Grasslands of Central Pennsylvania

On a day in late August, members of the Pennsylvania Native Plant Society visited what ecologist Roger Latham calls “wild-ungulate pastures” in Clearfield County’s Quehanna Wild Area. Latham, who has been working on a meadow and grass inventory of Pennsylvania, was searching for “meadows and grasslands that have persisted for a long while and for one reason or another seem likely to persist for some time to come.” He is also interested in relatively “new” meadows or grasslands that cover large areas such as those maintained by deer overbrowsing, hence our field trip to the Quehanna Wild Area.

As expected the ferns that spread easily from underground rhizomes–New York, hay-scented, and bracken–blanketed the area. A few old, twisted, black locust trees poked through the understory, but, for the most part, high deer densities had prevented tree regeneration for more than half a century. Some of the area was moist underfoot. The rest was dry and sandy.

When we took a closer look we found occasional wildflowers such as pearly and sweet everlasting, little St. Johnswort, grass-leaved goldenrod, arrow-leaved violet, and wood aster and shrubs that included black huckleberry, meadow-sweet, and Allegheny blackberry. We also identified five native grasses. Of those, an island of tawny cottongrass growing in the midst of swamp dewberry was especially striking. Five rushes and sedges completed our botanical inventory.

None of these plants were uncommon. Most were generalists that thrive on waste places, in sandy soils, or in moist meadows. We had not found hobblebush, fly honeysuckle, or American yew, all species whose recovery would indicate proper deer numbers, according to Latham.

Altogether Latham pronounced the area we explored low in species’ richness. He has looked at many such wild-ungulate pastures throughout Pennsylvania and discovered that they vary from site to site and patch to patch.

“Some areas,” he says, “are mostly dominated by lowbush blueberries, black huckleberry, meadow-sweet and other low shrubs, some by hay-scented fern and bracken, and some wetter areas by sedges, bulrushes, and rushes. A few areas are dominated by native grasses, usually mixtures of warm-season and cool-season species.”

Of course, what kinds of species grow in places depends, in part, on what species are within seed-dispersal distance and on the site’s fire history. Latham thinks that if wildfire has been common in an area, native grasses are more abundant because they respond more positively to repeated or severe burning than other plants. Still, that is only an hypothesis at this point.

However, compared to other remnant, native grassland and meadow types he has studied in Pennsylvania, including serpentine grasslands, xeric limestone prairies, mesic limestone meadows, diabase meadows, Great Lakes sandplains, coastal plain sandy meadows and riverine ice-scour meadows, wild-ungulate pastures are low in total species. They also are not refuges for populations of endangered and threatened species as all the native grassland and meadow types are. At least not so far.

“I wouldn’t rule it out, and I’m still looking for a rare species,” he says.

But it’s a lot easier to find rare species at places like the xeric (relatively dry), limestone Westfall Ridge Prairie in Juniata County, a calcareous rocky summit community that is itself globally rare and one of the best examples of its kind in Pennsylvania.

My son Dave and I first visited the area on a dismal, rainy day in mid-June back in 1996, shortly after The Nature Conservancy (TNC) had acquired a portion of the ridge.

“Are you sure anyone will be here?” Dave asked as we slithered our car uphill on a muddy farm road, following directions we had received from Karen Budd, who at that time was TNCs Science and Stewardship Assistant in charge of organizing volunteers.

But Budd, along with one local volunteer, also showed up, and, clad in rain parkas, we picked up several pairs of pruning shears Budd provided, and slogged steeply uphill on an even muddier track to our work area, our boots weighed down by thick, gummy, muck.

“Not only do TNC volunteers pay no attention to the weather,” she joked, “but they also volunteer, in part, to learn,” which explained her short lecture to us about the Westfall Ridge Prairie.

The Nature Conservancy, she told us, had acquired the core prairie property of 30 acres as a donation from its former owners–the Merril Benner family–in the fall of 1994. The surrounding 120-acre farm, also owned by the Benners, had been sold to a third party who had agreed to a conservation easement that limited development rights and restricted nutrient and biocide use.

The calcareous rocky summit has a southwest exposure that makes it hot and dry (when it’s not raining), and its limestone soil supports a wide variety of plants including two prairie grasses that are also native in the eastern United States–side oats gramma or tall gramma Bouteloua curtipendula and false gromwell or marble-seed Onosmodium molle var. hispidissimum.

Side oats gramma is indigenous to dry woods and is a clumping, warm-season grass that can adapt to a wide range of habitats and easily tolerate drought conditions. While it is abundant globally, it is a state-imperiled species in Pennsylvania.

