Péter Molnár

The Arctic is warming four times faster than the global average, with many Arctic species faced with unprecedented changes in their environments. Predicting effects of future change is difficult because measurements under current conditions may not reflect responses to never-before-seen scenarios. Determining the mechanisms that underly species’ responses to change can help overcome these limitations and improve forecasting and mitigation efforts. For polar bears, energetic constraints due to loss of sea ice hunting habitat have been identified as a fundamental process by which climate warming affects individuals and populations. Energetic models have been developed and applied to explain observed changes in population health and to project changes in reproduction and survival under different climate scenarios. Despite these advances, incorporation of such approaches into monitoring and management has been limited to date. Here, we explore potential applications of energetic modelling in polar bears. We highlight the iterative and interacting processes of data collection and model development, underscoring how each can inform the other to drive new insight and understanding. We also present case studies that provide step-by-step examples of how energetic models can inform proactive management and conservation planning. Scenarios considered include (i) potential impacts of supplementary feeding regimes, (ii) predicting effects of multiple interacting stressors on population dynamics, and (iii) determining effects of change across multiple time scales – from acute effects on demographic rates to chronic effects on individual health and fitness. Lastly, we consider how uncertainty can be quantified in energetic models to better address management objectives and to ensure outputs are robust and transparent. Although we focus on polar bears, we underscore how energy is a fundamental currency and our approach has applications to many other mammals, including other ursids.