QUADRAT DTP CASE: Rewilding and the return of interacting meso-predators: Understanding, modelling and monitoring predator-prey dynamics in non-equili

捕食是生态系统中一种有影响力的营养相互作用，可能限制或调节被捕食物种的丰度。涉及专业捕食者的捕食者和猎物之间的相互作用可能是紧密的，物种对之间的相互作用，有时会导致种群循环。在擅长切换猎物的多面手捕食者存在的地方，相互作用可能更加分散，涉及更多的物种。虽然关于捕食者-猎物相互作用的生态学理论已经很发达，但它通常没有考虑到多面手可用的替代猎物物种分布的空间差异。非空间近似的建模通常假设个体的随机混合以及捕食者和被捕食者物种之间的空间均匀相互作用强度。然而，被捕食物种在真实生态系统中的空间分布往往是异质性的，反映了栖息地和喜好分布的变化，对一些周期性种群来说，是自组织模式，如行波。因此，个体捕食者在经历他们最喜欢的猎物的稀缺时，将他们的注意力转向替代猎物的范围在空间上也是异质的。此外，行会内的捕食，一个物种杀死并吃掉另一个物种是司空见惯的。这项研究的目的是：i)促进对相互作用的捕食者丰度的空间差异及其猎物切换反应如何造成捕食压力和猎物性能的空间异质性的理解；ii)确定在什么情况下濒危的猎物可以从部分避难所中受益，以躲避捕食，这是一个具有多种保护应用的问题。长期的生态系统研究、大量现有数据和基尔德森林松貂的扩散为理解多个捕食者的影响如何可能是相加的，或者捕食者之间的相互作用，如便利或行会内捕食，是否可能导致捕食压力的高度空间异质性创造了机会。在这里，黄褐色猫头鹰的人口统计学反映了田鼠数量的变化。黄褐色猫头鹰是苍鹰和松貂的猎物。马丁捕杀苍鹰。在田鼠数量最多的年份，马丁和狐狸也依赖田鼠。研究目标是概括地描述选定的猎物、中层和顶层捕食者物种的丰度和人口结构变化的空间模式，以及这些模式如何与捕食者的丰度有关。-利用相机陷阱、捕获重新捕获、占据模型等方法，描述捕食者和中层捕食者物种经历的捕食压力的空间模式。-描述可能有助于上述模式的过程，包括猎物转换、捕食者之间的种内和种间相互作用以及对某些年龄段的捕食选择性。-在这部分脊椎动物群落的空间显式模型中综合经验信息，以预测生态系统在经历营养恢复时可能发生的变化。该案例学生是与英格兰林业公司的合作伙伴关系，提供获得多用途土地管理经验的机会。申请者将对人口和社区生态充满热情，渴望在~6个月/年期间收集现场数据，具有接受统计分析培训的能力和渴望，并热衷于与从业者合作。驾照是必不可少的。

Predation is an influential trophic interaction in ecosystems that may limit or regulate the abundance of prey species. Predator-prey interactions involving specialist predators may be tight and reciprocal between pairs of species, sometimes leading to population cycles. Where generalist predators, which are adept at prey switching, are present, interactions may be more diffuse, involving a larger number of species. While ecological theory concerning predator-prey interactions is well developed, it generally does not account for spatial variation in the distribution of the alternative prey species that are available to generalists. Modelling of non-spatial approximations typically assumes random mixing of individuals and spatially uniform strength of interactions between predator and prey species. However, prey species are often spatially heterogeneously distributed in real ecosystems, reflecting variation in the distribution of habitats and preferences, and for some cyclical populations, self-organised patterns such as travelling waves. Therefore, the scope for individual predators experiencing scarcity of their favoured prey to switch their attention to alternative prey is also heterogenous in space. Furthermore, intraguild predation, where one species kills and consumes another is commonplace. The aims of this studentship are i) to advance understanding of how spatial variation in the abundance of interacting predators and their prey switching response creates spatial heterogeneity in predation pressure and prey performance ii) to determine under what circumstances endangered prey may benefit from partial refuges from predation, an issue with multiple applications to conservation. Long term ecosystem studies, much existing data and the spread of pine martens in Kielder Forest create an opportunity to understand how the impacts of multiple predators may be additive, or whether interactions between predators, such as facilitations or intra-guild predation, may contribute to high spatial heterogeneity in predation pressure. Here, tawny owl demography reflects variation in the abundance of field voles. Tawny owls fall prey to goshawks and pine martens. Martens scavenge goshawk kills. Martens and foxes also rely on field voles in years of peak abundance. Research objectives are broadly - To characterise spatial patterns in abundance and demographic variation in selected prey, meso- and top predator species, and how these patterns relate to the abundance of predators.- To characterise spatial patterns in predation pressure experienced by prey and mesopredator species with potentially strong interactions with higher trophic levels using e.g. camera traps, capture recapture, occupancy modelling.- To characterise the processes, including prey switching, intra- and interspecific interactions amongst predators and selectivity of predation towards some age classes, that may contribute to the above patterns. - To synthesise empirical information in spatially explicit models of this subset of the vertebrate community to generate predictions on the way ecosystems may change while experiencing trophic rewilding.This CASE studentship is a partnership with Forestry England providing opportunities to gain experience in multi-use land management. Applicants will be enthused by population and community ecology, eager to collect field data during ~6 months/year, have an aptitude and eagerness to gain training with statistical analysis and be keen to work with practitioners. A driving licence is essential.