Adult whio with ducklings
Image: DOC

Archived content: This media release was accurate on the date of publication. 


An aerial pest control operation will protect at-risk native species in the Northern Ruahine Ranges from a surge of hungry predators this spring.

Date:  10 August 2017

Duncan Toogood, Acting Operations Manager for DOC’s Manawatu District, says the operation has been planned to give maximum protection to the highly valued species in the area. 

“This operation will offer a fighting chance to Ruahine populations of at-risk species, such as whio, kiwi, giant land snails, robins (toutouwai), kākāriki, bats (pekapeka), red mistletoe, dactylanthus, and Turner’s kohuhu.” 

Every 2-6 years beech trees flower and produce massive quantities of seed (called a mast). Sampling in February 2017 confirmed that a mast was occurring in the Northern Ruahine Ranges this year.

Beech masts provide a short-term bounty of food for introduced predators, driving them to higher numbers than usual.

“This increase in animal pest numbers could lead to the loss of the our threatened taonga species,” says Toogood. “Once the seed runs out, these predators will look for other food sources—our native species.”

The Department of Conservation plans to reduce rat, stoat and possum numbers with cereal baits containing biodegradable sodium fluoroacetate (known as 1080) over more than 30,000 ha in the Northern Ruahine Ranges.

Without predator control, only 5% of kiwi chicks hatched in the wild will make it to their fourth birthday, and for every three breeding pairs of whio, only two ducklings will make it to fledging.

“Pest control is an ongoing battle.  Every year we face new challenges that put our vulnerable native species at risk. To ensure the survival of these taonga, we need to act,” Toogood says.

“Aerial 1080 is the most effective large-scale pest control tool we currently have and monitoring shows it’s successful in protecting vulnerable species and allowing birds to produce more chicks to sustain and build their populations."

Community-led ground-based predator control is also helping to protect Northern Ruahine taonga species, says Toogood.

“There are four community trapping initiatives within the Northern Ruahine Battle for our Birds treatment area, servicing more than 1000 traps.

"These volunteers make a valuable contribution to protecting the taonga species of the Ruahine Ranges but trapping cannot keep up with the boom in predator numbers that follows a beech mast, especially over such large-scale, difficult terrain.”

The Northern Ruahine operation is one of 34 Battle for our Birds predator control operations taking place across the country this year that together cover about 800,000 ha or 10% of public conservation land.

Battle for our Birds is a nationwide predator control programme that supports DOC’s goal of protecting threatened species and making New Zealand predator free by 2050.

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