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Re: FLIGHTLESS BIRDS




PTJN@aol.com wrote:
> It seems to me that a sure fire way to ground the theory of the
> cursorial origin of flight is to require a running takeoff.

Why? (I'm really interested in your thinking here -- I'd like a better handle on
what people percieve as the problems of a running launch)

> There are alternatives to the "running" and the "insectivorous" aspects of
> "ground up" theory of flight.  Several folks have proposed that the leaping,
> flapping, bobbing, and jabbing behavior exhibited by carnivorous cursorial
> predatory birds such as the roadrunner during combat and mating are more
> reasonable models for preflight training among feathered, pre-avian theropod
> dinosaurs.  These highly energetic combat and mating techniques would select
> for all the basic flight musculature and neurological controls (braking,
> banking, altitude, pitch and attitude control, etc.) necessary for flight,
> without initially requiring flight.  They are also practiced at essentially
> zero ground speed, so no running is involved, and successful combat could have
> resulted in a meal of a fat little mammal instead of a dragonfly.

 I wouldn't say that this is 'more' reasonable, but it is certainly reasonable 
in
and of itself.  And animals developing the capability of flight would soon be
capable of taking advantage of arboreal niches even if they weren't initially
arboreal.. Why couldn't the origins of avian flight include a bit of 'all the
above'?

Jim