect sync causing the shape changes. I saw birds inside the
globe sometimes going in quite a different direction, with no effect on
the greater number. I do not clearly recall whether the apparent
density was greater in the center (uniform blob of birds) or at the
edges (hollow globe), but I think the latter.
At the end the flight pattern gradually lowered, accompanied with
greatly increased chatter, then rather suddenly they all swooped to the
cat tails below.
I think they were having a ball, drunk with the power of flight,
sociability and life. Two days later they were gone, off South
probably. Getting cold here.
Ol' Bab
On 12/9/2012 4:29 PM, mix...@bigpond.com wrote:
In reply to Jed Rothwell's message of Sun, 9 Dec 2012 14:42:32 -0500:
Hi,
[snip]
However, their ability to respond with speed
and precision to signals from others members of the flock is astounding.
Like many other biological phenomena, it seems almost supernatural.
..they only need to follow the bird in front of them, while keeping their
position to the right or left behind, as the case may be. This way the motion of
the flock leader propagates back through the flock.
Regards,
Robin van Spaandonk
http://rvanspaa.freehostia.com/project.html
