Right-of-Way Science

It’s a hot, dry day in late June when my 12-year-old granddaughter Elanor and I, along with 25 other folks, visit the First Energy/Penelec Right-of-Way on SGL#33. Our friend, Dr. Carolyn Mahan, Professor of Biology and Environmental Studies at Penn State Altoona, has organized one of four scheduled bee-collection dates for this well-studied right-of-way.

A group of visitors exploring the powerline right-of-way on State Game Lands 33, June 2017

A group of visitors exploring the powerline right-of-way on State Game Lands 33, June 2017 (Photo by Therese Boyd of Penn State on Flickr, Creative Commons license)

Research on the best way to manage right-of-ways (ROW) has been ongoing at this site since 1953, which is, by far, the longest study of any ROW corridor in the world. A large 500 kV transmission line in Centre County, it passes up and over the Allegheny Front through a heavily forested area.

On this day, students and faculty from Ohio State University have joined representatives from First Energy, vegetation-management companies, and the Pennsylvania Game Commission along with Penn State faculty, staff, and students and collectors willing to help snag bees with bug nets and put them in killing jars so the insects can be identified, studied, and then stored in Penn State’s Frost Entomological Museum.

Back in the 1990s, Mahan first started working on this site as a graduate student with Dr. Richard Yahner when bird and mammal studies were underway. Yahner authored numerous papers on this site before his untimely death in 2015. When Mahan took over the work then, she put an emphasis on native pollinators, along with continuing studies of birds and plant species. Once a month in May, June, July and August volunteers collect bees in six different 50×25 meter sites for two hours both morning and afternoon.

Another powerline in PA that appears to be using wire-border zone management

Another powerline in PA that appears to be using wire-border zone management (Photo by Nicholas A. Tonelli in Wikimedia, Creative Commons license)

Before the collecting began, we heard about the various treatments used in an effort to determine which ones were most useful in keeping the electric lines operative in all kinds of weather, yet did not harm the mammals, birds, and insects that live on the ROW. Although management methods have varied since 1953, in the mid-1980s, they adopted the wire-border zone method in which the area directly under the transmission lines (wire) is managed for grasses, forbs, and low shrubs and the narrow border zone on each side of the wires for low-to-medium-sized shrubs.

The vegetative-management company uses one of six treatments, including (1) mowing and using a diluted herbicide on the wire zone, (2) a high volume foliar herbicide treatment, again in the wire zone, (3) an ultra-low volume treatment with herbicide only on target vegetation in the wire zone, (4)a low volume basal bark treatment where herbicides are sprayed on individual target plants to control trees and shrubs up to six inches in diameter in both the wire and border zones, (5)mowing in the wire and border area and (6) hand-cutting with a chainsaw.

A killing jar filled with various species of bees collected by Elanor Bonta

A killing jar filled with various species of bees collected by Elanor Bonta (Photo by Elanor Bonta)

The site where we were to collect bees has had the low volume basal bark treatment which has been the most successful in creating early successional habitat for native bees. In addition, the border zones have reacted well to this treatment and are important for birds, Research Assistant Brad Ross reported.

After more than an hour in the hot sun listening to various speakers, we were eager to get started collecting and watched as Dana Roberts, a Research Technologist in Penn State’s Department of Entomology, demonstrated how to carefully net a bee and put it in a jar with acetone. Elanor didn’t need any lesson. She is very proficient with an insect net, having learned from her father who has been collecting beetles since childhood.

Elanor with her collecting net

Elanor with her collecting net (Photo by Therese Boyd, Penn State, used with permission)

I, on the other hand, am not proficient with a net so I was in charge of holding and opening the killing jar whenever she netted a bee. During the collection period she caught several bees while I noted the wide variety of wildflowers in the wire zone—common milkweed, evening primrose, whorled loosestrife, goldenrod—and other native plants such as sweetfern, spreading dogbane, Virginia creeper, dewberry, and hay-scented fern. But most of the bees we collected were nectaring on the beds and beds of blooming non-native daisies brought from Europe centuries ago.

I was also interested in Ross’s research. He conducts bird singing surveys on eight sites four times a year during the breeding season. In addition, he and his helpers search for nests on the ROW. They had found 63 nests, 15 more than in 2016. For birds, he concluded, “It’s a source, not a sink.” He showed us an eastern towhee nest in a black cherry tree sapling on a border site that had been cut with a chainsaw but not treated with herbicide. Nearby, a blackberry shrub harbored a chestnut-sided warbler nest. I also heard singing field sparrows and an indigo bunting.