False gromwell is indigenous to dry and calcareous rocky habitats, prairies, banks, and glades. In 1995 researchers had found 25 plants, less than similar counts in 1989 and 1992. Critically imperiled in Pennsylvania because of its extreme rarity, it too is apparently globally secure.

Both grass species only grow in the open and our job, that rainy day, was to cut out species threatening to overwhelm two small openings–smooth sumac, raspberry, Virginia pine, oaks, and the beautiful, small, purple-flowered tree redbud. But the caterpillars of a butterfly–Henry’s elfin (Incisalia henrici)–also a Pennsylvania rare species, feed on the flowers and young leaves of redbud. These pale to dark green caterpillars metamorphose into small, dark brown butterflies that nectar on redbud, fleabane, and phlox. Since their flight takes place in April and May, we had little chance of seeing any even when the rain slowed to a drizzle and below us we caught glimpses of the remote farming valley through swirling clouds.

Still, I wondered at the time why we should cut out redbud if it was the major host plant for Henry’s elfin in the Appalachians. A visit in May of 2005 to the Westfall Ridge Prairie with Latham and members of the Pennsylvania Native Plant Society cleared up this puzzle.

“Redbud is an invader of grasslands, and there’s plenty of it in the surrounding woods and along the edge of woods in Pennsylvania’s Ridge and Valley. Henry’s elfin probably occurs elsewhere in the Ridge and Valley where there is a good supply of redbuds and little or no pesticide use in the immediate vicinity,” Latham explained.

And why, if redbud is common and its other host plants, from southeastern Canada and the upper Midwest south to Florida and Texas, are similarly common, is Henry’s elfin uncommon, especially in the northern part of its range?

“I don’t think anyone knows why Henry’s elfin seems to be as rare in Pennsylvania and Indiana, for instance, as it is in Maine, Ontario and Wisconsin, even though Pennsylvania and Indiana are much closer to areas where it’s more common,” Latham answered. “My typical scientist’s response–more research is needed.”

On that sparkling, breezy, clear May day of our second visit to the Westfall Ridge Prairie, Latham also told us more about side oats gramma, which grows in shortgrass prairies in the West as well as in isolated patches in the Appalachians. Ten of the 15 known sites in Pennsylvania are on dry limestone prairies like the Westfall Ridge Prairie. Four more are on serpentine barrens. And how did it get to such isolated patches? Latham hypothesizes that perhaps its seeds had stuck to American bison and other extinct, grazing species such as giant horses, which spread the prairie grasses into the open areas of the eastern United States.

We re-found both grasses, but we also identified several other prairie flowers, specifically the showy orange-yellow hoary puccoon or Indian-paint Lithospermum canescens, the lance-leaved, tiny green-flowered wild licorice (Galium circaezans), the purplish-red-flowered wild-coffee or orange-fruited horse gentian (Triosteum aurantiacum), and the white-flowered false boneset (Brickellia eupatorioides), all of which like dry limestone prairies or barrens in Pennsylvania. So too does the shrub fragrant sumac or squawbush Rhus aromatica, which was covered with yellow flowers, a contrast to the white blossoms of black-haw Viburnum prunifolium that grows more commonly in woods, thickets, old fields, and along roads. Unfortunately, we also found the light purple flowers of spotted knapweed (Centaurea maculosa), a European invasive of native grasslands.

The patches of open grassland remain tiny, but at least the rare grasses are still there. In fact, the place remained much as I remembered it, an isolated prairie remnant surrounded by forest.

But that’s not good enough if we are serious about creating more native meadows and grasslands for wildlife habitat and biodiversity conservation. Altogether at least 150,000 acres of meadows and grasslands existed before the arrival of Europeans and only 350 acres remain today.

According to studies by Latham and others, the total limestone prairie area in Pennsylvania when Europeans arrived was probably about 25,000 acres. Today there are less than 10 acres left. The xeric limestone prairies, such as Westfall Ridge Prairie, are declining even faster than most of the other grassland types in Pennsylvania.

“Every time we lose another native grassland or meadow remnant that’s existed since pre-European settlement times, we’re losing an irretrievable part of our natural heritage and further degrading our options for effective restoration and research in the future,” Latham says.

And we are not only losing sites, we are losing species on sites that still exist because those sites are too small to maintain a healthy population during year-to-year fluctuations. If, for some reason, a rare species fails to reproduce one year, which regularly happens with even common species, that may be the end of it.

So, not only must we protect what little is left, we must increase their area by undertaking a vigorous restoration program that uses the native remnants as models for how such areas should look.

Most importantly, Latham says, these remnants “are the last and only sources left for the native, local genotypes of the plant species that have inhabited these ecosystems for many thousands of years. When a local population is extirpated due to loss of habitat, its unique genetic endowment is lost forever.”

