Rabbits eating through world heritage site

Australia's world heritage-listed Macquarie Island is being eaten alive by rabbits, largely out of the sight and mind of its custodians, the Australian people.

The need to protect its seabird habitats from the widespread degradation and destruction of the island's landscapes and vegetation is obvious as entire hillsides are undermined and denuded by the rabbits' constant burrowing and insatiable grazing.

New Zealander Keith Springer and his Tasmanian Parks and Wildlife Service team are headed back from the island across a lumpy Southern Ocean to Hobart, having completed their final reconnaissance mission before launching a pest eradication programme, the likes of which the world has never seen.

If it succeeds, Macquarie Island's 128sq km of coastline will be the largest land mass where rabbits and rodents have been eradicated.

The military-style offensive against the island's 80,000 rabbits and unknown number of rodents will be launched in May, while most of the wildlife is away at sea for the winter.

"It's a huge logistical challenge," said Mr Springer, who was the island's ranger during its feral cat eradication. "We need to get several helicopters, fuel, bait, equipment and a team of 20 skilled staff to a speck of land halfway to Antarctica.

"Daylight hours are short, weather conditions are harsh, and we really only have this one chance to get it right. When the baiting is finished, we need to be able to support hunters and dog handlers in the field for another five years.

"The dogs are a really important part of the team, but so are helicopter pilots and hunters who need to have the commitment, tenacity and attitude required to achieve eradication - it's a totally different ball game to hunting with population 'control' in mind.

"Success in eradicating rabbits and rodents will bring amazing changes to the island, with vegetation, seabirds and insects expected to flourish. Visitors to the island in a few years' time should see an island restored to what it should look like."

It's a juicy coincidence that a Kiwi, working for Tasmania which controls Macquarie Island, is employing the leading expertise of some of his countrymen in this field to right the wrongs of another New Zealander.

It was after all the men who slaughtered the island's seal and penguin colonies in the late 1800s for New Zealand blubber oil entrepreneur William Elder who brought rabbits to the island to provide a food source.

Tasmanian Parks and Wildlife Service general manager Peter Mooney says the A$25 million ($31 million) rabbit and rodent eradication joint venture with the federal Government will benefit not just Australia but other countries as the skills learned are exported.

"Taking the step from pest control to eradication is a first for Tasmania and taking it in one the world's harshest and most difficult terrains will show it can be achieved elsewhere," he said on board the Aurora Australis on Wednesday.

The first phase of the campaign will be a three-month "shock and awe" airborne assault on the pests, starting in May. Three or four helicopters will make three sweeps of the island, spreading 300 tonnes of delicious but deadly bait biscuits.

Station ranger Dave Dowie says friendly fire poisonings among the seabirds will be minimised due to low wildlife numbers on the island in winter.

Tests showed the scavengers - skua, kelp gulls and giant petrels - had little interest in the 10mm diameter, cereal-based anticoagulant baits, he said.

"Secondary poisoning is possible but because the toxin concentrates in the rabbits' liver, the bird would have to eat considerable amounts of poisoned rabbit for a lethal dose."

- AAP