Avian Magneto-vision (Was: Biological use of the Zeno Effect)

Remus Shepherd <remus@[EMAIL PROTECTED]
> wrote:
>    (Incidentally, I'm intrigued that this happens in avian retinas.  Do
> birds actually *see* magnetic north and south??  The mechanism creates a
bias
> in the outcome of a chemical reaction.  Could birds see everything to
the 
> north tinted one color, and everything to the south tinted a different
hue?)

   Just wanted to add something to this short discussion.  This time New
Scientist has a story about the magnetic sense of birds...and they seem to
think that yes, birds 'see' the Earth's magnetic field.

http://www.newscientist.com/article/dn13811-birds-can-see-the-earths-magnetic-field.html?DCMP=ILC-hmts&nsref=news1_head_dn13811

   And the Nature News article is here:

http://www.nature.com/news/2008/080430/full/news.2008.788.html

   Both stories have the Nature journal article reference.  I'll have to
get
down to my library to read that.

   So birds see magnetic north.  Possibly only at dusk, when the
cryptochromes
in their eyes are activated by the deep blue of the sky.

   I'm trying to imagine a sentient species with such an ability, and what
they might do with it.  I'd expect them to ascribe religious qualities to 
north and south, at least until their scientists figured out what the
colored
lights in their vision mean.

....                                                                  ... 
Remus Shepherd <remus@[EMAIL PROTECTED]
>
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