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Dr. John M. Fryxell
Professor & Chair
Department of Integrative Biology

Dr. John M. Fryxell


Office: SSC 2461
Ext.: 53630
Lab: SSC 2405/2406
Ext.: 53594


B.Sc. - Britsh Columbia 1977
Ph.D. - British Columbia 1985


My research focuses on interactions between behavior and consumer-resource dynamics. A mix of theoretical and empirical approaches is used to consider the dynamics of specific systems. Theoretical questions of interest include herbivore and carnivore movement in relation to resource availability and predation risk, optimal diet, patch selection, and dispersal patterns in heterogeneous environments, the effect of social interference and territoriality on consumer-resource interactions, and impacts of harvesting by humans on fish and mammal populations.

Empirical work has been concentrated on 3 different terrestrial ecosystems over the past decade: large herbivores and carnivores in Serengeti National Park (Tanzania), woodland caribou, wolves, and moose in boreal forests of northern Ontario (Canada), and mustelid carnivores and other small mammals in boreal forests of northern Ontario. In each case, my graduate students and I conduct detailed field and experimental studies of behavioral ecology of both predators and prey. Theoretical models are then used to assess the implications of behavioral strategies on population and community dynamics and model predictions are then tested against long-term observational data from terrestrial ecosystems.

Kevin McCann and I recently initiated a collaborative research program on spatial food web dynamics of phytoplankton and zooplankton populations in massive aquatic mesocosms in the new Limnotron facility at the Biodiversity Institute of Ontario. Initial experiments relate to resource- vs predator- and ratio-dependent functional and numerical responses, responses of predator and algal populations to pulsed versus continuous nutrient influx, resource- and density-dependent diffusion patterns by zooplankton and phytoplankton, and spatial pattern formation in relation to population fluctuations.

An ongoing applied research interest relates to sustainable harvesting of fish and mammal populations. Key questions relate to long-term stability of harvested populations due to dynamic variation in harvester effort, effects of bioeconomic dynamics on long-term stability of fish stocks and prices, and spatial processes in harvested populations with and without no-harvest reserves.

Selected Publications


Wildlife Ecology, Conservation and Management, 3rd edition
and An Introduction to R

Serengeti III

Wildlife Ecology, Conservation & Management, 2nd Edition

Individual Behavior and Community Dynamics

Animal Migration - a synthesis

Journal Articles

Holdo, R. M., Fryxell, J. M., Sinclair, A.R.E., Dobson, A., Holt, R. D. (2011), Predicted Impact of Barriers to Migration on the Serengeti Wildebeest Population. PLoS ONE 6(1): e16370. doi:10.1371/journal.pone.0016370.

Fryxell,J.M., Packer,C., McCann, K., Solberg,E.J., Saether, B., Resource Management Cycles and the Sustainability of Harvested Wildlife Populations. Science 328, 903 (2010)

Dalziel, B.D., Morales, J.M., Fryxell, J.M., Fitting Dynamic Models to Animal Movement Data: The Importance of Probes for Model Selection, a Replay to Franz and Caillaud. The American Naturalist,Vol. 175, 6, June 2010

Sinclair, A.R.E., Metzger, K., Brashares, J.S., Nkwabi, A., Sharam, G., Fryxell, J.M., Trophic Cascades in African Savanna: Serengeti as a Case Study, Tropic Cascades (Terborgh et all, eds), Island Press, pages 255-274, (2010).

Yott, A., Rosatte, R. Schaefer, J.A., Hamr,J., Fryxell, J.M., Movement and Spread of a Founding Population of Reintroduced Elk, (Cervus elaphus) in Ontario, Canada, Society for Ecological Restoration International, doi: 10.1111/j.1526-100X.2009.00639.x

Smith-Owen, N., Fryxell, J.M., Merrill, E.H., Foraging Theory Upscaled: The Behavioural Ecology of Herbivore Movement. Phil. Trans. R. Soc. B (2010) 365, 2267-2278, doi: 10.1098/rstb.2010.0095.

Johnson, C. A., Fryxell, J.M., Thompson, I.D., Baker, J.A. (2009). Mortality risk increases with natal dispersal distance in American martens. Proc. R. Soc. B. 276, 3361-3367.

