Figure 1: Tracking rates in the Porirua Western Forests KNE site area. Hover over the charts series to specific results, and click on legend entries to highlight and show/hide series. Use the month checkboxes on the top-right of charts to show/hide data from those monitoring months.
Figure 2: Porirua Western Forests KNE site area, showing the locations of the tracking tunnel lines.
Pest animal control regime: Possum and rodent control is undertaken with 216 Pelifeed bait stations using brodifacoum poison bait on a 150 m x 150 m grid. The network is serviced four times a year at intervals of three months by GW Biosecurity staff. The area is currently undertaking a bait trial to test whether a reduction in the amount of toxin (ie using only one cap of brodifacoum poison – 170 gms) in all bait stations, regardless of bait take, can maintain low pest numbers. In 2018 a sharp rise in rat tracking rates (see figure 1) led to an extra pulse of bait being utilised for one service before returning back to one cap baiting regime.
Mustelid control using 31 DOC 200 kill-traps is undertaken on an approximate 300-400 m grid. This is serviced by GW Biosecurity staff four times a year at three month intervals when the bait stations are being serviced.
Pest animal control milestones: The bait station network was installed in 1996. Baits containing brodifacoum, feratox and cholecalciferol were initially used, but since 2003 brodifacoum and small amounts of pindone have mainly been used. The dose of brodifacoum in the bait stations was temporarily doubled from one cap (170 gms) to two caps (340 gms) from December 2018 to March 2019 to bring the rat population back under control. Mustelid control began in 2003 using SAF predator traps that were replaced by DOC200 traps in 2008.
Surrounding pest control regimes: Bait stations, predator traps and possum traps are deployed in Pikarere Farm, with bait stations at Stuart Park and Whitireia Park (which is possum free). The Regional Possum Predator Control programme is controlling possums in the Ohariu area and DOC have a network of bait stations at Colonial Knob.