Examining mechanistic pathways driving the adaptive capacity of Arctic birds to respond to environmental change

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It is largely unclear whether organisms possess the adaptive capacity to respond to current rates of rapid environmental change (REC). My lab studies the adaptive capacity of underlying state-mediated mechanisms to enable organisms to respond to rapid environmental change (REC). We focus on three progressively integrated questions to test this paradigm in a diversity of systems facing REC (i.e., Arctic): i) how does environmental variation shape transcriptional, physiological and behavioural flexibility to maintain individual state?; ii) how do these flexible responses translate into optimal breeding decisions that maximize fitness?; and iii) how does the degree of intra and inter-individual level flexibility influence population resiliency in a changing world? More specifically, we field-test the global hypothesis that flexibility in a state-based regulatory mechanism - baseline corticosterone - bCORT - plays a key adaptive role in mediating how environmental variation influences individual state to optimize breeding decisions and maximize fitness. Relying on a highly integrative framework, we combine physiology, behaviour and transcriptomics to assess how flexibility in bCORT generates individual- and species-specific adaptive responses. Working in the Canadian Arctic is highly strategic given our framework since this ecosystem is changing faster than any on earth. Working with three avian models that span the pace-of-life continuum, we couple long-term, multi-year datasets with sophisticated and highly integrative experimental approaches to empirically field-test predictions of individually-based, state-dependent models. As such, our research pushes the forefront of science with a complex Individual x Environment x Life History (I x E x LH) framework to test adaptive responses to REC. Collectively, we are challenging integrative ecologists to increase the mechanistic complexity of how we all field-test the basis for variation in investment and fitness in free-living species. From an evolutionary perspective, we use this approach to uncover the mechanistic underpinnings of life-history variation that have largely eluded evolutionary ecologists for decades. From an applied perspective, we increasingly rely on these quantified linkages to predict when and how environmental change will shift individuals into maladaptive scenarios that negatively impact population growth. Overall, appreciating mechanistic complexity has numerous tangible advantages for furthering the theory that enables us to interpret how change impacts fitness. With the rapid increase in the multiple environmental stressors facing Arctic wildlife, this predictive yet flexible approach is more vital than ever for assessing whether organisms within rapidly changing Arctic ecosystems have the adaptive capacity to persist.