Spatially explicit population viability analysis of herbivore populations living in fission-fusion societies

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Population viability analysis (PVA) is a modelling tool used to predict the future size and extinction risk of populations, and commonly informs management and conservation actions. Although group size and movement tactics can have a strong impact on animal survival and reproduction, PVAs generally do not integrate principles of socioecology and movement ecology. The omission could reduce the accuracy of PVAs, especially for species living in fusion-fission societies. In such societies, the constant changes in group size directly influence the movement of group members, their foraging behaviour, and the mortality risk they face. Our objectives are to identify the key factors causing spatial variation in vital rates of gregarious herbivores, and use this information to develop a spatially explicit PVA framework for animals living in fission-fusion societies.****We will study free-ranging plains bison in and around Prince Albert National Park. This bison population faces wolf predation, as well as hunting outside of the park. We will conduct field studies to characterize the spatio-temporal patterns in age-specific vital rates, and identify the environmental factors responsible for those patterns. Field work will involve the extensive use of radio-telemetry. Traditional GPS collars will characterize the spatial dynamics of bison and wolves, whereas proximity collars will provide a detailed account of each interaction between collared bison and wolves. A number of bison will be fit with GPS-collars equipped with a video camera. The footage will provide a broad range of information such as food choice, duration of resting and forging bouts, and calf mortality. Concurrently, we will conduct field surveys to determine group size, vegetation quality, and the activity budget of non-collared bison. We will also collect biological samples for hormonal and DNA analysis. Overall, the field data will be used to 1) develop movement models for individuals living in fusion-fission societies established in patchy environments, 2) link food choice, physiological state, synchrony of activities, fusion-fission group dynamics, and predation risk, 3) identify the determinants of physiological stress, and their impact on animal distribution, and 4) determine the link between space use patterns and recruitment and adult mortality. This information will then become the basis for the development of a spatially explicit PVA.****The proposed research will provide one of the few spatially explicit, mechanistic PVA. Moreover, plains bison are threatened in Canada, and our PVA will provide essential information about the harvest pressure that the population can sustain, given the predation pressure it already faces. The research will contribute to elucidating the ecological links among behaviour, demography, and distribution, while increasing our understanding of a threatened population.***