I am broadly interested in the evolutionary interactions between physiology and behaviour, including topics traditionally contained in the field of physiological ecology and behavioural ecology. I seek to understand how the ecological and evolutionary interactions between behaviour and physiology can generate and maintain diversity in life-history strategies. I focus on the evolutionary and energetic consequences of variation in behavioural traits such as locomotor activity, exploration, aggressiveness, boldness, hoarding, and migration. I study if and how behaviour and energy expenditure are influenced by factors that are environmental (e.g., air temperature), ecological (e.g., food abundance, parasites), individual (e.g., age, reproduction, stress response), genetic (e.g., genetic correlations with other traits), or phylogenetic. My major line of research grows out of my PhD on the “energetics of personality” and the “pace-of-life syndrome”. Another facet of my research program focuses on the impacts of resource pulses and climatic variation on the behavioural ecology and evolutionary physiology of mammals. I study individual variation in combination with comparative studies at higher levels of biological variation (populations, species), as it yields complementary insights into how energetics and behaviour interact through evolution. I combine field and laboratory studies because the mix between the ecological reality of field studies and the precision attained in the lab provides a better understanding of the causes and consequences of variation in energy expenditure. From time to time, I also gather data from the literature and use the comparative approach to test my hypotheses. I also enjoy analysing data using statistical methods that take into account the relationship among study subjects, such at phylogenies and pedigrees.