The next great hunt

On a cold, sunny day on the treeless plains of north-central Montana, hunters close in on their prey. Several bison and their calves watch nervously as a pickup truck slowly circles them, a rifle pointed out of the passenger window. A shot rings out, and a few minutes later, a young bison calf plops down on the ground, grunting and squirming. The hunting party—a team of biologists—moves in, warily eyeing the larger bison, eager to get a blood sample and move away from the agitated creatures. Once they fill a giant plastic syringe, they give the calf a shot, and it stands up on wobbly legs and staggers back to the herd. Welcome to the American Prairie Foundation preserve, the front lines of the efforts to save America’s bison and restore a large swath of the North American Great Plains. The bison is often heralded as the nation’s first and greatest conservation victory—in the last century the population grew from fewer than 1,000 to half a million—but the story is not that simple. In the late 1990s, James Derr, a geneticist at Texas A&M, discovered that most of the roughly 500,000 bison in North America have a tiny amount of cattle DNA mixed into their genome—the consequence of ranchers crossbreeding bison and cattle a century ago. The revelation that all but 10,000 bison are hybrids shook the conservation community. In 2004, the American Prairie Foundation learned that their bison, which today number 45, are among the few that are pure. Others haven’t been as lucky. When Derr’s discovery came to light, scientists realized that conservation efforts then underway wouldn’t ensure the survival of genetically pure bison. Extinction is still a threat...MNN