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American Bison (Bison bison) Fact Sheet
American Bison (Bison bison)
Image credit: Jack Dykinga; released by the Agricultural Research Service, the research agency of the United States Department of Agriculture (ID# K5680-1); made available on Wikimedia Commons. Public domain.
Order: Artiodactyla (or Cetartiodactyla) (Even-toed hoofed animals: includes pigs, sheep goats, cattle, deer)
Family: Bovidae (cattle, water buffalo, bison, antelopes, goats, sheep and more)
Species: Bison bison - American bison
Subspecies: Bison bison bison - American Plains Bison
Subspecies: Bison bison athabascae - Wood Bison
Males: 554-907 kg (1,221-2,000 lb)
Females: 318-545 kg (701-1,202 lb)
Male: 3,040-3,800 mm (10-12.5 ft)
Female: 2,130-3180 mm (7.0-10.4 ft)
Male: 330-910 mm (1.1-3.0 ft)
Female: 300-510 mm (1.0-1.7 ft)
Brown, dark brown, or blackish-looking at a distance. Longest hairs on head, beard, and forelegs. Winter coat is wooly fur under coarse, protective guard hairs. Young are lighter in color.
|Distribution & Status
||Behavior & Ecology
Alaska, Canada, Montana to the U.S.-Mexico Border along the Rocky Mountain Range
American Wood Bison: parklands and woodlands
American Plains Bison: grasslands
Near Threatened (2016 assessment) (Aune et al. 2017)
Not listed (as of Aug 2019) (UNEP 2019)
(Wood bison, B. b. athabascae, deleted in 2017)
Population in Wild
Total population: 31,000 individuals; 11,000-13,000 mature
- Plains bison: 20,000 individuals
- Wood bison: 11,000 individuals
Walking, trotting, galloping, jumping. Can run up to 60 km/hr (35 mph).
Active during the day. Graze and ruminate. Wallow during the summer.
Gregarious. Fluid groups of females with calves, young males, and possibly 2-3 older males.
Mostly grasses. Sometimes, lichens, mosses, wild oats.
|Reproduction & Development
Males: about 4-6 years old
Females: about 3-4 years old
285 days, but may vary so females can give birth at the same time
15-25 kg (33-55 lb)
Age at Weaning
In the wild: 10 years
In managed care: 20-35 years; 40 years max.
- Once roamed in vast herds over North America; nearly exterminated from North America during 1800s and 1900s
- 2 subspecies: Northern (Wood Bison) and Southern (Plains Bison)
- Many live on private ranches today
- Non-territorial; migrate seasonally
- Males produce very loud bellows
- Tolerate cold weather extremely well
- Acute sense of sense and good eyesight
- Huge wave of domestication in recent decades; concern over genetic modifications and crossbreeding with cattle
About This Fact Sheet
© 2009-2019 San Diego Zoo Wildlife Alliance. Population estimates updated Nov 2018.
How to cite: American Bison (Bison bison) Fact Sheet. c2009-2019. San Diego (CA): San Diego Zoo Wildlife Alliance; [accessed YYYY Mmm dd]. http://ielc.libguides.com/sdzg/factsheets/ americanbison
(Note: replace YYYY Mmm dd with date accessed, e.g., 2015 Sep 10)
Disclaimer: Although San Diego Zoo Wildlife Alliance makes every attempt to provide accurate information, some of the facts provided may become outdated or replaced by new research findings. Questions and comments may be addressed to firstname.lastname@example.org.
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