A common yellowthroat in Pennsylvania using a shrubby habitat (Photo by Dave Inman on Flickr, Creative Commons license)

A common yellowthroat in Pennsylvania using a shrubby habitat (Photo by Dave Inman on Flickr, Creative Commons license)

Since 1982, scientists have identified over 44 bird species on the ROW, most notably nesting common yellowthroats, American redstarts, field sparrows, indigo buntings, chestnut-sided warblers and eastern towhees, all species that use grassy, shrubby nesting areas, especially blackberry, mountain laurel, blueberry, witch hazel, hay-scented fern and poverty grass.

Other, earlier studies of reptiles and amphibians found that small snakes such as northern red-belly and northern ringneck snakes use the wire zone and salamanders the border zone.

A two-year study of small mammals comparing species numbers and richness with the nearby forest identified eight species—white-footed, woodland jumping and meadow jumping mice, meadow and red-backed voles, short-tailed and masked shrews and short-tailed weasels—on the ROW and only two species in the adjacent forest.

Still another study on deer use of the ROW in the early 1980s before and after herbicide treatment showed that deer actually increased after the treatment, using it 48% more than the forest as they browsed heavily on the resulting herbaceous vegetation.

An eastern tiger swallowtail butterfly on a thistle in Pennsylvania

An eastern tiger swallowtail butterfly on a thistle in Pennsylvania (Photo by Henry T. McLin on Flickr, Creative Commons license)

Even butterflies proved to be more abundant on the herbicide-treated sites than on hand-cut ones. They, like the bees, are valuable pollinators for the many wildflowers where they collect nectar. On that two-year study, scientists identified such natives as Aphrodite fritillaries, little wood satyrs, monarchs, spicebush and eastern tiger swallowtails.

Most abundant of all, though, were the numbers and diversity of bee species on our collection day and the others throughout the designated spring and summer months. In a draft of a paper authored by the five scientist conducting the work, including lead Postdoctoral Scholar Laura Russo from the Penn State Center for Pollinator Research as well as Mahan, Ross, H. Stout and D. Roberts, which is under review at the Journal of Pollinator Ecology, they wrote that they had “net-collected 1,056 bee specimens representing 96 bee species,” only five of which were not natives, and two which had never been identified in Pennsylvania. In addition, all six bee families in North America were represented.

Once again low and selective basal bark treatment yielded the largest number of bees and they concluded that furthermore, “These ROW have potential to provide valuable conservation land if managed to promote biodiversity.”

Marcia and Elanor on the right-of-way in SGL 33

Marcia and Elanor on the right-of-way in SGL 33 (Photo by Therese Boyd, Penn State, used with permission)

Elanor and I enjoyed the chance to work with scientists for a morning and to see how valuable the open land of a ROW can be in providing habitat for native species that need shrubby, grassy areas. But while there is the possibility of such management on the two to three million hectares of ROWS in the United States, I couldn’t help comparing what I saw on the SGL#33 ROW with the small ROW that goes up and over our lower ridge-and-valley mountain. When we first moved here in 1971, it had been sprayed from the air, killing everything on it.

Gradually the plants and trees returned, and we were able to persuade the power company to hand-cut the trees and treat the stumps with herbicide. On the Laurel Ridge side the ROW reverted to mountain laurel, lowbush blueberry, scrub oak and sweetfern and on the steep south side of Sapsucker Ridge to hay-scented fern and pale corydalis. In the First Field and flatter areas on either side of the field that were also part of the ROW, blackberry shrubs, goldenrod and asters grow. As far as we could see, no trees threatened the wire zone. Pointing out to the many college classes we have hosted here over the years how well our ROW was managed, especially the healthy scrub oaks, also called bear oaks, loaded with acorns for wildlife every year, has always been part of our managed-land tours.

A scrub oak in the powerline on Laurel Ridge with a cicada

A scrub oak in the powerline on Laurel Ridge with a cicada (Photo by Dave Bonta on Flickr)

But last fall we heard chainsaws on the Laurel Ridge side. To our horror, the electric line workers had cut down all the scrub oak, having been told by their boss to cut all hardwood species. Although scrub oak can grow up to 20 feet tall in the best of circumstances, ours have never grown much higher than the mountain laurel. That’s because they grew on inhospitable mountain soil and formed a dense and extensive thicket.

It seemed especially bittersweet to lose valuable shrubby habitat to ignorance after spending so much time on a model ROW. Unfortunately, this heavy-handed attitude to ROWS is more the rule than the exception.


Gamelands Tour

view of SGL#108

view of SGL #108 on last October’s tour (all photos in this post by Bruce Bonta)

I’ve always preferred to walk rather than drive through the fields and forests of Pennsylvania. Still, I was tempted last October by a driving tour in nearby State Gamelands #108 and persuaded my husband, Bruce, to accompany me. It was a lovely autumn day when we found our way to a gamelands access road in Cambria County, not far from Prince Gallitzin State Park, and lined up behind a couple dozen cars.

