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Re: Science feather strength debate



> orientation, which showed that neither bird was capable of
> a complete flight stroke. 
Define "complete", not having the same stroke as modern birds, doesn't mean 
they didn't have a functional flight stroke.

> This study therefore inferred that both were limited
> to parachuting or gliding insofar as aerial locomotion was
> concerned. Then there's the matter of the keel - absurdly small in
> _Confuciusornis_, non-existent in _Archaeopteryx_.
Any keel at all would suggest some form of flapping to me.
If it is an attachment area for muscles for the wing... my imagination is 
insufficient to imagine what those muscles were used for if not flapping.

> Although elevation was
> required in order to become airborne (implying that these
> birds must have climbed trees in order to launch), the climbing and
> perching adaptations of _Archaeopteryx_ and _Confuciusornis_ were
> minimal.

I think it is too big of a leap to go from: obligate glider -> must climb 
trees. I also don't think it is correct to assume elevation was needed.
At many coastal areas, gliders can launch from more or less flat ground, from 
about a meter or two above sea level, and start soaring.

I'm still very curious about how reliable the local weather was for slope 
soaring. All I've heard is that archy was from an area that used to be islands.

There are many places now, where you don't need to flap, to regularly fly, and 
I can see a niche there for a species that cruises a few dozen miles of beach 
on the wing, looking for things that wash up, snapping up small crabs, or 
whatever when it comes across them.

http://www.youtube.com/watch?v=pQLDq2JFlx8
(start watching at around 3:00)
Did archie have a wingloading under 1 pound per square foot?
Was its aspect ratio over 6:1?
If so, it was likely a better glider than what is seen in the video.

Being a glider does not mean it was limited to short glides of a few seconds, 
in a duration proportional to the elevation it climbed beforehand.

I could imagine things becoming quite capable flyers, before becomi
rt a ridge soaring glider species.