The Department of Conservation (Doc) will carry out an
aerial 1080 predator control operation across more than
20,000ha in the Dart, Routeburn and Caples Valleys this spring,
as part of a South-Island wide operation that will cover about
Doc scientist Dr Graeme Elliott visited Queenstown recently
and released details of the operation in the upper Wakatipu
area at a public meeting that drew about 50 people. Dr
Elliott told the Otago Daily Times that after a heavy seeding
of beech trees in many South Island forests during the past
summer, known as a beech mast, rat and stoat numbers would
When the seed ran out in late winter, threatened bird species
were at risk of being decimated or could disappear completely
from some areas.
Although the beech mast appeared to be lighter in upper
Wakatipu, the operation would go ahead in the area because it
was home to one of the South Island's key mohua (yellowhead)
Although the three valleys already had a network of more than
1000 predator traps, they were not sufficient after a beech
mast, he said.
After a beech mast in 2011, trapping alone was insufficient
to protect some native bird species and mohua numbers fell
75% in the Dart Valley.
More than 90% of mohua disappeared from the Dart and Caples
Valleys in 2000, after a beech mast, but in the same area in
2006 and 2009, their numbers remained steady after aerial
1080 operations were carried out.
Other threatened birds in the Upper Wakatipu vulnerable to a
predator explosion were whio (blue duck), kaka, kakariki,
tuke (rock wren) and kea. The operation would cover up to
24,000ha across the three valleys and would take place over
two days, separated by a week, in September or October.
The operation would cost Doc up to an additional $8.2 million
nationally, which would come out of its existing budget.
The pellets containing the toxin were cylindrical, about 3cm
long, weighed 6g and were dyed green and laced with cinnamon,
to deter birds. They were dropped from helicopters at a rate
of about 1kg a hectare, or one pellet every 60sq m, he said.
All landowners, businesses and other groups directly affected
by the operation had been kept up to date by Doc's Queenstown
Doc would also temporarily close affected walking tracks,
erect warning signs and advertise in local newspapers.
Wanaka conservation services manager Chris Sydney said
recently that in the Mount Aspiring National Park,
preliminary data from seed monitoring showed a ''potentially
moderate'' amount falling in the West Matukituki area but
higher amounts in the Makarora area.
Mr Sydney said the size of the area where poisoning was
planned had increased ''quite dramatically'' to include
protection for more species, such as the rock wren, which
lived at higher altitudes.