At the gate we were greeted and handed several information sheets and a map that designated stops along our 7.5 mile, self-guided, one-way tour. We also tested our outdoor knowledge along the route by guessing the identity of marked trees and wildlife mounts including fisher, mink, ring-necked pheasant, black bear, barred owl, and bald eagle.

But we especially enjoyed stopping and talking to the agency personnel. I noticed the incredible abundance of pokeweed and staghorn sumac along the road and was assured by Joe McAnulty, one of the Food and Cover crew members, that they purposely widen roadsides to let in the sun, which encourages the growth of wildlife food, for example, the pokeweed and sumac, as well as blackberries and sassafras. They also allow wild grapevines to grow.

“We manage for animals,” McAnulty assured us.

With the help of special machines, also on display, they create wildlife openings in the forest to support native plants, legumes, or annual grains. They had just finished a prescribed 87-acre burn to encourage scrub oak to grow, which almost always produces a large crop of acorns every fall. In addition to the 23,086 acres of SGL#108, four workers are responsible for managing the 23,000 acres of four other nearby gamelands, McAnulty told me.

At another stop, we talked to a couple law enforcement personnel who showed us the amazing array of tools they need to foil lawbreakers. A deer exclosure, a couple shelterwood cuts, and a vernal pond were also highlighted on our route, but I was particularly eager to see a rehabilitated strip-mined area, which had been converted to a small-game and grassland nesting bird habitat.

Samara Trusso

Game Commission biologist Samara Trusso with short-eared owl habitat

There I talked to biologist Samara Trusso who told me that short-eared owls winter on the grasslands in February and March. This is important because there is a chance that they might breed there too, although so far no breeding has been recorded. The short-eared owl is one of Pennsylvania’s rarest breeding birds and is listed as endangered in the state. Pennsylvania is the farthest south this mostly circumpolar species nests and then only rarely.

Trusso also said that the rehabilitated strip-mined area provides grassy habitat for grassland birds because the sites have acidic, nutrient-poor soils that produce grasses and legumes and have a slower rate of plant succession. But she assured me that the 40% shrub component of this large acreage has no impact on grassland breeding birds that have been documented for the site—grasshopper, Savannah, and Henslow’s sparrows, northern harriers, eastern meadowlarks and bobolinks.

That was our last stop, but we drove a couple more miles through the grasslands.

“This looks like harrier country,” I commented to Bruce just as a northern harrier flew up and over the grasslands.

Then, as the area grew more shrubby and medium-sized conifers, including larch and red pine, as well as deciduous trees provided more cover; two cock ring-necked pheasants strolled out in front of our car and fought. It seemed a fitting end to what had been a worthwhile tour and one that has been given every fall except for a year when it snowed.

wildlife opening on SGL #108

wildlife opening on SGL #108

To my surprise, we emerged at a gate on State Route 865 near Blandburg at the top of the Allegheny Front, a mere 26 miles from our home. I immediately made plans to return and see the breeding grassland bird species. Snow in late winter foiled my attempts to hike in and see the wintering short-eared owls, but one lovely Sunday in late June, hoping to see the documented grassland breeding birds, we parked at the Blandburg entrance and hiked back the way we had driven on the auto tour. Bruce was armed with gameland maps he had gotten off the web and had plotted out a circular route for us.

The first couple miles, amid the conifers and deciduous trees, we heard common yellowthroats, field sparrows, and song sparrows. But then, alternating with the singing of song sparrows, I heard the dreamy, lisping tsit-tsit-tsit-teee-taay of a Savannah sparrow. He remained hidden in the shrubs, but his song was unmistakable. A few minutes later, I heard the thin, dry buzzy tumble of notes of a grasshopper sparrow. He too remained out of sight in the shrubs.

Sassafras on SGL #108 (seen on the October tour)

sassafras on SGL #108 (seen on the October tour)

We passed a large field white with daisies and heard a common yellowthroat sing both his familiar “witchity” song in addition to one of the less common variations of his song. A sudden breeze carried turkey vultures and a red-tailed hawk past. The hawk was then sent on its way by several red-winged blackbirds.

Eventually we reached the largest open section of grassland. The sun was hot and bright, and already it was late morning. I began to wonder if I would see any of the grassland birds. And then our luck changed. A Henslow’s sparrow sat in a dead shrub near the road and sang his quiet tsi-lick hiccup of a song. He was so close that we could watch him open his beak and sing over and over. I noted his short tail, flat, olive-colored head, big pale bill, finely striped breast, and reddish wings through my binoculars before he flew away.

