Conservation genetics and North American bison (Bison bison).

Area of Science:

• Conservation Genetics
• Wildlife Biology
• Population Genetics

Background:

• North American plains bison (Bison bison bison) populations drastically declined by the 1880s.
• Survival relied on a few private ranches and a Yellowstone National Park herd, creating a genetic bottleneck.
• Subsequent hybridization with cattle introduced non-bison ancestry into many conservation herds.

Purpose of the Study:

• To review the genetic status of North American plains bison conservation herds.
• To evaluate the impact of historical hybridization and bottlenecks on genetic diversity.
• To provide recommendations for improving the genetic health of conservation herds.

Main Methods:

• Review of historical records and genetic studies on plains bison populations.
• Analysis of effective population size and genetic variation in conservation herds.
• Evaluation of cattle ancestry prevalence and its implications.

Main Results:

• Present-day plains bison descend from fewer than 100 founders, impacting genetic diversity.
• Only 4% of approximately 500,000 plains bison are in conservation herds.
• A single conservation herd lacks cattle ancestry and exceeds 1000 effective population size.

Conclusions:

• Urgent need to address low genetic diversity and cattle ancestry in plains bison conservation herds.
• Strategies are required to mitigate inbreeding depression and maintain genetic variation.
• Effective conservation requires careful management of genetic resources for long-term bison viability.