Modelling possum barriers and control options

Audrey Lustig and Deb Wilson

Mathematical simulations of different possum trap densities were used to assess the effectiveness of control networks in the Halo Project area, north of Dunedin. Simulations showed that only one trap per 25 ha is required in a trap network spanning the Halo area, using automatic multi-capture traps, to keep possum populations low (<2% residual trap catch index).

Simulations of a semi-permeable barrier (eg. fence) along SH1 showed minimal effect on limiting the recovery of possum populations within the Halo control area. Elimination of possums from the Halo area could be achieved through trapping beyond Halo’s boundary.