The general belief ( as far as I know) is that minks cannot be cross
bred with the domestic ferret due to a difference in some minor genetics.
(that said I have seen information that states mink breeders often
interbred ferrets with minks in order to improve colors and or fur
patterns..  So I would love to be pointed to some definitive answers on
this one.)
 
However, it is definitely true that polecats can be interbred with
domestic ferrets and produce viable offspring ( and as polecats can also
be bred with minks, I am sure that even if a domestic ferret couldn't
breed with a mink, then a polecat/ferret hybrid could probably mate with
a mink, and/or a hybrid mink/polecat... ) but anyhow..  it is probably
unlikely in the US for these sorts of hybrids to appear ( polecat/ferret)
as there is not that many polecats in the US ( so I am led to believe)
however in Europe and new Zealand in particular I understand this is more
common.  The differences usually show up in the coloration ( for hybrid
ferret/polecat) and they can be larger, although size varies a lot in the
domestic species so this is not a real indicator..  They would or should
be more difficult to handle and more wary, and quite possibly more
intelligent then your average fuzzball due to the wild "stock" influence.
 
check the web for polecat ferret hybrid pictures and you will notice the
differences in coloration.
 
As a side note: It is my understanding that the feral population of
ferrets in New Zealand, were in fact interbred with Polecats during the
voyage from England, as it was known even then they would have problems
surviving in the wild, without some of the instincts of a wild ferret.
Therefore, the commonly held belief that ferrets can survive in the wild
"because everyone knows they do in New Zealand", can argued against by
the fact that they are "not" domestic ferrets but in fact "hybrids", and
real domestic ferrets would probably have died.
 
PS: for those who don't know, not only were ferrets released in New
Zealand, but so too were stoats, weasels, and polecats.
 
Darrin
[Posted in FML issue 4680]