But he is pleased that interest by both scientists and ordinary citizens in creating new native grasslands and meadows is growing. A recent workshop on grasslands co-sponsored by The Nature Conservancy and the Pennsylvania Game Commission was so popular that they had to turn people away.

Only 0.4% of pre-European-settlement acreage of native grasslands and meadows remains. With a commitment to restoration, we should be able to do much better. Maybe the next time we visit the Westfall Ridge Prairie, it will be spreading instead of contracting.

The Piney Tract

“Tsi-lick” went the Henslow’s sparrows. From every direction, they called as the cold wind swept over the prairie. Only it wasn’t a prairie. It was a rolling, brushy grassland in Clarion County called the Piney Tract. Also know as Mt. Zion, it is now officially State Game Lands 330.

My husband Bruce and I were visiting the tract with 26 other members of the Pennsylvania Society of Ornithology (PSO) during their annual meeting the third weekend in May.

As soon as we left our car, we joined a lineup of spotting scopes trained on one cooperative Henslow’s sparrow perched on the top of a grass stalk. Our field trip leaders–Mike Leahy and Gary Edwards of the Seneca Rocks Audubon Society–helpfully pointed out the identifying characteristics of the little sparrow–a flat, striped, olive-colored head, short tail, large, pale-colored bill, reddish wings, and lightly streaked breast. Still it looked like most other sparrows–lbj’s or “little brown jobs” as birders call them–but the Henslow’s unusual song helped to identify it.

Because they are secretive birds, hiding in the grasses, the best time to see them is during their breeding season, when they are singing, which in Pennsylvania is May and June. Like most grassland birds, Henslow’s sparrows are declining across their range, particularly in the Midwest prairies where the habitat is down to one percent of its former range. But here in Pennsylvania they have found a new habitat, that of strip mines reclaimed in grass, which are most common in Armstrong, Indiana, Venango, and southern Clarion counties.

The Piney Tract is one such reclaimed strip mine. Because of the passage of the Surface Mining and Control Act of 1977, C&K Coal Company, the owners of the area, saved the original topsoil and, after stripping the tract, planted a variety of legumes and grasses to revegetate the site. The grasses quickly took hold, and grassland bird species began breeding on the tract. According to Dan Brauning, the Game Commission’s Wildlife Diversity Section supervisor, the Piney Tract “probably represents the largest concentration of [Henslow’s sparrows] in the state,” over 1000 breeding pairs of this globally rare species. Folks in the Seneca Rocks Audubon Society, who have been keeping track of the bird species in the tract since it was reclaimed in 1979, have identified at least 130 species. During our visit we added species #131 as an osprey flew overhead.

At close to 2300 acres, the Piney Tract is a valuable swath of grassland, not only for Henslow’s sparrows, but also for vesper, savannah, and clay-colored sparrows, short-eared owls, upland sandpipers, northern harriers, and other grassland species as well as for game birds such as ring-necked pheasants, wild turkeys, and ruffed grouse. Deer, too, thrive there.

Under gray and lowering skies, we followed Leahy and Edwards along the gravel roads that bisect the area. They took us to a bare, mossy area covered with pellets and were not certain whether they belonged to short-eared owls, long-eared owls, or northern harriers, but we did learn that southern Clarion County has the most breeding short-eared owls in Pennsylvania. Back in 1988, writing for Pennsylvania Birds, the journal of the PSO, Margaret Buckwalter who, along with Walter Fye, has been monitoring the area since the early 1980s, tells of Fye’s discovery of breeding short-eared owls at both the Curllsville site southeast of the Piney Tract and the Piney Tract itself. Fye witnessed courtship and later found their ground nests and young, which, as a licensed bird bander, he was able to band. Since then up to three pairs have nested periodically on the Piney Tract. Buckwalter recalls a particularly memorable year back in 2001 when at least five young were found. Later that season, she says, Walter Fye reported a total of ten adults and juveniles. We didn’t see any owls on our May visit, but we heard singing bobolinks, field and song sparrows, prairie warblers, eastern meadowlarks, and common yellowthroats.

Leahy and Edwards also pointed out the site where the first breeding clay-colored sparrows in Pennsylvania had been documented by birder John Fedak in May of 1999 in a sparsely-planted island of red pines and shrubs. Looking much like a chipping sparrow, it is a little smaller and lacks a breeding male’s bright, rufous cap. Instead, the clay-colored sparrow has a light crown stripe and well-defined ear patch.

We could hear the insect-like, dry, three or four, low, buzzes of a singing clay-colored sparrow, and, after an intense search, spotted it on one of the pines just as the sun came out. After more watching, we could see that a pair was building a nest in a pine tree.

