The Changing

Forest and Bird, Issue 307, 1 February 2003, Page 32

The Changing

GEOFF KEEY

tells how

invading species are replacing native animals.

nder our feet is a natural world | that’s easy to overlook. Yet our insects and other small creatures also help make New Zealand such a special place. Like much of the rest of New Zealand’s unusual wildlife, our invertebrates — or animals without backbones — have evolved into weird and wonderful forms, including creatures such as giant land snails, metrelong earthworms, the prehistoric peripatus and strange-looking weta. Yet this unique world is quietly changing, as our native animals are displaced by new invaders. Some of the changes to the world beneath our feet are becoming obvious, even at home. People are finding that the praying mantis in their garden is now more often the introduced South African kind and not the native mantis it is displacing. The disappearance of the katipo as a South African spider replaces it was reported in Forest & Bird, November 2002. In recent years, however, public attention has focussed mainly on the large and the scary. Reports of a snake being discovered, or of black widow spiders hiding amongst the grapes, readily hit the news headlines with their potential to scare and shock. But there is also a whole range of alien invaders that we rarely hear about.

Every year hundreds of new plants and animals travel to New Zealand in goods and in shipping containers. Few survive the journey, such as the frog which was accidentally imported on the roof rack of a Mercedes from Europe and arrived in New Zealand recently in a crisp and blackened

state. Some do make it successfully, however, and like the painted apple moth (see box) become a threat to New Zealand’s native environment. In November 2002 the Office of Auditor General released an audit of what’s called ‘biosecurity risk management’ — stopping the accidental importation of potential pests. The report confirmed that inadequate inspection of shipping containers is currently one of the weakest links in New Zealand defences against invading pests and diseases. Less than one quarter of shipping containers arriving in New Zealand are inspected when they arrive. Those that are not inspected enable new pests to arrive in New Zealand undetected. As a check on what the risks of this are, MAF Biosecurity has recently surveyed shipping containers to find out what enters New Zealand that way. As part of the review, Officials inspected around 12,000 containers out of some 450,000 containers that arrive in New Zealand every year. They found a diverse (and disturbing) array of potential new pests. At the time of writing, the survey results were not fully analysed, but interim results document