An extensive network of 477 possum traps extends right across the 2000ha of the northern forest block in the East Harbour Regional Park (EHRP) using two types of kill trap - Possum Master and Timms traps. These are baited with a long-lasting cereal bait and an attractant made up of flour, icing sugar and spices is spread around the traps. Traps are checked by volunteers fortnightly in most cases, and monthly where catches are falling to very low levels.
Regular possum trapping has significantly reduced levels of possums in the forest. Prior to the start of regular trapping, the RTC (rate of trap catch) or number of possums caught per 100 traps was 27 per cent. In 2011 this had fallen to 1.4 per cent. This reduction in possum numbers will be a huge relief to both plants and animals in the Park.
The figure of 1.4 percent is well below the target level of 5 percent. This is the fourth monitor in a row that has been below the 5 percent level, confirming that possums have now been effectively suppressed in the Park for the last 5 years.
This chart indicates the number of possums being caught per year:
It is welcome reward for the MIRO trappers who regularly service the 447 kill traps scattered across the 2000 ha of the EHRP and it confirms the success of the park-wide trapping network set up in 2004 with the Greater Wellington Regional Council (GWRC) assistance.
Maintaining the trapping on a regular basis, servicing the huge number of traps required involves a massive physical effort and the results of this latest monitor are a testament to the dedication of the MIRO trappers. It is gratifying to consider the resurgence that will be taking place in the trees, birds, insects and the forest generally as a result of effectively suppressing these predators.