The sun enlivened the birds and as Leahy said, “Listen to the birds sing. They’re just ripping!” So they were, and our ears rang, especially with the “tsi-licks” of Henslow’s sparrows. On our way back to our cars we also saw the pair of northern harriers that nest on the Piney Tract flying past.

But we didn’t see the other grassland species we were looking for. The Piney Tract has been evolving, and more trees and shrubs are slowly moving into the grassland. No doubt that is why the clay-colored sparrow, which prefers scrub and brushy prairies, has adopted the area. So part of the management of the tract will involve getting it back to a prairie-type habitat by removing invasives such as multiflora rose and keeping black locust trees, Scotch and red pines from spreading.

At least one mowing experiment took place at the Piney Tract at the end of the twentieth century when Brauning, Mary Grishaver and Chris Grainer mowed sections of the tract and then compared the attractiveness of the mowed and unmowed sections to grasshopper, savannah, and Henslow’s sparrows. While grasshopper and savannah sparrows did not seem affected much by the mowing, Henslow’s sparrows were. They much preferred the unmowed areas, probably because mowing eliminated their song perches and reduced cover for their ground nests.

To see what the tract looked like when Fye and Buckwalter first saw it, Leahy and Edwards took us south to the more-recently reclaimed strip mines in Mt. Airy. One meadow rang with the songs of bobolinks, and I easily counted 50 singing males. On another meadow we both heard and saw a beautiful pair of upland sandpipers, a life bird for me. Listed as a Threatened Species in Pennsylvania, this thin-necked, brown-bodied bird has a light eyebrow stripe, white belly, and the long legs and bill that characterize sandpiper species. Best of all, though, is its haunting “whoolee, wheeloo” song.

We also finally had good views of savannah and grasshopper sparrows. Named for its dry, buzzy song that sounds like a grasshopper, the grasshopper sparrow has a flat head like the Henslow’s sparrow but an unstriped, buffy breast. The Savannah sparrow resembles a smaller song sparrow but is more heavily streaked and lacks the breast spot of a song sparrow and it has a distinctive, notched tail. Its song is more melodic than the grasshopper sparrow’s–“a dreamy lisping tsit-tsit-tsit, tseeee-tsaaay (last note lower),” according to the late, great Roger Tory Peterson. Both birds like to nest on the ground in open fields, prairies, and grasslands.

We finished our field trip with enthusiasm for the “eastern prairies” of southern Clarion County, and later learned more about the conservation groups that pulled together to save the Piney Tract from such threats as a motor sports park and industrial development. Shortly after Walter Fye discovered not only nesting short-eared owls on the Piney Tract but also the first Henslow’s, savannah, and grasshopper sparrows in the early 1980s, he, Margaret Buckwalter and other birders formed the Seneca Rocks Audubon Society in Clarion. Members began collecting breeding bird information on the reclaimed strip mines for the first Pennsylvania Breeding Bird Atlas and quickly established the importance of the Piney Tract for declining grassland bird species.

Then, in the 1990s, Pennsylvania was selected by the National Audubon Society as a pilot state for its Important Bird Area project (see my upcoming July column for more about the IBA). With all the birding information the Seneca Rocks Audubon had gathered on the Piney Tract, it was designated Pennsylvania Important Bird Area Site #21 in 1999 and named the Mt. Zion IBA. Later it was chosen as one of the 500 best IBAs in the United States.

In the meantime, Dan Brauning, then the Game Commission’s ornithologist, recognized the importance of the tract and helped to form the Mid-Appalachian Grassland Initiative Coalition (MAGIC) in 1998, which consisted of interested community leaders and local sportsmen’s and environmental groups, all of whom wanted to acquire the tract and manage it for local wildlife including the grassland bird species. The PGC also began managing it as part of its Farm and Game Program.

Then, in 2004, the C&K Coal Company declared bankruptcy. Representatives from the PGC, Seneca Rocks Audubon Society, Sportsmen’s Federation of Clarion County, Trout Unlimited, League of Women Voters, and PSO attended a meeting with the county commissioners to decide the future of the Piney Tract. Bernie Spozio of the Alliance for Wetlands and Wildlife, a local conservation group, asked the commissioners’ approval to purchase the property and received it. They then resold it, in three separate transactions last year, to the PGC, which bought it with the help of a 50 percent Federal-State Wildlife Grant reimbursement.

Later, at the annual PSO banquet, Bruce and I watched as Margaret Buckwalter received the Earl L. Poole Award for significant contributions to Pennsylvania ornithology in part because of her work to have the Piney Tract grasslands declared an IBA with global status and to have it purchased as a SGL. The Seneca Rocks Audubon Society was presented with the first PSO Conservation Award for their collective work to establish the Piney Tract as an IBA and to support the purchase of it by the PGC. Walter Fye accepted the PSO Conservation Award on behalf of the society and gave a short history of his relationship with the tract, beginning with his discovery of the many nesting grassland species, including a dickcissel in 1983, on the tract. These folks, and many others, deserve our thanks for working hard over the years to make certain that the Piney Tract became SGL#330.

