14 July 2004

Cook's petrel expected to thrive on Little Barrier Island

This summer is looking bright for Cook's petrel on Little Barrier Island (Hauturu) with the operation to get rid of kiore completed this week.

A boost in the survival of Cook's petrel chicks will be one of the early signs that Little Barrier is rat free. But it will be two years before this can be confirmed when the Department of Conservation will undertake intensive monitoring to check for kiore on the island.

DOC Auckland Conservator Rob McCallum said the second aerial rat bait drop on Hauturu was successfully completed on Monday in perfect conditions. It follows an initial drop in June.

"It's hugely satisfying to have the operation finished in just six weeks after more than six years of planning.

"We can now look forward in two years time to being able to confirm the pest free status of one of New Zealand's premiere island nature reserves."

Thousands more Cook's petrel chicks are expected to survive on the island without kiore to ravage the nests. In previous years up to 95 percent of chicks have been predated by the Pacific rat leaving the petrel population in a downward spiral.

But if Codfish Island (Whenua Hou) is anything to go by, the survival of Cook's petrel chicks will increase dramatically. After kiore were removed there in 1998, the chick survival rate leapt from 15 to 85 percent in the first year. Whenua Hou Nature Reserve was declared rat free in 1991.

Little Barrier is the world stronghold of this native seabird, with a population of 50,000 breeding pairs. The only other population is on Whenua Hou, near Stewart Island, which hosts several hundred of the birds.

With kiore gone from Hauturu other seabirds such as diving petrel, fluttering shearwater and grey-faced petrel are likely to return. The future of threatened species such as giant weta, Duvaucel's gecko and tuatara will also be more certain.

Removing kiore from Little Barrier is the second largest island rat eradication undertaken by DOC after sub-Antarctic Campbell Island. Some 55 tonnes of rat bait was spread over the 3083-hectare island in two separate applications.

ENDS

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