Henslow’s sparrows are found mostly in the western part of Pennsylvania on rehabilitated strip-mined areas because they like a buildup of dead litter and perennial stalks, according to Andrew M. Wilson in the Second Atlas of Breeding Birds in Pennsylvania. The State Wildlife Action Plan lists the Henslow’s sparrow as a species of High Concern because we have about nine percent of the world population. This native of the tallgrass prairie has lost much of its habitat to agriculture in the Midwest.

I was especially pleased to see favorites of mine—bobolinks that rose from a couple shrubs beside the road, the three males scolding, their buff-yellow napes and white wingbars a striking contrast to their black bodies. Then a brown-backed female with a brown stripe on her head joined the agitated males.

timber rattlesnake coiled to strike

the timber rattler that Bruce insisted on photographing

At the same time I noticed a timber rattlesnake crossing the gravel road in front of us. Bruce rushed up to snap several photos before it slid off into the field, causing still more anxiety on the part of the bobolinks. We watched them for as long as we could as we continued our hike past the grassland. Just as I was lamenting that I hadn’t heard or seen an eastern meadowlark, a male flew up from the middle of the field, flashing his yellow chest and throat, the latter with its black V necklace. Both the bobolinks and the eastern meadowlarks prefer to nest in hayfields, the bobolinks particularly in fields at 2,000 feet on the Allegheny Plateau. But early mowing has led to the demise of many young birds and so this high-altitude unmowed field is of great importance to those species.

From the top of the open grassland, we had a view in every direction encircled by mountains and forest. Despite the dry day, it was hot in the grassland, and gratefully we descended a trail down to a series of forested ponds. We sat on rocks beside one pond to eat our lunch. At another pond a female wood duck with her ducklings swam into cattail cover when they saw us. Singing woodland songbirds included wood and hermit thrushes, black-and-white and black-throated green warblers, ovenbirds, scarlet tanagers, cedar waxwings and indigo buntings.

Looking down on still another large pond from a small planting of red pines, we flushed a great blue heron. A ruffed grouse with half-grown young flew from the edge of the woods.

We spotted the first monarch butterfly of the season nectaring on yellow hawkweed, but it was near large areas of common and poke milkweeds growing beside the access road. That was where it would no doubt lay its eggs because monarch caterpillars only eat the leaves of milkweed species.

The last half-mile of our six-and-a-half mile hike was along State Route 865 where we saw and heard our first sign of people since we had parked our car. We were impressed by the remote peace and lack of even one piece of trash on this section of the gamelands. It was as far from the madding crowd as any place near our home—a prairie on a mountaintop where increasingly rare grassland birds thrive.

June Surprises

June is often the most exciting month of the year. Then I can count on close encounters with black bears on our trails. Not only are last year’s cubs on their own, but their mothers are being hotly pursued by eager males.

northern brown snake

northern brown snake (photo by Paula Scott)

We also add new species to Bioplum, a natural inventory of our property. But last June 5 we added a record three species in one day. Our caretaker family — Troy and Paula Scott — found a northern brown snake in their yard and promptly photographed it. Formerly named DeKay’s brown snake—Storeria dekayi dekayi—its species name still honors nineteenth century naturalist James Edward DeKay. According to Amphibians and Reptiles of Pennsylvania and the Northeastby Hulse, McCoy, and Censky, the northern brown snake “reaches its greatest densities in and around abandoned human habitation.” That made sense because the Scotts’ home is directly above the derelict home of our deceased neighbor, Margaret McHugh.

Later in the day, the Scotts saw a painted turtle on our road. It was probably a female looking for a nesting site because from late May to early July they leave slow-moving water in search of a gentle slope exposed to the sun in which to deposit their eggs.

I was disappointed to miss those two new species, but I was able to see the third new one of the day. Our friend, Lucy Boyce, who specializes in native plants, spent several hours with our son Dave in our three-acre deer exclosure, searching for new plants. The phone rang, and Dave told me to come and see two wild coffee plants — Triosteum perfoliatum — blooming in the wet, overgrown section of the exclosure.

Frankly, I had never heard of wild coffee, also called perfoliate horse gentian, fever-root, feverwort, and tinker’s-weed. Its erect stem has several pairs of large, opposite, oval, pointed leaves that meet and surround the stem. In the axils of the leaves grow reddish-brown or greenish elongated, bell-shaped flowers. It likes rich, moist woods and thickets, such as ours, and flowers in May and early June.

Wild coffee plant

Wild coffee (photo: Dave Bonta)

But even better than finding new species and seeing bears on our trails last June was my unexpected encounter with a rare animal. On a gorgeous day in mid-June, I slowly ascended Big Tree Trail on Sapsucker Ridge. It was a pleasant 63 degrees at 9:00 a.m. as I continued my walk along our forested ridgetop.

