ur
seals are common outside Halfmoon Bay and are often to be seen
sunbathing on the rocks fringing the various points and islands.
When boats draw near they usually dive into the water, although
they are not always so timid. Females with pups can get very aggressive
when they think their young are threatened and a couple of the
paua-divers around Stewart Island have received severe bites.
After almost being exterminated in the sealing days, the seals
are again on the increase and the staff at the salmon farm on
the island are now complaining that the nets around their ponds
have been ripped by seals trying to get at the fish inside.
Dolphins kept the boat company at several times
during the trip, skipping along by the bow wave. These were either
dusky or common dolphins, the most common species around here.
Hector's dolphin is seldom seen off Halfmoon Bay but is often
found between Stewart and the South Island. Even rarer is the
beautiful hourglass dolphin which seems to have its range to the
south of the island.
In the south of the island, in an area closed
to ordinary visitors, a number of fascinating finds have been
made, including the harlequin gecko, our rarest and probably our
most attractive lizard.
Also in the south, about 20 years ago, a colony
of the very rare kakapo was found in a mountainous area called
the Tin Range. The discovery was particularly exciting as the
colony included females. The female kakapo is smaller than the
male and more vulnerable to predators while sitting on its nest.
As a result, all female kakapo had long since disappeared from
elsewhere in the country, leaving only a few old bachelors.
Although free of mustelids, Stewart Island has
feral cats which were taking the birds. With considerable effort,
Don Merton, a conservation officer who specialises in endangered
birds, and other Department of Conservation officers, trapped
a number of birds and these were sent north to Little Barrier
Island in the Hauraki Gulf, one of our few predator-free islands.
This must have been a dramatic change in climate for the kakapo,
coming from the frozen wind-swept heights of the Tin Range to
a subtropical island. Unfortunately, although the birds survived,
no breeding has taken place. At the same time cat predation started
to increase drastically in the Tin Range with a consequent sharp
decline in the population and it became imperative to find somewhere
else for the few remaining birds.
Codfish Island, off Stewart Island's west coast,
was selected. The one major problem with Codfish was that it had
a large and healthy weka population introduced to the island about
the turn of the century. Weka are extremely efficient hunters
and in areas where they have been liberated they have decimated
ground-nestmg birds. Codfish is one of the few islands with nesting
populations of Cooks petrel, or titi, and over the years
these had been reduced to very low numbers by the weka. For the
sake of the titi, as well as to help the kakapo's chances of breeding
on Codfish Island, the weka were removed and many were released
on Stewart Island. It is hoped that Codfish Island represents
the turning point for the kakapo.