Management of wild dogs in Australia

Since their introduction some 3500 years ago, the wild dog has had a noticeable influence on the ecology of Australia. Although considered to have become a functional component of many terrestrial ecosystems, the predatory behaviour of wild dogs can have severe social, economic and environmental consequences (Fitzgerald & Wilkinson 2009).

As seen in Plate 1, wild dogs cover a large percentage of Australia and are found in a wide variety of habitat types. This makes the issues surrounding their management far more difficult, as no one method can be best applied to all situations.

While wild dogs are a major concern for agricultural stakeholders, it must be realised that these animals have an important role to play in the trophic web – as the top order predator. Typically, top order predators are strongly interactive species that exert top-down control on ecosystems through their direct predatory and competitive interactions with herbivores and smaller predators (Letnic et al. 2006). The influence wild dogs have on Australian native fauna is best understood using the trophic cascade theory which predicts that top predators have alternating positive and negative effects on lower trophic level and may indirectly enhance plant biomass (Hairston et al. 1960).

When wild dogs are removed from a system, macropod numbers often increase (Letnic et al. 2006) and this increase puts added pressure on food resources (grasses, etc) and habitats for many native mammals. Removal of the top order predator also allows the number of the meso-predators, in this case the red fox and cat, to increase; known as the Meso-predator release theory.

Plate 1. Generalised wild dog distribution across Australia in 2013 (Source: Promoting and supporting community-driven action for landscape-scale wild dog management (National Project Steering Committee 2014, p.11))

The impact wild dogs have on agriculture is far more visible. Not only do dogs account for loss of income from predation and lost production of livestock, they can spread disease and have negative psychological effects on the people who work the land. For example, in 2008/2009, it was estimated that wild dogs cost the Queensland grazing industry approximately $67 million (Hewit 2009).

Management of wild dogs has become increasingly important in recent times as their distribution is expanding into areas where they have not been seen for a very long while, and changes in land use has seen dog numbers build up in areas where they were previously controlled. Plate 2 shows areas of hybridisation between dingoes and European domestic dogs, with the majority of pure dingos relegated to desert areas of central and western Australia. The hybrids, who have little conservation significance, are seen to be most common in the high rainfall grazing country of the east coast which is also the key areas for livestock farming in Australia.

Plate 2. Dingo purity from DNA samples (Stephens 2011: Source: Promoting and supporting community-driven action for landscape-scale wild dog management (National Project Steering Committee 2014, p.12))

Up until recently, it has been predominantly land owners that have taken the primary responsibility for wild dog management in Australia. However, recently there has been a shift toward State and Territory Governments taking on more management responsibilities. The following common methods for wild dog control are currently being used across Australia with varying levels of success:

• Trapping;
• 1080 baits;
• PAPP poison baits – (in development);
• M-44/Canid Pest ejector;
• Shooting;
• Lethal trapping Devices;
• Exclusion Fencing; and
• Guardian Animals.

Each method has its own advantages and disadvantages and none are a perfect solution. If management of wild dogs is to be undertaken across a broad range of habitats and across a broad area of Australia, a coordinated approach under the guidance of the National Wild Dog Action Plan is required.

Prepared by Ed Swinhoe

References

Fitzgerald, G & Wilkinson, R (2009) Assessing the social impact of invasive animals in Australia, Invasive Animals Cooperative Research Centre, Canberra.

Hairston, N. G., Smith F. E. & Slobodkin L. B.(1960) Community structure, population control, and competition. The American Naturalist Vol. 94, pg. 421-425

Hewitt, L (2009) Major Economic Costs Associated with Wild Dogs in the Queensland Grazing Industry, Blueprint for the Bush. Queensland.

Letnic, M., Koch, F., Gordon, C., Crowther, M.S., & Dickman, C. (2006) Keystone effects of an alien top-predator stem extinctions of native mammals, School of Biological Sciences, University of Sydney, New South Wales.

National Project Steering Committee (2014) National Wild Dog Action Plan: Promoting and supporting community-driven action for landscape-scale wild dog management, Wool Producers Australia, Barton A.C.T.

Stephens, D. (2011) The molecular ecology of Australian wild dogs: hybridisation, gene flow and genetic structure at multiple geographic scales. The University of Western Australia, Perth, WA.

Thompson, L-J, Aslin, H, Ecker, S, Please, P & Trestrail, C (2013) Social impacts of wild dogs—a review of literature, ABARES, Canberra, prepared for AWI Ltd.