Dallas May can’t help but feel that something is missing. For more than a decade he’s been working to restore shortgrass prairie habitat to support wildlife on his family’s 20,000-acre ranch in southeast Colorado. His family rotationally grazes their Limousin cattle to give native grasses time to rest and recover, moving the 800 ebony and caramel-colored cows from pasture to pasture to feed on buffalograss and blue grama that grow near sand dropseed and little bluestem. Reintroduced black-footed ferrets scurry through tunnels in the loamy ground. Horned Larks and Grasshopper Sparrows sing from grass stalks, and elusive Eastern Black Rails scuttle through wetlands. But there’s one species May hasn’t seen move in yet: the Lesser Prairie-Chicken. “We’re hoping every day they show up,” he says. If the grouse do take up residence, it’ll be obvious come mating season. In early spring the stocky birds with bushy orange eyebrows gather at breeding sites called leks, where...