Control of pest mammals for biodiversity protection in Australia. I. Patterns of control and monitoring.
Foxes, wild dogs, feral cats, rabbits, feral pigs and feral goats are believed to have deleterious impacts on native biodiversity in Australia. However, although considerable resources have been expended controlling these six species, little is known about national patterns and costs of control and monitoring. We therefore conducted a survey of pest-control operations undertaken by conservation-focused organizations in Australia. A total of 1306 control operations were reported, with most conducted during 1998-2003: there was little information prior to 1990. Foxes and rabbits were the most, and feral cats the least, frequently controlled pest species. The total area on which control was undertaken in 2003, the year for which most information was available, ranged from ∼0.4×104 km2 for feral cats to ∼10.7×104 km2 for foxes. A wide range of techniques and intensities were used to control each of the six species. The estimated cost of labour expended on control in 2003 ranged from $0.4×106 for feral cats to $5.3×106 for foxes. Monitoring of the pest or biodiversity occurred in 50-56% of control actions in which foxes, wild dogs and feral cats were targeted, but only 22-26% of control actions in which rabbits, feral pigs and feral goats were targeted. Our results are discussed in relation to previous studies of pest animal control and monitoring in Australia.