Suddenly, I saw what I thought was a small gray squirrel coming towards me. It ran to a tree, climbed about three feet from the ground, and clung to the tree trunk. But instead of a fluffy tail, its tail was very long, thin, and sparsely-haired. Then it turned its head toward me and it didn’t look like the face of a squirrel, but like that of an overgrown white-footed mouse. I had only time to notice its large, roundish, shell-shaped ears, and its big, dark eyes before it jumped off the tree and disappeared. But I was almost certain that it was an Allegheny woodrat.

Years ago, on October 4, 1989 — my husband Bruce and our eldest son Steve had a perfect view of an Allegheny woodrat while driving up our hollow road at 10:45 p.m. What the woodrat was doing there was a mystery because its habitat, as described then in the literature, didn’t fit the supposed requirements of an Allegheny woodrat. They live in caves and talus slopes and the nearest talus slope on the far side of Sapsucker Ridge was farther away than a woodrat’s range.

Cal Butchkoski often squeezes into tight places in search of Allegheny woodrats

Cal Butchkoski often squeezes into tight places in search of Allegheny woodrats (photo: Bruce Bonta)

Their intriguing sighting led me to learn more about this native packrat. And, the following autumn, Bruce and I accompanied PGC Wildlife Technician Cal Butchkoski, as he climbed a hundred foot high rock outcropping in an old-growth hemlock forest. As part of a study by the Game Commission that began in 1982, he had set 40 live traps baited with apples for woodrats in the caves and crevices the evening before and wanted to release any captives as quickly as possible to minimize stress on the animals.

But when he released a male on my lap so Bruce could take photographs, the woodrat seemed anything but stressed. He spent several long, camera-clicking minutes climbing on my jean-clad legs before leaping gracefully to the floor of the cave and disappearing under a dead pile of leaves that was, in reality, his home. Made of sticks, shredded bark, grass and dried leaves, woodrat homes range in shape from cone-shaped to flattened.

At that time, Butchkoski showed us pencil-eraser-sized droppings in its latrine site under a nearby ledge which serve as a signpost for anyone looking for woodrats. These droppings last for decades and, depending on their condition, researchers can determine whether or not woodrats are still in residence. Needless to say, Bruce and our sons combed the talus slopes on Sapsucker Ridge but didn’t find any latrines.

Male Allegheny woodrat posing on author's lap

Male Allegheny woodrat posing on author’s lap (photo: Bruce Bonta)

While Bruce’s and Steve’s sighting seemed unusual because of the woodrat’s distance from its rock habitat, mine was equally surprising because Allegheny woodrats are nocturnal. On the other hand, even though it has been 20 years since I last looked into the ecology of Allegheny woodrats, researchers are still puzzled by many aspects of their lives.

Much has changed too. Back then the Allegheny woodrat was considered to be a subspecies of the eastern woodrat (Neotoma floridana) which ranges south to Florida and west to Colorado. It had lost its original species status Neotoma magister in 1957 when researchers had relegated it to subspecies status based on comparative studies of eastern woodrat skulls and skins. But using new molecular methods, researchers conducted mitochondrial DNA analyses of 114 woodrats from 33 locations and proved that Allegheny woodrats are indeed a separate species from eastern woodrats. In 1997 they were once again listed as Neotoma magister in the Revised Checklist of North American Mammals.

Furthermore, Allegheny woodrats are ecologically distinct from eastern woodrats because they live almost exclusively in caves, boulder fields, and talus slopes consisting of sandstone and/or limestone—so-called rock habitats. They build their nests on cave ledges, like the one we saw with Butchkoski, or in rock crevices

Cal Butchkoski weighs an Allegheny woodrat

Cal Butchkoski weighs an Allegheny woodrat (photo: Bruce Bonta)

Females claim the best habitats to construct their nests and raise their young. They breed as early as mid-March in Pennsylvania, and, after about 35 days, give birth to one to four naked, blind young. Their eyes open at two-and-a-half weeks, and they nurse until they are a month old. Then, although they may remain with their mother for a while, they begin to do their own foraging for leaves, fruit, mast, fungi, and even twigs. Once they are on their own, they build individual nests, because woodrats are solitary animals except during the breeding season. They don’t hibernate so they are busy collecting and drying food, such as fungi and fern fronds, to stuff into crevices for winter consumption. For the most part, they “exhibit high site fidelity and low dispersal rates,” according to researchers.

But Dr. Janet Wright and her students of Dickinson College, radiotracked an adult male for two years. He moved suddenly 3.6 miles along a ridgetop to a new site. She also discovered that woodrats will travel “considerable distances beyond the protection of rock slides in search of food and mates.”

