On the Pancontinental Jabiluka exploration lease, between July 1979 and September 1981, mammals of 30 native and five introduced species were recorded, with an overall trap success rate of 5% and an average of 1.9 sightings per spotlight-hour. Three major groups of mammal species corresponded to the primary groupings of vegetation in the study area: riparian woodland, dryland woodland and open forest, and sandstone. This last group was subdivided into three on site preferences. Two ungrouped species were found in a variety of habitats. The distribution of mammals was very patchy, and their abundance varied seasonally. This may result from rainfall patterns, fire occurrence and fire history, as well as from landform and edaphic factors. The species responded to the variation in environment and the consequent mosaic of habitats by three strategies: by rapid response to changes in microhabitat through increased dispersion or moving to more favourable habitats, by restriction to stable habitats, or by adaptation to a variety of habitats.