>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 [log in to unmask] [Posted in FML issue 2750]