Austral Ecology (2005) 30, 24–39 The responses of small mammals to patches regenerating after fire and rainfall in the Simpson Desert, central Australia M. LETNIC* AND C. R. DICKMAN Institute of Wildlife Research, University of Sydney, Sydney, New South Wales, Australia Abstract Patch-burning is frequently advocated as a management tool to enhance the biodiversity and pasture values of spinifex (Triodia) grasslands. In this study we compare the capture rates of small mammals in habitats regenerating shortly after fire (aged 1–5 years) and in long-unburnt habitats (aged >25 years). To unravel the effects of temporally and spatially variable rainfall on capture rates, the study was replicated at three locations spaced over 50 km apart that experience different rainfall regimes. Ten species of small mammals were captured over the course of the study, between October 1999 and June 2001. Pseudomys desertor showed a strong preference for long-unburnt habitats. Notomys alexis, Sminthopsis youngsoni and Sminthopsis hirtipes showed some preferences for regenerating habitats, but these were not consistent throughout the study. Factors indicative of temporal and spatial variation in rainfall, time and site had important effects on capture rates. High rainfalls associated with the La Niña phase of the El Niño/Southern Oscillation in 2000 increased seed production and prompted eruptions of rodent species and the carnivorous Dasycercus cristicauda. The greatest numbers of captures were made at the sites that received the highest rainfalls. We conclude that patch-burning regimes do not benefit small mammals directly, but are likely to increase the resilience of ‘fire-sensitive’ species that are dependent on dense spinifex by reducing the extent of wildfires. Key words: arid, Australia, fire, mammal, management, rainfall, scale, seed. INTRODUCTION Aboriginal management of vegetation using fire, often coined ‘fire-stick farming’ or ‘looking after country’, was once widespread throughout the spinifex (Triodia) deserts of central Australia and it continues in some locations (Gould 1971; Kimber 1983). ‘Looking after country’ entails burning of relatively small areas of land, so that there is a mosaic of both burnt and unburnt patches in the landscape (Reid et al. 1993). The predictable ecological succession following burning (Burbidge 1944; Winkworth 1967) results in an increase in the availability of plants both useful for food and attractive to game (Gould 1971; Kimber 1983; Latz 1995) when compared to almost mono- specific stands of long-unburnt spinifex. Small con- trolled fires also serve as firebreaks that limit the extent of potentially destructive wildfires (Saxon 1984; Burrows & Christensen 1990). In a landscape containing a mosaic of patches of differing ages after fire, there will be a spatially and temporally dynamic mosaic of structurally and floris- tically distinct habitats (Burrows & Christensen 1990; Haydon et al. 2000). The provision of fire-mosaics in spinifex grasslands has been reported to result in greater local species diversity, particularly of plants and reptiles (Noble 1989; Burrows & Christensen 1990; Masters 1996; Pianka 1996). Several authors have suggested that arid zone mammals may actively exploit fire-mosaics (Burbidge et al. 1988; Lundie- Jenkins 1993; Letnic 2002; Letnic 2004) and that the presence of fire-mosaics may play an important role in facilitating the persistence of arid zone mammal populations, particularly macropodids (Bolton & Latz 1978; Burbidge et al. 1988; Burbidge & McKenzie 1989). Post-fire environments provide a community of grasses and herbs more palatable to mammalian herbi- vores than stands of long-unburnt spinifex (Suijden- dorp 1981; Holm & Allen 1988; Letnic 2004). Thus fire mosaics are thought to offer individuals a variety of habitats, including long-unburnt areas with dense spinifex suitable for shelter that are near to food- rich regenerating areas suitable for foraging (Bolton & Latz 1978; Lundie-Jenkins 1993). Small mammals may also utilize fire-mosaics. For example, spinifex hopping mice (Notomys alexis) and sandy inland mice (Pseudomys hermannsburgensis) have been observed to move through areas regenerating after fire, presumably to feed, but shelter in the dense spinifex of long- unburnt habitats (Mutitjulu Community & Baker 1996; Letnic 2002). Despite observations of mammals utilizing fire mosaics, there is little evidence to suggest that any arid zone species is dependent on the presence of *Corresponding author. Present address: Parks and Wildlife Service of the Northern Territory, PO Box 496, Palmerston, NT, 0831. Accepted for publication February 2004.