Pursuit dynamics among australian marsupials and dogs: Comparative locomotor performance and escape probability

Predation can strongly influence population outcomes, and locomotor performance may be especially important during pursuit-evasion interactions. We hypothesised that differences in performance-based escape capacity could contribute to the abundance and distribution of prey populations. We compared the locomotor performance of northern brown bandicoots (Isoodon macrourus), which persist across mainland Australia, and northern quolls (Dasyurus hallucatus), which have declined on the mainland, with that of domestic dogs (Canis familiaris; multiple breeds, 3.4-44 kg) as an approximation of canid performance. Velocity, acceleration and changes in heading were extracted from top-down video footage and used to estimate relative escape performance. Dogs achieved the highest mean and maximum speeds, whereas quolls showed the greatest turning capacity. Bandicoots were the slowest, least agile and most predictable of the three groups. The ability of quolls to outmanoeuvre a pursuing predator may help explain their association with structurally complex habitats, where agility should provide a greater advantage. By contrast, the persistence and abundance of northern brown bandicoots are likely supported by other ecological traits because their locomotor capacity for avoiding pursuit predators appears limited. These findings show that locomotor performance alone cannot explain prey population outcomes, but may interact with habitat complexity to favour different escape strategies.