Perhaps it was the memory of a rainy April day at the Brucker Great Blue Heron Sanctuary of Thiel College, or perhaps it was my admiration for these elegant waterbirds and the chance to see them once again going about their familial tasks. Whatever the reason, I had volunteered to participate in a statewide survey of great blue heron colonies that the Pennsylvania Game Commission conducts every five years. I also persuaded my husband Bruce to serve as pilot and our son Dave as co-pilot of our northern expedition to check on two Clinton County heronries.
We chose last April 26–ornithologist/artist John James Audubon’s birthday–to check first on the Rosecrans Bog Natural Area colony in Bald Eagle State Forest. We had last seen that small heronry of 11 nests six years ago during a summer Pennsylvania Native Plant Society outing. At that time all of us had stayed far across the bog from it and watched quietly through binoculars, knowing that great blue herons are sensitive to disturbance near their nests.
I was eager to see the Rosecrans Bog colony again and following directions to the bog that Bruce had written for my book More Outbound Journeys in Pennsylvania, we reached Cranberry Road shortly after 9:00 a.m. To our surprise, it was gated and hostile signs claimed the road was private.
Bruce cracked open our Pennsylvania DeLorme Atlas and, after consulting it, he followed a maze of forest and back roads until he reached what appeared to be the closest public access. We parked the car and walked a succession of mostly uphill trails 1.8 miles to the bog.
The day was spectacular, bathed in the pastel shades of emerging tree leaves that glowed in the bright sunshine, so we didn’t mind the unexpected hike. Here and there the white of blooming shadbush lit up the understory and beside one rushing stream several hobblebush shrubs flowered. Occasional white birch trees dangled golden catkins that trembled in the breeze. Along the trail black-throated green and black-and-white warblers, ruby-crowned kinglets and blue-headed vireos sang and in the underbrush silent hermit thrushes raised and lowered their rufous tails.
When we reached the bog, we squished along its edge over sphagnum moss spangled with goldthread and the emerging leaves of Canada mayflower and fly poison. Canada geese called, red-winged blackbirds sang, and two pairs of wood ducks took off, protesting loudly. The bog looked almost the same as we remembered it, surrounded by a mixed hemlock-hardwoods forest, the open water punctuated by silvered tree snags. Those snags had held the herons’ nests. But a sad silence had fallen over the bog. There were no nests and neither sight nor sound of any great blue herons.
Great blue herons do abandon sites, especially if they are disturbed by humans in isolated areas. Perhaps sounds from nearby rural homes had bothered them. Since we were way behind schedule, we didn’t have much time to wonder where they had gone. Instead we quickly hiked back to our car and sat beside a tumbling stream to eat our lunch.
The bigger adventure lay ahead. All we had to go on was a brief description and point on a sketch map supplied by the folks who had checked out the site five years before. The so-called Lebo Run heronry of 13 nests existed in a remote beech, hemlock, and black cherry forest in Sproul State Forest. Bruce had carefully studied and measured the point against topographic maps of northern Clinton County and was confident he had pinpointed its location. After an hour’s drive over winding, back country roads, we reached a gravel forest road.
“Road closed 9.5 miles ahead, dead end,” the sign warned. It also should have said “Four-wheel-drive access only.” Fortunately, we were driving such a vehicle and Bruce had calculated that the colony was 7.5 miles away.
We pressed onward, creeping up a steep, narrow road with a several-hundred-foot drop-off and no guard rails. I spent my time staring in the opposite direction at the road bank covered with blooming long-spurred violets, spring beauties, wild geraniums, Canada mayflowers, mayapples, and mitrewort and hoping we would not meet an oncoming vehicle.
Finally, we reached the top of the mountain and drove for what seemed like miles, splashing through deepening potholes and trying to avoid the road crown that was too high even for our Pathfinder. The mostly hardwood forest had an understory of small hemlocks and white pines in some areas. Red maple trees shimmered with gold and red blossoms while red elderberry shrubs bloomed in the understory. Once we stopped to let a pair of ruffed grouse cross the road. Several times wild turkeys paraded past.
Then, off to our left, we noticed a large, recent timber cut, stoutly enclosed by solar-powered, five-strand, electric fencing. Bruce, who had been pausing frequently to check his calculations against trail markings, suddenly stopped the car, pointed to the fenced area, and said, “The heronry should be less than a quarter of a mile in that direction.”
