27 Jul 2016

Could audio be the answer to NZ's pest problems?

7:59 am on 27 July 2016

The silver bullet for getting New Zealand predator-free by 2050 could come in bait, toxin, genetically-engineered or even audio form, says a pest eradication consultant

  Ship rat eating a kereru egg

Ship rat eating a kereru egg Photo: CC BY NC 3.0 NZ Nga Manu Images

Pest eradication pundits are eyeing up the possibilities, following the government's plan to rid New Zealand of possums, stoats and rats.

Under the plan, the government will invest $28 million in a joint venture company, Predator Free New Zealand, which will identify predator control projects and attract private capital.

The government will contribute $1 for every $2 invested by councils and private groups.

Conservation Minister Maggie Barry said there were plenty of plans in the works.

Ministers at the predator free announcement: Nick Smith, Nathan Guy, Maggie Barry, Steven Joyce, John Key.

Ministers at the predator free announcement: Nick Smith, Nathan Guy, Maggie Barry, Steven Joyce, John Key. Photo: RNZ / Demelza Leslie

"About six weeks ago, I opened a research facility that was funded by Zero Invasive Predators. They are working on about half a dozen really promising areas where you can get inside the psyche of the predator and use high-pitched sound and light and things that are alternative to fences and toxins to be able to safeguard various areas."

Ms Barry said audio was one of the new fronts in pest eradication.

"So they're recording the sounds of baby rats at play, rat language and that kind of thing, and that's to attract stoats who like to eat baby rats, and it's a pretty simple, cheap and effective method."

But global pest eradication consultant John Parkes said it would take much more than that.

He believes the silver bullet for eradication could still come in any form.

"Might be a bait or toxin. Or it might be one of these new fancy genetically-engineered processes. The new genetic tools do hold out some hope, they also come with their own constraints - so people don't like genetic engineering and it's a bit like Pandora's box, open them up and you've got the lot, you can't turn them off."

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Andrea Byrom says 1080 is an acute toxin which some pests can escape. Photo: Supplied

Mr Parkes said wider use of 1080 would be no help because it was an acute toxin which some pests escape.

He said an equivalent was needed for stoats, possums and rabbits.

Andrea Byrom, from Landcare Research, specialises in pest management. She said some novel technologies may need revisiting.

"Some that are being talked about recently, for example, are the trojan female technique, where essentially you've got sneaky females that carry male infertility genes on the mitochondrial part of the DNA. There are things called gene drives, which are not technically genetic modification, but it's certainly editing the gene to, for example, instil infertility into a population."

Ms Byrom said it could be a decade before such tools were deployed on an island, to make sure they were safe.

But, she said, it was a direction the country needed to think about if it was serious about vanquishing pests by 2050.