More 1080 or local extinctions

Birds and bats could be threatened with local extinction if the Department of Conservation (DOC) cannot make more aerial 1080 drops this mega-mast season.

Forest & Bird warns that a plague of rats sweeping unchecked across parts of the country will be followed by an invasion of stoats by spring.

While DOC says it is under way with its biggest predatorcontrol programme so far, Forest & Bird spokeswoman Debs Martin considers it is still not enough during the mega mast – heavy seeding – of beech and rimu trees, and tussock.

Martin, regional manager for the top of the South Island, said the threat to wildlife had reached ‘‘crisis’’ level with rats ‘‘pouring out’’ of some forests where there was no predator control.

In 2011, then parliamentary commissioner for the environment Dr Jan Wright warned that without more 1080 use across larger areas of mainland New Zealand, kiwi could vanish from unprotected areas within a generation and other native birds could also disappear.

In her report then, she said 1080 was cost-effective and safe, and any proposed moratorium would destroy more of the landscape.

Martin said yesterday large blocks of conservation land that had just failed to make ‘‘the cut’’ for 1080 control, and slivers of land that had been sliced off bigger areas, were at risk of ‘‘local extinctions’’.

‘‘Nelson Lakes is one area that is on the list to get predator control but it just missed the cut. They are tracking huge numbers of rats there at the moment.

‘‘There are also areas in the Kahurangi National Park shaved off that could do with more drops.

‘‘The Mokihinui [River] catchment has whio and long-tailed bats – these areas that are just missing out are where there could be local extinctions if the work isn’t done.’’

In the past, even if DOC had been given extra money, it could not expand its 1080 operation due to constraints on helicopters and the amount of 1080 bait, Martin said. ‘‘We have heard those constraints no longer exist.’’

The Government needed to invest more in aerial 1080 operations, she said.

DOC’s director of national operations, Hilary Aikman, said the department could not carry out predator control in all conservation areas where native species were threatened by increased numbers of rats and stoats.

‘‘The current programme over 1 million hectares is as much as DOC staff and contractors can deliver this year.’’

It was not feasible to increase the size of the programme.

‘‘There is some flexibility to include additional proposed sites if operations at some priority sites don’t proceed, due to rodents not reaching predicted damaging levels.

‘‘DOC closely monitors rodent levels to inform whether each predator-control operation is necessary.’’

Martin said only 12 per cent of conservation land – less than 4 per cent of New Zealand – was being treated with aerial 1080.

She hoped some of the work earmarked as priority would not be needed and those resources would filter down instead to the second tier.