The influence of fire mosaics on mammal occurrence in north-western Australia

Abstract

Understanding the relationship between fire and species habitat preferences is critical in an era of rapid environmental change. In northern Australia, large, intense, and frequent fires are thought to be a primary cause of mammal population declines, particularly through their influence on habitat suitability. Here, we used a large species presence database in combination with satellite-derived fire history data to assess the influence of fire attributes, including burn extent, frequency, and pyrodiversity, on the likelihood of occurrence of eight mammal species in north-west Western Australia. The likelihood of occurrence declined for some species with an increasing proportion of recently burnt habitat and increased for most species with an increasing proportion of long unburnt habitat. The occurrence of six species was negatively correlated with increasing fire frequency, while the occurrence of four species was positively correlated with increasing pyrodiversity. Our results indicate that fire likely plays an important role in influencing mammal occurrence in the Pilbara and support previous research indicating that frequent large-scale burns have a mostly negative impact on small to medium-sized mammals in northern Australia. To improve mammal habitat suitability, land managers should aim to reduce the extent of large late dry season burns and increase the availability of mature spinifex grasslands.