An Ancient Bond with the Land
Surviving the Ice Age
The steppe bison (Bison priscus) lived until the end of the last Ice Age, about 10,000 years ago. It was much larger than modern bison, with enormous horns projecting sideways from its head.
Bison populations increased when their grazing competitors, such as mammoths, horses and camels, died out in North America at the end of the Ice Age. As herd size increased, the body size of individual bison gradually decreased. Bison reached their present size about 5000 years ago and had smaller horns that bent backward.
These changes may relate in part to intensive hunting pressure from growing human populations. The smaller animals formed ever-larger, more tightly bunched herds for their own protection. Bison hunters responded by inventing new hunting techniques, including bison jumps and pounds.