Université du Québec à Rimouski
Ph.D. candidate
Supervisor: François Vézina
Oliver Love, University of Windsor
Start: 2022-09-26

Project

Responses to thermal extremes in an Arctic cold specialist
RESEARCH PROBLEM: Climate change, particularly the rapid warming of Arctic regions, is expected to significantly affect cold-adapted species. The snow bunting (Plectrophenax nivalis) is a small songbird known for its extreme cold endurance. Recent research from our research group showed that buntings measured after arrival on their Arctic breeding grounds had very limited capacity to endure moderate heat, possibly because of the species’ extreme adaptations to the cold. However, it is currently unknown to what degree cold adapted species such as buntings can adjust to increasing temperatures. Snow buntings have also been in severe decline (~60-75% in the last 60 years) with no apparent causes. Therefore, the objective of my doctoral study is to investigate the snow bunting’s capacity to acclimate to heat. I plan to execute this using the following three projects. METHODOLOGY: 1) Thermal acclimation study will be conducted on captive buntings exposed to ambient temperatures from current to future predicted scenarios and markers of condition and performance will be measured. 2) Thermoregulatory polygon is a new approach to study heat exchanges in active endotherms based on routine measurements of the metabolic rate. It helps to determine the thermal limits where heat production and dissipation are balanced in active animals. I will generate individual thermal polygons by measuring the required metabolic parameters on captive snow buntings kept at UQAR. Next, performance tests will be conducted at several temperatures to test the validity of these predictions. 3) Previous research from our group suggests that the extreme cold endurance may result in a weak tolerance for moderate heat. To test this negative relationship, I will measure the maximal thermogenic capacity and heat tolerance of wintering wild birds. Currently, only a few studies have considered the direct effects of increasing ambient temperature on the thermal biology of cold-adapted species. This is of serious concern as these species have evolved to survive in cold conditions which might lead to limited thermoregulatory capacity at warmer temperatures. Overall, my thesis will provide a fundamental understanding of the responses of cold-adapted Arctic breeding species facing warming climate.

Keywords

Heat acclimation in cold-adapted species, Arctic warming , Thermoregulation, Metabolic performance, Phenotypic flexibility