Prescribed burning benefits threatened mammals in northern Australia

Despite substantial investment in prescribed burning for biodiversity conservation there has been surprisingly little demonstration of its efficacy in achieving intended conservation aims for fauna. In the case of northern Australia’s threatened mammal fauna, most studies have reported negative responses to fire. We used satellite-derived fire scar imagery and small mammal survey data to compare fire regimes and threatened mammal abundance before and after implementation of broad-scale prescribed burning in north-western Australia. Specifically, we tested: (1) whether prescribed burning was effective in changing fire regimes; (2) whether all mammal species and functional groups responded to prescribed burning; and (3) what regional fire and environmental variables explained changes in mammal status. Low-intensity, patchy prescribed burning in the early dry season reduced the extent of high intensity late dry season wildfires. In sandstone habitats the abundance of all mammals, and the large marsupials and specialist rodent functional groups, increased concurrently with early dry season prescribed burning. All mammals and the small dasyurid functional group in woodland habitats also increased during this period. Early dry season prescribed burning extent was the strongest explanatory variable for mammal increases. Early dry season burning was also the strongest explanatory variable for woodland mammal abundance, but these mammals also had a positive association with extent of large patches of old growth vegetation (> 4 years since fire). Generalist rodents did not respond to prescribed burning and two other species declined following prescribed burning in one habitat. Generalist rodents and the two declining species had a negative association with extent of late dry season fire and a positive association with old growth vegetation (interacting with patch size). These results suggest an increased application of patchy early dry season prescribed burning of up to ca. 30% of the area will benefit positive fire responder species of threatened mammals including large specialist rock/arboreal rodents and most marsupial species. For mammals such as generalist terrestrial rodents with predominantly negative associations with fire, managers should seek to increase the size and extent of old growth vegetation.