The Department of Conservation (DOC) will undertake an aerial drop of 1080 in the Makarora area next month in response to “skyrocketing” rodent numbers.

An increase in food supply from the recent heavy seeding event - also known as a mast season - has caused the surge in introduced predators including rodents and stoats.

“Rodent levels have been monitored at sites, including Makarora Valley, where rare and endangered native species are under greatest threat,” the local DOC team said in a statement.

“Rodent numbers have reached critical levels, and we need to respond with a predator control operation.”

During a heavy seeding event or mast season, a larger number of tree seeds are produced, which should benefit native species.

Instead, this has been “hijacked” by introduced predators and, a few months later, with all the seeds eaten, the rodent population turns to eating native species.

DOC said without the 1080 drop the natural heritage and biodiversity values within the Makarora Valley are put at risk. 

“There are rare native species here that will suffer heavy losses if we don’t act including mohua, whio, kākā, kākāriki, rock wren/pīwauwau and bats/pekapeka.”

Distributing biodegradable cereal pellets containing 1080 is the safest and most effective method we have to control introduced predators over large areas, DOC said.

The bait targets rodents and possums and stoats are controlled through secondary poisoning as they feed on the carcasses of the dead rodents. 

“Helicopters will accurately distribute bait across 36,000 hectares of the forest along pre-determined and monitored flight paths. This is the only viable way to control introduced predators in Makarora due to the vast and rugged terrain.”

The operation is planned for the first clear weather window in March.

During the control operation the Blue Pools carpark and Cameron Flat Campground will be closed, as well as the immediate surrounding public conservation land. 

The closure will last two days for the pre-feed application, and two days for the toxic bait

application 1-6 weeks later.

1080 is poisonous to humans, domestic and game animals and in areas where the toxin has been applied, dogs are highly at risk until poisoned carcasses have disintegrated, which can take four-to-eight months or longer.

Risks can be eliminated by following these rules: Do not touch bait; Watch children at all times; Do not eat animals from this area or within the buffer zone outside the treatment boundary (2km for deer and pigs, 200m for rabbits, and 1km for hares, tahr, wallabies and possums).

Before entering the operation area after March 1, DOC recommends people check the DOC website, or contact the Tititea/Mt Aspiring Visitor Centre for more information on closures.

PHOTO: Sarah Forder