Investigating the Drivers and Consequences of Individual Dietary Specialization in an Arctic Marine Top Predator

Abstract

Due to climate warming, reduced sea-ice extent and concentration in the Arctic has altered prey availability and limited foraging opportunities for polar bears (Ursus maritimus). My thesis examined individual foraging patterns across the Foxe Basin and Davis Strait subpopulations to identify drivers and consequences of dietary specialization. Using quantitative fatty acid signature analysis and proportional similarity (PSi) scores, I assessed how dietary specialization varies across intrinsic and extrinsic factors, and its relationship to body condition. Results revealed distinct diets and differing levels of specialization influenced by intrinsic and extrinsic variables. Sea-ice metrics were linked to variations in prey choice and individual specialization, suggesting altered access to preferred prey. Differences in individual specialization corresponded to variations in body condition, suggesting demographic groups experience energetic costs differently. These findings emphasize the role of individual-level variation in a warming Arctic, and underscore the importance of continued monitoring for polar bear conservation and management.