Re: Fw: Dinosaurs and birds

[Michael Habib <mhabib5@jhmi.edu>]

On Wednesday, April 4, 2007, at 11:16  PM, Anthony Docimo wrote:

> > Subject: Re: Fw: Dinosaurs and birds
> > Date: Wed, 04 Apr 2007 22:37:46 -0400
>
> > Note that running birds do not deploy their wings while sprinting, 
> > unless it is during launch.  Wings *can* be used for certain agility 
> > actions on the ground, such as clearing obstacles or certain turning 
> > maneuvers.  However, those are a separate consideration from what was 
> > being discussed before.
>
> could maniraptors (not birds) with feathered arms  have had an 
> advantage over maniraptors lacking feathers on their arms, when it 
> comes to those turning manuvers and clearing obstacles?

Perhaps, but only if the arms had fairly significant foils.  To help in 
clearing obstacles, the animals would need to produce significant lift 
in a leaping launch.  Turning maneuvers are a bit more tricky.  Turning 
in terrestrial locomotion and turns via aerodynamic lift in flight are 
quite different.  Melding the two gets a bit odd.  Nonetheless, 
airfoils might be usable to maintain balance during very tight turns on 
the ground, though modern running birds don't seem to utilize this very 
often.  Some birds do seem to use the wings for balance on occasion, 
however.  Secretary birds sometimes deploy the wings briefly during 
running maneuvers; they also use them as decoys/shields during prey 
capture.

Perhaps others on the list have further thoughts on this.

Cheers,

--Mike H.