Foot-thumping as an alarm signal in macropodoid marsupials: prevalence and hypotheses of function

• 1 Alarm signalling as a means to reduce predation risk is an important component of the behavioural repertoire of many species. It has previously been noted that many of the macropodoid marsupials (kangaroos, wallabies and rat‐kangaroos) produce a foot‐thump, an audible signal created by striking the ground with one or both feet, that is most likely an alarm signal.
• 2 The prevalence of foot‐thumping within the macropodoids and hypotheses of its function as an alarm signal have been poorly documented. To address this issue, we investigate the prevalence of foot‐thumping in macropodoids and interpret possible function according to current alarm signalling theory. Evidence for foot‐thumping was found in almost all macropodoids. In light of this, the behaviour appears to be a conservative trait that may have arisen alongside or followed the evolution of bipedal locomotion, and suggests that this trait carries significant benefits that transcend ecological and predation differences among species.
• 3 Nine alarm signal hypotheses were explored in order to determine the function of foot‐thumping in macropodoid marsupials. However, the existing evidence for consistent function remains inconclusive. Therefore, a series of predictions were developed to provide the foundation for future research to investigate more thoroughly the function of foot‐thumping in macropodoid marsupials.