Not so much as a nibble: sun setting on wildlife paradise's rabbit war

FOR more than a year, hunters have scoured windy hills and tussock flats through sub-Antarctic cold and still there is no sign.

The wildlife paradise Macquarie Island looks to have been saved from the rabbit.

Lush megaherb fields once razed by rabbit teeth are splendid again. Steep slopes denuded to the point of landslide are clothed in green. But the hunters and their dogs have work ahead.

''There are still three or four rabbits we haven't accounted for,'' said Macquarie Island's pest eradication program manager, Keith Springer.

''It's starting to look like a success but we're still hesitant to say that.''

Rabbit eradication would be the climax of a decades-long struggle against introduced pests in the designated United Nations Educational, Scientific and Cultural Organisation biosphere reserve and World Heritage site.

Rabbits, rats and mice have lived on the island since 19th-century sealers brought them and their numbers exploded after 2003.

Myxomatosis and calicivirus had some success against an estimated 100,000 strong rabbit population but the great blow was a saturation poison baiting of the island by helicopters through the winter of 2011.

The $24 million federal-state program appears to have knocked over the rabbits, as well as eradicated rodents from the 34-kilometre Southern Ocean wildlife sanctuary.

Total victory depends on the rifle-equipped hunters and their dogs.

''It's a pretty tough, field-based job,'' Mr Springer said.

''There are low temperatures, constant strong winds, fog and the terrain is challenging as well.''

The 13 hunters split up into small teams and headed out for tiny field huts for a month at a time, accompanied by labradors, springers and terriers trained to ignore the teeming seal and seabird colonies.

Over winter, conditions were so cold that hunters reported if they stopped walking, they would freeze within minutes.

In the months immediately after the helicopter baiting, the teams accounted for 13 rabbits, including a doe and kittens.

But since November 2011, no rabbit has been seen, nor their droppings or prints.

Scavenging bird populations also badly hit by the poison baiting appear to be recovering.

More than 2200 birds - mainly skuas and giant petrels - died from eating baits or the carcasses of the rabbits and rodents, Senate estimates heard.

''We have noticed a bit of an increase in breeding numbers for these birds,'' Mr Springer said.

Where the greenery was reduced to a close-cropped grassland, a mosaic of flora is reappearing.

A botanical ecologist with the Tasmanian government, Jennie Whinam, found that for the first time in years of work on Macquarie Island, she was able to see an entire landscape without rabbit damage.

Sights such as swathes of the native silver-leaf daisy, Pleurophyllum hookeri, ''just bring joy to my heart'', Dr Whinam said.

Ground-nesting grey and cape petrels, which deserted the island under predation from rats, are also coming back.

Mr Springer said the plan had been to hunt for three years after the baiting. ''I think we'll send another team down next year and, if they haven't found any evidence, that would be it,'' he said.

A win on Macquarie Island would offer global lessons in pest eradication and the restoration of natural ecosystems.

''Certainly, it is the largest eradication exercise globally for the rabbit,'' Mr Springer said.

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