Page 9 - 2008 NZ SUB ANTARCTIC ISLANDS - SMARTPHONE

Actually, DOC has many exotics to deal with, thanks to the wholesale importing of mammals that
the European settlers accomplished in very short order. A list of animals DOC is currently
dealing with include the following: Argentine ants, deer, feral goats, various fish species, feral
horses, wallabies, possums, rainbow lorikeets, rats, stoats, ferrets and weasels, tahr and wasps!
Of course, the list of exotics is incomplete because we have not even mentioned all the non-native
plant types which are out-competing New Zealand’s own species. Needless to add, DOC has a
huge and never-ending mission.

The major weapon DOC workers employ to try to control the brushtail numbers is a natural plant
toxin called 1080; actually it is sodium monofluoroacetate. It has the advantage of being water
soluble and biodegradable. But its use is not without controversy since native birds, fish, insects
and reptiles do succumb when they ingest it. Many studies have been conducted to make the
poison less attractive to any of the native creatures. At present the poison is embedded in a cereal
host which has proven to be alluring to the brushtails but relatively uninteresting to birds and
other native species. There is a “by-catch” aspect to the strategy, but it is small enough that the
scientists believe that this poison is their most effective culling agent. 1080 has the added value
of being very effective with the 4 species of rats that have established themselves on the two main
islands. The Subantarctic islands have been rendered rat-free due to the use of 1080 as have some
other of the islands belonging to New Zealand and now functioning as preserves. The poison is
dropped from the air and then the kills are monitored by DOC workers on the ground—both the
intended and unintended deaths are counted and recorded so that improvements in delivery
systems can be researched.

Just for fun, it is good to mention a couple of very ironic discoveries we made. In 1870 the then
Governor of New Zealand imported 4 species of wallabies from Australia to create a zoo on a
small islet off the North Island. The zoo never had any cages because it was believed that the
wallabies would never swim across open water and that supposition did turn out to be true.
However, the wallabies found the little island very much to their liking and found everything they
needed for survival and reproduction. Soon they had eaten all the native species of plants (they
are herbivores) and it became necessary to feed them and keep their numbers down to something
manageable. These creatures are living well on the largess of the New Zealanders who support
the island zoo.

The irony is that two of those species are nearly extinct in Australia and DOC is cooperating with
Australian biologists in a breeding and relocation program to return the endangered wallabies to
their own homeland!

In a park on the North Island are herds of feral horses which are also very destructive of native
habitats, especially the native plants. The herds are controlled and kept in a reserve area, but
every time the DOC must cull the numbers, a great protest goes up from the New Zealand
humans who do not wish to see these horses destroyed. Sounds like home with our wild
mustangs and burros, doesn’t it? So, just as our Department of the Interior has attempted, DOC
periodically offers the excess horses for adoption. And just as it is here at home, never are
enough of the animals adopted to keep the herds at the optimum levels. Incidentally, these feral
horses are really domestic horses who were allowed to run free in years past—again, just like our
mustangs

Another amazingly ironic disconnect: while New Zealand is being overrun with brushtail
possums, there is still an odd import business which thrives fairly well—frozen brushtail possum
meat is imported into NZ from Australia for human consumption! Why don’t New Zealanders
who like this meat hunt the creatures in their own country where they are such an enormous pest?

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