Long distance movements and the use of fire mosaics by small mammals in the Simpson Desert, central Australia

Abstract

Using recapture data and radio-telemetry, the movement patterns of small mammals occupying burned and unburned habitats in the Simpson Desert, western Queensland were investigated. Long-term, between trap sessions, recapture rates of small mammals ranged from 7.3 % for Sminthopsis youngsoni to less than 1 % for Pseudomys desertor. Seventeen individuals including Pseudomys hermannsburgensis, S. youngsoni and Notomys alexis were observed to make longdistance movements (> 500 m). The longest recorded movement in this study was 5.7 km by a male S. youngsoni. Telemetry and recapture data indicate that individual P. hermannsburgensis, S. youngsoni and N. alexis can move more than 700 m and up to 2 km in a single night. Radiotracked P. hermannsburgensis and N. alexis utilised a mosaic of burned and unburned habitats in a single night of foraging. Low rates of recapture for small mammals in the Australian arid zone suggest that the populations of many species consist largely of transient individuals. Some species of small mammals appear to have sufficient mobility to locate resource rich patches and utilise habitat mosaics along a continuum of scales. These range from long-distance and presumably unidirectional migrations of 10 km or more, through to nightly movements in the order of several hundred metres to 1 - 2 km.