Marianne Turcotte

Université du Québec à Rimouski
M.Sc. candidate

Supervisor: François Vézina
Oliver Love, Université de Windsor
Start: 2022-09-01
End: 2024-08-10


Snow bunting's body composition and thermal conductance in the winter between sexes
The snow bunting (Plectrophenax nivalis) is a migratory passerine that winters in temperate regions, particularly in the snowy plains of Canada. The wintering range differs between sexes, along a latitudinal gradient, which implies different physiological constraints depending on the sex. Indeed, in the more northern portion of the wintering range, there is a greater proportion of males while a greater proportion of females is found further south. There is evidence that females have a higher proportion of body fat than males, regardless of latitude. This signature, if true, could have consequences on the proportion of lean tissue, tissues that are involved in heat production. However, this conclusion is drawn based on the Fat Index, a visual categorical measure. Females are also structurally smaller, which could imply higher heat loss than males. Thus, females would have a double constraint contrary to males, which could potentially contribute so sexual segregation in the winter. This study aims to further document differences between sexes in the body composition of snow buntings using quantitative magnetic resonance (QMR), providing empirical data including the amount of lean mass and lipid mass. This study also aims to compare heat loss between the two sexes by determining conductance, using respirometry.


Masse lipidique, Masse maigre, Migration différentielle, plectrophane des neiges, physiologie