A second massive poisoning operation in two years - costing $20.7 million - is planned to hit a predicted boom in rats and stoats later this year.
Conservation Minister Maggie Barry says new money will come from this year's budget to pay for the Department of Conservation's Battle for the Birds 1080 poison operations to help protect native wildlife.
Another year of heavy beech forest seed fall - called a mast - has provided about one million tonnes of food for the pests. The poisoning operations should knock down their populations before they turn on native birds.
"DOC scientists have confirmed the seed fall predicted last year has eventuated," Ms Barry says.
"We must respond if were to protect our native birds and animals from the threat - and the funding will enable DOC to achieve this."
In 2014 a one-in-15 year mast season sparked the first Battle for our Birds, a $21M poisoning operation over 600,000ha, which DOC scientists said was largely successful.
All the indications were that this mast was on a similar scale but with more seed falling in the South Island, Ms Barry said.
This time DOC would drop 1080 over more than 800,000ha. Drops would be backed by trapping and ground control programmes.
"By taking what we've learnt from our response two years ago were able to increase the targeted area, protecting more precious habitat and more bird populations," Ms Barry said.
Pilot projects will also test the effectiveness of self-resetting traps to keep pests permanently out of an area following a 1080 operation.
DOC has said the last operation improved the nesting success of rock wren, mohua, robin and riflemen was significantly higher in areas treated with aerial 1080 than those without.
However, some native birds died from 1080, including four out of 48 tracked kea.