Search

Context: Small and medium-sized native mammals have declined precipitously across northern Australia. Feral cats have been implicated in causing declines and ongoing suppression of populations. Aims: The aim of the present study was to evaluate the response of small and medium-sized native mammal populations when cat predation was removed. Methods: A field experiment was conducted in a tropical savanna environment of northern Australia. Three experimental treatments were applied to six plots to compare and contrast responses of native mammals to predator exclusion and the additive effects of frequent fire. Plots were monitored regularly between 2013 and 2017. Key results: After 4 years of monitoring, no significant difference in capture rates of native mammals was detected between cat-accessible plots and those where they were excluded. Conclusions: There was no evidence of population recovery of native mammals in response to predator exclusion. There was some evidence that frequent burning, independent of cat exclusion, adversely affects native mammal diversity. Implications: Although predation by feral cats is a major threat to small and medium-sized native mammals, disturbance from fire, and grazing by introduced herbivores, have been shown to significantly impede native mammal population recovery in tropical savanna ecosystems. Management programs that solely focus on suppressing feral cat populations may be inadequate in ameliorating ongoing mammal declines in landscapes with other significant disturbance regimes. Feral cats have been implicated in driving declines of small native mammals in northern Australia, but it remains uncertain to what extent cat predation is primarily responsible for such declines, or for suppressing their recovery. We monitored population responses of native mammals to cat exclusion, and the potential interactive effects of fire. Native mammal populations did not increase in response to cat exclusion but are negatively impacted by frequent burning regimes. Photograph by the Northern Territory Government. [ABSTRACT FROM AUTHOR]