Long-range movements of small mammals in arid Australia: implications for land management

This study investigated movements of seven species of small mammals at study areas in arid Western Australia and Queensland. Populations of all species fluctuated dramatically in abundance over time, with the recapture rate for individuals averaging at a low 11.3%. Mean long-distance movements ranged from 1.04 km in the marsupial Sminthopsis hirtipes to 6.34 km in the native rodent Pseudomys hermannsburgensis; the maximum distance recorded was 14 km. Long-range movements occurred independently of sex, age and reproductive status in all species, but tended to increase during or after rain in the study regions. Individuals moved toward areas of rainfall, probably because rains produce local increases in food resources. We suggest that long-range movements are crucial in allowing small mammals to exploit both permanent and ephemeral refugia of increased productivity, hence facilitating long-term persistence in regional areas. Although protection of fixed refugia can be achieved by land reservation, conservation goals for small mammals and other biota will be met more realistically by improving land management throughout the arid zone with the involvement and cooperation of all land users.