Bald Eagle State Park, Centre County, Pennsylvania

About Bald Eagle State Park

At this popular central Pennsylvania park, 5,900 acres surround a 1,730-acre flood-control lake behind a large earthen dam on Bald Eagle Creek. Park visitors hike, camp, fish, boat, hunt, and view wildlife.

When the U.S. Army Corps of Engineers acquired the land in 1965, most of it was being farmed. Since then, the area has grown up into brush, pole-stage forest, and mature forest. Different habitats provide living space for many birds, including ruffed grouse, wild turkeys, and songbirds, and for mammals such as cottontail rabbits, white-tailed deer, black bear, foxes, and raccoons. Ducks and geese use the lake, as do bald eagles and ospreys.

Bald Eagle State Park is in the Bald Eagle Valley just south of the Allegheny Plateau; the valley is an important north-south corridor for migrating birds, including woodcock. To benefit wildlife, the Pennsylvania Game Commission helps manage about 5,000 acres of land at Bald Eagle State Park. The project described below is an ambitious landscape-scale effort that joins habitat creation with scientific research.

Improving the Land for Woodcock

In the 1990s a group of state and federal agencies launched a Native Plant and Early Successional Stage Habitat Restoration Project to combat non-native plants that had invaded the former farmland and to restore the mosaic of old fields and fencerows that existed when the park was established.

Wildlife technicians are combating invasive shrubs. Here, a large honeysuckle was cut down and its stump sprayed with an herbicide, killing this aggressive non-native shrub.

Land managers have begun testing a range of mechanical, chemical, and biological treatments to control non-native invasive plants, developing a protocol for combating these exotics that can be used on other Pennsylvania state parks and on public lands throughout the Northeast.

The project divides the park into ten management units. On four of the units, totaling almost 2,500 acres, workers have begun controlling invasive plants (mainly multiflora rose, Tatarian honeysuckle, and autumn olive) and encouraging the regrowth of native shrubs including dogwood, alder, hawthorns, and haws.

Wildlife technicians have used chainsaws, a Hydro-Ax machine, a brush hog pulled by a tractor, and a skid loader with a mower and tree-shear attachment to cut strips and blocks of habitat, suppressing invasives along with aggressive native plants, such as red maples and slippery elms, that offer few benefits to woodcock and other young-forest wildlife.

In some areas, cover strips stretch from low, damp areas uphill through progressively drier soils, letting woodcock shift within the feeding habitats during damp or droughty periods. Stands of mature aspens have been cut, spurring the trees’ underground root systems to send up a dense regrowth of shoots among which woodcock and other wildlife can rest, feed, and rear young.

An extensive road network affords access to the different units. In 2002, cutting and other operations began on units 2 (Upper Greens Run), 4 (Lower Greens Run), 5 (Park Office area), and 6 (Camp Ground area). Once undesirable trees and exotic shrubs are under control in these and other areas, the young-forest habitat will be kept on a 25-year rotation, with 20 percent of each unit cut back every five years.

Over two winters in 2002-2004, managers cut around 40 acres. In 2008-2009 they cut another 30 acres. In 2009-2010 they cut new strips next to older ones, totaling 24 new acres. More cutting took place in 2010-2011.

Moist-soil acreage surrounding the lake has tremendous potential both as woodcock breeding habitat during spring and summer and as crucial feeding habitat for migrating timberdoodles in spring and fall.

Science

Woodcock

Biologists for the Pennsylvania Game Commission, Ruffed Grouse Society, and Wildlife Management Institute have run singing-ground surveys in the park since 2004.

In 2009, male woodcock were heard singing on the south side of the lake for the first time in five years, in patch clearcuts and clearings made during the preceding winter.

In 2010, biologists ran three singing-ground survey routes and heard 33 singing male woodcock on 22 stops.

Golden-Winged Warblers

In 2008 Dr. Jeffrey Larkin, a conservation biologist at Indiana University of Pennsylvania, began a study of golden-winged warblers at Bald Eagle State Park. The project will determine the extent to which the warblers breed in the area; verify the size and density of breeding birds’ individual territories; and identify and characterize the habitat types that most benefit this species, whose numbers are declining across its range.