Holdo, Ricardo M., Holt, Robert D., Fryxell, John M. Opposing Rainfall and Plant Nutritional Gradients Best Explain the Wildebeest Migration in the Serengeti. The American Naturalist, Vol. 173 (4), April 2009.

Holdo, Ricardo, Holt, Robert D, Fryxell, John M. Grazers. browsers, and fire influence the extent and spatial pattern of tree cover in the Serengeti. Ecological Applications, 19(1), 2009, pp. 95-109.

Fryxell et al. (2008) Multiple movement modes by large herbivores at multiple spatiotemporal scales. PNAS 105:19114-19119.

Börger, L., Dalziel, B.D. & Fryxell, J.M. (2008). Are there general mechanisms of animal home range behaviour? A review and prospects for future research. Ecology Letters, 11: 637-650.

Andruskiw, M., Fryxell, J.M., Thompson, I.D., & Baker, J.A. (2008). Habitat-mediated variation in predation risk by the American marten. Ecology. 890 (8). pp. 2273-2280.

Dalziel, B.D., Morales, J.M., & Fryxell, J.M. (2008). Fitting Probability Distributions to Animal Movement Trajectories: Using Artificial Neural Networks to Link Distance, Resources, and Memory. The American Naturalist, Vol. 172, No.2., pp.248-258.

Haydon, D.T., Morales, J.M., Yott, A., Jenkins, D.A., Rosatte, R. & Fryxell, J.M. (2008). Socially informed random walks: incorporating group dynamics into models of population spread and growth. Proc. R. Soc. B 275, pp: 1101-1109.

Kittle., A.M., Fryxell, J.M., Desy, G.E., Hamr, J. (2008). The scale-dependent impact of wolf predation risk on resource selection by three sympatric ungulates. Oecologia 157: 163-175.

Fryxell, J.M., Mosser, A.,M Sinclair. A.R.E. & Packer, C. (2007). Group formation stabilizes predator-prey dynamics. Letters, Nature, Vol 449, pp.1041-1044.

Thompson, I.D., Maher, S.C., Rouillard, D.P., Fryxell, J.M., Baker, J.A. (2007). Accuracy of forest inventory mapping: Some Implications for boreal forest management. Forest Ecology and Management 252, pp 208-221.

J.B. Falls, E.A. Falls, and J.M. Fryxell. (2007). Fluctuations of deer mice in Ontario in relation to seed crops. Ecological Monographs, 77(1), pp. 19–32.

A.R.E. Sinclair, S.A.R. Mduma, J.G.C. Hopcraft, J.M. Fryxell,R. Hilborn, and S. Thirgood. (2007). Long-Term Ecosystem Dynamics in the Serengeti: Lessons for Conservation. Conservation Biology Volume 21, No. 3, 580–590.

T. Broquet, N. Ray, E. Petit, J.M. Fryxell and F. Burel. (2006). Genetic isolation by distance and landscape connectivity in the American marten (Martes americana). Landscape Ecology 21:877–889.

T. Broquet, C. A. Johnson, E. Petit, I. Thompson, F. Burel and J.M. Fryxell. (2006). Dispersal and genetic structure in the American marten, Martes americana. Molecular Ecology 15, 1689–1697.

Fryxell,J.M., Lynn, D.H., Chis, P.J., (2006). Harvest reserves reduce extinction risk in an experimental microcosm

Fryxell, J.M., I.M. Smith, and D.H. Lynn (2005). Evaluation of alternate harvesting strategies using experimental microcosms. Oikos 111:143-149.

Fryxell, J.M., J.F. Wilmshurst, A.R.E. Sinclair, D.T. Haydon, R.D. Holt and P.A. Abrams. 2005 Landscape scale, heterogeneity, and the viability of Serengeti grazers. Ecology Letters, 8: 328–335.

Morales, J.M., D.T. Haydon, J. Frair, K.E. Holsinger, and J.M. Fryxell. 2004. Extracting more out of relocation data: Building movement models as mixtures of random walks. Ecology, 85(9): 2436–2445.

Fryxell, J.M., J.F. Wilmshurts and A.R.E. Sinclair. 2004. Predictive models of movement by Serengeti Grazers. Ecology, 85(9): 2429–2435.

