Posted by
Parks, Raymond on
URL: http://friam.383.s1.nabble.com/Meeting-at-St-John-s-tomorrow-tp523290p523310.html
Hugh Trenchard wrote:
> Thanks for all your comments.
I just now had a moment to try and catch up with FRIAM and read your
thread.
As far as drafting goes, I would suggest that there may be some use
of wingtip vortices, a normally harmful phenomenon.
> Also, Phil, I would argue that strong leadership is not a factor in vee
> formations. As we all know, self-organized phenomena arise without leaders
> to guide the emergent patterns - I can't think of why it would be any
> different for frigatebirds. The formations must self-organize from some
> principle of interaction - in the case of organisms that save energy by
> drafting, it is the coupling between them that occurs because there is a
> physiological or energetic advantage to their coupling (ie. to their
> drafting).
At least with respect to geese, the leadership of the formation
changes frequently.
> On the note about the decline of traveling geese, I really can't speculate.
> I live on the west coast of Canada in British Columbia and I still see vee
> formations going in all directions. But perhaps global warming is a factor
> in the distances they need to fly now - maybe they can stay farther north
> all year round.
I think the primary driver of the decline of traveling geese is
burgeoning population. There now are so many geese that the full
population may not be supportable in the northern latitudes, even during
summer. I know that I live on what is a major migration path with the
winter home of geese about a hundred miles south of ABQ. Right now, we
have tens of thousands of geese who have made a permanent home in the
central Rio Grande valley, where I live. One interesting aspect of this
is that the coyotes in the village of Corrales, my home town, are
starting to exhibit cardiac problems from eating too much rich food.
--
Ray Parks rcparks at sandia.gov
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