Sub-Antarctic rabbit cull to save Macquarie Island

Commonwealth Bay, Antarctica: Australia is planning the world's biggest pest eradication programme on the sub-Antarctic Macquarie Island, where thousands of mice and rabbits are damaging the world-heritage island.

The pests are causing so much environmental damage that native flora and fauna, including species of seals, penguins and sea birds, are at risk, Australian wildlife officials say.

The eradication exercise will involve aerial baiting and about 12 hunters and 11 dogs. It is due to start in May 2010.

"It will be the largest eradication worldwide for rabbits, rats or mice," said Keith Springer, eradication manager with the Parks and Wildlife Services in Australia's Tasmania state.

Australia's Macquarie Island lies about half way between New Zealand and Antarctica, where the cold polar water meets warmer water, and is one of the few islands in the Pacific sector of the Southern Ocean where fauna in the region can breed.

The long, thin island is a breeding place for millions of seabirds, mostly penguins. Seals, including the world's largest species, the elephant seal, haul out on the beaches for breeding.

Around 80,000 elephant seals arrive on Macquarie each year.

Return of fur seals

Fur seals are beginning to re-establish populations on the island after being nearly exterminated by commercial operations in the early 19th century.

The A$24 million (Dh73 million) eradication project will require about 300 tonnes of poisonous bait being scattered over the island.

But the key to success will be the delivery of fresh bait using large storage containers that can transport the bait and keep it protected from weather, condensation and pests.

Six English Springer spaniels are being trained to detect rabbits, but ignore penguins, seals and seabirds.

Two of the spaniels, Ash and Gus, travelled to the island in late October 2009 for training in the conditions they will face on the island during winter 2010.

"The two dogs performed really well on Macquarie but were a bit overwhelmed by the number of rabbits at first, they didn't know which scent to follow first," said Springer.

Insulated kennels have been built to ensure the dogs can withstand Macquarie's extreme oceanic climate with heavy cloud, strong westerly winds and a rainfall of 900 millimetres a year.

Rabbits were introduced to Macquarie by seal hunters as a source of food around 1878. It is believed there are between 60-100,000 rabbits currently on the island.