© APBison walk toward the corral during the recent annual roundup at The Nature Conservancy's Tallgrass Prairie Preserve in Pawhuska, Okla.
An estimated 60 million bison roamed the prairie when Columbus arrived in the New World in 1492. By 1900, only hundreds were left after herds were slaughtered for meat, pelts and sport. Although there are now half a million bison in the United States, researchers have discovered that most of them carry cattle genes - placing the animals at risk.
In the Oklahoma Flint Hills, an autumn moon set on The Nature Conservancy's Tallgrass Prairie Preserve as scientists and cowboys gathered at dawn recently for the annual bison roundup. Instead of horses, wranglers climb aboard trucks. They rumble toward a herd of 2,600 bison standing quietly in a nearby pasture. They drive part of the herd into a tight group, and then stampede them into a holding trap.
The shaggy beasts' heaving breath swirls through the corral into a thick, white fog. Over the next 10 hours, ranch hands use plastic paddles to spank the bison through a maze of alleys and corrals toward their annual physical.
© APOver the next 10 hours, ranch hands use plastic paddles to move part of a herd of 2,600 bison through a maze of alleys and corrals toward their annual physical.
In turns, each bison slams into the examination chute. A brace closes around its neck and heavy grates squeeze it still. A bull is checked for injuries, given a shot and weighed. He stands 6 feet at the shoulder and weighs almost 2,000 pounds.
The huge bison huffs with anxiety. Up close, he seems prehistoric - his shaggy brown head hangs low beneath a humped spine, curved horns showing bits of blood. Preserve director Bob Hamilton says he may look like a bison, act like a bison and even smell like one - but he's a cattle hybrid. And if he carries maternal cattle DNA, that could impair his metabolism and his offspring.