Predator-Prey Dynamics in a Wolf-Ungulate System

Montana State University, Bozeman MT

Investigators

Abstract

0074444 Garrott This project will investigate wolf-ungulate interactions in Yellowstone National Park. The research capitalizes on a rare ecological experiment resulting from the reintroduction of wolves into the park after a 60-year absence and builds upon a long-term database compiled by the scientists. Most elk mortality prior to wolf reintroduction has been attributed to starvation (i.e. resource limitation). It is predicted that wolf predation will substantially increase elk mortality, and that the consequences of this predation will be an appreciable decease in population size toward an alternative equilibrium. The unfolding experiment provides an opportunity to test the influence of "bottom-up" versus "top-down" ecological processes in regulating populations. Aerial monitoring and intensive ground-based backtracking will be employed to estimate prey selection, predation rates, and total number of animals killed. Data from this investigation will provide the basis for a new predator-prey model that is both stochastic and age-structured. Results of this project, as well as complementary international collaborations, will significantly enhance wildlife science in large mammalian systems and facilitate design of sound endangered species programs.