Effectiveness of the eastern grey kangaroo foot thump for deterring conspecifics

Abstract

Overabundant wild populations of herbivores often present challenges to primary industry, competing with stock, and damaging crops and property. Eastern grey kangaroos (Macropus giganteus) are one of seven macropodid species that are considered a problem in agriculture in Australia. Most deterrent devices available commercially use sounds that do not occur in nature (i.e. artificial sounds), which often have a short-lived or no effect on the target species, whereas trials with biologically significant sounds are often more effective and provide greater resistance to habituation. I used a playback trial of an eastern grey kangaroo foot thump, a biologically significant signal that is given in response to a predator and is usually followed by flight. I determined its effectiveness compared with a recording of background noise (control) for deterring kangaroos over a seven-week period. Kangaroos significantly increased their vigilance levels in response to the foot thump, but not in response to the control signal. Just over 60% of kangaroos took flight in response to the foot thump and the control signals, but more kangaroos took flight in the first 3 s when the foot thump was played. The foot thump shows potential as a deterrent of eastern grey kangaroos for primary industry, and is less likely to suffer from habituation because it is a natural sound.