Another researcher, Dr. Petra Bohall Wood, in West Virginia, found that woodrats, particularly males, do move away from their birth site between their juvenile and adult years. From these studies and others I looked at, I hypothesized that the woodrat I encountered still had its grayer youngster coat and was either searching for food or dispersing. The previous fall had been a terrific mast year when woodrats are especially prolific so perhaps young woodrats were more inclined to find a new home. And that woodrat Bruce and Steve saw years before was probably also dispersing.

There is another extensive talus slope less than a mile away on our neighbor’s property. Unfortunately, it had been heavily logged the previous year which may have sent any woodrats living there in search of a new home, because recent studies seem to indicate that the best habitat surrounding rocky areas should include an oak/hickory forest rich in mast. In fact, a large intact forest buffer 1.2 miles from the forest edge is ideal, something we don’t have below our talus slopes but do on our ridgetop.

Pennsylvania is thought to have five percent of the world’s population of Allegheny woodrats. Most of the population is now in the Appalachian south, although more study of populations needs to be done in those areas. It has gone extinct in Connecticut, New York, and the southeastern portion of Pennsylvania where it used to be common. Pennsylvania has relegated Allegheny woodrats to threatened status, and they are protected under the Game and Wildlife Code. Game Commission biologists, including Butchkoski, have been engaged in long-term monitoring to find out how dense populations are at each site. Previously, from 1982 to 2006, Pennsylvania biologists conducted 1,255 surveys at 802 habitat sites and found evidence of current or former woodrat occupation at 443 sites. Of those sites, 246 were still active and 197 were not. They hope to maintain breeding populations in the Appalachian Plateau, Ridge and Valley Province, and the upper Susquehanna River drainage.

The Allegheny woodrat returns to his home after release

The Allegheny woodrat returns to his home after release (photo: Bruce Bonta)

But why are Allegheny woodrats disappearing? That question has haunted researchers from the beginning, and over the years a number of suggestions have been made. After all, their rock habitats are not very accessible to most people. Researcher Kathleen LoGludice summed up biologists’ hypotheses in The Allegheny Woodrat; Ecology, Conservation and Management of a Declining Species edited by J.D. Peles and Janet Wright. First and foremost, is a decrease in food that began with the disappearance of the predictable, yearly crop of American chestnuts and then the woodrats tried to adjust to boom-and-bust acorn cycles, especially during years of heavy gypsy moth infestation when oaks are too stressed to produce any acorns.

Habitat fragmentation caused by new or widened roads, quarries, industrial wind farms, utility lines, communication towers, and natural gas drilling rigs makes it increasingly difficult for woodrats to move safely from one rock habitat to another.

Finally, as packrats, they collect both edible and inedible material. One “midden,” as it is called, examined in Centre County in 1941, contained three quarts of deer pellets. Three other middens discovered by the same researcher yielded a baseball cover, can labels, a cigarette pack, cloth, a shoe heel, yarn, rusty tin cans and pieces of string. None of these items pose a threat to Allegheny woodrats. But as their habitat fragments and residential and agricultural fields move closer, generalist species, especially raccoons, increase. With raccoons come raccoon roundworm which is fatal to woodrats that collect and eat raccoon feces.

Raccoons also prey on woodrats as do great horned owls, coyotes, weasels, fishers, and black rat snakes. We certainly have abundant numbers of these creatures on our property. And hopefully my sighting is a sign that we have a population of Allegheny woodrats too.

Female Allegheny woodrat with two babies by Alan Cressler

Neotoma magister, female and two babies, Lowe Gap cave, Bledsoe County, TN (Creative Commons-licensed photo by Alan Cressler)


For more information on this charismatic animal, consult the Pennsylvania Game Commission website. The Allegheny Woodrat: Ecology, Conservation and Management of a Declining Species, edited by J.D. Peles and Janet Wright, is also an excellent source.

Louisiana Waterthrush

Louisiana Waterthrush in North Carolina by Bill Majoros (Creative Commons BY-SA)

Louisiana Waterthrush in North Carolina by Bill Majoros (Creative Commons BY-SA)

Sometime in early April, I hear the ringing song of a Louisiana waterthrush near our Plummer’s Hollow stream. One of the first neotropical migrant birds to return, he comes winging in from as far south as northern South America and southern Cuba.

This handsome brown warbler, his whitish breast streaked with brown, looks more like a thrush than a warbler. Along with his congener, the northern waterthrush, the Louisiana waterthrush wades on long, pink legs in streams and bobs his tail and rear like a spotted sandpiper.

I spend a lot of time along our mile-and-a-half, first order stream, watching and listening to these fascinating birds. By mid-April there are usually four males staked out along the stream singing, defending their long, narrow territories and courting the returning females. It’s important to catch their singing early, though, because as soon as they pair up, the males slow down and almost stop singing.

