OVERCOMING THE COMPENSATORY RESPONSE OF AN INVASIVE PREDATOR

人类活动使许多动物物种穿越地球仪。其中一些已经建立并破坏了自然生活在它们入侵地区的物种。能够利用广泛猎物的入侵性捕食者物种尤其成问题，并对一些本地物种的灭绝或灾难性衰退负责。如果要保护这些本土物种，自然资源保护主义者必须进行干预，通常是通过积极地清除入侵物种的个体。然而，只有在岛上才能移除最后一个个体。在其他地方，在可预见的未来，有必要继续控制这些入侵物种。这是昂贵的，只能在国家公园或保护区等具有保护价值的地区进行。同样重要的是，保护主义者要学会尽可能有效地控制这些外来物种，以便本地物种真正受益，但也是为了能够保护尽可能大的地区，以获得一定的资源。学术生态学家一直在研究捕食者和猎物之间的相互作用。他们已经了解到破碎的栖息地可能对物种的可能性产生的影响，而不会导致其他物种的灭绝。生态学家现在意识到，两个物种之间由第三个物种介导的间接相互作用可能在成功和减轻入侵方面发挥重要作用。他们还设计了方程来预测捕食者从种群中移除猎物的速率如何随猎物种群的丰度而变化。他们还更好地了解了导致人们离开出生地的条件。我们的建议是学术生态学家，环保主义者和野生动物资源的用户之间的伙伴关系，将使用捕食者-猎物理论和新的经验数据，制定一个以科学为基础的管理策略，以保护受保护的和迅速下降的哺乳动物，水鼠，受到入侵的美国水貂捕食的人口。该项目将在高地边缘的凯恩戈姆斯国家公园进行。首先，我们需要知道到达控制地区的移民人数下降的速度有多快，因为这个地区距离未控制地区更远。这一点很重要，因为它将告诉我们必须控制多大的区域才能使中心的水貂数量保持在较低水平。为此，我们将在一段时间内从河流中清除水貂，并在发生水貂化时对其进行监测。其次，我们将考虑如何成功的捕猎者的变化，水貂变得稀缺。我们将发现是否存在一个密度，低于这个密度，捕兽者就不再对捕兽感兴趣或效率低下。考虑到参与者的不同动机，我们还将发现各组诱捕者是否会有不同的诱捕成功率。第三，我们要问的是，某些山谷中兔子的存在是否会补贴捕食它们的水貂种群，然后它们可能会继续前进，捕食山谷中其他地方的水鼠。这可能会导致兔子和水鼠在同一个山谷里找不到，即使兔子肯定不吃水鼠！如果水貂需要兔子在苏格兰高地成功繁殖，集中在这些地区的水貂控制工作可能是非常有效的。最后，我们将整合我们的研究结果的模型，可用于探索不同的管理策略，包括1。增加捕貂者的数量，即使在水貂稀少的情况下，他们仍然有动力和有效地捕捉水貂。只在我们希望保护的区域的中心增加这些陷阱的数量3. 3.扩大国家公园下游捕貂的区域，尽管对在这些区域捕貂感兴趣的人越来越少。在核心区的重点地区控制兔子。

Many animal species have been transported across the globe by human activities. Some of these have become established and damage the species that naturally live in the area they invaded. Invasive predator species able to use a wide range of prey are particularly problematic and are held responsible for the extinction or catastrophic declines of some native species. If those native species are to be preserved, conservationists must intervene, often by actively removing individuals of the invasive species. Removing the last individual however is only possible on islands. Elsewhere, it will be necessary to continue controlling those invasive species for the foreseeable future. This is expensive and can only be done in areas selected for their conservation value, such as national parks or reserves. It is also important that conservationists learn to control those alien species as effectively as possible, so that the native species really benefit, but also in order to be able to protect as large areas as possible for a given amount of resources. Academic ecologists have been studying the interactions between predators and their prey. They have learned about the impact of that fragmenting habitats may have on the likelihood of species not causing the extinction of other species. Ecologists now realise that indirect interactions between two species mediated by a third species, may play an important role in the success and mitigation of invasions. They have also devised equations to predict how the rate at which a predator remove prey from a population varies with the abundance of a prey population. They have also gained a better understanding of the conditions that cause individuals to disperse away from the area where they were born. Our proposal is for a partnership between academic ecologists, conservationist and a users of wildlife resources that will use predator-prey theory and new empirical data to devise a science-based management strategy to safeguard populations of a protected and rapidly declining mammal, the water vole that is subjected to predation by the invasive American mink. The project will take place in the Cairngorms National Park, on the fringe of the uplands. First, we need to know how fast the number of immigrants arriving in an area where control has taken place declines, as this area is more distant from uncontrolled areas. This is important at it will tell us how large an area must be controlled to keep the mink population low in its centre. For this, we will remove mink from sections of rivers for a time and monitor recolonisation as it takes place. Second, we will consider how the success of trappers changes as mink become scarce. We will find out whether there is a density below which trappers are no longer interested in trapping or are ineffective. Given the different motivations of participant to the project, we will also find out whether groups of trappers will have different trapping success. Third, we will ask if the presence of rabbits in some valleys does subsidies mink populations that prey on them, and may then move on and prey on water voles elsewhere in a valley. This may result in rabbits and water voles not being found in the same valley, even though rabbits certainly do not eat water voles! If mink require rabbits to breed successfully in upland Scotland, concentrating mink control effort in those areas may be very effective. Finally, we will integrate our results in models that can be used to explore the relative merits of different management strategies including 1. Increasing the number of trappers that remain motivated and effective in trapping mink even when they are scarce 2. increasing the number of those trappers only in the centre of the area we wish to protect 3. expanding the area where mink are trapped downstream from the national park, even though fewer people are interested in trapping mink in those areas 3. controlling rabbits in key sites in the core area.