Record poison drop planned to save New Zealand's endangered birds

The largest ever pest control operation in New Zealand's history was launched Thursday, with plans for aerial drops of the controversial 1080 poison.

The "Battle for our Birds" operation would protect New Zealand's most vulnerable and unique native bird species from the potentially catastrophic explosion of rats and stoats as a result of a beech mast event in forests, said Conservation Minister Maggie Barry.

1080 (sodium fluoroacetate) is a poison that is biodegradable, dilutes quickly in water and does not build up in the food chain, according to the Department of Conservation (DOC).

Heavy seedfalls, known as masts, are triggered by climatic conditions and the sudden abundance of food leads rapid increases in rat and stoat numbers.

Aerial 1080 drops had been confirmed for 19 sites covering more than 720,000 hectares, Barry said in a statement.

"Doing nothing to prevent these vermin from decimating native birdlife is not an option," Barry said.

"We'll not only be saving 12 priority species from the real risk of local extinction, but the landscape-scale pest control will support the entire native ecosystem."

An additional 10 sites covering 200,000 hectares would be monitored for rodent numbers and would see 1080 treatment if pest numbers reached levels that threatened populations of native species.

The first drop was planned for next week and drops would continue through the southern winter.

The last heavy beech seeding operation in 2014 saw significant breeding benefits for native birds such as mohua, whio, kea and rock wren.

"Improved nesting success continued in the pest control areas the following year, showing ongoing benefit for these species," Barry said.

"If we didn't use 1080 to knock down predator populations, many precious taonga (Maori for "treasure") native species would be extinct by now. It really is that simple," said Barry.

"We will not back away from using 1080 at this stage -- we can't ignore the science and stand by while our treasured native species are hit by another predator plague pushing them into further decline and possible extinction," Barry added.

The main threat to many of New Zealand's native plants and animals comes from introduced predators such as possums, rats and stoats.

Monitoring showed most native species were not at significant risk from 1080 operations, said the DOC website.

However, its use has been controversial over the years with opponents saying it poisons non-target animals and contaminates the environment. Endit