My research focuses on the foraging ecology and conservation of Arctic carnivores. By examining the trophic relationships between top predators and their prey, we can define the structure of food webs and monitor changes in ecosystems over time. By understanding where, when, and how predators hunt for food, we can better act to protect wildlife populations and entire ecosystems.
Much of my research has involved the use of fatty acid signature analysis to examine the diets of marine and terrestrial carnivores. This technique is based on the knowledge that ingested dietary fatty acids (such as “omega-3’s”) are predictably incorporated into a predator’s fat stores. Therefore, the fatty acid profile of an animal can be used to make inferences about its foraging habits.
Long-term climate warming is having rapid and widespread effects on northern ecosystems. This in turn is altering the relationships between northern aboriginal communities and the wildlife populations they utilize. Accurate information on the current structure and functioning of food webs will help us predict how wildlife populations will change in the future and how these changes will impact the lives of people in the North. FES is uniquely positioned to examine the complex ecological, social, and economic changes that will result from a warming Arctic environment.
Rode, K.D., E.V. Regehr, D. Douglas, G. Durner, A.E. Derocher, G.W. Thiemann, S. Budge. 2013. Variation in the response of an Arctic top predator experiencing habitat loss: nutritional and reproductive ecology of two polar bear populations. Global Change Biology.
Derocher, A.E., J. Aars, S.C. Amstrup, A. Cutting, N.J. Lunn, P.K. Molnár, M.E. Obbard, I. Stirling, G.W. Thiemann, D. Vongraven, Ø. Wiig, and G. York. 2013. Rapid ecosystem change and polar bear management. Conservation Letters.
Cherry, S.G., A.E. Derocher, G.W. Thiemann, and N.J. Lunn. 2013. Migration phenology and seasonal fidelity of an Arctic marine predator in relation to sea ice dynamics. Journal of Animal Ecology 82: 912-921.
Thiemann, G.W., A.E. Derocher, S.G. Cherry, N.J. Lunn, E. Peacock, and V. Sahanatien. 2013. Effects of chemical immobilization on the movement rates of free-ranging polar bears. Journal of Mammalogy 94: 386-397.
Thiemann, G.W. , S.J. Iverson, I. Stirling, and M.E. Obbard. 2011. Individual patterns of prey selection and dietary specialization in an Arctic marine carnivore. Oikos 120: 1469-1478.
Peacock, E., A.E., Derocher, G.W. Thiemann, and I. Stirling. 2011. Conservation and management of Canada’s polar bears in a changing Arctic. Canadian Journal of Zoology 89: 371-385.
Thiemann, G.W., N.J. Lunn, E. Richardson, and D.S. Andriashek. 2011. Temporal change in the morphometry–body mass relationship of polar bears. Journal of Wildlife Management 75: 580-587.
Cherry, S.G., A.E. Derocher, K.A. Hobson, I. Stirling, and G.W. Thiemann . 2011. Quantifying dietary pathways of proteins and lipids to tissues of polar bears. Journal of Applied Ecology 48: 373-381.
Molnár, P.K., A.E. Derocher, G.W. Thiemann, and M.A. Lewis. 2010. Predicting survival, reproduction and abundance of polar bears under climate change. Biological Conservation 143: 1612-1622.