Long-term benefits and short-term costs: Small vertebrate responses to predator exclusion and native mammal reintroductions in south-western New South Wales, Australia

Context: The success of conservation fences at protecting reintroduced populations of threatened mammals from introduced predators has prompted an increase in the number and extent of fenced exclosures. Excluding introduced species from within conservation fences could also benefit components of in situ faunal assemblages that are prey for introduced predators, such as reptiles and small mammals. Conversely, reintroduced mammals may compete with smaller mammals and reptiles for resources, or even prey on them. Aims: In a 10-year study from 2008, we examine how small terrestrial vertebrates respond to the exclusion of introduced predators, the feral cat (Felis catus) and red fox (Vulpes Vulpes), introduced herbivores and the reintroduction of regionally extinct mammal species. Methods: Differences in the yearly relative abundance of reptiles and mammals according to habitat type and whether sites were fenced or not, were tested using multivariate generalised linear models. Next, we calculated univariate P-values to identify individual species that showed significant relationships, positive and negative, with any of the explanatory variables. Key results: Total captures of reptiles were lower inside the conservation fence in all years, whereas total captures of small mammals were markedly higher inside the fenced area, notably in dasyurids. Conclusion: Our results showed that conservation fences can deliver benefits for some fauna (but not all) beyond facilitating the reintroduction of highly threatened mammals. Implications: Our results demonstrated the consequential impacts of introduced predators on the Australian small mammal fauna, and showed that predator-exclusion fences can be an effective conservation intervention for this guild.