Modelling possum re-invasion on the Otago Peninsula

Charlotte Patterson, Phil Seddon, Yolanda van Heezik and Deb Wilson

How do we stop possums re-invading the Peninsula after eradication? Mathematical simulations showed possum re-invasion to be gradual, with immigration limited by the geography of the buffer zone — the urban area across the base of the Peninsula. Over time, re-invasion becomes more rapid as populations re-established in areas with high-quality habitat.

Recommendations from the research are to prioritise rigorous eradication and detection to ensure no possums remain on the Peninsula at the end of the final eradication phase, and increase the density of traps and sustain effort long-term in the buffer zone, particularly in known habitat corridors, including the coastal strips.