A favorite place for waterthrushes is below our Waterthrush Bench, and last spring their activity was especially interesting. On April 18 I watched two singing waterthrushes bobbing their tails as each one tried to stay above the other when they landed on mossy logs, tree branches, and in the stream itself. They moved several hundred feet upstream before flying back down stream, and I wondered if they were two males in a territorial dispute or a pair involved in a courtship ritual.

Louisiana Waterthrush in Ohio by Matt Tillett (CC BY)

Louisiana Waterthrush in Ohio by Matt Tillett (CC BY)

The last day of April, as I sat on Waterthrush Bench, I watched a waterthrush as it poked about in the puddles of a backwater, pulling aside rotted leaves in what ornithologists call ”leaf pulls” as it searched for food. Although 89 to 98% of waterthrush feeding consists of quick, jab-like strokes called “picks,” “leaf pull” is an alternate strategy. In both cases, they are searching for aquatic insects and invertebrates. According to one study in northeastern Connecticut, before the leaves emerge waterthrushes engaged in “leaf pull” 42% of the time and “picks” 54%, but “leaf pulls” decreased and “picks” increased as their breeding season progressed and trees leafed out.

After my waterthrush stopped “leaf-pull,” it waded about belly-deep in the water. Then it flew up on a moss-covered log spanning the backwater to preen. All the while it preened its breast, neck, belly and under its tail, that tail kept pumping as regularly as a metronome.

Years ago, again on the last day of April, in the deepest part of the hollow, which is overhung with hemlock and beech trees, I walked quietly downstream and saw a pair of Louisiana waterthrushes in the water in front of me. They didn’t notice me when they turned over wet leaves in the stream. As I followed and watched, the male walked a couple yards behind the female. Unlike most warbler species, the male and female look alike, so I was relying on a description of this courtship tactic by ornithologists. The male made a “zizzing” sound and fed the female. Then they continued alternately foraging and poking at the stream bank. After I followed them for fifteen minutes, they suddenly saw me, chipped warning notes, and flew off.

Last spring, on the fourth of May, a Louisiana waterthrush swayed and scolded on a branch overhanging the road near Waterthrush Bench. Somewhere nearby in the road or stream bank there must have been a nest with eggs. I remembered my son Steve’s discovery a quarter of a century ago of a nest he found in the road bank as he walked up the road. The female flushed in front of him and performed her broken wing act. Following his description, I easily found the nest four feet from the ground, tucked in over a rock well-padded with dead leaves. An overturned sapling provided a roof above the five whitish eggs spotted with irregular brown spots that lay in a nest of dried grasses.

Louisiana Waterthrush nest by Todd W Pierson (CC BY-NC-SA)

Louisiana Waterthrush nest by Todd W Pierson (CC BY-NC-SA)

The nest had been built on the south side of the ravine by both parents. They dug a shallow cup in the bank’s soil and hauled in fallen leaves from the forest floor to fill the cup and provide a short pathway to the nest, a task that ornithologists say takes three to four days. Incubation by the female lasts 12 to 14 days and the altricial nestlings go from naked to fully feathered in nine or 10 days when they fledge. The nest Steve found did produce not only nestlings but fledglings, and I saw both the nestlings and their fledging.

Since then, we’ve never found another nest but suspect that most are along the stream bank and in the interstices of uprooted trees, which are the usual nesting places for Louisiana waterthrushes.

The bird that scolded me last May then waded into the stream and poked up food from the wet moss on the rocks or from the swiftly-flowing water. Like the dippers of the western United States, Louisiana waterthrushes are wedded to clean, running streams. It jabbed quietly in the crevices, living its enviable life in the moving water whose babble blocks out all other sounds.

Its affinity for water makes it an ideal species to use when assessing the ecological health of streams, researchers discovered at the Powdermill Nature Reserve in southwestern Pennsylvania. This biological field research station of the Carnegie Museum of Natural History in Pittsburgh is best known for its long-running, year-round, bird-banding program begun in 1961 by Robert Leberman.

Louisiana Waterthrush foraging in the Eno River, NC by Bill Majoros (CC BY-SA)

Louisiana Waterthrush foraging in the Eno River, NC by Bill Majoros (CC BY-SA)

Leberman’s assistant, Robert Mulvihill, now at the National Aviary in Pittsburgh, along with Leberman, chose the Louisiana Waterthrush as a model for looking at bird populations back in 1996. After all, two streams — Powdermill Run and Laurel Run — hosted Louisiana waterthrushes. But those two streams differed in one important aspect. Powdermill Run’s water has a neutral pH of 7, but Laurel Run’s was an acidic pH of 5, the result of acid mine drainage from a small, hand-dug coal mine on nearby private land.

More than 50 years after this 30-year-long disturbance, it still impacts Laurel Run despite the best efforts of a local watershed association that installed a Successive Alkalinity Producing System to filter water through organic material and limestone into a settling pond to lower the acidity and remove heavy metals, as well as an attempt by the Department of Environmental Protection, using bioremediation techniques, to further improve stream quality.