A sign on the fence instructed hunters to hold up the bottom strand with a stick and crawl under.
“We’re hunters,” Dave argued. “We’re hunting for great blue herons.” He held the fence strand up for Bruce and me as we wriggled under, bellies flat on the muddy ground, and we did the same for him. With compass in hand, Bruce led the way through a maze of green-leaved fire cherry and two-year-old white pine seedlings.
Once again the area was eerily silent. All we heard was the sound of wind in the trees. We rolled under the fence on the far side of the cut and cast about for any sight or sound of herons. Then we sent Dave off to hike quickly for a mile in either direction in case Bruce had miscalculated. After half an hour, Dave returned with a stiff neck and nothing more.
Glumly we retraced our steps. This time we looked more closely at the size of the stumps left in the timber cut. Once Bruce stopped in the middle of it and said, “This is where I had calculated the colony was.” I remembered then that great blue heron colonies are protected only during their breeding period. Once the herons leave, in August, trees holding nests can be cut. Or possibly they could have gone elsewhere even before the logging. But studies have shown that road-building and logging within a third of a mile of a colony can cause herons to abandon their nests.
“Fool’s errand,” I kept thinking as we drove those long, rugged miles back down the mountain. How could we have lost two heronries in five years?
We weren’t the only volunteers who couldn’t find heronries. Out of approximately 83 known colonies in the late 1990s, 29 had disappeared. On the other hand, volunteers had discovered 15 new colonies and 36 old colonies had increased in size. Still, statewide there was a net loss of nests.
Great blue herons are not endangered species. But the loss of forested wetlands, their preferred nesting habitat, is a problem throughout the mid-Atlantic states. Human disturbance is another although it often depends when in their courtship and nesting cycle the disturbance occurs. Not only that, but some colonies react more strongly to disturbance than others.
Here in Pennsylvania great blue herons return in late February or early March. Although they will use the same site year after year, they usually choose a new mate and a new nest. The largest and heaviest of North American herons, they stand four feet tall, weigh between six and eight pounds, and have a seven-foot wingspan. More gray than blue, their white heads sport dashing black plumes. They have long, white, black and reddish-brown necks, golden, daggerlike bills, and greenish-brown legs. Both their bills and legs flush red during courtship and the skin between their eyes and bills turns lime green. They also come adorned with fresh, grayish-blue plumes that splay from their breasts and backs.
They put all this finery to good use during prolonged courtship displays that include bill snapping, neck stretching, wing preening, circle flights, crest raising, fluffed and arched necks, bill clappering, and bill duels. Throughout the colony, great blues fight over the sticks used to refurbish old nests and build new ones. All of this is, of course, a noisy process.
The male does most of the gathering of foot-long sticks which he breaks off from branches, picks up from the ground, or steals from neighboring nests. He presents his mate with the sticks and she places them in the nest–a platform of sticks, lined with pine needles, dry grass, moss, or small twigs, that is three to four feet in diameter and 30 to 40 inches across. The female lays two to six dull, pale blue eggs and both sexes incubate the eggs for 27 days. They spend another two months feeding and brooding their young, often flying 12 miles or more to find food for them. Great blue herons mostly eat fish, but they also take amphibians, insects, reptiles, mammals, crustaceans, and birds.
When the young herons are three months old, they explore the adjoining treetops by first hopping out of the nest and into nearby branches. Then they learn to use their bills as hooks and pull themselves farther from their nests, branch by branch. At four months of age they are on their own.
All the herons leave their colonies and most revert to their singular life of stalking, often belly-deep in the water of marshes, lakes, and rivers, in search of food. Most of Pennsylvania’s great blue herons leave the state by mid-October and spend their winters in the Caribbean or in Central America although some do remain here year-round.
Our largest colonies are in the glaciated northern corners of the state. Northwestern Mercer County holds the most nests. It was there that I sat mesmerized over a decade ago in a covered shelter at the Brucker Great Blue Heron Sanctuary of Thiel College and watched through my binoculars as the largest great blue heron colony then in Pennsylvania set up housekeeping for the year.
But it too disappeared. The 190-nest site was abandoned in 1997 and nobody knows why. But Ed Brucker, who had been studying the site since the mid-1970s, and Bob Ross, who helped him to save it from logging in the 1980s, are pretty sure where those herons went. At the time the Brucker heronry was abandoned, the nearby Barrows heronry, which is along the Little Shenango River, doubled in size. According to Ross, it is now the largest in the state, with over 400 nests, and may be one of the largest non-insular colonies in the northeast north of the Chesapeake Bay.