Thirgood, S.J., A. Mosser, S. Tham, J.G.C. Hopcraft, E. Mwangomo, T. Mlengeya, M. Kilewo, J.M. Fryxell, A.R.E. Sinclair, and M. Borner. 2004. Can parks protect migratory ungulates? The case of the Serengeti-Mara wildebeest. Animal Conservation 7: 113–120.

Haydon, D.T. and J.M. Fryxell. 2003. Using knowledge of recruitment to manage harvesting. Ecology 85(1):78-85.

Boyce, M.S., J.S. Mao, E.H. Merrill, D. Fortin, M.G. Turner, J. Fryxell, and P. Turchin. 2003. Scale and heterogeneity in habitat selection by elk in Yellowstone National Park. Ecoscience 10(4):421-431.

Vlasman, K.L. and J.M. Fryxell. 2003. Seasonal changes in territory use by red squirrels, Tamiasciurus hudsonicus, and responses to food augmentation. Canadian Journal of Zoology 80:1957-1965.

Fortin, D., J.M. Fryxell, L. O’Brodovich, and D. Frandsen. 2003. Foraging ecology of bison at the landscape and plant community levels: the applicability of energy maximization principles. Oecologia 134:219-227.

Fortin, D., J.M. Fryxell, and R. Pilote. 2002. The temporal scale of foraging decisions in bison. Ecology 83(4):970-982.

Illius, A.W. and J.M. Fryxell. 2002. Methodological problems with estimating patch depression during resource depletion. OIKOS 98:3.

Fryxell, J.M. 2001. Habitat suitability and source-sink dynamics of beavers. Journal of Animal Ecology 70:310-316.

Fryxell, J.M., J.B. Falls, E.A. Falls, R.J. Brooks, L. Dix, and M. Strickland. 2001. Harvest dynamics of mustelid carnivores in Ontario. Wildlife Biology 7:151-159.

Fryxell, J.M., C. Bergman, D. Fortin, and J. Wilmshurst. 2001. On the scale dependence of foraging in terrestrial herbivores. Pages 271-275 in Proceedings of XIX International Grasslands Congress (Gomide, J.A., W. Mattos, and S.C. da Silva, eds), FEALQ, Sao Pedro, Brazil, 1097 pp.

Bergman, C.M., J.M. Fryxell, C.C. Gates, and D. Fortin. 2001. Ungulate foraging strategies: energy maximizing or time minimizing? Journal of Animal Ecology 70:289-300.

Wilmshurst, J.F., J.M. Fryxell, and C.M. Bergman. 2000. The allometry of patch selection in ruminants. Proceedings of the Royal Society of London (Series B) 267: 345-349.

Sinclair, A.R.E., C.J. Krebs, J.M. Fryxell, R. Turkington, S. Boutin, R. Boonstra, P. Seccombe Hett, P. Lundberg, and L. Oksanen. 2000. Testing hypotheses of trophic level interactions: a boreal forest ecosystem. Oikos 89:313-328.

Bergman, C.M., J.M. Fryxell, and C.C. Gates. 2000. The effect of tissue complexity and sward height on the functional response of wood bison. Functional Ecology 14: 61-69.

Donkor, N.T. and J.M. Fryxell. 2000. Lowland boreal forest characterization in Algonquin Provincial Park relative to beaver (Castor canadensis) foraging and edaphic factors. Plant Ecology 148: 1-12.

Fryxell, J.M., J.B. Falls, E.A. Falls, R.J. Brooks, L. Dix and M.A. Strickland, 1999 Density dependence, prey dependence, and population dynamics of martens in Ontario. Ecology 80(4):1311-1321.

Wilmhurst, J.F., J.M. Fryxell and P.E. Colucci. 1999. What constrains daily intake in Thomson's Gazelles? Ecology 80(7):2338-2347.

Fryxell, J.M., J.B. Falls, E.A. Falls and R.J. Brooks. 1998. Long-term dynamics of small-mammal populations in Ontario. Ecology 79(1):213-225.


BIOL*2060 Ecology
BIOL*3110 Population Ecology
BIOL*4150 Wildlife Conservation and Management
ZOO*4410 Field Ecology

Grad Students

Derek Morningstar (MSc)

Post Doctoral Fellows

Dr. Tal Avgar
Dr. Gustavo Betini