Journal of Heredity Advance Access published online on May 4, 2009
Journal of Heredity, doi:10.1093/jhered/esp024
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Perspective |
Conservation Genetics and North American Bison (Bison bison)
From the School of Life Sciences, Arizona State University, Tempe, AZ 85287–4501
Address correspondence to Philip W. Hedrick at the address above, or e-mail: philip.hedrick{at}asu.edu.
The many millions of North American bison in the mid-19th century were reduced to near extinction by the middle 1880s. Plains bison, the subspecies found in the United States, were saved from extinction primarily by 5 private ranchers and the survival of a small herd in what is now Yellowstone National Park. This bottleneck resulted in the present-day plains bison population being descended from less than 100 founders. In addition, many conservation herds have cattle ancestry because of hybridization promoted by these ranchers in the late 1800s and early 1900s. Today, although there are around 500 000 plains bison in North America, only 4% (20 000) are in conservation herds. Only 1 conservation herd with no known ancestry from cattle has an effective population size of more than 1000. Here I review and evaluate this situation and provide recommendations for the reduction of cattle ancestry, avoidance of inbreeding depression, and maintenance of genetic variation in the conservation herds of bison.
Key Words: bison • effective population size • genetic variation • hybridization • inbreeding • mtDNA
Corresponding Editor: C. Scott Baker
Received January 20, 2009
Revised March 31, 2009
Accepted March 31, 2009