Book excerpt: For twenty years Dan O’Brien struggled to make ends meet on his cattle ranch in South Dakota. But when a neighbor invited him to lend a hand at the annual buffalo roundup, O’Brien was inspired to convert his own ranch, the Broken Heart, to buffalo. Starting with thirteen calves, “short-necked, golden balls of wool,” O’Brien embarked on a journey that returned buffalo to his land for the first time in more than a century and a half. Buffalo for the Broken Heart is at once a tender account of the buffaloes’ first seasons on the ranch and an engaging lesson in wildlife ecology. Whether he’s describing the grazing pattern of the buffalo, the thrill of watching a falcon home in on its prey, or the comical spectacle of a buffalo bull wallowing in the mud, O’Brien combines a novelist’s eye for detail with a naturalist’s understanding to create an enriching, entertaining narrative.