Opponents of the controversial poison 1080 are furious at a planned bombardment and say the Conservation Minister is misleading the public.
Rat and stoat numbers are expected to skyrocket this year as their food supply is boosted by an unusually large seed drop from beech trees, known as a mast.
The Department of Conservation's (DOC's) five-year battle plan will double the amount of conservation land protected through the use of 1080.
The $21 million project aims to protect 25 million native birds a year over the next five years.
Hailed as DOC's largest-ever species protection programme and dubbed the 'Battle for our Birds', it was unveiled yesterday by Conservation Minister Nick Smith.
"Our native birds are in decline and the kiwi will not exist in the wild for our grandchildren unless we do more to protect them," Dr Smith said.
The application of 1080 is backed by scientists researching predator control, and the Parliamentary Commissioner for the Environment, Dr Jan Wright, has called for more use of it.
But Farmers Against 1080 (FATE) spokeswoman Mary Molloy, a South Westland dairy farmer, said she was appalled that Dr Smith had also claimed 1080 did not kill birds. DOC's own records showed that between 2 per cent and 80 per cent of specific bird species were killed by 1080 drops, she said.
A 1080 operation at Arthur's Pass last year killed five kea among 39 monitored birds. Information still wasn't available on how many kea outside the monitored group died, Mrs Molloy said.
"There's just so many, many points against blanket using of it (1080).
"It was developed as an insecticide, so clearly it will affect insects. Our iconic kiwis eat insects."
The poison was not biodegradable, as claimed, she said. Nor had there been any New Zealand studies on the impact on humans living near 1080 drops.
The poison was inhumane, causing excruciating deaths.
Stoats were not killed by 1080, and rat populations often boomed after being decimated, Mrs Molloy said. Rats had overwhelmed homes beside the state highway between Hokitika and Whataroa following 1080 drops in 2010.
Trapping or cyanide were better options.
Another 1080 opponent, Kumara Environmental Action Group spokesman Laurie Collins, of Hector, also disputed the minister's statements.
"To make a statement that there's no birds being killed (by 1080) is just ridiculous."
Increased 1080 use was about DOC receiving enough funding to stay afloat, not about protecting birds.
"If we're losing millions and millions of birds every year, as was said by Nick Smith, we wouldn't have any birds left. Logically what he is saying is a load of rubbish.
"I think he's very poorly advised by a group that have a vested interest to keep this going."
Mr Collins said that during his 14 years working for the Forest Service, mainly in animal control, there had never been the pest problem DOC now claimed existed.
The Forest Service's use of 1080 was more conservation-minded and controlled than DOC's, he said.
"They've just gone mad with it. DOC's plans for Kahurangi Park is going to put over 40 million pellets around, and it's made out of bird food."
There was no evidence this year's beech mast would be worse than usual, or that pest populations would explode, Mr Collins said.
Dr Smith said the plan aimed at helping to protect the great spotted, brown and tokoeka kiwi, kaka, kea, whio (blue duck), mohua (yellowhead), kakaraki (orange-fronted parakeet), rock wren, long- and short-tailed bats, and giant snails. It was also expected to help save other native birds, reptiles, insects and trees and plants.
The $21m programme would come from DOC's $335 million annual budget, Dr Smith said.
'Fresh funding needed'
Meanwhile, the Government has been called upon to throw fresh funding at its "'Battle for our Birds" to save the Department of Conservation having to defer projects to meet the new programme's big cost.
The cost will be drawn from DOC's $335 million annual budget, and a department spokesperson confirmed this would mean reprioritising projects to enable funding for urgent pest control
"The current beech mast requires a rapid response and lower priority projects will be deferred until the new financial year."
The World Wildlife Fund applauded the urgent action, but DOC needed extra funding to "avert this conservation crisis, not required to reshuffle it's meagre resources", the group's head of NZ conservation projects, Lee Barry, said.
"DOC funding is already stretched to breaking point - yet the Government announced on Tuesday they have $1 billion of new money to spend this year - why not provide just a little of this to protect our precious kiwi, whio and other species with are under attack?"
Green Party conservation spokesperson Eugenie Sage said the Government needed to re-order its spending priorities, "to ensure we protect our native birds and bats from extinction and that other vital conservation work will still get done".
"Other vital conservation work should not have to be sacrificed because of this once in a 15 year beech mast event. Without additional funding that is what will happen."
Meanwhile, experts have backed the urgent action.
Dr Andrea Byrom of Landcare Research said there was no doubt pest numbers - particularly rats and mice - would explode this year in response to the phenomenal mast year the country is likely to experience throughout the South Island and parts of the North Island.
"In places that are not protected from predators, many of our iconic native birds, lizards, frogs, weta and snails will continue to decline," she said.
"With the pest control plan outlined for the 35 sites around the country, these species will have a chance."
In the short term, preventing the pest explosion would enable these species to successfully breed and thrive in the absence of pests during the next breeding season.
"In the long term, DOC's proposed plan will prevent localised or even national extinctions of taonga species like mohua in high-priority areas," she said.
The planned drops would be enough to "hold the line" and get a "pulse" of breeding and recruitment through the coming year for native species in the targeted areas.
After a 1080 drop, a few possums, rats, stoats and mice would survive, and their numbers will slowly begin to build up again over the next few years, she said.
"DOC will very likely want to re-treat some areas when the next mast year occurs - usually three to five years' time - again to prevent the pest irruptions."
In non-targeted areas with no 1080, there would be two kinds of impacts on our native fauna - a direct impact of predation on the species, and the indirect impact of competition, which would see predators chomp their way through the seeds, fruits and invertebrates that were food for native birds and lizards.
"The net result is a step-wise'decline in the areas that are not protected by 1080," she said.
"Of course, there are a lot of passionate keen people out there doing pest control using ground-based methods, but these tend to be smaller areas compared to the larger areas that can be covered by aerial 1080."
Associate Professor Alex James, of the University of Canterbury's School of Mathematics and Statistics, said 1080 aerial drops were our most effective control method.
"The planned drops will be enough to reduce predator numbers enough to allow native species to use the mast year for their own benefit," she said.
"The science is very clear - the planned 1080 drops are the best way to manage the predator outbreak that will follow this year's mast event.
"In areas without predator control we can expect to see significant decreases in native species numbers this year.
'Where the populations are already small - which is too many of our native species - the effect of this could be devastating."
- additional reporting Jamie Morton