| Tóm tắt: | <p>A core challenge for ecologists is to understand how biotic and abiotic processes influence demography and the dynamics of populations through time. I explore how ageing, social processes, and population conditions drive demography, movement, and community dynamics in a restored population of wolves Canis lupus in Yellowstone National Park, USA. I combine the analysis of empirical data for multiple species with models designed to simulate the dynamics of the system in which they live and interact, focussing on social and demographic processes in wolves.</p>
<p>I assess the utility of movement data for identifying functional senescence—declines in biological functions with age—in wild populations. I use long-term GPS data to describe movement across lifespans, identifying elevated rates of movement in older individuals and a pronounced annual cycle in movement rates.</p>
<p>I show that the fundamental demographic rates of survival and recruitment depend on attributes of individual wolves and their social groups, as well as effects of competition and population. Despite evidence that demographic performance is positively related to group size, packs are consistently small in Yellowstone. This apparent contradiction may derive from an inequality in fitness between breeding and non-breeding individuals in socially reproductive groups. To test this, I construct a group and age structured model simulating Yellowstone’s high-density wolf population, and find that by constraining group size, dispersal imparts a substantial regulatory effect on the population. This work forms a foundation for future work to understand the environmental and social basis for dispersal in a large carnivore.</p>
<p>Finally, to examine whether the reintroduction of wolves led to the changes in Yellowstone’s community structure observed in the past three decades, I use a novel approach to model community dynamics by parameterising for direct species interactions. I find that widespread and complex indirect effects emerge across the community and show that wolf predation has cascading effects that lead to the gradual recovery of vegetation.</p>
<p>This thesis provides new insights into the social and environmental basis of demography in an ecologically important carnivore and details the role of predator restoration in shaping community dynamics.</p>
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