Vermont’s Interstate 91 is well traveled, but it’s a far cry from a busier superhighway close behind our house in St. Johnsbury. This major (but quieter) thoroughfare has two-way traffic all day and all night, with motel stops and permanent homes scattered along the way. I call it I-21, honoring an age I scarcely remember.
It is a rock wall.
The work of our predecessors in Vermont and New Hampshire was prodigious. Evidence of their labors remains long after houses collapse and fields return to woodland. Sturdy rock boundaries still define property as they course up and down hills, passing straight through today’s forests.
Our forebears levered rocks from the soil and transported them by stone boat and ox to where a wall was being built. The walls served as stockpiles of unwanted stones—and to let newcomers know, this field is mine.
Certain animals stake out territory too, which they stoutly defend during their occupancy, but just as naturally give up without claim when their use—or their life—is done. Their transit to and fro is purposeful and shared, and it’s the highway upon which they travel that interests me.
How wild animals must have rejoiced over the appearance of rock walls. A ground squirrel might have a good home on a ledge outcrop, but the next rock face might lie beyond a forest populated by hungry owls and weasels. A chain of rocks allows a chipmunk to traverse a hillside safely, ducking into narrowed openings whenever an alarming shadow appears or furtive footstep is heard.
Traffic along our old wall (sometimes crossing over, sometimes stopping to rest and hunt) is varied and constant. Here is what I’ve seen in descending order of size (dogs and cats not included): deer, coyote, fox, raccoon, porcupine, skunk, snowshoe hare, woodchuck, fisher, gray and red squirrels, wood rat, ermine, chipmunk, meadow vole, deermouse, garter snake, American toad, wood frog, and red eft. Birds include turkey, ruffed grouse, barred owl, raven, crow, and a slew of perching birds, great and small. Bluejays, tree sparrows, and wood thrushes alight on the stones, nuthatches explore crevices, juncos scratch leaves between rocks—and may be taken by a resident sharp-shinned hawk.
I sit on the wall, peer into its recesses, use a magnifier to examine its many surfaces. A lesser parade goes by, for which there is no easy accounting: beetles, locusts, crickets, true bugs, caterpillars; cavity-dwelling bees and wasps, earwigs, ants, springtails, wolf and jumping spiders, harvestmen and mites; also centipedes, millipedes, sow bugs, snails, and who-knows-what other small, busy creatures.
A rock wall’s animals actively select lanes and locations according to need and opportunity, but seldom with regard to orientation or quality of stone. One rock surface or cavity usually is as suitable and can be as well populated as another.
Plants on the wall and within its crevices are more determinate in their preferences. Only in certain locations and under specific conditions will you find coarse, tangled, or velvety mosses, thallus liverworts, horsetails, clubmosses, or ferns. Pioneers in the form of birch and maple seedlings take root bravely in accumulated humus. Lichens, strange interdependent partnerships between fungi and algae, but named as individual species, appear as flat encrusting (crustose) forms or the upright sort (fruticose), or they resemble curly scales (foliose). Lichens are everywhere and almost anywhere on the rocks, slow to appear, but long to survive, often nonspecific when it comes to placement as long as there is a modicum of light.
Not so for mosses and liverworts. Their many kinds are zoned in response to specifics of substrate, moisture, sun, and compass bearing. Certain forms grow only on the north side of rocks—some prefer the south, and some prosper where water drips accumulate and diffused light arrives from any direction.
A fallen, decaying branch wedged between the rocks nourishes fungi of every size and color, and occasionally colonies of those other-world slime molds that carry out their strange lives partly as animals, partly as plants.
A wall doesn’t always tell the truth, especially if a few component rocks have recently come from elsewhere, dumped by a farmer clearing a new field. Or a single stone with north-preferring moss on one side is shifted so the plant colony now faces south.
Time spent near a rock wall discloses a different world, an inviting plenitude of life ready for close study. Take note of presence, of interrelationships, seek patterns dictated by exposure, shelter, sun, shade, and whatever other environmental elements come to mind. Be patient. Larger animals using the wall as thoroughfare or boundary aren’t going to oblige when you draw near, so observe their passage from a distance. Binoculars help.
The outcome? A rare gift—an awakening to unexpected communities and curious lives in a forgotten rock wall.