Abstract The failure of broadscale management to protect some threatened species has led to an increase in the use of islands and fenced reserves as translocation sites or foci for intensive threat mitigation. Although highly successful at excluding some threats, these sites may be prone to ecosystem imbalance due to the absence or removal of predators and competitors. We documented population trends and environmental impacts of the burrowing bettong, (Bettongia lesueur), a threatened herbivorous macropod reintroduced to a 1400 ha fenced reserve in arid Australia for 17 years after release. The population increased from 30 individuals to an estimated 1532 individuals (1.09 per ha), a density up to ten times higher than wild populations. There was little evidence that population growth was density dependent, the average intrinsic rate of increase (r) was 0.125 and population size was unrelated to rainfall, body condition or reproductive output. Browse damage on palatable plant species increased, and cover of palatable shrub species decreased, with increased abundance of bettongs. Activity of another reintroduced herbivore, the greater stick-nest rat, (Leporillus conditor), declined as bettong abundance increased while a reintroduced species not reliant on herbage was unaffected. The burrowing bettong has been successfully reintroduced to the Arid Recovery fenced reserve but the positive average intrinsic rate of increase, inflated population density and impacts to resident plant and animal species suggests the population is now overabundant. This is the first documented case of overpopulation of a reintroduced species at a restricted site in Australia, highlighting the importance of preparing overpopulation management plans and considering reintroductions of species from all trophic levels including native predators.

中文翻译：

---

好东西太多了；成功的重新引入导致受威胁哺乳动物的种群过剩

摘要 大规模管理未能保护一些受威胁的物种，导致越来越多地使用岛屿和围栏保护区作为易地或集中减轻威胁的地点。尽管在排除某些威胁方面非常成功，但由于捕食者和竞争者的缺失或清除，这些站点可能容易出现生态系统失衡。我们记录了穴居贝通 (Bettongia lesueur) 的种群趋势和环境影响，这是一种受威胁的食草巨足类动物，在释放后 17 年被重新引入干旱澳大利亚的 1400 公顷围栏保护区。种群数量从 30 只增加到估计 1532 只（每公顷 1.09 只），密度是野生种群的 10 倍。几乎没有证据表明人口增长依赖于密度，平均内在增长率 (r) 为 0.125，人口规模与降雨量、身体状况或生殖产出无关。对可口植物物种的浏览破坏增加，可口灌木物种的覆盖率下降，而 betongs 的丰度增加。另一种重新引入的食草动物，即大棒巢鼠（Leporillus conditor）的活性随着 bettong 丰度的增加而下降，而重新引入的不依赖于牧草的物种不受影响。穴居动物已成功重新引入干旱恢复围栏保护区，但正平均内在增长率、人口密度膨胀以及对常驻植物和动物物种的影响表明人口现在过剩。