Mass rat sterilisation

Mass rat sterilisation could be the answer to New Zealand's pest free future

 ContraPest would make female rats incapable of producing babies.

Making rats infertile on a mass scale could be the answer to New Zealand's pest problem. 

While the technology to make rodents infertile has been trialled in places like New York conservation minister Maggie Barry said it would likely still be a few years before it could be implemented here. 

Barry floated the idea at a funding announcement in New Plymouth on Thursday for Taranaki's Mounga Project, which aims to ramp up pest eradication and native bird re-introduction in Egmont National Park over the next 10 years. 

Maggie Barry, Jamie Tuuta and Steven Joyce announced four new investors for the Taranaki Mounga Project on Thursday.

"There's still a need for 1080, we have to do what we have to do in the meantime to bring predators down to a manageable level," she said. 

After pests were culled back with 1080, Barry said it would pave the way for the Department of Conservation to use pest trapping technologies that were only just starting to emerge. 

The Taranaki Mounga Project aims to reduce predator numbers in Egmont National Park and ramp up native bird re-introduction.

This could include ContraPest, a permanent contraceptive for female rats which when consumed, as a bait, kills off the rat's eggs in the womb and hence its ability to have babies. 

These technologies could come in many other forms like self-resetting traps, drones or utilising GPS tracking to kill pests, economic development minister Steven Joyce said. 

"Technology is becoming available to actually help us take on this predator free by 2050 challenge," he said. 

Joyce said making rats infertile with bait was on the cards for New Zealand, but was still "awhile away" from being implemented here.

"With technology like drones or GPS it's going to make it easier to deliver large swathes of predator free areas."

However Joyce said it would be "a while yet" before the likes of ContraPest was used in New Zealand. 

He said there wasn't a "final pathway" on how to tackle the predator free New Zealand by 2050 goal but believed it was "likely to be doable".

"We're not looking for a silver bullet, it will take a range of methods to achieve our goal."

As well as announcing future predator control methods Joyce and Barry were in New Plymouth to announce new investors for the Taranaki Mounga Project, on top of the $28 million the crown has put in to get the ball rolling. 

DOC, the NEXT Foundation and Taranaki iwi were the primary partners and investors of the project but have now been joined by Shell New Zealand, TSB Community Trust, Jasmine Social Investments and Landcare Research. 

Taranaki Mounga Project chairman Jamie Tuuta said all eight Taranaki iwi viewed the mountain as their ancestor and collaboration was key to achieving a pest-free goal for the national park.

"So we can enjoy the bird song on Mt Taranaki, because sadly today it is silent," he said. 

Tuuta said the project was an ambitious but necessary vision to safeguard Taranaki's ecology for future generations.

The first stage of the mounga project was spearheaded by DOC with a non-toxic bait drop last week to draw predators to the area before the poisonous 1080 can be dropped in the same area. 

This year's 1080 drop will be the last of DOC's six-yearly drops in the park before it moves to dropping the toxin every three years at half the dosage.