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Togunov, Ron R.

University of British Columbia

Animal behaviour may represent an early response to variation in habitat suitability. Identifying factors that promote behaviours may be particularly important in areas undergoing environmental change. Recent advances in remote tracking, satellite imagery, and associated methodologies have enabled behavioural research in animals occupying remote environments where direct observation is impractical. Moving habitats (e.g., drifting sea ice) elicit complex behaviours, affect the apparent movement of animals, and are associated with high observation error. In this thesis, I investigated the foraging ecology of polar bears (Ursus maritimus) during the winter. First, I investigated the accuracy of a commonly used model for sea ice motion using dropped GPS collars. I showed that these satellite-based models underestimate the drift speed and have large errors estimating its direction at low speeds. Second, I developed models for remote-tracking data to study behaviours with orientation bias (e.g., relative to wind). Using a popular class of statistical models, hidden Markov models, I developed movement models that allow for error-prone environmental data. I showed that my method effectively recovered behaviour and outperformed other methods when faced with coarse environmental data. Last, I developed a model to correct for sea ice drift and investigated the effect of diurnal, seasonal, and environmental covariates on polar bear behaviour. I identified a peak in diurnal activity later in the day compared to other populations, as well as an increase in activity as the season progressed, which may be indicative of an increase in active foraging. I also identified spatial patterns of distribution with respect to season, ice concentration, and bear age that may reflect high habitat quality in western Hudson Bay and the potential presence of competitive exclusion. My thesis provides a novel assessment of the error present in remotely-sensed sea ice drift models and data that can be used to improve them in the future. In addition, my thesis presents models that can be applied to investigate important, and previously difficult to model, behaviours with orientation bias across taxa. Finally, my thesis expands on our understanding of polar bear foraging ecology with novel insights on its association with the environment.

Text

2022-09-29

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/82795

Zoology

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/