Trends in the distribution and abundance of bison in Wood Buffalo NationalPark

We summarized changes in the distribution and abundance of bison (Bison bis on) in Wood Buffalo National Park from 1971 to 1998. Based on annual aerial counts, a significant decline in bison abundance has occurred from approxi mately 11,000 animals in 1971 to 2,300 animals in 1998. The decline occurre d south of the Peace River, which includes the Peace-Athabasca Delta. Cow a nd calf counts south of the Peace River from 1989 to 1996 indicated low cal f production and very low yearling survival. It is not clear what factors a re responsible for the decline. We suggest that long-term, multi-disciplina ry research is required to further understand the changing dynamics within the Wood Buffalo National Park ecosystem.