Constantine Slobodchikoff and colleagues synthesize the results of their long-running study of Gunnison's prairie dogs (Cynomys gunnisoni), one of the keystone species of the short-grass prairie ecosystem. They set their research in the context of the biology of the five Cynomys species found in the United States and Mexico, and detail their investigation into the prairie dogs' sophisticated system of barks, yips, and chirps, which Slobodchikoff argues represents a referential communication capable of fine distinctions among predators.Seen as vermin that spoiled valuable rangeland, prairie dogs were long the subject of eradication campaigns and are now threatened by habitat loss and the loss of genetic diversity. The authors hope their research will help to pull the prairie dog back from the brink of extinction, as well as foster an appreciation of larger conservation challenges. By examining the complex factors behind prairie dog decline, we can begin to understand the problems inherent in our adversarial relationship with the natural world. Understanding these interactions is the first step toward a more sustainable future.