The endangered bison

An estimated 40-million to 70-million bison roamed North America before 1800. They were almost all killed off by humans. Some were hunted to sell and others were killed as a sporting activity.

Less than 1,000 were left alive by 1900. Of those remaining animals, 25 were in Yellowstone National Park, U.S.A., protected from poachers by the army. Another 250 were in Wood Buffalo National Park, Canada. The rest were kept by five cattle ranchers who had captured the bison to preserve the species and to crossbreed them with other bovine animals in hope of creating hardier livestock.

There are about 300,000 American bison left in North America thanks to the work of conservationists. Scientists say that most of the remaining American bison have inherited genes from cattle. These hybrid animals look like pure-breed bison. They all appear to have descended from the animals created by those early 20th century ranchers.