Long-term field studies of predator-prey dynamics in large vertebrate systems are rare, owing to the difficulties and expense inherent in researching them. The focus of this project is to treat the recent reintroduction of wolves into the Yellowstone National Park as a natural experiment to study predator-prey dynamics in a large-mammal system. The research builds on the strength of extensive pre-wolf demographic studies of a discrete population of elk, the wolves' primary prey, with this proposal extending the comparative post-wolf research. We have strong evidence that wolves are significantly altering elk vital rates, and anticipate continuing research will demonstrate important top-down influences of wolves on their prey and allow us to refine and better parameterize our mathematical models representing predator-prey interactions in large mammal systems. There is growing support from large segments of society to restore large predators to landscapes that can sustain viable populations. These conservation actions are highly controversial, however, with much of the debate focused on the potential for predators to substantially change the ecosystems. Therefore, insights gained from the proposed work will not only advance our ecological understanding of predator-prey dynamics, but will also contribute objective and reliable information that can be used by both the public and natural resource professionals to formulate ecologically sound and publicly acceptable wildlife management programs.
