In the eastern half of the United States, people live closer today to "more animals, birds, and trees than anywhere else on the planet at any time in history" – that's the strange snapshot at the heart of Jim Sterba's 'Nature Wars,' a provocative look at how suburban sprawl is pitching man against nature in confounding new ways.

Most of us grew up keenly aware that ours is an endangered planet: Ecosystems are collapsing, and wild species are slipping daily into oblivion. So the idea that we're actually drowning in trees is hard to accept. "The rest of the world has all sorts of problems," says Sterba, "but our little patch is an embarrassment of riches." Over the past 150 years, trees have made a dramatic comeback in the U.S., recolonizing abandoned farmland in New England and the Midwest, forming a vast canopy under which more than half of us now live. "John Gordon, head of the Yale School of Forestry, used to say if you look down on Connecticut in summer, you see unbroken forest," says Sterba. "But when the leaves fall off, you see stockbrokers. We live in forested sprawl" – and, increasingly, we're sharing it with wild animals, from deer to bears.

Once the landscape's most formidable predators, humans have become unwitting habitat engineers, crafting a lacework of gardens, parks, and leafy backyards with abundant food, water, and shelter, in which animals that wobbled on the brink of extinction are now thriving.

The problem, says Sterba, is that the primary way in which most Americans now connect with wildlife is the backyard bird feeder (a practice he says our ancestors would find "bizarre"). The kitchen window has become an extension of the small screen: a framed portrait of an idyllic world. Since the 1880s, filmmakers have dressed out a wilderness patrolled by animals who are just like us. Bears, which colonists treated as a menace and had nearly exterminated by 1800, reappeared in the 20th century as cuddly movie and TV characters (or as monsters, stalking the woods like serial killers). But as forested sprawl extends its reach and more animals move in (cougars and wolves are on their way), wildlife is breaking through the "fourth wall," invading our yards, garages, houses, going from "novelties to nuisances."

Take the case of white-tailed deer, whittled down to one percent of pre-colonial numbers by commercial hunters in the 19th century. They're now so ubiquitous they've ignited "suburban deer wars," dividing communities into "Kill Bambi" and "Save Bambi" factions who argue over what to do (sterilize, relocate), before arriving, inevitably, at a discussion of culling the herd. Deer, Sterba points out, represent a renewable resource, an organic, free-range source of protein that's essentially wasted. That goes for trees, too, he says: Massachusetts now has more trees than it did 300 years ago but uses just two percent of its forest for furniture, paper, and other wood items. "So where are we getting our forest products?" he asks. "We're cutting down rainforests in Borneo. We ought to become locavore foresters."

Indisputably, our forebears "exploited and sullied" the natural landscape, taking many creatures to the edge of extinction, and we've disengaged from the natural world, in part, to protect it. But we can't protect a world we no longer understand, says Sterba. Using resources thoughtfully – whether that means regulated hunting or careful timbering – connects us with their limits: "Americans think of wilderness as some pristine place over the mountain, and somehow the landscape we occupy is sullied by our presence. But that landscape is an ecosystem, and we have an obligation to manage it for all its occupants. We've made mistakes in the past, but we've learned from them – we have a rare second chance to save the forest."