I never expected to be conducting a choir of American toads at Enlow Fork. After all, this state game land (#302) in southwestern Washington and Greene counties is better known for its incredible diversity of plants and birds. Yet there I was, on the first day of May, surrounded by singing toads as I sat on a log beside the Enlow Fork of Wheeling Creek.
Instead of facing away from the shoreline to trill their advertisement calls to perspective mates, as they usually do, the male toads faced me. With each long, musical trill, a toad inflated his front vocal pouch. He looked like he was blowing a large, greenish bubble. But it was the harmonizing of their trills that reminded me of choir-singing.
As a devoted wood frog courtship observer for many years, I had never detected any difference in pitch when they emitted their duck like, quacking advertising calls. Yet the American toads were trilling on different pitches! Mesmerized by their singing, seemingly just for me, I listened awestruck until they swam off. Later I learned, from Lang Elliott’s excellent The Calls of Frogs and Toads, that my ears hadn’t deceived me. “Each male in a chorus sings at a slightly different pitch (1500-2000 Hz),” Elliott writes. “Males alternate and overlap their calls in a pleasing manner.”
Ever since our arrival at Enlow Fork that May day, we had been amazed by the number of toads singing, mating, and laying eggs. Long, double strands of black eggs clogged mud puddles. Along the edge of the slow-moving stream, many toads were locked in amplexus, a mating embrace in which the male clasps the female around her chest with his front legs while she extrudes eggs that he fertilizes as she lays them.
But enough about the wonders of toads. We had come to see the wildflowers and birds that this narrow, remote valley, tucked down between the hills of southwestern Pennsylvania, is known for. As we pulled into the parking lot at noon, members of the Three Rivers Birding Club (and turkey hunters) were pulling out, but not before we heard and then saw a singing white-eyed vireo. Unlike the sound-alike, monotonous songs of most vireos, the white-eyed vireo song is a unique “chick-a-per-weeoo-chick” according to the late Roger Tory Peterson. It can also be distinguished from other vireos by its yellow spectacles around its startling white eyes.
The only singing white-eyed vireo I had previously seen in the state was in Delaware County at White Clay Creek State Park. White-eyed vireos breed primarily and irregularly in the southern part of Pennsylvania, but today seem to be most common in the southwestern counties. That was not always the case. Back in 1940, W.E.C. Todd, in his Birds of Western Pennsylvania, wrote that white-eyed vireos were rare in the western part of the state. However, since the annual Breeding Bird Survey began in 1966, the most white-eyed vireos in Pennsylvania have been counted in the southwestern counties.
We continued to stand in the parking lot listening for birds, and even though it was midday, which is usually not a good time for songbirds, on that warm, humid day they remained active and vocal. We quickly heard a Baltimore oriole, blue-gray gnatcatcher, yellow warbler, wood thrush, scarlet tanager, Louisiana waterthrush, and, most exciting of all, another sought-after, more southern species, the yellow-throated warbler.
Since the mid-1970s, yellow-throated warblers have greatly expanded their range in Pennsylvania, particularly in the southwest. Long time resident birder, Ralph Bell, first recorded them in Greene County in 1971. They continued their movement northward during the next two decades, reaching Lycoming County in 1988. Most yellow-throated warbler nests have been built either high in sycamore or white pine trees. In fact, the subspecies Dendroica dominica albinora, which is the dominant breeding subspecies in most of Pennsylvania, is often called the sycamore warbler. Judging from the many sycamore trees at Enlow Fork, this handsome, gray-backed warbler with a black eye mask, white eyebrow stripe, and brilliant yellow throat has found ideal nesting habitat.
Our next southern bird species sang from the top of a flowering apple tree at the edge of a field–a striking chestnut-breasted, black-bodied orchard oriole. This species is most common in the southwest and southeast corners of the state. At Enlow Fork, I saw several orchard orioles, and although they are not as “flashy” as Baltimore orioles, they appear so rarely on our mountain that I was pleased to see them at Enlow Fork.
I had hardly recovered from the excitement of observing orchard orioles when I heard and then saw a singing blue-winged warbler. A bird of brushy, edge habitat, it is most common in western and eastern Pennsylvania but still rare in the ridge and valley and high plateau sections of central Pennsylvania. Its “blue” wings are more gray than blue, but its white wing bars, yellow face and underparts, and black line through its eyes are distinctive field marks. Still, it is not nearly as lovely as its close relative, the golden-winged warbler. Both species like the same habitat but, unfortunately, where the two species overlap, the blue-winged is more competitive, so as blue-wings have expanded their range, golden-wings have dwindled.
