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 [EMAIL PROTECTED] IDART Project Lead Voice:505-844-4024 IORTA Department Mobile:505-238-9359 http://www.sandia.gov/scada Fax:505-844-9641 http://www.sandia.gov/idart Pager:800-690-5288 ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
