While this post is more in the interest of the Fellow Ferret Geeks List, I
am cross posting it to the FML because of it's possible value in answering
ferret legalization questions for non-Geek members.
 
I have lost the original question, but someone asked me if I knew if any
references existed regarding the DIRECT ocmpetition of American mink with
ferrets.  Not specifically for ferets, but there are a few for mink vs.
polecats.  The best as far as I am concerned, is the following:
 
Thierry Lode 1993 Diet composition and habitat use of sympatric polecat
and American mink in western France.  Acta Theriologica 38:161-166.
 
Basically, the paper says that European polecat and American mink compete
partially for food and habitat in western France.  Evidence suggests the
American mink has partially marginalized the niche possessed by the
European polecat through direct competition.
 
Also, in a communication with Dr. Lode, he told me "...polecats (and
European mink M lutreola) are also directly preyed by feral American minks.
I found a female polecat killed and partially eaten by a male mink near
Redon (NorthWestern France).  By the way, polecats tend to decline where
American minks occur.  Feral American mink populations are mainly
restricted in Bittany although some individuals were found throughout the
country."
 
Dr. Lode would know; he is currently one of the most frequent publishers
of scientific data on polecats and mink in the world.  In short, he is a
world expert in the matter.  (He also has a web page with references and
very interesting and useful material on it.  You can find it at:
<http://sciences.univ-angers.fr/ecologie/BibliographyMustelid.html>
 
Since European polecats possess hunting behaviors, olfactory imprinting,
and predator advoidance behaviors that are better than found in
domesticated polecats, it is reasonable to assume the occasional lost or
misplaced ferret could not fair better than a wild polecat existing within
an environmental niche sympatric (or living in the same area) with and
being out-competed and preyed upon by mink.  In North America, the habitats
best suited for feral ferrets are those which are already possessed by
several species of weasels and the American mink.  In more than a century
of confirmed ferret breeding in the USA, there exists not a single feral
ferret colony.  Why?  One major reason is they cannot out-compete the local
mustelids enough to establish a permanent presence.  Sorry CaCaLand Fishing
Gestapo and Cranioanal Impaction Society.  You need to do a wee bit of
reading.  Hell, you need a wee bit of a cranial enema.
 
Bob C and 16 Mo' Fartin' (not feral) Ferrets
[Posted in FML issue 2929]