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(Aune et al. 2017)
- Total population
- 31,000 individuals in 68 conservation herds
- Mature individuals
- 11,000-13,000 individuals
- Prior to 1800's: estimated 50 million B. bison bison in North America (Nowak 1999)
- Late 1800's: bison in North America were nearly extinct.
- 1889: 835 bison living in the United States (Grzimek 1990)
- 1891: Wood Bison (Bison bison athabascae) offered legal protection by Canadians
- 1905: American Bison Society founded at New York city's Bronx Zoo; Theodore Roosevelt was honorary president,
- 1920's: Wood Bison (B. b. athabascae)numbered around 1,500
- 1920's: 6000 Plains bison introduced to Wood Buffalo National Park in Canada, transmitting bovine tuberculosis to Wood Bison
- 1957: A small wild population of B. b. athabascae discovered in Canada's Wood Buffalo Park (Nowak 1990)
- 1979: Wood bison classified as endangered
- 1988: Wood bison downlisted to threatened
- 2008: About 150 free-ranging bison live at the 125,000 acre Camp Pendleton in southern California. These animals descend from 14 individuals donated in 1973 by the San Diego Zoo.
- Near Threatened (2016 assessment) (Aune et al. 2017)
- Stable population trends.
- Not listed (UNEP 2019)
- Wood bison, B. b. athabascae, subspecies listed in Appendix II in 1997; deleted in 2017
Endangered Species Act
- Bison bison bison: not listed
- Bison bison athabascae: Threatenened
Threats to Survival
- Habitat loss
- Hunting in 1800 and 1900's nearly exterminated bison in North America. (McDonald 1981)
- Their gene pool experienced a bottleneck but genetic diversity hasn't declined significantly.
- Some researchers argue that bison will increasingly be eradicated by genetic modification as they are domesticated. (Lott 2002)
- Over 90 percent of bison in North America are "undergoing domestication'" (Lott 2002)
- Cattle genes found in nearly more than half of public herds in the U.S. and Canada and in all but one of 50 sampled private herds. (Halbert & Derr 2007)
Halbert & Derr (2007)
SDZWA Library Links
Fact Sheet Index
Fact sheet index, San Diego Zoo Wildlife Alliance Library
Home page, San Diego Zoo Wildlife Alliance Library
Email the librarians at firstname.lastname@example.org