Re: Bambiraptor complete!

["James R. Cunningham" <jrccea@bellsouth.net>]

Williams, Tim wrote:

> The argument is centered not so much on whether forelimb feathers would
> reduce the *ground-running* speed for the predator, but whether the forelimb
> feathers would unduly effect the rapid motion of the forelimbs - such as
> when they were rapidly deployed against prey.

I'm aware of that, and as I said, it ain't much.

>  But I would agree that, in
> either case, the effect would be minimal.

Yup, me too.

> >Some birds can still fly with 30% of their feathers gone.
>
> But wouldn't it depend upon exactly what *part* of the body the feathers
> were lost from?

Of course.  I'm referring to wing feathers.  Some hummingbirds lose up to 30% of
their wing feathers during the moult.

>  If the 30% loss of feathers all came from the wing tip, it
> would be much more serious to the bird's aerodynamic performance than if it
> that missing 30% were contour feathers from the body or along the humerus.

Quite true.  See comment above, about some hummingbirds.

> Similarly, if a parachuting proavian, using the feathers attached on its
> hands to guide its "flight path" to the ground, were to lose those feathers,
> then it could have a serious impact on the predator's behavior.

Yes, though if I were the birdie, I wouldn't worry much about it till the
increased airspeed due to the feather loss became greater than I could deal with
upon landing.

> These are all hypotheticals; but I think they're germane to some of the
> current models that seek to explain how theropods came to fly.

I fully agree.

Jim