Predation by invasive species is a major threat to the persistence of naïve prey. Typically, this negative effect is addressed by suppressing the population size of the invasive predator to a point where the predation pressure does not hinder the viability of the prey. However, this type of intervention may not be effective whenever a few specialised predators are the cause of the decline. We investigated the effects of varying levels of specialised invasive stoats (Mustela erminea) abundance on the long-term viability of simulated kiwi (Apteryx spp.) populations. We explored four scenarios with different proportions of highly specialised stoats, which were those that had a ≥ 0.75 probability of predating kiwi eggs and chicks if they were within their home range: (i) a stoat population composed mostly of generalists (mean: 0.5 probability of predation across the population); (ii) 5% of highly specialised stoats and the remaining being generalists; (iii) 10% of highly specialised stoats and the remaining being generalists; and, (iv) half highly specialised stoats and half generalists. We found that stoat home range sizes, rather than stoat density or the density of highly specialised stoats, was the main driver of kiwi population trends. Stoats with large home ranges were more likely to predate kiwi eggs and chicks as these were more likely to fall within a large home range. More broadly, our findings show how the daily individual ranging and foraging behaviour of an invasive predator can scale-up to shape population trends of naïve prey.

外来入侵物种的捕食是对幼稚猎物持续存在的主要威胁。通常，通过将侵入性捕食者的种群大小抑制到捕食压力不会阻碍猎物生存能力的程度，可以解决这种负面影响。但是，只要一些专门的掠食者成为下降的原因，这种干预措施可能就无效。我们研究了不同水平的入侵物种（Mustela erminea）的丰度对模拟猕猴桃（Apteryx）长期生存能力的影响。spp。）人口。我们研究了四种具有不同比例的高度专业化沙特的场景，如果它们在其居所范围内，则它们有≥0.75的概率被奇异鸟和小鸡捕食：（i）一个由多面手组成的沙特族人口（均值：0.5概率整个人口的捕食情况）；（ii）5％的高度专业化的人才，其余为通才；（iii）10％的高度专业化的专家，其余为通才；（iv）一半高度专业化的专家和一半通才。我们发现，矮胖的家庭范围的大小，而不是矮胖的密度或高度专业化的矮胖的密度，是猕猴桃人口趋势的主要驱动力。家庭范围较大的Stoats较奇异鸟蛋和小鸡更早，因为它们更可能落入较大的家庭范围。更广泛地，