Bison - America's Largest Mammal, Life In The Herd, The Continuing Generations, The Disappearing Bison

The American bison (Bison bison) is a large, herbivorous land mammal native to the grasslands and open forests of North America. It is a member of the family Bovidae, which also includes cattle, sheep, and goats. When French explorers first saw these large, shaggy, cow-like animals, they called them boeufs, the French word for "cattle." This later became anglicized into the word "buffalo," a name still applied to the bison, despite the fact that there are other bovids in Africa and Asia more properly known as buffalo.

There are two subspecies of American bison, the plains bison (B. b. bison) and the wood bison (B. b. athabascae ). The wood bison lives west and north of the plains bison, and is larger and darker in color. Because its habitat is open woodland and muskeg, it does not live in such huge herds as the plains bison once did. However, some taxonomists do not recognize wood bison and plains bison as separate subspecies.

Bison probably came to North America from Eurasia during the most recent ice age. They did this perhaps 25,000 years ago, by travelling along a land-bridge across the present-day Bering Strait. The land-bridge existed because sea level was lower then, owing to so much of Earth's water being on land in the form of glacial ice. The only Eurasian remnant is the European bison or wisent (B. bonasus), which now only survives in protected forest on the borderland of Poland and Belarus. Another population of wisents in the Caucasus Mountains became extinct in 1925. The wisent is somewhat smaller than the American bison and does not have as large a hump.