On Fri, 19 Sep 1997, Burton Guttman wrote:
>
> Jane Stewart wrote:
>
> > A very good bird watcher once told me that swallows beat their wings
> > together and swifts alternate.
>
> That's one of those old wives tales (if you'll pardon me for what is
> probably now a politically incorrect phrase) that should be have been
> expunged from biological folklore long ago. Maybe swifts _appear_ to be
> beating alternately, but I'll bet it's not even aerodynamically possible
> for a bird to move that way.


it is not what is actually happening -- only what *appears* to be
happening.

dale goble
moscow