What is a Dog?By Raymond Coppinger and Lorna CoppingerUniversity of Chicago Press, 2016Look at the pictures in any issue of the National Geographic going back a hundred years, and you'll see them. They'll never be the actual subject of the photo, but behind every gap-toothed old sage in Kathmandu, behind every flirting young couple in Zanzibar, behind every struggling family in Ecuador, behind every black-eyed bush elder on the outskirts of the Amazon, behind every hunched team of Arctic explorers rimed in hoarfrost, behind every strutting Texas rodeo star … eating or sleeping or slinking or just standing incuriously in countless hundreds of photos will be dogs: scrappy, dun-colored pi dogs, village dogs, feral dogs, dump dogs.No matter where you go, you'll find them. In the villages of Namibia, they roam the roads and brush. In the outermost slums of Chongqing, they drift in little groups. From Cusco to Trieste, you can watch them continuously, almost casually, interacting with the fringes of busy human society. Even in the more disease-nervous and socially-fussy countries of the developed West, they're present in numbers that would surprise virtually all the human inhabitants of those places. From Annapolis to San Mateo, from Brooklyn to Baja California, you can find whole populations of these dogs if you have a little patience and are willing – and brave enough – to spend time in the municipal garbage dump overnight.In What Is a Dog?, the follow-up volume to their thought-provoking 2001 book Dogs: A New Understanding of Canine Origin, Behavior, and Evolution, biologist team Raymond and Laura Coppinger continue to turn re-evaluative insights on these deceptively familiar creatures. The question that makes up the title of their new book is by no means rhetorical.On one level, it's an easy question. A dog is a canid quadruped with forty-two teeth, advanced auditory and olfactory senses, a tight-knit social structure, and extremely adaptive eating habits. Despite ringers like the hyena or the Tasmanian wolf, everybody knows a dog when they see one.The Coppingers make a convincing case that goes well beyond the standard paleolithic-man-tames-wolf-cubs scenario presented in every textbook in the world about the phylogeny of dogs. Their study looks at “the pervasive dogs of the world” with fresh eyes, and they start by asking basic questions:

Some of us in the dog world are irritated by statements that scientists have found the truth about the origin of dogs – as if a single origin was identifiable. Look! We found the first dogs, the oldest dogs, the Adam-and-Eve dog. That is truly silly. The search must be for a population of dogs. At that point you have to ask the question, What is a dog, anyway? What are we searching for?

As in their previous book, so too here: the search centers not so much around the transition from wild to domestic – that familiar wolf-to-dog storyline – but rather from domestic to domesticated, a distinction the Coppingers insist upon:

There is no question that dogs are a domestic animal, just as pigeons are a domestic animal. “Domestic” simply refers to the animals that live around or with or beside people or simply in the presence of people: the domestic dog, the domestic rat, the domestic pigeon, and the domestic chicken. Also there is the ubiquitous house sparrow ( Passer domesticus), which lives not only in cities and villages but also on farms. The house mouse, cockroach, and bedbug are all more common around humans than anywhere else. All in some sense are referred to as domestic – the domestic cockroach!

Our authors argue that Carl Linnaeus was right way back in 1758 when he classified Canis familiaris as a distinct species rather than some kind of abridged version of a wolf or a coyote or a jackal. The domesticated Canis familiaris is as ubiquitous a part of human culture as fire or the wheel, of course; in the 21st century Western world, the pet business is a multi-million-dollar industry catering to the two hundred dog breeds that have come in the last 150 years to be synonymous with dogs just in general. This has led to a numerical success – there are more golden retrievers in the world than wolves – but also a numerical narrowness that will surprise many readers of this book. Only two hundred million of the world's dogs are pets; the vast remainder (the Coppingers strain their imaginations and put the number at one billion, but this is actually wildly conservative) are domestic but not domesticated members of Canis familiaris: they are dependent on the food-waste of human cultures (without which, our authors assert far too confidently, they would simply die off), but they retain full control over their eating and mating activities. Their packs are ragged and stalked by brutally high puppy mortality, but they are not subject to the caregiving whims of humans.What Is a Dog? traces the life-cycles of some of these ragged packs in various parts of the world and continues to sketch in a rough natural history of this omnipresent background-species. The systematic application of their ethological principles can sometimes lead the Coppingers into summaries that, while fascinating and almost certainly true, will nevertheless strike some dog owners as a bit too detached for comfort:

The reason dogs make good pets is in large part because they have this innate behavior of finding somewhere to sit and wait for food to arrive, which is exactly what our pet dogs do. Their niche is scavenging food from humans. They are like ravens and foxes that scavenge food from wolves or humans. Where is that dog food supply? Look for humans, and there it is. Why are dogs nice to people? They are the source of food. Dogs find some food source that arrives daily and they sit there and wait. Being somebody's “pet” isn't all that different from being a dump dog or a street dog or a village dog.

