In response, DoC's Tiakina Ngā Manu predator control programme, previously known as Battle for our Birds, will see more than 66,000 hectares of trapping with the remainder - more than 900,000 hectares - aerial dropped DoC 1080 operations.
Sage said it's a step up from the largest programme overseen by former National Party Conservation Minister Maggie Barry, of 840,000 hectares in 2016, when there were significant but smaller mast events.
Priority sites for predator control include Kahurangi, Abel Tasman, Arthur’s Pass, Westland, Mt Aspiring and Fiordland national parks, the Catlins and Whirinaki.
In a mast year, trees produce large amounts of seed. This boosts rodent numbers, and in turn stoat numbers. When the seed is gone, the plague of predators turn to native birds, bats, lizards and insects.