Great blues come and they go and I frequently see one fishing quietly along the Little Juniata River when I cross the bridge. The closest known heronry is in Rothrock State Forest near Greenwood Furnace State Park. Birder Greg Grove found it in 2000 when it contained four nests. Last year it had ten. Part of the colony is on an “island” formed by the East Branch Standing Stone Creek and all the nests are in tall white pines even though there are also tall hemlocks and deciduous trees in the forest.
Great blue herons don’t always nest in colonies so it is possible that the herons I see on the river have nested individually in some hidden, wetland forest. Wherever they come from, I am grateful for their regal beauty as they stand alertly in the water, waiting to stab a fish, but lifting off if I show an interest in stopping and watching them.
Occasionally we are reminded that the Little Juniata River flows past the northeast end of our mountain when unexpected visitors from the river appear here.
Imagine, for instance, my husband Bruce’s surprise when driving down our narrow, gravel, wooded, hollow road one spring morning and encountering a large snapping turtle plodding up toward him. This happened twice in the almost 30 years he commuted to State College. One turtle was only a quarter of a mile from the river, but the other had made it over a mile. In both cases, Bruce stopped the car and waited patiently for it to get out of the way.
Each time I was green with envy and rushed down to look for the creature. I was hopeful that the turtle was a female and looking for a place to lay her eggs. After all, the American or common snapping turtle Chelydra serpentina serpentina has been known to live in small streams like ours and to bury a clutchful of 11 to 83 white eggs in the mud of streambanks. But both times we never saw another sign of a snapping turtle. Whatever they had been doing on our road, they obviously had turned around at some point and headed back to more suitable habitat in the river.
Water birds have also made unexpected visits here. Last April Bruce saw a belted kingfisher sitting on a tree branch at the edge of First Field, at least a mile and a half from the river. Since April is a migration month for kingfishers, it may have been resting before moving down to the river where belted kingfishers have nested for years in the riverbank. As we cross the one lane, steel bridge over the river, we often see them flying back and forth and hear their loud, rattling calls. Sometimes one even perches on the wooden bridge railing.
A more frequent avian visitor has been the great blue heron. Still, I was startled to flush one from the edge of the Far Field one morning. According to Robert W. Butler, who has written the definitive account of this species for THE BIRDS OF NORTH AMERICA, although great blue herons are primarily fish eaters, they will stalk over upland fields in search of voles and other rodents. Yearlings, which often have a hard time catching fish, are most likely to hunt for small mammals in fields. So, perhaps, that great blue heron I saw, and the others that occasionally fly over our First Field, are not out of place at all, but merely searching for food.
Probably the most amazing avian river visitor appeared here on October 4, 1989. It was one of autumn’s glorious days–breezy, cloudless, and crisply cool. As I descended First Field through the locust grove, I heard a high-pitched cree-cree-cree. It could only have been an osprey. I stopped and scanned the sky with my binocular. Finally, I spotted it circling above me, a fish clasped tightly in its talons.
It made several passes over the field and then flew to a tree branch on Sapsucker Ridge where it stood and looked around silently. Moving slowly, I sat down in the locust grove and watched it through my binocular. The top of its white head glowed in the sunlight, while its broad, dark, eye and cheek stripe flowed down the back of its neck like a cowl. It sat motionless, ignoring the fish in its talons, and only looked alertly around when a nearby pileated woodpecker called.
After half an hour, I slowly stood up and started moving toward the osprey, hoping for a closer view. This aroused it from its reverie, and it started calling again as if warning me off. Then it leaned forward, displaying snowy white underparts, before taking flight, still grasping the brown fish it had probably caught in the river. No doubt it had been migrating since the migration period for ospreys in Pennsylvania extends from the second or third week in August to the fourth week in October.
Our mammal visitors from the river have been even more surprising because our Plummer’s Hollow stream, which originates from springs in First Field, is never much more than five feet wide as it flows the mile and a half down to the river. Because, in summer and fall, it is often barely a trickle, it does not support fish although it does have a good population of crayfish and provides a damp environment for salamanders.