Devoted dog owners who are convinced they share more of a bond with their animals than simply approximating the 8:45 garbage truck delivery will bridle at these kinds of reductions, but for the Coppingers, it really is all about food. They at one point maintain that one of the keys to the translation of pi dogs into beloved pets is simply that dogs are animals “that can eat in the presence of people” – something that most kinds of domestic animals would very much rather not do even when they're very young. Dog puppies, in contrast,

… are a cinch to adopt. They may be the easiest of any species to adopt. They can and will gorge feed, which is unusual for infants in the animal world. They can eat almost anything. They can eat solid food, starting in the nursing stage at twenty-five days. They can eat anything a human can and lots that a human cannot. Cooked grain or meat, fecal material, and rotten vegetables are all possibilities – the waste products of the human diet. They have teeth and can tear and chew at an early age. They even starve better and longer than most animals.

Most feral dogs starve to death, but then, according to our authors, most wolves starve to death as well. It's a precarious business to occupy a food-niche, which is what the world's pi dogs do. The Coppingers travel to many countries and interview many people, but time and again, their investigations bring them to the big municipal dumps that occupy the ignored periphery of every city of any size. These dumps are the sites of regular and frequent influxes of human refuse, a great deal of which dogs can eat – and do eat, sharing the space with both rival groups of dogs and also pigeons and rats and other domestic scavengers. It's a very different reality from the highly controlled food-experience had by the domesticated members of Canis familiaris:

Food for our dogs migrates to our house in the form of kibbles, from somewhere, perhaps the Kansas wheat or Iowa cornfields and Chicago slaughterhouses. Who knows? None of the ingredients of our dog's food comes from our yard or town or even our state. And we don't leave any garbage in our yard. Nothing around our house or our neighbor's house would support a population of dogs – except the purpose-made food that comes in bags labeled dog food.

The regular arrival of human refuse often goes hand-in-hand with copious amounts of human scorn; the Coppingers hardly need field work to show them that many human societies view feral dogs as nuisance animals, pests who can also be dangerous. A loose-knit pack of hungry dump dogs is not a welcome thing to encounter for most humans in semi-rural areas (several of the people our authors interview give handouts to one group of dump dogs in part to encourage the territoriality that will protect against other groups of dump dogs), and even potential violence is only part of the problem – after all, roughly 70,000 humans die every year of rabies, to name just one dog-transmitted disease. So, perhaps inevitably, the Coppingers come around in their book to questions of population control, and its near-impossibility when it comes to animals as numerous and adaptable as feral dogs. Heartbreaking tales abound, made familiar by, among other things, the Western media's revelation that cities like Sochi, Athens, and Beijing conducted massive killing campaigns against feral dogs in the run-up to their respective Olympics. Many thousands of dogs were killed in all three cases, and yet all three places still host large and growing dog populations.Raymond and Lorna Coppinger are admirers of the pariah dog. They look at these creatures, with their lean 30 pounds and their short fur the color of sand and their deep, knowing eyes, and they see niche-animals of great hardiness and likability, the true root stock of the various pampered breeds who sleep pressed against us on the couch. Those breeds would whimper in fright at the prospect of sleeping outdoors in winter or wresting a morsel from a rat the size of a cat. They undeniably relish the comforts their cousins will never know. But when they murmur and pump their legs while sleeping, they're dreaming of freedom.____Steve Donoghue is a writer and reader living in Boston. His reviews have appeared in The Washington Post, The National, The Wall Street Journal, The Boston Globe, and The Christian Science Monitor. He is the Managing Editor of Open Letters Monthly, and hosts one of its blogs, Stevereads.