Forest Ecology

More Than Just Trees

Early visitors to Mount Gretna appreciated its natural beauty. They took part in Campmeeting and Chautauqua nature studies. And they wrote glowingly of trailing arbutus, orchids, violets, ferns, mountain laurel, and fungi.

Governor Dick still has an abundance of natural beauty. Spring wildflowers such as bloodroot, jack-in-the-pulpit, rue anemone, round-lobed hepatica, and solomon’s seal take advantage of spring sunshine, blooming before trees cast the forest into a deep summer shade. Understory trees such as shadbush, redbud, and dogwood also bloom at this time.

Amphibians are active throughout the spring. The shrill whistles of breeding peepers and the guttural croaks of wood frogs begin the amphibian breeding season. Warmer days bring out American toads, bullfrogs, and green frogs. Though silent, salamanders are no less active. Red-backed salamanders are one of the most abundant forest species, averaging two or three individuals every square yard.

Birdsongs fill the forest every spring as waves of warblers, vireos, thrushes, and other migratory songbirds seek out forests like Governor Dick. Having flown all night, they spend the day resting and refueling before continuing on their migration.

But many birds stay. Ovenbirds, worm-eating warblers, red-eyed vireos, scarlet tanagers, and wood thrushes are just a few of the species that need large, undisturbed forests like Governor Dick to successfully nest.

Flycatchers, along with warblers and vireos, perform a valuable service by controlling insect populations. Pewees, phoebes, and great-crested flycatchers can be seen throughout the summer as they hunt for insects to feed their hungry families.

By summer’s end white wood asters and Virginia knotweed are blooming. Birds are beginning their journey south. Also flying south are the seemingly delicate Monarch butterflies. They must survive storms, mountains, and hungry birds on their way to Mexico. During September, a steady stream of monarchs fly past Governor Dick’s observation tower. Also flying past are hawks. Unfortunately, the cage added in recent years atop the tower makes hawkwatching nearly impossible. Distant, moving birds are obscured by thick, black, blurry lines when viewed through binoculars.

Nevertheless, hawks still pass overhead. Broad-winged hawks (sometimes hundreds at a time), bald eagles, kestrels, and ospreys begin in late August and September. Sharp-shinned, Cooper’s, and red-tailed hawks follow. Black and turkey vultures arrive by November. Red-shouldered hawks, harriers, golden eagles, and goshawks also pass Governor Dick.

Governor Dick Tower and MeadowThe tower is probably most popular in October. During the peak of fall foliage the platform is standing-room-only on weekends. Ladybugs by the thousands are also drawn to the tower, bringing with them nuthatches, wrens and other birds hungry for a crunchy snack.

Winter is a good time for long, exploratory hikes. The risk of poison ivy, ticks and copperheads is less. There are no wildflowers to trample or nesting birds to disturb. And the rock formations, geology and geography are more easily studied.

Forest Fragmentation

Governor Dick’s 1,105 acres are an ideal sanctuary for both people and wildlife. Unfortunately, the view from Governor Dick’s observation tower is not as ideal. Cities, towns, farms, developments, and forests already cut up by logging and development stretch out in all directions.

Preserved forests like Governor Dick provide critical wildlife habitat for deep forest species that can’t survive in human-modified environments. These forests also protect watersheds, improve air quality, affect climate, and are a source of recreation and relaxation. However, many of these forests suffer the ill-effects of forest fragmentation.

Forest fragmentation occurs when forests are cut up into smaller patches. Logging, development, and trails break up the forests, increasing the openings and edges that make it more difficult for deep forest species to survive.

As forest fragmentation increases, so does predation. Raccoons, feral cats, blue jays, crows, and foxes are just some of the predators that regularly prey upon young birds and eggs. They do this primarily within a few hundred feet of forest edges. Trails and roads also serve as conduits allowing predators access deeper into forest interiors. Cowbird parasitism and competition with non-native birds like starlings and house sparrows also follows forest fragmentation and human disturbances.

Neotropical songbirds migrate annually from tropical regions to northern forests like Governor Dick. Many need large, unbroken tracts of forest to nest successfully. Unlike year-round birds, migration schedules don’t allow neotropical songbirds time to adjust to changes, find new territories, or try repeated nesting attempts if their first attempt fails.

Studies conducted by the Wild Resource Conservation Fund, Penn State, and Hawk Mountain Sanctuary found that the wood thrush nesting success rate dropped significantly in forests under 200 acres. Governor Dick’s 1,105 acres would seem sufficient. But with fragmentation around its edges and spreading within its interior, it’s quickly being cut up into smaller and smaller fragments. Many species of warblers, vireos, tanagers, thrushes, and flycatchers are also declining due to fragmentation.

Migrants also fall into what are known as ecological traps. This is where they continue to attempt nesting in what appears to be a healthy forest, but because of fragmentation are unable to maintain healthy populations due to low reproduction rates.