Altogether I identified 31 bird species at Enlow Fork even though I was thoroughly distracted, not only by the American toads but by the bewildering numbers and species of wildflowers. At last, on this my third visit to Enlow Fork, I saw the wildflower it is renowned for–the blue-eyed Mary (Collinsia verna). Primarily a plant of the central and southern states, it grows only in the southwestern portion of Pennsylvania. This delicate, bi-colored flower has two white upper lobes and three rich violet-blue lower ones. Stunning carpets of blue-eyed Mary cover moist meadows and woods and “her praises…are loudly buzzed by myriads of bees that are her most devoted lovers,” Neltje Blanchan wrote back in 1916. We too heard the steady drone of wild bees and bumblebees coming from the beds of blue-eyed Mary.
Three shades of dwarf larkspur (Delphinium tricorne)–blue, violet, and white–grew amid the drifts of blue-eyed Mary, along with wild geranium. To see blue-eyed Mary would have been reward enough for me, but that day and the following one, when we joined members of the Pennsylvania Native Plant Society for more botanizing, we identified many more wildflower species. We were led by Ralph Mumma, a wonderfully enthusiastic elder who has survived two heart attacks but was still eager to be out and looking for wildflowers in his favorite part of the state.
Both days we walked the gated road/trail and detoured over the “hogback” that nourishes, in its narrow band of woods, an astounding diversity of wildflowers including early ragwort, mayapple, sessile or toadshade trillium, twinleaf, Virginia bluebell, blue cohosh, trout-lily, cut-leaved and two-leaved toothworts, and Greek valerian, also called spreading Jacob’s ladder (Polemonium reptans). Clusters of blue-violet, bell-shaped flowers waved from the top of the stems of Greek valerian, but many of the other wildflower species on the hogback were early bloomers and had faded or were finished flowering for the year. So too were the squirrel corn, Dutchman’s breeches, white and red trilliums, bloodroot, and wild ginger in the woods beside the trail. Still, we knew them all by their distinctive leaves.
Blue and purple continued to be the predominant colors of the day–wild blue phlox, bluets, dame’s-rocket, and wild bergamot also blossomed at Enlow Fork. But the deep scarlet petals of fire pink and the drooping red and gold flowers of columbine added still more color to the wildflower extravaganza. Altogether, we found 84 wildflower species including the endangered in Pennsylvania Nuttall’s hedge-nettle Stachys nuttallii, formerly known as Riddell’s hedge-nettle S.cordata, which grows on the moist, rocky slopes above the floodplain. This member of the Mint family has six pale rose-purple flowers but doesn’t bloom until June.
Several western and southern tree species also grow at Enlow Fork and most were in flower. The loveliest were the rose-purple blossoms of redbud beside the trail. Redbud is abundant in the southern portion of the state, growing preferentially in limestone soil such as that at Enlow Fork.
Ohio buckeye, also known as fetid or stinking buckeye (Aesculus glabra), bore showy, bell-shaped, yellow flowers. Its alternate names refer to the foul odor of its twigs when they are broken. A small tree, growing no higher than 40 feet, this southern and midwestern species reaches its easternmost limit in western Pennsylvania.
Pawpaw was also in bloom, sporting three-parted, greenish to purplish-brown blossoms. But it is better known for its elongated, orange-fleshed fruit, beloved of opossums, squirrels, birds, foxes, raccoons, and discerning humans. The alternate names for this southern and midwestern tree–wild banana and custard apple–are attempts to describe its taste and texture, which Charles Fergus says, in his excellent Trees of Pennsylvania, has “a consistency like custard or cooked sweet potato, and when I slurped it up, it tasted…like banana but with a hint of something exotic–mango maybe–and an overlying pleasant sweetness.” Found only in the southern third of Pennsylvania, pawpaw likes to grow in moist stream valleys.
We didn’t see the fourth southern Pennsylvania tree species, also a lover of moist, limestone soils, the yellow or chinquapin oak, but it too lives at Enlow Fork. So do two interesting ferns–the walking and bulblet–that we also overlooked. And who knows how many more birds and wildflowers we missed. That’s why we are returning to the fabulous Enlow Fork Natural Area this spring. Maybe the toads will sing for me again.