GRAY TREEFROGS

27 MAY. A welcome new voice, one that I have been anticipating for some days now, breaks out as I wade the swale. After the first choruses of wood frogs and peep frogs herald spring's arrival, these loud trills of the gray treefrogs signal the season's steady progression toward summer. As is typical of their intermittent, infrequent daytime vocalizing, the treefrog chorus comes up all at once from hidden places in the emergent shrub borders and occasional islands of shrubs and saplings in this great, grassy vernal pool. It rings out for three or four minutes, then suddenly drops off to silence. I make one of my annual notations: "Hear first gray treefrogs."

Having no proper voice of my own to celebrate the seasons—I am as silent as the turtles in my wanderings—I am happy to have the calls of frogs, songs of birds, sounds of wind and water, to serve as my expressions. I love being silent as much as I love being in the silence, that is, of being where there is no human noise for some periods of time. (There is no lasting freedom from human sounds, but even a minute is sweet and healing.) Here are only the voices of nature and at times no sounds at all. In time another chorus erupts and rises up all at once, as though on cue from some conductor invisible to me but seen by dozens of frogs in their scattered hiding places. What baton is raised to set them all singing at the same instant? They fill the mild May afternoon with their vibrant trilling and then, as though the baton has been brought down, end their chorus as abruptly as they began it. This one communal voice of the many has always mystified me. Silence takes over again, above the still water lying beneath leisurely white drifts of cumulus clouds, soft in the sky with their blurred edges.

About to wade on, I hold still, arrested by a thought: "Hold on ... these frogs are here, all around me." Although by day they sound like—and evidently I have been content to regard them as—disembodied voices, spirits and sprites, phantoms of spring who come to life by night, the frogs do exist in the physical universe. There are no large trees with great cavities and sloughs of bark in this seasonally flooded wetland; it doesn't seem possible that all of these frogs can be completely hidden from sight.

I have gone out to look for them by flashlight when they take up their all-night chorusing with resounding enthusiasm. Such searches in pitch-black darkness in the shrub swamps that these frogs favor for breeding have always been quite difficult. Some, such as rhodora, buttonbush, or blueberry swamps, are all but impenetrable and often complicated by treacherously deep, mucky, boglike substrates. At times I have had to suddenly grab hold of branches and stems to keep from going under in deep sinkholes. This is an alarming enough experience in broad daylight, let alone by night.

As is the case with spring peepers, it is nearly impossible to pick out the call of an individual treefrog from the deafening many, and all the more difficult to track the call to the frog who sings it out. Gray treefrogs are good ventriloquists, their loud trills seeming to come from anywhere and everywhere—everywhere but where they are. Encounters with them outside of their several-week-long breeding season, when they have departed from the wetlands and dispersed through the upland forests, are uncommon chance events. In boyhood, one of the rare places I could count on finding them away from their breeding pools was above the treetops, on a water tower I climbed, with barely suppressed terror, in games with friends.

As a consequence of my avid turtle focus, my eyes are virtually always on the water. I can miss an entire day's sky except for its reflections on the waters I wade. Now, with a new quest in mind I look upward. I let my eyesight ascend trunks and stems, then move along horizontal branches, trying to penetrate mazes of woody forkings and criss-crossings, layers and layers of leaves; my eyes become treefrogs looking for treefrogs. With nothing specific to go by, save that I do know what these frogs look like, I keep my head tilted to the canopy. I find it even more awkward to wade looking up than looking down. From all my years of looking for turtles, I have become something of a specialized animal, one with a neck permanently inclined to the water and ground at my feet.

Some friends who conduct fieldwork with birds once told me that they are often in wetlands and yet never see turtles. A group asked me to guide a tour and give them pointers on how to look for them. Lesson number one proved quite basic. After fifteen minutes or so I looked up to see them all with heads skyward, eyes affixed to binoculars. Those who observe birds are obviously accustomed to seeing what they seek considerably more frequently than those who look for turtles. "You won't find turtles in trees," I called out to them. But then, many of my bird sightings have come by way of a reflection on the water.

