KEY POINTS:
Researchers say they are closing in on genuine, and more humane alternatives to the controversial poison 1080 - described by authorities as a "necessary evil".
In the latest research to be presented today at the New Zealand Ecological Society Conference in Christchurch, Lincoln University researcher Dr Charles Eason will outline exciting progress made in developing new products to replace 1080 and other toxins for combating pests such as possums and rabbits.
"We already have some tools that are partial replacements," Dr Eason told the Herald.
"But it's not just a single silver bullet - it will be several tools. There is a whole pipeline of new products and developments coming on stream to take the pressure off 1080."
In August, following a review, the Environmental Risk Management Authority endorsed the continuing use of 1080 - with stringent conditions.
Erma chairman Neil Walter said 1080, used to kill possums, stoats, rats and rabbits, had "deeply divided" New Zealanders, but was a "necessary evil".
Opponents called the Erma decision a "whitewash". Its continued use prompted a threat by hunters to let their dogs free in a kiwi sanctuary in Tongariro Forest.
Police recently charged a West Coast man with laying deadly 1080 baits on the steps of Parliament earlier this year.
United States congressman Pete DeFazio is seeking support for a bill to outlaw the manufacturing of the poison in his own country for shipping to New Zealand. He argues it is a potential tool for terrorists.
Dr Eason said a key was to make new poisons useable in aerial drops - one of the key advantages of 1080.
"Although 1080 does a very good job, ideally it wouldn't have the secondary poisoning risk it causes with dogs, and ideally it would be more humane than it is."
One new poison in testing, known as Papp, prevents oxygen being carried to the animal's brain and causes a painless death.
DoC senior adviser Herb Christophers said he doubted there would be any immediate alternative to 1080, but DoC fully supported Dr Eason's research.
DoC was not "wedded to the use of 1080", but it was still required for aerial drops to cover large areas and difficult terrain.
"There has been a long line of potential alternatives for many years and none have come anywhere near the efficacy of 1080 for the job at hand," Mr Christophers said.