Predator-Prey Systems: the Wolves in Yellowstone

wolves chasing elk

Professor Mark Boyce
Professor of Ecology, University of Alberta, Canada

Predation is increasingly recognized as an ecological process that structures natural communities, and has been targeted as an important focus for conservation, notably informing the “rewilding” movement for reintroducing apex and meso-predators to natural environments across the world, involving wolves, cougars, lynx, bears and dingos, among many others. Yet, others have argued that the extent and magnitude of trophic cascades has been overstated and that few clear examples exist in terrestrial ecosystems, especially for behaviourally-driven trophic cascades.

A trophic cascade is an ecological phenomenon triggered by the addition or removal of top predators and the reciprocal changes in the relative populations of predator and prey through a food chain, with often dramatic changes in ecosystem structure and nutrient cycling.

Professor Mark Boyce will review the details of this debate with a particular focus on the iconic wolf recovery in Yellowstone National Park and conclude that, as predicted by theory, we see spatial and temporal variability in predator-prey systems that likewise generate spatial and temporal variability in the expression of trophic cascades. Outside protected areas in western North America, however, humans have a dominant influence that overwhelms trophic cascades and can result in bottom-up influences on community structure and function.

About the Speaker:

Mark S. Boyce received his Bachelor of Science from Iowa State, Master of Science from University of Alaska, and MPhil and PhD degrees from Yale University.  He was a NATO postdoctoral fellow at Oxford University.  He is Professor of Ecology and holds the Alberta Conservation Association Chair in Fisheries and Wildlife at the University of Alberta.

His research specialty is the population ecology of vertebrates and he currently supervises 8 graduate students and postdocs.  He is a Fellow of the Royal Society of Canada and was awarded the Mirosław Romanowski Medal by the Royal Society of Canada in 2016 for applications of science to solve environmental problems. In 2017 he was awarded the C. Hart Merriam Award by the American Society of Mammalogists.