Male golden-winged warbler captured in a mist net.

In 2010 Larkin and his colleagues began their third field season of capturing and banding territorial males and taking blood samples for the Golden-Winged Warbler Atlas Project at the Cornell Laboratory of Ornithology. The biologists located nests and determined clutch size and whether young birds successfully fledged from the nests. As more young forest is restored and created, Larkin will study how the golden-winged warbler population responds.

Following field research in 2008 and 2009, Larkin and his colleagues recommended future habitat management practices for key warbler areas, including leaving some standing trees for male golden-winged warblers to use as song perches during the breeding season.

Their team designed the 2010 work plan for the Native Plant and Early Successional Stage Habitat Restoration Project.

During winter 2009-10, workers made four 25-acre cuts (termed “manipulation plots”) specifically for golden-winged warblers. The cuts opened up shrubby areas that were getting too thick for the warblers. Next to each cut, a 25-acre area was left untreated as a control. The researchers designed the habitat prescriptions based on earlier field research, in which more than 120 golden-winged warbler territories were mapped and their habitat features closely examined.

Larkin and his graduate students will collect population and habitat-use data for at least two years on these paired sites. Larkin believes that each 25-acre manipulation plot may provide habitat for up to four pairs of golden-winged warblers.

Larkin also supervised the creation of three similar study areas about 20 miles northwest of Bald Eagle State Park in the Sproul State Forest in western Clinton County. There the land is dominated by mature forest. It is drier, rockier, and at a higher elevation than Bald Eagle State Park. In the Sproul, golden-winged warblers appear to be restricted to regenerating clearcuts and parts of a 10,000-acre area that burned in a wildfire in the early 1990s.

This new study site is at a high elevation in Sproul State Forest about 20 miles northwest of Bald Eagle State Park.

Paralleling the work done at Bald Eagle, during the winter of 2009-10 workers made three 25-acre cuts, each next to a 25-acre control area. In 2010 and 2011, Larkin’s research team will survey vegetation, breeding birds, and small mammals on the manipulation plots and control areas, and will map territories of golden-winged warblers and record their nesting success rates.

Preliminary results from 2010 showed that another young-forest species, whip-poor-will, has already occupied the newly opened habitats on Sproul State Forest. Past research studies have indicated that golden-winged warblers will start breeding in logged forest stands after 4 to 5 years and will continue using the stands for 12 to 15 years.

Larkin believes that blackberry is a key shrub for golden-winged warblers in this high-elevation, dry-forest setting. The Pennsylvania Bureau of Forestry, a partner in the study, is working with Larkin to explore ways of providing wildlife habitat on sites that cannot be managed for high-quality timber, as well as learning how best to harvest timber on higher-quality sites to create young forest that will benefit golden-winged warblers, Appalachian cottontail rabbits, whip-poor-wills, and other species.

Funding and Partners

Pennsylvania Department of Conservation and Natural Resources, U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service, Pennsylvania Game Commission, Ruffed Grouse Society, California University of Pennsylvania, Indiana University of Pennsylvania, Wildlife for Everyone Endowment Foundation, Woodcock Limited of Pennsylvania, U.S. Geological Survey, National Fish and Wildlife Foundation, Northeast Association of Fish and Wildlife Agencies, Wildlife Management Institute.

How to Visit

Bald Eagle State Park is in Centre County, Pennsylvania, along PA Route 150 between Milesburg and Lock Haven. It is open, free, to visitors year-round. For details and a downloadable map, see http://www.dcnr.state.pa.us/stateparks/parks/baldeagle.aspx.

The Pennsylvania field office of the U.S. Fish and Wildlife Service, in nearby State College, PA, coordinates the Native Plant and Early Successional Stage Habitat Restoration Project at Bald Eagle State Park. For more information, contact Adam Smith, 814-234-4090 x 235 or email him at adam_smith@fws.gov.