Q:"Are the Black Footed Ferrets closely related to our ferrets?  They seem
   to look a lot alike."
 
A: The black footed ferret is the domesticated ferret's evil twin.
 
Forget the fact that domesticated ferrets are domesticated, and throw those
characteristics out the window for a while.  So for this first part, assumed
the domesticated ferret is just another species of polecat.  With that in
mind, there are four closely related polecats that inhabit the northern
hemisphere; the domesticated ferret (_Mustela furo_), the European polecat
(_Mustela putorius_), the steppe polecat (_Mustela eversmanni_) and the
black footed ferret (Mustela nigripes_).  All four of these species are
very similar in size, shape and coloration, with European polecats being
the largest and darkest of the group, and black footed ferrets being the
smallest and lightest colored.  The black footed ferret is interfertile with
the steppe polecat, and the domesticated ferret is interfertile with the
European polecat.  Reliable reports indicate the European polecat and the
domesticated ferret are interfertile with the steppe polecat.  I know of no
attempts to breed domesticated ferrets or European polecats with the black
footed ferret, although it is likely it can occur dspite the European
polecat and domesticated ferret having two more chromosomes than the black
footed ferret and steppe polecat.
 
Behaviorally, these four species are also quite similar.  All are strict
sexual territorialists, which means they allow opposite sex members into
their territory, but exclude others of their own sex, with the trait
somewhat less in the black footed ferret.  All are primary carnivores and
eat meat 98% or more of the time.  All are adapted for hunting in tunnels,
and all seem to rely on some extent on burrowing animals for their dinner
(rabbits, squirrels, prairie dogs).  The females are induced ovulators,
they all have a single litter per year (the domesticated ferret can have
two when in captivity, but only one when wild, such as with the New Zealand
feral ferrets).  All are olfactory hunters, all have close up vision only,
and all tend to hunt underground.
 
There are some marked differences, mostly with the black footed ferret.  The
most obvious being the black footed ferret is a hunting specialist, hunting
prairie dogs rather than being the generalist predators characterized by the
other three.  The black footed ferret is also quite small compared to the
other polecats, with males averaging the size of the larger female
domesticated ferrets.
 
The black footed ferret is not actually a ferret at all; it is a polecat,
which essentially means it is a large weasel.  Its name came from it's
superfical resemblance to the domesticated ferret; they look more like a
cimmamon or chocolate siamese point than a sable.  I have closely inspected
the study skins at the American and Smithsonian museums, and it would be
difficult to tell a black footed ferret from a domesticated ferret at first
glance.  Black footed ferrets have a more triangular-shaped head, and their
ears are have more of a point to them (they are still rounded, but the top
edge seems to have a slight point to it).  Interestingly enough, I have
noted a similar trait in most polecats, and Tui, 1/4 European polecat, has
a similar ear point.
 
Other than that, all four of the polecats are remarkable similar.  The main
differences between the domesticated ferret and the rest are in behavior,
brain functions and skeletal morphology.  From an evolutionary standpoint,
it is clear the four species are closely related, and are a minor deviation
from the rest of the weasels (all weasels have _Mustela_ as the first part
of their name).  As a minor point, other than size and exact prey, the
differences between polecats and weasels are rather small; they share most
of the traits already discussed.
 
In terms of the recent FML bbf-thread, almost anything you read about the
black footed ferret can apply to some extent to the domesticated ferret, as
well as the other way around (excluding domestication-related traits of
course).  In fact, because of the insights afforded for our domesticated
carpet sharks from discussions of either polecats, black footed ferrets, or
even weasels, I personally feel they are appropriate to FML discussion,
especially if tied to the care or treatment of our little fellas.
 
Bob C and 20 MO Waskawee Weasels
[Posted in FML issue 2349]