Animals must balance the energy they intake with the energy they spend on activities that are important for reproduction and survival (e.g., resource acquisition, predator avoidance, etc.). I am interested in understanding the causes and consequences of variation in energy use and how behaviour, the environment and individual characteristics interact to impact energy expenditure of free-ranging mammals.
Photo by: Kevin Chan
Photo by: Adam Sprott
Photo by: Pauline Vuarin
Current PhD Research
Recent media coverage on lynx-hare research in Kluane (Up Here Magazine article) and on the long-distance movements of two collared lynx (Alaska Fish and Wildlife News article, CBC A New Dayradio interview, CBC North article, Copper River Record article). Also, check out a few of our study animals (lynx and hares) on the CBC's nature documentary "The Wild Canadian Year", here.
To date, our understanding of the link between individual energy expenditure and broad-scale ecological phenomena is limited, likely due to the challenge of monitoring the energetic status of free-ranging animals over ecologically-relevant temporal or spatial scales. Traditionally, energetic studies have employed methods that are limited in their capacity to measure metabolism and energy expenditure over broad spatial and temporal scales; however, recent advances in biologging technology (i.e., miniaturized animal-borne data loggers that relay information about an animal’s behaviour, physiology, and environment) have opened up new possibilities for studying behaviour and energetics in the field. For my PhD, I am combining traditional methods (i.e., respirometry and doubly-labeled water) with more recent biologging methods (accelerometers, heart rate and body temperature loggers, VHF/GPS collars) to obtain estimates of energy expenditure of Canada lynx, snowshoe hares, and North American red squirrels in the northern boreal forest. With these data I aim to verify relationships among activity-time budgets, heart rate, body temperature and daily energy expenditure in order to predict overall energy requirements of free-ranging animals outfitted with these dataloggers. Continuous sampling of behavioural, spatial, energetic and environmental data, over multi-seasonal and multi-annual time periods will allow me to estimate energetic status of these three species over ecologically-relevant spacial and temporal scales and gain a better understanding of how the energetic status of a free-ranging mammal changes in their highly variable environment. My field work is based at Squirrel Camp in southwestern Yukon, just outside of Kluane National Park (one of the most beautiful places to visit; see Photos). Ecological monitoring and research has occurred in this area for decades and I am fortunate to be part of the extensive team of professors and graduate students that have done work there. Thank you to the Champagne and Aishihik and Kluane First Nations for allowing us to conduct work on their traditional territory and be part of such an amazing place.
Photo by: James Turner
M.Sc and B.Sc Research Selection has favoured a range of adaptations that help maintain positive energy balance in the presence of seasonal environmental variation and periods of energetic constraint, one of which is torpor and/or hibernation. The optimal expression of torpor may vary for different individuals depending on a range of factors (e.g., body condition, sex, age etc), which creates the potential for biologically significant variation in torpor use. Very few studies have looked at how an individual's behavioural tendencies (or personality) influences their torpor expression. So, for my honours project, I helped develop the first behavioural test for personality in bats and used it to test the hypothesis that individual personality (i.e., activity and exploration) influences basal metabolic rate and summer torpor expression of little brown bats. For my masters, I followed this up looking at the influence of body condition, sex, age, and personality on over-winter torpor expression and energy use in big brown bats. I also investigated repeatability and heritability of body condition and torpor expression using molecular markers and quantitative genetics to determine if certain hibernation traits have the capacity to evolve in response to selection. Field research was conducted in central Manitoba and northwestern Ontario, predominately on First Nations traditional territory; thank you to those communities, namely the Misipawistik Cree Nation, for allowing us to conduct our work there. Note: Hibernating bats are being killed in large numbers by a devastating disease called White Nose Syndrome, caused by a cold-loving fungus that grows on bats as they hibernate. This disease was discovered in New York state in 2006/2007 and, since then, has spread rapidly across north eastern North America, killing millions of bats. Read more about it here and what you can do to help here.