Re: large fossil birds

[jrc <jrccea@bellsouth.net>]

I'd like a copy of that PDF

----- Original Message ----- 
From: "Michael Habib" <mhabib5@jhmi.edu>
To: <dinosaur@usc.edu>
Sent: Thursday, December 01, 2005 11:09 AM
Subject: Re: large fossil birds


> >  Minimum induced drag for a cranked wing occurs with a more triangular 
> > tip.
>
> This doesn't surprise me, because it matches familiar biological patterns 
> (ie. species using cranked wings generally have tapered tips). Why is it, 
> though, that cranked wings have a different optimal tip profile?

Optimization of the spanwise load distribution for minimum induced drag is 
different for cranked wings than for straight wings. (that's a non-answer if 
I ever saw one -- will fish out some references for you -- prompt me if I 
forget).

> Interestingly, some eagles use very long, shallow stoops and will morph 
> their wings gradually as they pick up speed to continually minimize drag 
> (and probably also to increase wing loading to some degree).

Yes.
> Makes sense to me.  In terms of maximum speeds, there is a rather fun 
> anecdotal paper that describes an albatross utilizing winds from a strong 
> Antarctic storm to fly at a sustained average speed of 127 km/hr for 9 
> hours (the animal had been tagged with a electronic tracker previous to 
> the observation).  Apparently it's the fastest recorded sustained soaring 
> flight speed (note that the speed given is the ground speed).  I have the 
> reference in pdf for those curious.  It's obviously not a good example of 
> the 'normal' conditions, but it's still fun to read.
>
> Cheers,
>
> --Mike