DOC staff member catching whio
The first 12 years of the project provided some clear lessons on what is achievable for ecological restoration in the forested back country of New Zealand. In particular, we have learnt that recovery of vulnerable species such as kokako, mistletoe and whio is possible in this environment.
The recovery of these species and others has been possible through the control of key pest animal species. We now know that we can control most pests through the use of a network of traps serviced by competent operators. The work is ongoing, and there are still lessons to learn and efficiencies to be gained.
The use of traps to control pests in the rugged and access-limited environment of northern Te Urewera is a major point of difference between this and other projects. There have been many lessons learnt, for example:
- Year-round rat control to low levels is possible using trapping as the principal control technique. Rat trapping over large areas can be effective at controlling rats to low levels, particularly when trapping is used in conjunction with a toxin employed in a ‘knockdown’ capacity
- Possum control targets can be achieved by employing workers on performance-based contracts
- Kill traps are an effective tool for possum control, and over the medium-term are probably cheaper than live-trapping
- Two-yearly possum control to low levels can maintain mistletoe (Peraxilla tetrapetala) populations while four-yearly possum control cannot
DOC staff weighing whio
Other lessons learned include:
- Deer control using ground-based hunters with specialised dogs can increase the abundance of palatable tree seedlings
- Feral dog control and the training of other dogs in avian avoidance are important to protect kiwi
- Many advances and lessons have been learnt in regard to managing contractors for pest control programmes, e.g. tendering, selection, management, auditing and performance measures. A particular example is the use of hand-held GPS units as an effective auditing and monitoring tool
- Involvement of local community members in work programmes is immensely beneficial and central to the long-term success of the project
We have learnt that the Background Area / Core Area model is feasible as a method for ecosystem restoration on a landscape scale. However, many aspects of this approach have yet to be refined and this is where the work of the next 10 years will be largely be focused.