"The European polecats are the same species as the domestic ferret"
 
Sorry, but this is not completely true.  The Domestic Ferret (Mustela
putorius furo)is a sub-species specific of the European Polecat (Mustela
putorius putorius).  These are two distinctly different, albeit closely
related, animals.
 
There are many significant differences between the two.  Size and
musculature.  The polecat sees in color the ferret in black and white.
Shape of the skull and placement of the eys.
 
I recommend reading "Some behavioural differences between the European
polecat, (mustela putorius), the ferret, M. furo, and thier hybrids" by
Trevor Poole, Department of Zoology, University of Wales (July 1971)
 
To refer to them as the same is to add fuel to the confusion as to whether
the Domestic ferret is domestic or wild.
[Posted in FML issue 1406]