General information on possum control

Why is over $80 million spent on possum control every year?

possumThe Australian brush tailed possum was introduced into New Zealand in 1837 to establish a fur trade. The possum population flourished here - so much so that their presence has serious implications for farming and for the survival of many of New Zealand's endangered plant and animal species.

Consider these Facts:

  • These cute furry marsupials ravage the bush — it has been estimated they chew up seven million tonnes of vegetation a year.
  • Possums thrive in the New Zealand environment because they have no natural predators, and the native vegetation is so lush. Because our conditions are so favourable, they often breed twice in one year.
  • Ten years ago the number of possums in New Zealand was estimated to be around 70 million. Now, the best informed estimate would put that figure at around 50 million, but the number has not been confirmed as the cost to do so would be better spent reducing possum numbers even further.
  • Possums will seek out their favourite food ahead of other species and eat them out to extinction. Some New Zealand plant species such as native red mistletoe, pohutukawa, kohekohe and northern rata are absolute delicacies for possums and are amongst New Zealand's endangered species.
  • It was recently discovered that the supposedly vegetarian possum also eats birds' eggs and chicks. So, as well as destroying our native birds' habitats and food sources, they prey on eggs and chicks of endangered bird species like the kiwi, kokako, and kereru.
  • Possums and ferrets are the main wild vectors (or carriers) of bovine Tb in New Zealand, and are a major cause of Tb in cattle and deer herds. It is necessary to reduce the levels of bovine Tb in cattle and farmed deer if the risks of trade barriers being applied to our exports of farm products is to be managed.

Possum Control Works

  • After Kapiti Island was made possum free in 1983, vegetation such as kohekohe, rata and fuchsia rapidly recovered. By 1988, recorded bird densities doubled.
  • Rangitoto Island had almost lost all of its pohutukawa forest. Since 1080 was used, it is now a blaze of colour through the summer months. There are also ten times more tui and silvereye.
  • Native land snails recovered in Kahurangi National Park following an aerial 1080 operation in 1997. In a 500m2 plot, snail numbers increased from 54 to 147, with large numbers of juveniles present.
  • Over the last five years, possum control programmes have been the main driver of a 60% reduction in Tb levels in New Zealand's cattle and deer herds.
  • Kokako numbers have continued to increase in the Mapara Reserve, in the Waikato, with possum control one of the key factors in the success. In 1989, no kokako chicks were raised. In 1994, after 1080 control, 52 chicks were raised.

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