What makes a mountain tremble? Ravenous deer herds


For close to half a century, a forest in central Pennsylvania’s Perry County — about 5 square miles of mature hardwoods — has been a sanctuary; a place free from hunting, trapping and logging; where the natural world can remain “free as far as possible from molestation,” where visitors can “be enlightened and educated…”

The quotations are from the will of Florence Waring Erdman, of Philadelphia. Most of her estate went to protect the forest as a memorial to her mother, Florence Jones Reineman.

And the Reineman preserve has surely provided an education, visited frequently by students from nearby Dickinson College in Carlisle. But its lessons, still evolving, are nothing Erdman imagined.

Ash Nichols, a literature professor, has come on a brisk November afternoon to walk the woods with his nature-writing class. Their text: Aldo Leopold’s classic 1940s essay, “Thinking Like A Mountain,” one of the earliest popular expressions of ecological thought, is still pertinent.

The essay opens with the howl of a wolf, “a deep, chesty bawl that . . . rolls down the mountain . . . every living thing pays heed . . .” but only the mountain, Leopold wrote, “has lived long enough to listen objectively.”

Most hunters of his era, including a younger Leopold, assumed fewer wolves meant more deer, and exterminating wolves “would mean hunters paradise.”

But he came to realize that “just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer.” As a forest scientist, Leopold was seeing “newly wolfless mountains . . . every edible bush and seedling browsed to death . . . as if someone had given God a new pruning shears and forbidden him all other exercise.”

Professor Nichols does not have to do much teaching today. The woods at Reineman speak eloquently. Their wolves, as in all Eastern forests, are long gone; and deer hunters — our best, poor substitute for top predators — have been kept out of Reineman’s 3,400 acres for many decades.

“Thousands of acres and not a single sapling coming up here,” said Gene Wingert, a Dickinson biologist. Deer browse them to the ground as fast as they come up.

As far as the eye can see — and you can see a long ways through this forest — there’s no shrubby understory, no midstory of younger trees. For miles it’s a savannah, invasive Asian stiltgrass flowing up the hillsides beneath 70-year-old hardwoods, themselves browsed of limbs as high up as a deer can stretch.

Only in a few “exclosures,” areas about 85 feet square that have been fenced from deer by Dickinson botanist Carol Loeffler, does anything close to a natural forest grow. One tiny exclosure is chockablock with oak, hickory, tulip poplar, maple, birch, black gum and other species. “If we took the fence (erected in 1992) down, only a couple bigger tulip poplars would survive,” Wingert said.

The herds of white-tailed deer that populate Penns Woods were nearly extinct, maybe 5,000 statewide, in the early 1900s. Deforestation, extermination of predators and year-round market hunting were the reasons.

Now, managed for sport hunting, the population is an estimated one million, with about 750,000 hunters killing around 330,000 deer annually. Another 100,000 are estimated hit each year by Pennsylvania motorists, among whom there were 60 deaths and 4,400 serious injuries in a recent seven-year period (“Most Dangerous Animal in Pennsylvania” read the Philadelphia Inquirer’s headline).

Ecologists say deer in Pennsylvania and most states remain too numerous for maintaining the full diversity of plants, songbirds and other components of woodland ecosystems, though Pennsylvania’s management lets trees regenerate in many forests.

But “no other threat to forested habitats is greater at this time,” argues a recent article on deer impacts by biologists from The Nature Conservancy.

It is ironically the deers’ current top predator that protects them at high levels. Most hunters feel there’s scarcely such a thing as too many deer; and their license fees pay to run Pennsylvania’s Game Commission.

Some Dickinson faculty would like to see Florence Erdman’s will changed to allow at least some hunting in the Reineman Preserve. In coming decades as more of the big trees die, nothing is there to replace them.

Wingert, however, sees the preserve as a long-term ecological study. Several thorny, inedible species like Asian barberry are just beginning to come up above the stiltgrass. Will they eventually form dense enough protection to let trees regenerate?

There’s also preliminary evidence that the streams running off Reineman to Chesapeake Bay carry more polluting nitrogen than less deer-impacted forests. “A link between deer and nitrogen (pollution) is important to study further,” Wingert said.

You wonder what Florence Erdman, who died in 1960, would say today. She had no idea what deer could do, unchecked. As a classroom and laboratory, the preserve has value; as a forest, less and less. There’s a sadness that modern society has made of deer something closer to pests, to be controlled, rather than the animal early naturalist John Muir called “invincibly graceful . . . adding beauty and animation to every landscape.”

Editor’s note: Tom Horton covered the Bay for 33 years for the Baltimore Sun and is author of six books about the Chesapeake. Distributed by Bay Journal News Service.

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