Large herbivores are essential ecosystem components in the temperate northern hemisphere. They play critical roles in ecosystem functioning by influencing seed dispersal and nutrient cycling as well as shaping the structure and distribution of habitat for other species. In recent history, large herbivore populations have severely declined as a result of human activities, such as hunting, urban development and habitat modification. Some ungulate species are exceptions to this trend, and are now widespread in developed regions, such as Europe and North America. The expansion of ungulates alongside the growth and development of human populations has led to a diverse range of beneficial and detrimental interactions. Studies of their behaviour in human-dominated landscapes can provide important insights into the ecological processes that enable coexistence. This thesis focussed on the case study of fallow deer (Dama dama) in the UK, which is an excellent example of a large herbivore successfully inhabiting a complex landscape of human activities and land-use. The aim was to explore how humans influence the spatiotemporal behaviour of deer and provide evidence to support sustainable population management.

Existing evidence for the effects of population management on deer and other UK ungulate species was systematically mapped to identify key knowledge gaps and provide recommendations for future research and policy-making. The results revealed that the current extent of evidence is limited and unevenly distributed across species, interventions and outcomes. Empirical studies were conducted to address some of the knowledge gaps identified for fallow deer. An array of 29 motion-activated camera-traps were deployed in woodland sites to monitor deer in the Elwy Valley region of North Wales, UK. The local population in this area is largely isolated and provides a valuable opportunity to study the behaviour of deer at a tractable landscape scale. Data from the camera-trap survey were used to examine the influence of temporal, environmental and anthropogenic factors on patterns of daily activity and woodland habitat-use. Deer exhibited clear, non-random patterns of activity across the diel cycle and habitat-use was mostly driven by environmental landscape features (tree cover and slope). The results revealed different and interacting effects of lethal (hunting) and non-lethal (recreation and woodland management) human disturbance and show how deer resolve trade-offs between risk avoidance and resource acquisition in human-dominated landscapes. These studies also demonstrate the utility of camera-trap surveys in expanding the range of data collected on ungulate populations to support an adaptive approach to management. Simulations were used to assess the optimisation of camera-trap surveys, with a focus on the use of covariates in occupancy models. The results offer guidance to practitioners to improve the robustness and efficiency of camera-trap studies and population monitoring programmes.

As human populations continue to grow and the demands for natural resources intensify, the potential for conflict with large herbivores increases. This thesis provides robust scientific evidence that may be used to develop strategies for coexistence, which conserve the important ecosystem-level benefits of large herbivores while mitigating their impacts on human interests.