Predator-prey dynamics is perhaps the most studied and controversial topic in ecology, because virtually every organism is predator, prey, or both and there is no consensus as to how such systems behave. Long-term studies of predator-prey dynamics in large vertebrate systems are rare, owing to the difficulties and expense inherent in researching them. This research will continue a long-term study (16 years) of a wolf-elk-bison predator-prey system in Yellowstone National Park. The focus of this project is to treat the reintroduction of wolves into the Yellowstone ecosystem approximately 10 years ago as a natural experiment to study predator-prey dynamics in a large-mammal system. The research builds on the strength of a 7-year, pre-wolf demographic study of a discrete population of elk, the wolves' primary prey, and comparable data on bison, the wolves alternate prey in this system. A pervasive human impact on ecosystems is the removal of top predators. While large predator reintroduction has recently become a widely accepted conservation practice, the ecosystem effects remain a scientific controversy and societal concern. Because most predator-prey systems consist of multiple prey, evaluating predator-prey dynamics in this newly established wolf-elk-bison system will yield immediate applied management and conservation insights for large mammal systems.