Where Have All The Birds Gone?

Where Have All The Birds Gone? ornithologist John Terborgh asked in his book back in 1989. I was reminded of his question early last October when I noticed that the migrants were few and far between and the woods strangely silent.

Then the National Audubon Society released its State of the Birds USA 2004 report. Touted as “the best data available since [Rachel Carson’s] Silent Spring to report on their [birds’] overall health,” the report did little to relieve my fear that bird numbers are diminishing. Based on national Breeding Bird Survey data from 1966 through 2003, the report primarily sums up the status of 645 bird species native to the continental United States that use one of four major types of natural habitat–grass, shrub, forests, or wetland/water.

Until the Breeding Bird Survey was launched by Chandler Robbins and his colleagues at the Patuxent Wildlife Research Center, there was no good data about habitat loss and its effect on birds even though most of the loss of America’s forestlands and wetlands occurred before 1966. Nevertheless, the report concludes, “wetland and forest species continue to suffer from the effects of poor land management.” Furthermore, “poor land use decisions, certain agricultural practices and overgrazing have caused the dramatic decline of grassland and shrub-land birds.”

The Audubon report assigned all species to one of three categories, the green, yellow, or red Watchlists, based on assessments made by four research groups–Partners in Flight, Waterbirds for the Americas, the U.S. Shorebird Council, and the North American Waterfowl Management Plan.

Although habitat loss and mismanagement are the most serious threats to birds, climate change, air and water pollution, pesticides, and collisions with buildings, towers, and wind turbines are also problems.

Grassland birds have suffered the greatest losses. Of 47 species, 10 are on the red Watchlist (those of highest concern), six the yellow Watchlist (those of moderate concern), and 31 the green Watchlist (those of no or low conservation concern). But even some birds on the green list are still experiencing rapid declines, although their survival is not threatened at this time. For instance, both eastern meadowlarks and bobolinks are green list birds, yet since 1966, less than 40 years ago, the former has declined by 66% to about 10 million birds and the latter to 11 million birds, half of its 1966 population. Short-eared owls, on the yellow list, have decreased by 69% to about 2.4 million birds. Dickcissels are also on the yellow list and Henslow’s sparrows on the red. All are grassland birds that live in Pennsylvania, and dickcissels appear on our own state “Birds of Concern” list as a threatened species.

Historically, Pennsylvania was almost entirely covered in forests, but with the clearing of land for farming after the arrival of European settlers, grassland bird species moved in from the Midwest. Today our grassland birds are threatened by overgrazing, frequent haying, invasive plants, and the selling of farm land for development. Ironically, some grassland birds species, such as short-eared owls and Henslow’s sparrows, are finding refuge on reclaimed strip mines.

According to the Audubon report, shrub-land bird species are also in steep decline. Of 107 species, 71 are green species, 24 yellow, and 12 red, giving them the highest proportion of yellow species. Since most of our shrub-land is in the western United States, namely sagebrush and chaparral, most of the threatened bird species are western species. However, eastern shrub-land habitat is also disappearing due to forest succession, overbrowsing by deer, and urbanization, and a few species on the list do live in Pennsylvania, i.e. the blue-winged warbler on the yellow list and the golden-winged warbler on the red.

Birds that need water are also in peril, both in Pennsylvania and in the United States in general. The Audubon list includes wetlands as well as rivers, ponds, lakes, open ocean, and beaches. Of the 268 water and wetland birds, 212 are green, 31 yellow, and 25 red. Once again even many on the green list are of concern, for instance, the northern pintail, which has declined 63% to 7.5 million birds.

Here in Pennsylvania the yellow birds are American black ducks, prothonotary warblers, and American woodcocks, none of which are on our Pennsylvania list. However, nine of our 14 birds of concern–American and least bitterns, great egrets, yellow-crowned and black-crowned night herons, king rails, common and black terns, and sedge wrens–are primarily wetland species.

Nationwide, half of our freshwater wetlands have been destroyed. In Pennsylvania the estimate is 56%. As the Pennsylvania Game Commission’s ornithologist Douglas A. Gross wrote in Birds: Review of Status in Pennsylvania back in 1998, “The loss of emergent wetlands is one of the greatest factors in the decrease in Pennsylvania’s bird diversity and the cause of the decline of many of its most imperiled species.”

Woodland species are also declining, which brings me back to my original question: where have all the birds gone? I see woodland birds in migration on our forested mountain every spring and fall, and many woodland species breed here, but both breeding and migrant bird numbers are down. The Audubon report verifies this. Of 164 woodland species, 71 are green, 24 are yellow, and 12 are red.

