Landcare Research - Manaaki Whenua

Landcare-Research -Manaaki Whenua

Possum Control Cost Calculator

The Possum Control Cost Calculator is an online publicly-accessible spreadsheet, containing mathematical formulae that can estimate the monetary costs of possum population control operations. It has been designed as a working tool to assist wildlife pest managers in planning operations, however it is also used by researchers, ecoepidemiological modellers, and as a teaching aid. It is free for use.

The spreadsheet allows the user to vary several input parameters in order to explore costs using different control options (e.g. aerial control via poison-drop, ground control using traps or poison, etc.). Some examples of the variable input parameters include choosing different aircraft types (if selecting aerial control), evaluating different trap, poison and/or bait types (including bait stations), and assessing different possum monitoring devices (if estimating post-control residual possum activity).

There is also an approximation calculator, based on measured possum relative density, to predict the number of possums that would need to be removed to achieve any specified residual trap-catch value for the possum population after control, should that be an objective.

Spreadsheet users are required to have some basic preconception of their preferred operational activities (e.g., whether pre-feeding is to be used or not, whether deer repellents will be required to be included in the bait, what the residual trap-catch target is etc.). For each permutation of the input parameters, the spreadsheet will provide the user with estimates of total operational costs, costs per hectare and costs per habitat hectare.

All calculations and cost estimates are in New Zealand dollars using metric distance and area values.

The spreadsheet parameters are regularly updated by Landcare Research staff to represent current real-world economic values; however it does not take into account miscellaneous peripheral costs that may be additional to an approved operation (e.g. costs for public consultation and operational notification, printing, distribution and erection of warning signs, liability insurance costs etc.).

Landcare Research encourages widespread use of the spreadsheet calculator, but accepts no legal or financial responsibility for operational outcomes in lieu of practices recommended from the calculator.