We work on the functional interactions between physiology, performance, and behaviour, including topics traditionally contained in the field of physiological ecology, behavioural ecology, and quantitative genetics. We seek to understand how the ecological and evolutionary interactions between metabolism, performance, and behaviour can generate and maintain diversity in life-history strategies. We focus on the evolutionary and energetic consequences of variation in behavioural traits such as locomotor activity, exploration, aggressiveness, boldness, and food hoarding. We regularly 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. One of our major line of research is on the “energetics of personality” and the “pace-of-life syndrome”. We study individual variation in combination with comparative studies at higher levels of biological variation (populations, species), as it yields complementary insights into how energetics, performance, and behaviour interact through evolution.
We 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, we also gather data from the literature and use the comparative approach to test our hypotheses. We generally enjoy analysing data using statistical methods that take into account the relationship among study subjects, such at phylogenies and pedigrees.
Basal metabolic rate
Daily energy expenditure
Life history strategies
Maximum metabolic rate
Resting metabolic rate
Thermal reaction norm
Favourite Research topics
Energetics, Performance, and Personality
This research lies at the interface between ecology, physiology, and behaviour. We seek to understand the causes and consequences of individual co-variation in physiology and behaviour, which may help understanding the fundamental factors that underlie slow-fast life-history strategies. The conceptualisation of the link between animal personality and energy metabolism (paper #8) generated multiple ideas as to how these traits should interact with each other. For example, it is highly intuitive to think that personality is related to energy expenditure and resting metabolic rate because it is costly to express behaviours such as exploration, boldness, and aggressiveness. It is also possible that physiological constraints related to energy expenditure limit behavioural plasticity through time and/or among situations, which may create evolutionary trade-offs. This is why it is crucial to integrate personality and metabolism within an evolutionary framework, which is what the “pace-of-life syndrome” concept attempts to do (paper #13). The linkages between energetics and personality can also be studied within the classic “morphology-performance-fitness” framework (paper #20). Indeed, the integration of performance traits within research on the energetics of personality fills an important logical gap within the “pace-of-life” syndrome concept.
Climatic and environmental influences on Physiology and Behaviour
We also seek to understand the effects of climatic and environmental variation on physiology and/or behaviour. This broad research theme covers a large variety of topics and study models such as the effect of climate on hawks’ migrating behaviour (paper #1) and canids’ basal metabolic rate (paper #2), the effect of pulsed resources such as lemming peaks and goose eggs on the hoarding behaviour of arctic foxes (papers #3, 4, 6, and 7). During my PhD, I studied how resting metabolic rate changes as a function of resource pulses (paper #22) and number of parasites hosted in chipmunks (papers #11 and 18). I also found stabilizing selection on RMR and negative impacts of parasites on the growth rate and survival of juvenile chipmunks during a year of low food availability (paper #21). Recently, I showed how the effect of environmental temperature on RMR is different in species using torpor vs. species that don’t (paper #23). Work in collaboration with M. Humphries showed how an important but oft-overlooked phenomenon (i.e., the substitution of the heat required for thermoregulation by the heat produced by activity) may be an important determinant of the activity patterns and metabolic ecology of endotherms, and how it can generate commonly observed macro ecological and latitudinal patterns in energy expenditure (paper #15).
Thermal reaction norms of metabolism and behaviour
We also work on individual variation in thermal sensitivity of metabolic, behavioural, and performance traits. It is widely known that metabolism doubles or triples in rate whenever temperature increases by 10ºC. The variation in thermal sensitivity among species and populations can sometimes be considerable and is often thought of as resulting from natural selection. However, the demonstration of heritable among-individual variation in thermal sensitivity necessarily precedes any attempt to determine its selective significance. Thus, one of our current research objectives is to quantify individual variation and heritability in thermal sensitivity for various metabolic, behavioural, and performance traits and the genetic correlations among them. Most quantifications of thermal reaction norms for physiological, behavioural, and performance traits are done in isolation from each other. As a result, we currently have little knowledge on whether thermal reaction norms of performance, reproductive success, behaviour, and metabolism are functionally integrated, despite the fact that this information is crucial to understand the evolutionary potential of a species to adapt to a gradual rise in temperature. In collaboration with Matthew Gifford, we showed the presence of significant individual variation in the thermal sensitivity of both standard and maximal metabolic rates in slimy salamanders (paper #30). In this study, we showed that the thermal sensitivities of standard and maximal metabolic rates were correlated at the among-individual level. The next step is to evaluate if different thermal reaction norms are heritable and genetically correlated, because this will determine the constraints on evolutionary responses to changing thermal regimes. Thus, this research topic unifies the two research themes above, as the general objective is to test whether a suite of metabolic, behavioural, and performance traits are functionally integrated along an environmental variable (temperature).