The Department of Conservation has completed its Battle for our Birds aerial pest control in Nelson Lakes National Park to protect native wildlife from predator plagues.
The aerial 1080 pest control, carried out yesterday (December 3) is aimed at protecting vulnerable populations of bush robins, kiwi, kaka, kea and giant snails over 9,000 hectares – about nine percent of Nelson Lakes National Park. The pest control area includes the Rotoiti Nature Recovery Project area by St Arnaud, the Travers and St Arnaud Ranges and the East Sabine valley.
Monitoring showed rat tracking levels in the park rose from 9% in February to 36% in May and 57% in August.
The rising rat numbers have been due to an unusually heavy beech seed-fall, known as a mast, providing abundant food. With plentiful rats and mice to feed on, stoats produce more young than usual causing their numbers to surge in summer.
Aerial 1080 predator control knocks down rat numbers. Stoats are reduced through their eating poisoned rodent carcasses.
The pest control began in early November with aerial application of non-toxic baits that encourages rats to eat the cereal baits containing biodegradable 1080 pesticide.
DOC Rotoiti/Nelson Lakes Conservation Services Manager John Wotherspoon said without this pest control threatened native wildlife would have been decimated by the growing predator numbers.
“We know that rats and possums have already taken robin and kea eggs and chicks in monitored nests. This operation gives us a greater chance to protect these at-risk species from predation during nesting when they are at their most vulnerable.”
Warning signs advising of the risks of the pesticide are in place at key points in the Nelson Lakes National Park, including at the start of tramping and walking tracks, DOC campsites, jetties and road ends.
The Nelson Lakes pest control is among 25 Battle for our Birds operations nationally using aerially-applied 1080 over about 700,000 hectares of conservation land to protect native wildlife from rat and stoat plagues. Aerial 1080 predator control has been completed over more than 90% of the total area so far.
The Battle for our Birds pest control programme is targeted to protect the most at-risk populations of mōhua/yellowhead, kākāriki/parakeet, kiwi, whio/blue duck, kea, kākā, giant land snails and native bats.
Aerial 1080 pest control enables rapid knock down of plague levels of rats and stoats are substantially reduced through eating poisoned carcasses. Ground control on its own cannot protect threatened bird and snail populations from beech mast predator plagues.