Hi
 
I apologise for my response being delayed.  As a university administrator
I get a lot of e-mail to do with work which I need to attend to before I
get down to the rest of my mail.
 
My main point of reference is a book called, The Handbook of New Zealand
Mammals , edited by Carolyn M.  King and Published by the Oxford
University Press at Auckland (NZ) in 1990.  The ISBN is 0 19 558177 6
 
The issue about the identity of feral "ferrets" may be covered
satisfactorialy by the quote below which is from page 323 regarding
variation in the appearance of observed animals.  It should be noted that
the ferret section heading in the book refers to the animal as Mustela
furo.  As far as I can tell the section was written in either 1988 or 1989.
 
"VARIATION
 
It is possible that the original introductions included wild polecats
(M. p. putorius) as well as ferrets. There is much variation in coat
colour, which Wodzicki (1950) took to mean that there were "
at lesat two wild animals to which the term 'ferret' is frequently
applied"; but these variations may be found within one litter (B.K.
Clapperton, unpubl.). Most New Zealand ferrets are still docile
 when trapped, even after generations in the wild, which implies that
there is little wild polecat in their ancestry (B.M. Fitzgerald, unpubl.)."
 
I don't have the Wodzicki reference but will track it down if anyone
has a need for it.
 
In terms of their origins the quote is from page 324:
 
"HISTORY OF COLONIZATION
 
"By the middle 1870's , rabbits were becoming a serious agricultural
pest in NZ. Farmers demanded that the natural enemies of the rabbit,
including ferrets, should be introduced into NZ to control them.
The first releases involved only a few animals (the earliest known, in
the valley of the Conway River in 1879, included only five ferrets);
but starting in 1882 thousands of ferrets were imported from Australia
and Britain, and thousands more were bred locally by the Department
of Agriculture until 1897 and by private individuals until 1912. Ferrets
were liberated first ... (geographical details given).  From these areas,
they spread throughout the then existing pasture lands, and even into
the forests, assisted by enthusiastic government agents and the
protection of the law.  By the turn of the century, they were well
established in the wild, but had themselves come to be regarded as
pests; legal protection was removed in 1903, and the first control
campaigns began in the 1930s."
 
I'm not sure what it takes to provide an iron-clad case for these being
ferrets & not polecats.  The releases were designed for expediency
rather than scientific research & so there is little documentation.
Even if there were some polecats involved their genetic contribution is
likely to have been pretty heavily diluted over the years.
 
As a closing comment you may be interested to know that New Zealand law
permits the importation of ferrets which the Ministry of Agriculture
and Fisheries describe as "Ferrets (MUSTELLA PUTORIUS). "  Whats in a
name?
 
Lawrence Roberts
[Posted in FML issue 1189]