Managing the Impact of Recovering Mobile Predators on Endangered Birds Through Prey Switching: A Field Experiment in a Habitat Restoration Landscape i

通过猎物转换管理恢复移动捕食者对濒危鸟类的影响：栖息地恢复景观中的现场实验

• 批准号: 2445659
• 金额: --
• 依托单位: University of Aberdeen
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2445659
• 关键词: Managing; Impact; Recovering; Mobile; Predators

The restoration of ecosystems is being implemented in large areas in Scotland with the goal of reinstating lost biodiversity and ecosystem functions. The Cairngorms Connect partnership aims to restore natural habitats including Caledonian pine forests over nearly 600km2. Within this area, the density of over-abundant red deer is being reduced through culling, habitat is recovering, persecution of predators does not occur, and predator control is extremely limited. As a result, populations of hitherto persecuted predators are recovering.While tree regeneration is spectacular in some glens, we lack any ability to predict how restoration will alter ecosystem processes. Specifically, there is much uncertainty about how iconic native species such as capercaillie and black grouse, which have been in decline and are the focus of significant conservation efforts, will fare in landscapes with a fuller complement of native predators. This is a conservation dilemma requiring evidence.A corollary of the drive to reduce deer grazing pressure is that a substantial amount of deer grallochs (the viscera of culled deer) is discarded at the shooting locations and thus available as artificially introduced food to vertebrate predators, almost year round. We hypothesise this external input of resources allows predators to buffer variation in field vole density and maintain higher densities than in an unmanaged ecosystem.The conservation dilemma is underpinned by the functional, aggregative and numerical responses of a guild of varyingly mobile, vertebrate generalist predators able to exploit different prey with varying degrees of profitability. Some of these prey experience multi-annual cycles (field voles and red grouse) and their distributions each follow distinct gradients from headwaters to valley floors.In this project, we will evaluate a management intervention that involves1. Removing grallochs to reduce predator density in key areas when resources dictate territory size.2. Provisioning of carcasses and grallochs at regularly-spaced food dumps during the eight-week nesting and brood-rearing season to act as diversionary feeding for predators exploiting the area occupied by endangered ground-nesting birds;The premise of this application is that the eggs and chicks of capercaillie and black grouse, by virtue of being ephemeral, are trophically trivial resources to predators, such that the frequency of spillover predation they experience reflects variation in abundance of other more important prey.Our objective is to establish where in relation to the spatial distribution of prey species, and when in relation to the multi-cycles of abundance of other prey species, it is most efficient to manipulate predator food subsides. This requires empirical and modelling studies of the functional and numerical response of the predator community to landscape level changes in resource availability.Capercaillie and/or black grouse population parameters, the main response variables, will be measured using various field surveys and genetic capture-recapture surveys, with DNA extracted from faeces and feather collected according to a structured sampling design, and analysed using spatial capture-recapture models. Predator and prey density will be estimated using standard field methods and trail cameras.The research is important because it seeks to evaluate a management option that would make it possible to reconcile habitat restoration with priority species conservation and sheds light on how mobile predators exploit alternative prey with cyclical/transient dynamics in heterogeneous landscapes. It is impactful because it seeks to achieve this in a landscape under active restoration by a multi-institutional partnership in an iconic ecosystem of Scotland.

目前正在苏格兰大片地区恢复生态系统，目的是恢复失去的生物多样性和生态系统功能。Cairngorms Connect伙伴关系旨在恢复自然栖息地，包括近600平方公里的喀里多尼亚松林。在这一地区，过度丰富的红鹿的密度正在减少，通过扑杀，栖息地正在恢复，捕食者的迫害没有发生，捕食者的控制是非常有限的。因此，迄今为止受到迫害的捕食者的数量正在恢复。虽然树木再生在一些峡谷中是壮观的，但我们缺乏任何能力来预测恢复将如何改变生态系统过程。具体来说，有很多不确定性的标志性本土物种，如capercaillie和黑松鸡，这已经在下降，是重要的保护工作的重点，将如何在景观与更充分的补充本土捕食者。这是一个需要证据的保护困境。减少鹿放牧压力的一个必然结果是，大量的鹿grallochs（被捕杀的鹿的内脏）被丢弃在狩猎地点，因此几乎全年都可以作为人工引入脊椎动物捕食者的食物。我们假设这种外部输入的资源允许捕食者缓冲的变化，在田鼠密度和保持更高的密度比在一个未管理的ecosystem.The保护困境的支持下的功能，聚集和数量的反应一个公会的变化移动的，脊椎动物通才捕食者能够利用不同程度的盈利能力不同的猎物。其中一些猎物经历多年的周期（田鼠和红松鸡），它们的分布都遵循不同的梯度从源头到谷底。在这个项目中，我们将评估管理干预，涉及1。当资源决定领土大小时，在关键区域去除grallochs以减少捕食者密度。在为期八周的筑巢和育雏季节，在间隔固定的食物堆放场提供尸体和草鸡，作为捕食者利用濒危地面筑巢鸟类所占区域的转移性食物;本申请的前提是，由于松鸡和黑松鸡的卵和幼雏是短暂的，因此对于捕食者来说是营养上微不足道的资源，这样，它们所经历的溢出捕食的频率反映了其他更重要的猎物丰度的变化。我们的目标是建立与猎物物种的空间分布有关的位置，以及与其他猎物物种丰度的多周期有关的时间，操纵捕食者食物补贴是最有效的。这需要对捕食者群落对资源可用性景观水平变化的功能和数字响应进行实证和模拟研究。将使用各种实地调查和遗传捕获-再捕获调查测量Capercaillie和/或黑松鸡种群参数，根据结构化抽样设计收集粪便和羽毛提取DNA，并使用空间捕获-再捕获模型进行分析。捕食者和猎物密度将估计使用标准的现场方法和trail cameras.The研究是重要的，因为它旨在评估一个管理选项，这将使它有可能调和栖息地恢复与优先物种保护，并揭示了如何移动的捕食者利用替代猎物与周期性/瞬态动态异质景观。它是有影响力的，因为它寻求在苏格兰标志性生态系统中通过多机构合作积极恢复的景观中实现这一目标。