>Date:    Wed, 21 Jul 1999 12:10:33 +0200
>From:    Urban Fredriksson <[log in to unmask]>
>
>"Eric A. Schwartz" <[log in to unmask]> wrote:
>>I'm afraid I don't have the actual citations, but I recall that ferrets
>>have zero color vision and do not have binocular vision, whereas actual
>>polecats have at least some color perception and do have binocular vision.
>
>Haven't you seen ferrets track objects with both eyes?  Has anyone really
>shown that the retinas of ferrets and polecats don't have the same
>receptors?
 
Since their eyes and pupils are both black, I'd have to answer no to that
one.  I have seen them turn their heads, but I can't definitively say that
it was their eyes they were 'looking' with.  Especially since Hershey kept
turning her head to investigate things even after she was both blind from
catarracts and deaf.  I'd guess, but just based on anecdotal evidence, that
they are actually orienting the whiskers towards the object, not the eyes.
About the only functional impairment Hershey had after she was blind and
deaf was that she didn't wake up when I came home until I reached into her
pillow and started petting her.
 
As to the retinas, as I said, I don't have the original citations, just
memories of them being posted here some years back.  Perhaps it was out of
_Biology and Diseases of the Ferret_?  My copy is in a box on its way to
the new apartment, so I can't check there, but if anyone has a copy handy,
it might be worth checking for the original references there, and/or for
more detailed information in general.
 
On a semi-related note, one glaring error was so obvious I missed it the
first time around, and it didn't hit me until someone emailed me personally
on a related issue: The domestic ferret is not, as asserted by the DFG
ferret web page, closely related to the black-footed ferret.  That's such a
well documented issue that citations should not be hard to come by, nor
should it be at all difficult to completely embarrass the individual who
wrote that page by holding up such an obvious mistake.
 
Lastly, I was just thinking, it might be worth looking up some articles on
the captive breeding of the b.f.f for further evidence of the tameness of
the domestic ferret:  young b.f.f males are provided domestic ferret females
to practice mating with, since they are considered much safer than their
own species, and are not a waste of a good breeding female for training
purposes.
 
TTFN
 
Eric A. Schwartz
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[Posted in FML issue 2750]