Stoats threaten kaka

By SIMON COLLINS

Stoats are wiping out the females in New Zealand's unique parrot species, the kaka.

The stoats, introduced from Britain in the 1880s in a vain bid to control possums, are also killing 60 per cent of kiwi chicks.

Scientists say that both kaka and North Island brown kiwi will become extinct within a few years unless the stoats are controlled.

"The North Island brown kiwi are functionally extinct right now, in the sense that they are not maintaining their population and that will inevitably lead to extinction," said Landcare Research kiwi expert John McLennan.

But the Conservation Department is creating mainland refuges for the birds by trapping and poisoning the stoats and possums.

Dr McLennan said stoats were killing the female kaka and their chicks by climbing the trees where they nest.

The department said females dropped to as little as one-seventh of the kaka population in the Waihaha Forest, west of Taupo, in a 1994 survey.

Its latest study found that stoats killed eight out of 10 female kaka slain by predators in six forests between 1996 and 2000. The rest were killed by possums.

The study found that kaka chicks survived in only 10 per cent of the nests found in two Nelson Lakes forests, and in 38 per cent of nests in the Whirinaki Forest near the Urewera National Park.

Dr McLennan said survival rates for kiwi were even lower - about 5 per cent. But survival rates were much higher - 80-87 per cent - where poisoning and trapping was controlling possums and stoats.