Kiore: management or eradication?

Forest and Bird, Issue 279, 1 February 1996, Page 20

Kiore: management or eradication?

Ian Close

* rat-free islands

HE KIORE or Polynesian rat is one of the most widely distributed rats in the world, ranging from Bangladesh to Easter Island. Its introduction into fragile island environments by Polynesian seafarers, is part of one of the great biological holocaust stories of the past 10,000 years. Introduced to New Zealand by early Maori, kiore soon spread throughout the two main islands. The effect of kiore on native plants and animals was, and is, not always obvious as they tend to remove smaller, less visible items in the food chain. But we now know that kiore were responsible for the local or total extinction of a wide range of insects, frogs, lizards, birds and bats in this country. To gain a full appreciation of the damage wrought on New Zealand's native biota by kiore, first visit a rodent-free island like Aorangi in the Poor Knights group where at night the whole place is alive with animals that crawl, walk, run, slither, creep, or just sit motionless waiting for a meal to pass by. Next, visit an adjacent island with kiore as the only introduced predator, and spot the difference. At night the place appears quite dead, apart from those animals either too big for a kiore to tackle, or simply out of their reach. The issue of kiore eradication has been complicated by claims from some Maori

that as the rat had been a traditional food source it was a taonga with emotional and historical importance to a number of iwi. Two years ago DoC attempted to develop a "Strategy for the management of kiore on New Zealand islands". The rat is found on 15 islands in the DoC estate (less than four percent of its total New Zealand distribution which includes Fiordland). The draft document included suggestions that while the department would continue to eradicate kiore from highly sensitive islands, it would also preserve the rat on others. The response from Forest and Bird and many other conservationists was

summed up in the question: why is the department that is charged with maintaining this country’s indigenous biodiversity involving itself in the protection of an introduced rat? Announced in October last year, the final strategy is as it should be. DoC will take no responsibility for the protection of kiore, and the rats will be eradicated, when feasible, from those islands where they are a risk to native fauna. The department will have regard to Maori cultural perspectives about the rat and will give assistance to any groups wishing to translocate kiore to special "reserves" in areas of low conservation value.