Of the world s dogs, only 1 out of every 4 could be considered pets, provided with food, shelter, breeding, grassy parks, doggie spas and day care. But millions of dogs roam the planet. These are village dogs, or neighborhood dogs those that live in Masai villages, the streets of Calcutta, or that inhabit the Mexico City Dump. They are unrestrained, they are not owned, and, most importantly, humans exert no control over their reproduction these are dogs, not pets. Like other wild species, these dogs have evolved to particular niches, often in the vicinity of humans, as they are highly adapted scavengers. And their adaptation is behavioral and morphological the dogs themselves tend to look alike. Measurements of temple dogs in Thailand are strikingly similar to mountain dogs of Ethiopia, to the urban dogs of Nassaue and Mexico City. We read rarely of these dogs, but their story is one of incredible natural selection. And they provide a fascinating means of exploring what it actually means genetically and behaviorally to be a dog. Raymond and Lorna Coppinger have studied these dogs for nearly four decades, and building upon their "Dogs, "which we published in paperback, they here present the first general interest book on these dogs. The book runs counter to the many books now available about companion dogs and particular breeds. Many a bulldog or greyhound afficianado may be disappointed to learn how little their beloveds actually resemble dogs. The dogs the Coppingers introduce here are hardly our best friend they are responsible for the 70,000 human deaths from rabid bites each year. They also are the world s second largest public health problem sexually transmitted diseases being the first. "What is a Dog? "explores the natural history of these dogs. What resources (food, water, shelter) are available to them? How are those resources shared or competed for? How does an animal convert food into energy without being eaten itself? How does the physical environment, the ecological landscape, shape behavior? Readers dog lovers and those curious about animal origins in general will walk unleashed into a new appreciation for just what it means to be a dog."