On Aug 10, 2004, at 3:33 PM, Travis Edmunds wrote:
From: "Robert J. Chassell" <[EMAIL PROTECTED]> Reply-To: Killer Bs Discussion <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] Subject: Re: Horses Date: Sat, 7 Aug 2004 21:25:13 +0000 (UTC)
Ronn!Blankenship <[EMAIL PROTECTED]> wrote
... some types of birds have five types of cone cells, suggesting that they can see colors we can't.
Can you tell us more? This is deep.
Just asking a question here. Does anyone know or remember which type of bird navigates by actually 'looking at' the Earth's magnetic poles? Apparently they can actually see something like a red orb which they use as a landmark of sorts.
This <http://www.ks.uiuc.edu/Research/magsense/ms.html> appears to be the source
of the image showing the "red orb" (the image appeared in the document labeled
"Graphs and Stuff" in Ronn's "Birds, was Horses" message of a couple of days ago.
I don't think the image was intended to suggest that birds actually see a red orb,
but to suggest that some kind of visual indication of magnetic orientation may be
incorporated into avian vision.
Dave
Tern for the Worse Maru
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