Once again, even a green species, such as the pine siskin, is in steep decline, having dropped by more than half since 1966 to 22 million birds. Wood thrushes are on the yellow list–down to 14 million, again half as many as in 1966. The cerulean warbler numbers are even worse, less than a quarter of what they were, at a total of about 560,000. Worm-eating warblers, which also nest on our mountain, are on the yellow list, along with Kentucky, Canada, and bay-breasted warblers and red-headed woodpeckers. Still on the green list, but in declining numbers, are Louisiana waterthrushes and scarlet tanagers.

Woodlands, according to the Audubon report, are threatened by “unsustainable logging, plantation forestry, overgrazing by deer or livestock, new tree diseases, invasive species, conversion to agriculture, too-frequent or too-scarce fire, resource extraction, urbanization, and fragmentation by roads and utility lines.” Most of these threats are all too familiar to those of us concerned about conservation in Pennsylvania. Could it be that the growth of population in nearby valleys, the increase in roads and vehicles, the erection of cellphone towers, and the unsustainable logging by many of our neighbors on our mountain have contributed to declining breeding bird numbers here?

The Audubon report concludes with an estimate of North American bird species that have undergone the greatest population declines from 1966 to 2003. At the head of the list is the rusty blackbird, sustaining an unbelievable 97.9% loss, followed by Henslow’s sparrow at 96.4%. Other birds on the list that breed in Pennsylvania is number 7, short-eared owl (80.3%), followed by cerulean warbler (79.6%). Loggerhead shrike is number 10 (77.1%) and is also on Pennsylvania’s Birds of Concern list. Number 11 is grasshopper sparrow (also 77.1%), number 15 is field sparrow (68.8%) and number 16 northern bobwhite (67.6%).

Some of the declines are bewildering such as that of rusty blackbirds. They have a vast breeding range throughout most of the boreal region of Canada and Alaska so Partners in Flight scientists think that the loss of forested wetlands where rusty blackbirds spend their winters in the southeastern United States might be part of the problem. The cerulean warblers are most threatened by mountaintop mining in Appalachian forests, but efforts by conservation-minded citizens have so far not halted that pernicious practice.

Species that need periodic disturbances to survive include red-headed woodpeckers, prairie warblers, American woodcocks, and Kentucky warblers, and scientists recommend active management to create such habitats in places where they no longer occur naturally. Northern bobwhites have almost been extirpated in Pennsylvania. They, like many grassland species, need farmland with fencerows, habitat that is difficult to find. Loggerhead shrikes also like hedgerows and occasional trees and shrubs in fields and pastures. After a 50-year absence as breeding birds in Pennsylvania, loggerhead shrikes began breeding in Adams and Franklin counties in low numbers. Grasshopper sparrows, like Henslow’s sparrows and short-eared owls, have benefited from grasslands created on reclaimed strip mines in Pennsylvania.

The threats to birds species and numbers are huge, yet the National Audubon Society is confident that we “can help keep common birds common and reverse the decline of globally threatened species.” If you are a landowner, manage it for birds. We’ve noticed, as our forest has aged, that several mature woods’ species, such as black-throated green warblers, blue-headed vireos, Acadian flycatchers, and winter wrens have started to breed here, and every year their numbers increase. Our forest also provides a haven for cerulean warblers, wood thrushes, worm-eating warblers, scarlet tanagers, and Louisiana waterthrushes. Due to natural periodic disturbances and our maintenance of 40 acres of meadows, we have enough early habitat to satisfy such species as eastern towhees, field and song sparrows, and golden-winged warblers.

Homeowners should make their yards havens for birds, the Audubon report suggests, “by creating a pesticide-free habitat of native plants, providing supplemental food and water, and putting out birdhouses…” They also recommend that folks keep their cats indoors, buy shade-grown coffee because it creates important winter habitat for migratory songbirds, and participate in citizen-science projects such as Christmas Bird Count, Great Backyard Bird Count, National Migratory Bird Count and Project FeederWatch, to increase our knowledge of bird populations. We should also support the purchase of public lands and defend those we already have from bad land management practices, for instance, our national and state forests, gamelands, and the 95 million acres of land and water managed by the U.S. Fish and Wildlife Service. In other words, the more wild lands we have, the better for the birds.

Finally, three species appear on the Audubon list with a 0–Eskimo curlews, Bachman’s warblers, and ivory-billed woodpeckers. Last April, as my husband and I sat in a cabin at Raccoon Creek State Park eating breakfast, we heard on our radio the most exciting news for birders in decades–at least one ivory-billed woodpecker still lives in a most unexpected place –the Cache River National Wildlife Refuge in northeastern Arkansas. And it was discovered not by a scientist, but by a kayaker–Gene Sparling–who had posted his finding on his website.

