Accounting for feral pigs

Business principles are being used to find the most cost-effective means of controlling one of the Wet Tropics region’s most destructive pests – feral pigs.

Dr David Smorfitt, a senior lecturer at James Cook University’s School of Business, has developed the Feral Pig Management Model.

The model uses cost-benefit analysis to determine whether the resources needed to manage feral pigs justify the end result.

“Feral pigs often live and hide in natural areas such as forestry land or national parks, but they also include agricultural areas in their relatively small home range,” Dr Smorfitt said.

“They can cause environmental damage in natural areas, but that’s hard to quantify. I have focused on the damage they do that’s more easily costed – damage to crops like sugar cane and banana farms.

“The researchers Bomford and Hart estimated the national annual agricultural crop damage from feral pigs at $100 million, a figure that is likely to be quite conservative.”

To develop the model, Dr Smorfitt examined crop damage and feral pig control efforts on 11 banana and 19 sugar cane farms in the Wet Tropics region.

He also analysed environmental, biological and horticultural data collected by officers of the Department of Environment and Resource Management (now Biosecurity Queensland).

“Using research undertaken by the Government and other researchers, I developed a feral pig bioeconomic model for the Wet Tropics region,” he said.

“The model takes into consideration the costs of control methods, such as trapping, poisoning and shooting, as well as the financial value of the crop damage that is prevented by those methods.”

Dr Smorfitt said his model showed that for feral pig control to be effective it had to be ongoing.

“It shows that irregular control of the feral pig population, say a big effort every five or 10 years, is little better than having no control measures at all,” he said.

“It also indicates that if we removed 70 per cent of the feral pig population in the Wet Tropics area, without ongoing controls the population would be back to its original size within two years.”

Dr Smorfitt stressed that he had no silver bullet to solve tropical Australia’s feral pig problem.

“In fact, eradication of feral pigs on a regional or national level is highly unlikely to be achieved, because the cost of achieving that would be unacceptable.

“Therefore the more relevant question is what resources are needed to keep feral pig damage to a manageable level. And that’s what the model can help with.

“It can be used to assess which strategies will achieve the most cost-effective feral pig control over a 20-year period.

“Whether that’s done via trapping, baiting or shooting, the model shows that our efforts to control feral pigs need to be ongoing and at a relatively high intensity.”

Dr Smorfitt said his bioeconomic model could be adapted for use with different pest mammals in other regions.

“It would need population data specific to that animal, and information on the crops it damages and the region it is in,” he said.

“However, there are still substantial gaps in the information needed for a comprehensive socioeconomic analysis of the impact of feral pests in Australia.”

“Here in the Wet Tropics we still don’t have answers to questions such as how many pigs a square kilometre of forest can support, or whether there are some environmental factors that might be helping to limit population growth.”

Dr Smorfitt said he was concerned that new research would not be undertaken, following the recent loss of scientific staff at Biosecurity Queensland.

“A lot of my modelling is based on the data gathered by Queensland Government researchers over 32 years, but these positions have now been made redundant.”

An accountant with an interest in natural resources, Dr Smorfitt did much of the work for his PhD through the University of Queensland. He teaches in the School of Business at James Cook University in Cairns.

Issued March 11, 2013

Media enquiries: E. linden.woodward@jcu.edu.au T. 07 4232 1007