Re: Bird (Dinosaur?) vision

[Jeff Hecht <jeff@jeffhecht.com>]

Oddly, a paper just out shows that captive songbirds don't sleep much 
during migration season when they are going through migration 
behavior, suggesting that migrating birds may get very little sleep 
without suffering the cognitive decline usually associated with loss 
of sleep. The birds do suffer cognitive decline if deprived of sleep 
at other times. The paper is in Public Library of Science Biology  
(V. 2 (7), DOI: 10.1371/journal.pbio.0020212)

It has also been suggested that the birds may "doze" with eyes open 
to watch for predators, while effectively getting some sleep. -- Jeff 
Hecht

At 3:24 PM -0600 7/22/04, Ken Carpenter wrote:
> sleep?
>
> > > >  <Lawrence_Dunn@smbcgroup.com> 22/Jul/04 >>>
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>
>
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> Is it true that some birds can see only movement -- that they cannot "see"
> something that is not moving?  I've recently had this suggested to me, but
> I'm not sure I see the sense of it.  Is there such a condition in nature?
> If so, what is it called?