Salamanders and vernal wildflowers are also vulnerable to logging, development and forest fragmentation. Their slow reproduction and dispersal rates make it difficult for them to recolonize disturbed areas. Some have been shown to show little recovery decades, even a century, after logging has occurred.

Salamanders spend most of their lives under the leaf litter and logs on the forest floor. Open areas and trails become barriers to many species, disrupting movements and isolating already shrinking populations. And salamanders that survive the crush of logging equipment may not survive the warmer ground temperatures as the removal of trees allows more sunlight to heat the forest floor.

Many non-native plants thrive where native vegetation is disturbed or removed. Freed from the normal checks and balances of their native lands, they overrun and choke out native species. Most of the spring wildflowers growing along Mt. Gretna’s trails are aliens growing at the expense of wildflowers.

Every tree removed from the forest by logging robs the forest of the benefits of the tree’s death. Dead trees may remain standing for many years. Woodpeckers excavate cavities, which are then used by many species, such as owls, chickadees, flycatchers, flying squirrels, and white-footed mice.

When the tree finally falls it serves the needs of many other species. Chipmunks, mice, and salamanders burrow underneath. Ants and beetles bore into the rotting wood while mushrooms and seedlings sprout from it. As the tree decomposes it provides valuable nutrients to the soil while serving as a barrier to erosion.

Sometimes logging is claimed to be needed for fire prevention. However, it is primarily drought, not too many trees, that increases the frequency and severity of forest fires. Logging opens up forests to more rapid drying and greater wind circulation, thus exacerbating their effects and therefore the risk of fire.

Even the most careful logging can’t avoid disrupting the forest. Wildlife communities are changed. And logging usually removes the healthiest trees from the forest – those most needed to provide seeds for future generations of healthy trees.

The forestry management plans of the Bureau of Forestry and Pennsylvania Game Commission tend to favor the timber and hunting industries. This prevents many forests from growing 200-year-old trees and becoming older growth forests needed by species like the barred owls and goshawks, and species that require long recovery periods. There are even some songbirds that only choose century-old trees in which to build their nests.

Forests are complex webs of animal, plant, and fungi interactions. Every new trail, building, and disturbance upsets these delicate, time-tested balances. Some people don’t start worrying till a species becomes endangered. But as Rosalie Edge, founder of Hawk Mountain Sanctuary said, “the time to save a species is when it’s still common.” Governor Dick is home to many species that can no longer be considered common.

Not every forest has to serve as a source of lumber, paper, and profits.
Some forests need to be left alone, to serve as alternatives to whatever forestry practices are currently in vogue. They also serve as invaluable templates to aid in the healing of other forests damaged by years of logging, mismanagement, and abuse.

Governor Dick is unique. It is the last best chance to provide this area with its only large, older growth forest with species that can’t be found elsewhere. It was already preserved and is not needed for development, timber, or other natural resources. But it will remain unique only as long as its caretakers resist the urge to “improve” it.

Pileated Woodpeckers

If there is one bird that exemplifies Governor Dick, it is the pileated woodpecker. The pileated is our largest woodpecker, about the size of a crow, with a striking black and white plumage and a large, bright-red crest. Its voice may sound familiar, sounding like a loud Woody Woodpecker laughing maniacally from deep within the forest.

Like its southern cousin, the ivory-billed woodpecker, pileateds prefer thick, mature forests with lots of dead trees and fallen logs. Unfortunately, ivory-billed woodpeckers were unable to adapt to the clearing of forests. It may already be extinct, though a few may still survive in Cuba.

Pileated woodpeckers came close to following the ivory-billed’s fate, but its taste for a wider variety of foods and its ability to adapt to second-growth forests allowed it to make something of a comeback. But they are still limited to large, undisturbed forests with lots of older trees and are still vulnerable to forest fragmentation.

Carpenter ants, found in fallen logs and old stumps, are a favorite food. Bristles on the tip of a pileated’s long tongue holds a sticky saliva which allows it to pick up insects. Insects make up most of its diet, but pileateds also eat fruit, acorns, nuts, and sap.

Pileateds are non-migratory, year-round residents. Young birds rarely travel more than 20 miles to find new territories. They excavate nesting cavities out of old, rotten trees. Their strong bill and powerful neck muscles make their head an effective jackhammer, both for excavating cavities and searching the wood for insects.

Their loud hammering echoes thoughout the forest as large wood chips fly, covering the ground beneath the tree like mulch. And like other woodpeckers, the males rapid drumming every spring is a signal for attracting females and telling other males that this is his territory.

Pileated woodpeckers are regularly seen around Governor Dick, though not necessarily on every visit. Its large size, loud laugh, and scarcity throughout much of its range contributes to the wildness that makes Governor Dick a unique place to visit.

Other woodpeckers to look for around Governor Dick are downy woodpeckers, red-bellied woodpeckers, hairy woodpeckers, northern flickers, and yellow-bellied sapsuckers.

Postscript: The text of this section is borrowed from an abandoned Friends of Governor Dick website from 2002; minor formatting and editing has been added. We would love to know who penned these words, if you recognize them, please use the contact form to reach out.