Consequently, Louisiana waterthrushes breed early and abundantly on Powdermill Run and late and sparsely on Laurel Run because of the lack of macroinvertebrates, especially caddisflies and mayflies, in the acidic Laurel Run. In fact, by 2009, no waterthrushes bred on Laurel Run, yet over the more than ten years of monitoring, Powdermill Run remains a hot bed of successful, breeding waterthrushes. Apparently, the availability of the proper food — namely macroinvertebrates that favor clean water — is very important for attracting breeding Louisiana waterthrushes.

This study also made some natural history discoveries about Louisiana waterthrushes, according to Mulvihill, who directed the research. The males of this supposedly single-brooded, monogamous species occasionally engage in opportunistic polygyny, defined as pairing with two females at the same time. Eight times during the study, waterthrush pairs re-nested or double brooded after their first successful fledging of young. One female that started out on Laurel Run in her first year of breeding, transferred to Powdermill Run and brought off successful families for at least eight years.

Louisiana Waterthrush by Big Dipper 2 (CC BY-NC-ND)

Louisiana Waterthrush by Big Dipper 2 (CC BY-NC-ND)

Today, Steven Latta, Director of Conservation and Field Research at the National Aviary, continues Louisiana waterthrush research, studying one of its wintering grounds in the Dominican Republic. He’s especially interested in how water quality there affects the survival of the birds and whether or not they return to their breeding grounds. He also wants to use the species to understand what affects neotropical bird populations throughout the year. He writes, in a recent article in Birding, that “in addition to acidification, breeding success is likely linked to sedimentation and other forms of stream contamination, combined with the loss of surrounding vegetative cover in the riparian corridor… Preliminary results suggest that older, more mature forests with relatively high canopy cover, coupled with perennial streams that do not run dry in mid-summer droughts, are key drivers to reproductive success for such bird species.”

Back at Powdermill, scientists are now concerned about the impacts of natural gas drilling on water quality, macroinvertebrates and Louisiana waterthrushes. And they have joined other ornithologists in the state to study the affects of hydraulic fracturing on streams throughout Pennsylvania. They hope that birders will help by counting waterthrushes along streams and reporting their numbers to their local watershed association. Two territories per kilometer are considered a healthy number of waterthrushes along a stream.

Louisiana and northern waterthrushes were once lumped along with ovenbirds into the genus Sieurus, which means “to shake or move the tail,” but for decades Dr. Kenneth C. Parkes, the late curator of birds at the Carnegie Museum of Natural History, argued that the waterthrushes should be separated from ovenbirds. They differ too much in behavior, singing, structure, the way they move, their juvenile plumage and how long they keep it, as well as other differences that only ornithologists could sort out.

Louisiana Waterthrush shows a very wide and long white line over its eye - photo by Ken Schneider (CC BY-NC-SA)

Louisiana Waterthrush shows a very wide and long white line over its eye - photo by Ken Schneider (CC BY-NC-SA)

It took a Ph.D student in the Molecular Systematics Laboratory at the Swedish Museum of Natural History in Stockholm, George Sangster, who admired Parkes’s work, to prove his point. Using genetic analyses, he discovered that ovenbirds were only distantly related to waterthrushes.

On the strength of his work, the North American Classification Committee of the American Ornithologist’s Union agreed to put the waterthrushes in their own genus. Furthermore, they accepted Sangster’s name — Parkesia — in honor of Kenneth C. Parkes because of “his lasting contributions to avian taxonomy, molt terminology, hybridization and faunistics.”

Sangster finished his manuscript about his discovery in the Bulletin of the British Ornithologists’ Club in late July of 2007 and “hoped to inform Dr. Parkes about my intention of naming a genus after him,” Sangster told Paul Hess who wrote about this in PSO Pileated, The Newsletter of the Pennsylvania Society for Ornithology. “It was when I looked on the Internet for a contacting address that I found out that he had passed away only a week before.”

Only three other Pennsylvanians have been honored with a bird genus — William Bartram, Thomas Say, and Alexander Wilson. All of them lived and worked in the late eighteenth and early nineteenth centuries, and all were residents of Philadelphia.

How sad that Parkes never knew of his genus. But how serendipitous that one of the species Leberman and Mulvihill decided to study at Powdermill has not only become important in stream ecology but also honors a fellow western Pennsylvanian who, like them, devoted his life to the study of birds.

The late Dr. Kenneth C. Parkes (left) and Robert Mulvihill at Donegal Lake near Powdermill, 1982

The late Dr. Kenneth C. Parkes (left) and Robert Mulvihill at Donegal Lake near Powdermill, 1982