Abstract Context. Translocations have been widely used to re-establish populations of threatened Australian mammalian species. However, they are limited by the availability of sites where key threats can be effectively minimised or eliminated. Outside of ‘safe havens’, threats such as exotic predators, introduced herbivores and habitat degradation are often unable to be completely eliminated. Understanding how different threats affect Australian mammal populations can assist in prioritising threat-management actions outside of safe havens. Aims. We sought to determine whether translocations of the greater bilby to two sites in the temperate zone of South Australia could be successful when human-induced threats, such as prior habitat clearance, historic grazing, the presence of feral cats and European rabbits, could not be completely eliminated. Methods. Greater bilbies were regularly cage trapped at two translocation sites and a capture–mark–recapture study was used to determine survival, recruitment and population growth at both sites. Key results. Our study showed that bilbies were successfully translocated to an offshore island with a previous history of grazing and habitat clearance, but which was free of exotic predators. At a second site, a mainland exclosure with feral cats and European rabbits present, the bilby population declined over time. Adult bilbies had similar survival rates in both populations; however, the mainland bilby population had low recruitment rates and low numbers of subadults despite high adult female fecundity. Conclusions. The results indicated that past grazing and habitat clearance did not prevent the bilby population on the offshore island establishing and reaching a high population density. In the mainland exclosure, the low recruitment is probably due to feral cats predating on subadult bilbies following pouch emergence. Implications. The results demonstrated that the bilby, an ecologically flexible Australian marsupial, can be successfully translocated to sites with a history of habitat degradation if exotic predators are absent. At the mainland exclosure site, threat mitigation for bilbies should focus on control or eradication of the feral cats. The control of European rabbits without control of feral cats could lead to prey-switching by feral cats, further increasing predation pressure on the small bilby population.

中文翻译：

---

受威胁的大耳袋狸 (Macrotis lagotis) 的两个易地种群的生存、补充和种群增长的比较研究

摘要上下文。易位已被广泛用于重建受威胁的澳大利亚哺乳动物种群。但是，它们受到可以有效地最小化或消除关键威胁的站点的可用性的限制。在“避风港”之外，外来掠食者、引入的食草动物和栖息地退化等威胁往往无法完全消除。了解不同威胁如何影响澳大利亚哺乳动物种群有助于优先考虑安全港之外的威胁管理行动。目标。我们试图确定当人为威胁（例如先前的栖息地清除、历史性放牧、野猫和欧洲兔子的存在）无法被人为威胁时，将大耳袋狸易位到南澳大利亚温带地区的两个地点是否会成功完全消除。方法。大袋兔经常被困在两个易位点的笼子里，并使用捕获-标记-重新捕获研究来确定两个地点的存活率、招募和种群增长。关键结果。我们的研究表明，兔耳袋狸成功地转移到一个有过放牧和栖息地清除历史但没有外来掠食者的近海岛屿。在第二个地点，一个有野猫和欧洲兔子的大陆围栏，随着时间的推移，bilby 种群数量下降。成年 bilbies 在两个种群中的存活率相似；然而，尽管成年雌性繁殖力高，大陆兔耳袋狸种群的招募率和亚成体数量都很少。结论。结果表明，过去的放牧和栖息地清除并没有阻止离岸岛屿上的比尔比种群建立并达到高种群密度。在大陆围栏，低招募可能是由于野猫在育儿袋出现后早于亚成年兔。影响。结果表明，如果没有外来捕食者，比尔比是一种生态灵活的澳大利亚有袋动物，可以成功转移到栖息地退化历史的地点。在大陆围场，减轻对比比犬的威胁应侧重于控制或根除野猫。在没有控制野猫的情况下控制欧洲兔子可能会导致野猫转换猎物，进一步增加对小兔耳袋狸种群的捕食压力。在大陆围栏，低招募可能是由于野猫在育儿袋出现后早于亚成年兔。影响。结果表明，如果没有外来捕食者，比尔比是一种生态灵活的澳大利亚有袋动物，可以成功转移到栖息地退化历史的地点。在大陆围场，减轻对比比犬的威胁应侧重于控制或根除野猫。在没有控制野猫的情况下控制欧洲兔子可能会导致野猫转换猎物，进一步增加对小兔耳袋狸种群的捕食压力。在大陆围栏，低招募可能是由于野猫在育儿袋出现后早于亚成年兔。影响。结果表明，如果没有外来捕食者，比尔比是一种生态灵活的澳大利亚有袋动物，可以成功转移到栖息地退化历史的地点。在大陆围场，减轻对比比犬的威胁应侧重于控制或根除野猫。在没有控制野猫的情况下控制欧洲兔子可能会导致野猫转换猎物，进一步增加对小兔耳袋狸种群的捕食压力。如果没有外来掠食者，一种生态灵活的澳大利亚有袋动物可以成功转移到栖息地退化历史的地点。在大陆围场，减轻对比比犬的威胁应侧重于控制或根除野猫。在没有控制野猫的情况下控制欧洲兔子可能会导致野猫转换猎物，进一步增加对小兔耳袋狸种群的捕食压力。如果没有外来掠食者，一种生态灵活的澳大利亚有袋动物可以成功转移到栖息地退化历史的地点。在大陆围场，减轻对 bilbies 的威胁应侧重于控制或根除野猫。在没有控制野猫的情况下控制欧洲兔子可能会导致野猫的猎物转换，进一步增加小兔耳袋狸种群的捕食压力。