Tim Gallagher, editor-in-chief of the Cornell Laboratory of Ornithology’s Living Bird, saw the posting while researching a book he was writing on ivory-billed sightings over the years. On February 27, 2004 Gallagher, veteran birder Bobby Harrison, and Sparling headed into the Cache River NWR, part of a vast, 500,000 acre bottomland forest of old growth and younger trees that also includes the White River National Wildlife Refuge. Paddling canoes into the area under Sparling’s leadership, Gallagher suddenly spotted a large black and white bird that flew across in front of them at close range and in good light, a mere 68 feet away. There was no doubt that it was a ivory-billed woodpecker.

Such a discovery is a “spectacular ray of hope,” Cornell lab’s director John Fitzpatrick said. Since then there have been six more sightings of a male ivory-billed in that area and the hope is that at least a small breeding population of ivory-bills lives in the depths of what is still an almost impenetrable wilderness–wilderness owned mostly by the national government and by private landowners who have kept it wild.

Surely such a fantastic discovery should embolden all of us to re-examine our own priorities and try to do as much as we can to ensure that in another 40 years bird numbers will have zoomed back to at least 1966 levels.

“My dream is that my great, great-grandchildren will be able to see a place like the virgin cypress forests we once cut down–and with the ivory-billed flying through it,” Gallagher said.

My dream is that the United States will be such an incredible haven for large populations of woodland, shrubland, grassland, and wetland birds, that we will no longer need Audubon reports when my great-great-grandchildren are alive.

Little Loggers

Last winter I spent more time watching meadow voles beneath our feeders than I did birds. The heavy snowfall in early December provided perfect cover for them and when most of it melted later in the month, the voles’ runways were easy to see. Several voles had nests near our feeders and often their dark gray heads poked out of them to grab a seed or two.

One Saturday afternoon I sat at our bow window watching birds while I listened to the Metropolitan Opera radio broadcast, but I ended up being more interested in meadow vole behavior. On that day, they ventured farther from their nests along their open runways to eat birdseed, and I often mistook them for dark-eyed juncos until they moved. By finding and then focusing my binoculars on a nest entrance, I was able to get excellent views of the plump, beady-eyed creatures sitting there, running along their runways, or feeding with gray squirrels, juncos, and mourning doves. The squirrels chased the birds and each other but didn’t seem to see the voles. Maybe that’s because these nervous little engines of energy move incredibly fast. Once I saw two, one right after the other, dive into a nest entrance.

Well into January, I continued my vole watching. Probably there were more than two but only a couple were out at the same time. They would pick up a seed with their front paws and, sitting on their back haunches, eat it much as a squirrel might (they are, after all, both members of the Order Rodentia). The voles used our discarded Christmas tree, along with the tree sparrows, song sparrows, and juncos, as cover when they ventured out to nibble dried and still-green grasses on the periphery of the feeder area. Juncos startled them whenever they flew in or foraged near their nest entrances, and the voles always darted back into their nests. But they also paid attention to the birds’ frequent alarms, and when the birds flew up in a panic, the voles dashed for cover.

After a month of vole-watching, snow and ice once again sealed them off from the outside world, an ideal situation as far as the voles were concerned because they were safe from many of their enemies, especially avian predators such as hawks, owls, blue jays, and crows. Even many of their larger enemies–foxes, opossums, skunks, and feral house cats–would have found it difficult to break through the thick ice layer that covered the foot of snow on our mountain during much of February.

In the meantime, the voles lived in their surface runways beneath the snow, where their other major predator–weasels–could have chased them down, or in their five-to eight-inch-in- diameter, globular-shaped nests of grasses where they huddled together to conserve energy during the coldest days of winter. Most often, such groups consist of juveniles staying with their mothers although occasionally one or two adult males may join them. They also ate the roots, tubers, leaves, seeds, fruits and grasses they had previously cached above and below ground in preparation for winter.

In late February two fifty-degree days quickly melted the icy snow cover, and once again the meadow voles were visible below the feeders as they ran along their open runways. But even more amazing were the immense number of vole runways that meandered through the dried grasses of First Field like the mazes in children’s magazines and activity books. These patches of torn-up, matted grasses that scrolled themselves across the landscape had been painstakingly constructed by the voles’ sharp teeth as they snipped off any green sprout that surfaced. Slightly wider than a garden hose, their previous under-the-snow passageways were now exposed to the sunlight and the eyes of predators. Their many domed, grassy nests were also open to the outside world.Vole runways did not cover all of First Field. Voles particularly like the thick cover of bluegrass and First Field still harbors pockets of it that were planted decades ago so that was where many of the nests and runways were concentrated. They also like moist areas of dense vegetation, made up primarily of grasses and sedges. Both the lower portion of our once-lawn, a former wetland, and a three-acre wetland at the bottom of First Field above the stream, were crisscrossed by vole runways. Along the runways, occasional piles of little, brownish-green pellets marked the voles’ communal toilets.