Head tilted up, I let my eyes do most of the moving; I take a stride or two and scan my surroundings. This is how I look for turtles, but with my head inclined to the water or the earth rather than the canopy. And in considerably less time than is entailed in searching for something new to me, perhaps within seven minutes, I see a treefrog. Whether, as on some uncommon and fortuitous occasions, I find what I am seeking almost immediately, or whether it happens only after long searchings, sometimes over several seasons, there is something sudden and startling about finding the sought-after. The two-and-a-quarter-inch frog is settled into the narrow crotch of a nearly perpendicular forking upreach of winterberry holly, in a welter of vertical and horizontal branches. Mimicking the color and pattern of winterberry bark, he has become one with his embracing surroundings. He appears to have inflated himself somewhat in order to leave no froglike outline, to become an indistinguishable part of the whole. Loose folds of skin obscure what might be the revealing contour of a leg. In a group of animals known for their crypsis in color, pattern, and motionlessness, the gray treefrog is legendary. He doesn't move as I approach and look at him closely from different angles, even when I move some slender branches in order to get a photo of him.

With several strides and turnings of my head I see another. This is how it is: one must find a treefrog (or wood turtle or any of the other most hidden ones) before one can find a treefrog. This one is on a dead branch arching from a dying elm sapling at the edge of the alder-winterberry border that rings the large, open central zone of reed canary grass and tussock sedge in this vernal pool, which is unusual in its wetland class for its size and its abundant and varied vegetation. Here the treefrog quite successfully passes himself off as one of the knobs and branch stubs of the stressed elm. I am reminded of musk turtles who mimic bumps on logs when they climb riverine deadfalls to bask; the head and legs hang down, pressed against the log, and the knoblike dome of the shell very closely approximates a branch stub.

My third frog is not so well hidden, perched on a horizontal stem of winterberry in a setting with a more open canopy, about four feet above my head. With his front legs tucked under his chin and his feet curled into fists, he looks down on me with the insouciance of the Cheshire cat. His bower is crowded with leaves, through which the strong sunlight passes, and he has taken on the green cast of his glowing ambiance. This chameleon-like adaptation produces at times rather green gray treefrogs. As I look up at him I am struck by the thought that these frogs have been watching me for years and also by the humbling realization that I, with my reputation for being an especially keen observer of nature, have been wading this seasonal wetland from thaw until it dries up in midsummer for three decades, and it has not occurred to me until today to try for a daytime sighting of one of these tree-dwelling amphibians. From the angle of one's eyes to the focus of one's mind, one can never have enough ways of seeing. And no matter how hard we look, however much we see, there is inevitably much that goes unseen.

Gray treefrog.

My fascination with this game-cum-challenge of finding the treefrog in the swale leads me to make out the most cryptic one yet. He is settled in a small hollow at the branching base of a red maple. Anything recognizable as part of a frog is all but lost in the confusion of color, pattern, texture, and scrambled outlines of scaly tree bark layered with lichen. Bark and lichen are as much a part of this frog's ecology as woodland and wetland. I record him in my notebook as "lichen with eyes." I impress myself with this discovery. It is always reassuring to find that my eyes can still do such work, make such interpretations. It is largely a visual language that I endeavor to read in the wetlands and their surroundings.

The frog does not blink as I bend over him for a close-up photo, shifting my camera around, almost in his face. I wonder at what point he would consider that danger—or even death itself—was so imminent that he would make a leap for it. Although I am loath to cause any disturbance, my curiosity, which I suppose I could justify as a scientific need to know, leads me to reach out and touch a finger to his back. He gives two quick, thrusting kicks of his hind legs and then pulls himself back exactly into his former position. This irrevocable evolutionary commitment to camouflage is like that of wood turtles I find on land, who will not alter the freeze-frame pose they take immediately upon detecting me (which is nearly always before I see them), even when they have stopped in midstep, unless I actually touch them. But the turtle has a court of last resort, one adaptation left when going unseen has failed: his shell. The treefrog would seem to be completely defenseless once detected by a predator. I do not know whether this species has a final chemical ploy, a skin secretion like that of a toad or red eft, that would deter a predator from taking it in its mouth. And I have even seen toads failed by their toxicity.

I cannot imagine finding a more occult treefrog, though there must be some I have been unable to descry in this quest. And I wonder how many turtles I have overlooked in my search for frogs. Any one thing intimately observed inevitably means many things left unseen. I shift back to a turtle focus and begin to read water and sedge and grass instead of emergent shrubs and saplings. I am elated at the discoveries I have made, at adding something of such significance for me to the bank of search-images I have been building since that long-ago boyhood day when I saw my first turtle in the wild. It is this deep fund of search-images, based on years of the most dedicated looking—though there is an intuitive aspect as well—that guides me as I continue to follow that trail through marsh and swamp, along river and stream.