An exercise was conducted to evaluate the effectiveness of plans to eradicate feral pigs in an exotic disease emergency. The study site was an area of 120 km2 on the southern edge of the Macquarie Marshes in western New South Wales. Shooting from a helicopter accounted for 946 pigs at a rate of 39.2 per hour. This was at an average of 1.65 shots and a cost of $11.77 per pig. A further 43 were shot from the ground or trapped. Of an estimated initial population of 1238, 80% was removed. Telemetry studies conducted in conjunction with the exercise indicated that some pigs became attuned to the significance of a hovering helicopter and modified their behaviour to avoid detection. Movements also emphasised the need to match the boundaries of feral pig eradication zones with natural boundaries, where overlapping home ranges are minimal and densities low. Eradication of feral pigs during an outbreak of exotic disease may be an unrealistic goal, and it may be more efficient to aim to eradicate the disease within the feral pig population. This would be achieved by isolating those pigs carrying the infection; it does not necessarily require the removal of all feral pigs.
Enteric disease outbreak reporting, New South Wales, Australia, 2000 to 2005