By late March, the meadow voles had begun breeding as the promiscuous males competed for the attention of promiscuous females. After a gestation period of 21 days, a female has her first of eight or nine litters in a season. Those litters range in size from one to 11, with an average, in Pennsylvania, of five to seven. She is bred almost immediately after bearing a litter and has a mere three weeks to tend her young, which are born blind, pink, hairless, and helpless, before she has another litter.

At one week, the young are already covered with fur and their eyes are open. At two weeks, they are weaned, and the following week they are on their own. The females of a litter can breed at four weeks of age and the males at five. All this breeding makes the meadow vole the most prolific mammal in Pennsylvania. Without a wide variety of predators, they would quickly overrun their habitat, especially every third or fourth year when their numbers are high. Back in 1924, one captive female, observed by Vernon Bailey, a mammalogist for the United States Biological Survey, produced 17 litters in one year and a daughter from her first litter had 13 litters that same year.

The meadow vole, whose scientific name in 1815 was Mus pennsylvanica (Pennsylvania mouse) for its type locality in meadows below Philadelphia, is now Microtus pennsylvanicus or Pennsylvania small ear, referring to the vole’s tiny ears. Also popularly known as the field or meadow mouse, it is no friend of the white-footed mouse of field and forest. When vole numbers are high, mouse numbers are low which may explain why we had no mice in our old farmhouse last year. Researchers aren’t sure how the voles keep mice out, but they suspect that the much larger and more pugnacious voles may attack and chase any mice they find. Certainly, I frequently observed the voles chasing each other from the birdseed.Both mice and voles are a necessary part of the food chain, supplying endless meals for larger creatures. But do they serve other purposes in the natural world?

Ecologist Richard S. Ostfeld and his associates at the Institute of Ecosystem Studies in Millbrook, New York, have been studying the effect mice and voles have on tree regeneration in old fields. He built nine, one-third of an acre enclosures in old fields and filled them with high (400), medium (175), or low (80) densities of voles per two and a half acres. In each enclosure, he planted tree seedlings of species that colonize old fields in the eastern United States and discovered that the high-density voles killed 95 percent of the seedlings, the medium-density 80 percent, and the low-density 65 percent. They showed a definite preference for red maple, white ash, and the invasive tree-of-heaven and disliked white pine and red oak. Even those seedlings that they didn’t eat, they clipped off near ground level, leaving distinctive, diagonally cut stumps. For some reason, which the scientists haven’t figured out, voles like to keep their homeland free of tree seedlings.

A separate study of white-footed mice found that they only ate tree seeds. Between the mice and voles, establishing a forest in an old field seemed almost impossible.

The next enclosures Ostfeld built were at the boundary between forest and field, since trees usually invade old fields at the edge of the forest. He left the forest end of the enclosures open, figuring that the voles would stay in the field and that mice would move between field and forest. Again he established the same densities of voles as the previous set of enclosures and again they ate the same kind and number of tree seedlings. The mice turned up their noses at those species and instead ate the seeds of red oaks and white pines.

Over the years, Ostfeld found that few tree seedlings of any species survived if vole numbers were high and mice numbers low, but many tree seedlings thrived if mice numbers were high and vole numbers low. As an ecologist, Ostfeld was fascinated by the influence of the “little loggers,” as he calls voles, on the natural world.

“These rodents…play a strong role in preserving attractive vistas and maintaining the open habitats favored by such other wildlife as deer, turkeys, woodcocks, and bluebirds,” he wrote in Natural History magazine. “And meadow voles, by excluding white-footed mice from some habitats, may reduce the risk of Lyme disease, which is carried by ticks that feed off (and are infected by) these mice.”

Could that be why we have not, so far, seen a tick on our mountain? Or why the wetter portions of our field have not been invaded by any tree seedlings in the 32 years we have lived here?

Everything is indeed connected to everything else as more than one ecologist has observed. And unraveling those connections remains a daunting task even for scientists. Our fields, after all, are not the fields that Ostfeld studied and our voles and mice may prefer and dislike different tree species.

The complexities of the natural world continue to fascinate me and I have Never Enough of Nature, as the late, great scientist Lawrence Kilham entitled one of his books. Who would have suspected that meadow voles, in addition to providing food for many predatory birds and mammals, could not only control mice numbers but the regeneration of forests?