Dodging the rain over the weekend I did my bit to make New Zealand predator free by 2050. After shaking the snail droppings out of my trusty backyard tunnel rat trap, I rebaited it. Then slid it back into place alongside the ill-fitting gate leading under the house.

Not sure what triggered the move. Might have been the plump rat brazenly wandering across the Meola Creek walkway on my way to the supermarket earlier in the week.

Or possibly the visitor who inquired about the strips of silver sticky-tape covering the air vents in the elaborate light rose in my old villa lounge. A reminder, I confessed, to the rat that I poisoned many year ago, who tried to get his own back in a very smelly way.


These days, thanks to a steady supply of brodifacoum bait inside the trap, the dreaded patter of little feet across my pressed steel ceilings at this time of year is now a rarity.

But the need to replace the bait over the cooler months on a regular basis suggests that predator-free in my backyard is still just a dream.

A just-published scientific review of the tools being used to try to reach the nationwide Predator Free 2050 goal comes to a similar conclusion.

Written by leading scientists involved in the fight, they conclude, "Current techniques will probably be inadequate to effect nationwide eradications and new tools (possibly based on genetic technologies) will probably be required."

Rather understating the uproar likely from the Green minority in the Government in raising the dreaded spectre of genetic modification, they surmise "the use of some new technologies may be contentious".

By that they're referring to such possibilities as modifying genes in the pest mammals to, for example, make them more susceptible to certain toxins, or to render them infertile, or possibly result in only males being born.

To me, engineering a way to allow possums and rats and stoats and the like to become extinct "naturally" over time seems eminently more humane than bombing our forests with vast quantities of a poison annually and condemning endless generations of these animals to a slow death — all at great expense and without achieving the desired end.

Under the current pest control regime, 25 million native birds are killed each year by predators — along with countless native bugs and plants.

Amongst the army trying to combat this destruction are 200,000 volunteers and the Department of Conservation which in the last Budget got $81.2 million for predator control over four years.

In the next two years, DoC plans the largest aerial 1080 poison drop ever — covering one million hectares of native forest. But this leaves the other seven million hectares of its estate for the pests to hide out.

Predator Free 2050 chairman Sir Rob Fenwick has been quick to endorse the latest report's call for new weapons to fight the battle.

He wants a "public conversation" about the "risks and rewards" of revisiting the great genetic modification debate of 15 years ago. This time, not in relation to food we eat, as during the Corngate hysteria, but in relation to ridding the country of pest species.

Two years ago he advocated a military style campaign against invader predators. He said at the time, "Today the threat of invasion is here, the invaders are possums and rats and stoats and wild cats that are destroying the things we love and create our national identity."

Unfortunately, despite the latest calls from the scientists and Sir Rob, Green Party Conservation Minister Eugenie Sage refuses to invest in research into genetically modified organisms and technologies.

She told DoC and Predator Free 2050 to rely on the old arsenal of mass poisoning and trapping, which at present are, at best, ensuring the current crisis situation gets no worse.

Maybe she's just marking time until the Pied Piper turns up and leads them all back overseas from whence they came.