Protecting vulnerable land from high wallaby densities: Stage 2

Summary

The agile wallaby is a common species in northern Australia and is considered a pest by pastoralists, who claim that high density wallaby populations cause environmental degradation, significantly increase production costs (e.g. labour, fencing), and ultimately affect farm viability.

This project was a scoping study to identify the issue, costs, management options and research needs required to underpin collective development of a wallaby management plan that can be endorsed by industry stakeholders.

The implementation of an agile wallaby management plan in the Northern Territory will be complex and difficult. The most prominent hurdles for an effective management plan appear to be logistics, personnel and the size of the area that requires management. Currently, the best approach for wallaby management is a combination of fencing and shooting.

Objectives

The project aimed to develop a statistical model to provide a qualitative and quantitative assessment of the scale of the wallaby problem and identify general concepts that support cost-effective management options (i.e. looking at density damage functions and then options).

Key findings

• Wallaby-proof fencing prior to intensification is the best option for properties that are planning to increase livestock production.
• Comparing estimates of economic losses, the cost of the current alternatives for control and the potential increase in revenue after management; it appears that agile wallaby management by culling alone is feasible for properties with pest populations higher than 1,854 individuals per km2.
• For properties with improved pastures (i.e. higher carrying capacities), a combination of wallaby-proof fencing and shooting can be economically feasible, with return of investment in as little as five years.
• High densities of wallabies only affected grass biomass, but had no effect on pasture composition or structure even after a year.

Benefits to industry

In the Top End, agile wallabies are estimated to consume 244,240 kg/km2 of pasture per year, and this project has provided information to support the implementation of an agile wallaby management plan in the Northern Territory to help reduce this burden.

MLA action

The results of this project could inform future work on finalising a decision about whether or not to proceed with the culling of agile wallabies. However, the ability to make this decision is outside of MLA's role and must be determined by the Northern Territory Department of Primary Industries and Fisheries.

Future research

The feasibility of obtaining subsidies through revenue from wallaby harvesting seems promising, but is still to be determined by the Northern Territory Department of Primary Industries and Fisheries.

AgriFutures Australia (formerly RIRDC) is investigating the viability of marketing wallaby meat for consumption.