So what was a mink doing halfway up the hollow, poking its nose in woody debris spanning the stream one April day in 1997? Mink, after all, prefer to eat muskrats, although they will settle for small mammals such as voles, mice, shrews, cottontails, and even squirrels, all of which live in our hollow. And crayfish are a favorite summer food, followed by muskrats, frogs, fish, snakes, small mammals, and waterfowl.
Again, I was not lucky enough to see the mink, but Tim, one of our hunters, was taking a noonday walk, and had an excellent view of the creature. Perhaps it was a female in search of a den site since mink will sometimes construct dens along the banks of streams or under stumps and logs, and they commonly give birth in April or May. But they usually take over abandoned muskrat houses, and, so far, we have not seen muskrats up here.
Early last May another hunter friend, Jeff, drove up to show us the body of a nursing mink he had found by the side of the highway next to the river. As we admired her almost untouched, silky, chocolate brown coat, we could see why mink fur is so popular. Her death by car meant that her litter of from four to nine probably perished, although both parents do rear the young and bring food to the den. But weaning the kits does not begin until they are five to six weeks old. Since wild mink usually live three to six years, we wondered if the dead female was the same mink Tim had seen three springs ago? As usual, nature presented us with more questions than answers.
Then, last February 27, we had our strangest visitor yet from the river. It was 42 degrees and overcast at dawn. Misty rain had been falling off and on for days and most of the snow had melted. Every spring on the mountain spouted water into our stream. Lying in bed, I could hear water rushing down the drainage ditches. Another dull day, I thought, as I listened to one of three wintering song sparrows singing.
But, as I went into the kitchen, the intercom buzzer from our guesthouse went off. Our eldest son, Steve, who was visiting for the weekend, yelled, “Mom, come quick! There’s a beaver in the stream below the guesthouse.”
At first I didn’t believe him. But as he insisted, I grabbed my binocular, pulled on my boots and jacket, and ran down in time to see an adult beaver emerge from the culvert pipe beneath the road. I was amazed at how large it was especially when it stood up on its hind legs beside the drainage ditch to look around. We had plenty of time to study its paddle-shaped tail lying flat on the lawn and admire its sleek, dark brown coat.
Although our sons Dave and Steve stood with me on the guesthouse porch less than 50 feet from the beaver, quietly talking, it seemed supremely unconcerned by us. Perhaps it was looking over the terrain and trying to decide if it had potential as a future home. But two houses and three adult humans were probably enough to discourage it. After five minutes of indecision, it continued up the drainage ditch toward the powerline right-of-way, wading through the six inches of flowing water.
I rushed back to our house to rouse Bruce who grabbed his camera and tripod. Together we ran up our driveway to the powerline right-of-way ahead of the beaver. While I stood on one side, scanning downstream with my binocular, Bruce crossed the ditch and set up his camera and tripod on the embankment above.
When the beaver came into view, I called quietly to Bruce, “Here it comes.”
Remaining still and out of sight, I watched while the beaver attempted to climb over a fallen tree and then toppled over backward. Undeterred by that setback, it tried again and made it over what must have been the last of dozens of fallen trees that span the stream.
It waddled determinedly up the ditch, by then only intermittently filled with meltwater. Finally, it sensed Bruce above it and stopped. Again it sat up on its hind legs and peered toward Bruce, who shot picture after picture before the beaver slowly turned around and headed downstream.
Again we watched from the guesthouse porch as it went down into the culvert pipe and emerged in the stream directly below us. Hopeful that it might set up housekeeping in our marshy meadow, I didn’t follow it down the mountain. But our marsh is only an acre at most, and it doesn’t have enough of the preferred winter food trees–aspen, sugar maple, tulip poplar and willow–or the aquatic plants, forbs, and grasses that beavers eat in the summer. They also like flat terrain or valleys and large streams with enough water for damming. Like the mink, the beaver ultimately rejected our marginal beaver habitat, or so we surmised. Still, I searched the stream for several days before giving up hope.
Probably the beaver we saw was a two-and-half-year-old that had voluntarily left its parents’ lodge and was looking for a home of its own. But it was a couple months ahead of schedule according to the books I checked. Usually a mature beaver leaves its parents and younger siblings between April and September and becomes a floater segment of the population, following water courses as far as twelve and a half miles from its natal home in search of its own turf.
This beaver, like many of the wild creatures we encounter here, had not read the books and had instead set out on its own during February’s thaw, convinced by the sound of running water that spring was here to stay.