The Ecology of bison movements and distribution both in and beyond Yellowstone National Park.

In 1968, Yellowstone National Park (YNP) moved from a 33 year (1934-1967) period of culling ungulate populations for achieving predetermined stocking levels to a regime of ecological management under which populations of bison and other ungulates are allowed to fluctuate in the park without human intervention. With growing numbers of bison, management has become dominated by two major linked controversies; namely, the risk to livestock of transmission of brucellosis from bison moving beyond the park boundary, and criticism of the effects of winter use by snowmobiles on bison movements and range expansion, including transboundary movements, bison condition and population dynamics.

This project was initiated to: 1) provide a thorough, independent assessment of the state of knowledge of the ecology of bison movements and distribution within the context of current published concepts and theories; 2) provide recommendations for adaptive management of uncertainties and gaps in reliable knowledge within an adaptive environmental assessment and management framework, which involves organizing people to link science to management.

The principal investigators, based at the University of Calgary, Faculty of Environmental Design, were chosen because of their lack of previous association with issues related to YNP bison ecology or winter use management, allowing them to assess the state of knowledge and adaptive management from an unbiased perspective. The project was commissioned by the National Park Service. The research contract was administered by the Rocky Mountains Cooperative Ecosystems Studies Unit (RM-CESU) at the University of Montana.

The assessment entailed review of 1) literature on ungulate distribution, including Yellowstone National Park publications and planning documents, 2) key informant interviews for gaining rapid understanding of the system and unpublished knowledge, 3) development of a strategic level bison population and winter distribution model, and 4) key informant technical workshops to refine the model. In addition, 5) a workshop was held with environmental non-government organizations to review the concepts and knowledge upon which the assessment and model are based.

The assessment is summarized below. We first present key findings derived from key informant knowledge and interpretation of empirical data on population and spatial ecology. Secondly, we provide a summary of key findings derived from a systems model. Then we summarize key uncertainties and data gaps that may be addressed through monitoring and basic research. To be effective, adaptive management requires learning from key management experiments defined with the agreement of stakeholders and carried out under scientifically rigorous experimental designs. We identify key challengesfor adaptive management, including how agencies are organized to collaborate on and coordinate policy development, management experiments, and procurement of scientific research and monitoring data in the long term. Finally, we offer recommendations for addressing these challenges.