Otago Polytechnic

Capable NZ facilitator Mawera Karetai believes we need to improve control of possums and wallabies.

In Eastern Bay of Plenty two pest species, the possum and the wallaby, are well-established. Neither has a natural predator in New Zealand. As a member of the Conservation Board at the time, Mawera Karetai was aware that if the species were not controlled then destruction of the  forest canopy by possums and of the forest understory by wallabies could lead to forest collapse which would be a serious environmental loss for the region.

Mawera undertook to investigate this issue for her Masters in Professional Practice, supervised by Malcolm Macpherson and John Gualter. She began by finding out how the possum and wallaby populations had become established. Population characteristics provided clues into how they could be managed going forwards. Mawera also considered how the current pest management system was working. 

Her thesis concluded that:

  • Possums are a major problem, to which every available resource should be applied (except aerial dropping of 1080 bait poison, due to effects on endemic species of birds, insects and aquatic life).
  • Wallabies should be easier to control, indeed it is possible to completely eradicate them.

Mawera hopes that her thesis will be useful for all those involved in conservation estate management and pest control. As she says:

Usefulness is key to happiness!




March 2019