Native mammals across northern Australia have suffered severe decline, with feral cats (Felis catus), introduced herbivores and changed fire regimes being implicated as drivers. However, uncertainty surrounding the relative contribution of each of these threats, and the interactions between them, is limiting the development of effective management strategies. The absence of introduced herbivores and cane toads (Rhinella marina) on Groote Eylandt, Northern Territory, provides an opportunity to evaluate some hypothesised threats in isolation of others. We used camera traps to investigate the correlates of native mammal distribution and abundance at 112 lowland savanna sites across Groote Eylandt. Two large grids of camera traps were also deployed to obtain estimates of feral cat density. We hypothesised that native mammal populations would be negatively associated with feral cat occupancy as well as frequent, large fires. Native mammal site‐occupancy on Groote Eylandt was generally higher compared to mainland Northern Territory. Feral cats were infrequently detected, precluding both an estimate of feral cat density and an evaluation of the relationship between feral cats and native mammals. We found no evidence that native mammal site‐occupancy or relative abundance is negatively associated with frequent, large fires. The relatively healthy state of native mammal populations on Groote Eylandt is likely due to the low density of feral cats, the benign fire regime and the absence of large introduced herbivores and cane toads. However, due to a lack of historical data, the current state of mammals should not be taken as evidence that these populations are safe from decline. This study highlights that the apparent resilience of mammal populations is a result of complex interactions between factors that vary substantially across the landscape. Caution is therefore required when making broad inferences about the drivers of mammal decline from studies that are spatially and temporally limited.

中文翻译：

---

Groote Eylandt 上哺乳动物的现状：避风港还是缓慢燃烧？

澳大利亚北部的本土哺乳动物遭受了严重的衰退，野猫（Felis catus）、引入的食草动物和改变的火灾制度都被认为是驱动因素。然而，围绕这些威胁中的每一个的相对贡献以及它们之间的相互作用的不确定性限制了有效管理策略的发展。北领地 Groote Eylandt 上没有引入的食草动物和甘蔗蟾蜍（Rhinella marina），这提供了一个机会来评估一些假设的威胁，并与其他威胁隔离开来。我们使用相机陷阱调查了 Groote Eylandt 的 112 个低地稀树草原地点的本地哺乳动物分布和丰度的相关性。还部署了两个大型相机陷阱网格，以获得野猫密度的估计值。我们假设本地哺乳动物种群与野猫的居住以及频繁的大火呈负相关。与北领地大陆相比，Groote Eylandt 的本土哺乳动物栖息地普遍较高。很少发现野猫，这排除了对野猫密度的估计以及对野猫与本地哺乳动物之间关系的评估。我们没有发现任何证据表明本地哺乳动物的栖息地或相对丰度与频繁的大火灾呈负相关。Groote Eylandt 上本地哺乳动物种群相对健康的状态可能是由于野猫密度低、火灾状况良性以及没有引入大型食草动物和甘蔗蟾蜍。但由于缺乏历史资料，哺乳动物的现状不应被视为这些种群数量不会减少的证据。这项研究强调，哺乳动物种群的明显恢复力是整个景观差异很大的因素之间复杂相互作用的结果。因此，从空间和时间有限的研究中对哺乳动物衰退的驱动因素进行广泛推断时需要谨慎。