In the last decade, the field guide has become the most common type of book about nature. Field guides are not new, of course. In one form or other, they have been around for at least a century. Roger Tory Peterson’s A Field Guide to the Birds, originally published in 1934, played a major role in creating the sport of birding, and its success inspired not only other bird guides but a whole series of Peterson Guides that covered practically every visible aspect of nature, from stars and planets to seashells.

Peterson was directly involved only in his bird books and in a wildflower guide, but all the many volumes in the Houghton Mifflin series used his identification system wherever possible. The Peterson system, which is copyrighted, uses a small number of field marks to differentiate entities of similar appearance. I can’t use a word more precise than “entity” because the Peterson system has been applied to everything from mollusks to white dwarfs.

The Peterson bird guides–the original described only eastern birds, but a volume covering western birds was published in 1941–had little true competition for several decades. Richard Pough of the American Museum of Natural History published a two-volume Audubon guide to North American birds in 1946. A two-volume work is a bit cumbersome for field use, but it did allow Pough to include some information on nesting habits and behavior that wouldn’t have fit into Peterson’s more compact books.

Golden Books published a one-volume guide to North American birds in 1966, with Chandler Robbins of the U.S. Fish and Wildlife Service as principal author. The Golden guide pulled some customers away from Peterson.

But the typical nature book of the late 60s and the 70s was either a how-to account of outdoor activities like backpacking or an introduction to ecology, an inspirational look at the way nature works. The leader in the former category was The Compleat Walker by Colin Fletcher. The first edition became a best-seller and something of a publishing phenomenon in 1968. A thorough revision followed in 1974. Fletcher is an engaging writer who can make backpacking in summer in Arizona sound appealing, and his books helped set off a backpacking boom that soon overcrowded trail systems from Georgia to the Brooks Range.

This boom, like most of the other recreational booms of the past 30 years, was fueled by the ultimate boom: babies. Further force was provided by remarkable advances in equipment. The backpacker of the 50s carried a canvas tent and wooden poles in a pack mounted on a flat board that bore no relationship to the contours of the human back. If you have ever tried to roll up a wet canvas tent, you can appreciate how much easier things got when synthetics like nylon replaced canvas as the tent makers’ choice.

The equipment shift created a major change in the relationship between humans and the wilderness landscape. When I was in the Boy Scouts way back when, the camping techniques we learned all fell into the general category of woodcraft. We were taught how to cut down saplings to build temporary shelters and how to make comfortable beds out of spruce boughs. By 1970 such skills were not only unnecessary, they were positively harmful. The backcountry was so full of wilderness trekkers that if all of them had cut fresh spruce boughs for beds, the forest would have looked as if it had been dosed with Agent Orange.

With aluminum cookware, a stove fueled by white gas, a nylon tent, and a sleeping bag filled with polyester, a backpacker could “Take only pictures, leave only footprints,” as the motto of the times advised. Of course, treading lightly on the wilderness required oil fields on Alaska’s North Slope and vast bauxite strip mines in Jamaica, but that irony was something nobody liked to think about.

The new ethic and the new equipment also severed the intimate relationship between backpacker and wilderness. If you were going to rely on spruce boughs for bedding you had to know what a spruce tree looked like, but the modern trekker with his house on his back and his skin coated with Deep Woods Off could see the world as a show, a flattened image like the picture on a movie screen. As long as his equipment held out, he didn’t need to know anything about the world he was traveling through.

That was an ultimately unsatisfying way to relate to nature, and its shallowness was beautifully revealed in books like Aldo Leopold’s Sand County Almanac, a wonderful work that popularized the science of ecology.

Things are happening out there, Leopold told us. It’s not just a vista, it’s a process, or more precisely, a whole bewildering set of processes whose operations sustain the lives of all the individuals and all the species on earth. We can’t hope to understand these processes completely, but if we are willing to learn about them, we can comprehend some pieces of this complexity and get at least a vague, general sense of the whole. But like Adam in the garden, we can’t discover a new world until we can put names to things. And that’s where the field guides come in.

My wife, Glenda Daniel, and I lived through this evolution. In the early 70s we wrote two where-to guides to backpacking, one describing trails in the midwest, the other covering the southern Appalachians. Then in 1977 Glenda wrote Dune Country, a field guide to the Indiana Dunes, and in 1981 we wrote A Naturalist’s Guide to the North Woods for Sierra Club books.

The latter book grew out of our experiences on some land we bought in Taylor County, Wisconsin. Our 40 acres was an absolutely undistinguished second-growth woods pocked with alder thickets that were underwater every month except August, when they were just muddy. Our land was not the sort of place that got selected as a nature preserve, but we had nesting marsh hawks, American bitterns, barred owls, and rotted-out white pine stumps so big the two of us could stand inside them.

We cleared a space big enough for a 10- by 16-foot tent, and took advantage of our free-lancers’ status to spend a big piece of every summer exploring our land and other interesting places in the neighborhood. We waded through acres of bogs, compared spring wildflowers in pine woods with the ones that grew in sugar-maple forests, and searched for boreal chickadees and Connecticut warblers.

We began to get a feel for the region. The flat, movielike image, the meaningless jumble of shapes, textures, and colors, became coherent; the rare species we used to miss suddenly jumped out at us. Our new view allowed every plant and animal its individuality while combining each separate organism into a whole whose beauty was levels beyond what any movie image could show.

The search for that kind of experience of nature has provided a large part of the impetus behind the explosion of field guides, especially the habitat guides that have followed the Sierra Club’s pioneering efforts. One of the best of these has just been published by NorthWord Press, Inc., of Minocqua, Wisconsin. Called The Northwoods Wildlife Guide ($19.95), it was written by Janine Benyus with substantial assistance from various members of the staff of the U.S. Forest Service’s North Central Forest Experiment Station in Saint Paul.

The beauty of the book is its specificity. It covers only the transition-forest region that dominates the northern portions of Michigan, Wisconsin, and Minnesota. Since late in the last century, the cool woodlands of that region have been prime vacation destinations for those of us living in the hotter, duller parts of the midwest. The book divides these woods into 18 separate habitat types, and describes the prominent vertebrates likely to be found in each.

Each species gets a general introduction, followed by detailed tips on exactly where to look, what to look for, and what to listen for. So we learn that LeConte’s sparrows can be found in sedge meadows, that they seldom fly very far, that their nests are usually found on or near the ground at the dry edges of the meadows, and that their song is a single, repeated “thin, husky, and insect-like” note.

We learn that dawn and dusk are the times to look for meadow voles, that their nests are balls of dried grass hidden under rocks and logs, that their runways are paths about an inch wide usually roofed over with grasses, and that early spring, when the grasses are matted down, is the best time to look for them.

If you are looking for deer, hunt for scrapes–patches of bare ground scraped clean by a buck’s hoof and then urinated on as a message to rival males and possibly interested females.

The guide also includes a list of hot spots, places where wildlife watching is likely to be particularly productive, a month-by-month almanac describing what you can see and when you can see it, and a listing of state ornithological groups and other organizations involved with conservation in the north woods.

The thing I like best about this book is its emphasis on sitting down and shutting up. The best way to see animals is to find a likely spot and then make yourself as inconspicuous as possible. The animals are there, if you have the patience to let them come to you. Nature rewards silence and immobility.