A number of possum control options were discussed with EBOP pest animal officers, from cyanide (Feratox) to brodificoum (Pest Off) but there are drawbacks to both. Two experienced contractors visited the site recently and have decided to set up a pilot project using a new product to test their effectiveness in this kind of setting. Warrior traps, supplied by Connovation Ltd, are a user and environmentally friendly trap that humanely kills possums.
39 traps were initially attached to trees showing ‘possum sign’ across the previous 6 lines and volunteers began checking traps and data gathering at weekly intervals. Initial kill rates were very high and traps needed to be cleared after a few days but within one month the rate had declined. Over the space of just thirteen weeks more than 100 possums were trapped in the 40 hectare reserve.
The possum trapping is regarded as being very successful. Initial high trapping rates are recorded with an easing of the mortalities. It can be concluded that the resident possum population has been reduced and the numbers are expected to trail off even more significantly. This coincides with a decrease in the number of rodent bait stations being interfered with, presumably because of a lower possum population. February 2008 saw 2 additional lines added to the reserve. This allows more coverage to the edges of the perimeter. There are now 60 warrior traps spread over 8 lines.
Possums being trapped are increasingly at the perimeter of the reserve, indicating the resident possum population has been greatly reduced and now mainly new immigrants are entering the site. As possum numbers have declined, the volunteers now only check the lines every 2 weeks. Over 220 possums have been trapped between July 2007 and May 2009, with no juveniles caught from May 08 – May 09. 6 mustelid traps have also been included in the reserve.
In conjunction with local landowners, further measures are being taken to extend the trapping perimeter, thereby helping to create “Fortress Puketoki”.