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Re: New MANIAC book is out! -good/poor flyer

On Feb 22, 2010, at 3:26 AM, Erik Boehm wrote:

Indeed. But they can launch vertically at albatross grade
body weights. That does not strike me as poor.

I have never observed this behavior in the wild turkeys I see, they always seem to attempt to run away first, and then start to fly, it may be dependent on the nature of the threat.

I think it is dependent - flushing with cursors, like dogs, seems to provoke a burst launch more readily than human presence. There is a great paper by Askew and Marsh about burst launching birds, that compares the ability across multiple size classes, with the largest being wild turkeys. Contact me offlist if you'd like a copy - I'll hook you up.

Also- from other threads on here(mainly pterosaur vs bird launching), it seems with birds, a large portion of the initial impulse comes from the legs of the bird, if that is what allows this supposed behavior, I wouldn't say that makes them good flyers, but good "launchers". And if that ability is correlated to the leg muscles, that makes sense for birds that walk rather than fly when given the chance.

An excellent observation, and a reasonable distinction. My primary argument is not necessarily that your definition of poor versus good flyer is wrong, but only to point out that any such distinction has to be carefully defined, at which point the use of the terms becomes rather moot. I caution against the use of "good" and "poor" when talking about avian flight, especially when the terms are not defined. In my mind, launching is part of flight - and as such, having strong hindlimbs can be seen as an advantage for one phase of flight, which also happens to be highly functional for walking and running. Such distinctions are essentially a matter of personal discretion, and as such, I urge those on the list publishing on subjects related to flight (or any area of locomotion) to discuss the topics in terms of more objective characteristics, and drop (or specifically define) more arbitrary distinctions like "good", "poor", or "weak".



Michael Habib
Assistant Professor of Biology
Chatham University
Woodland Road, Pittsburgh PA  15232
Buhl Hall, Room 226A
(443) 280-0181