As urban sprawl squeezes in tighter and tighter around some national parks, it can turn some parks into wildlife sanctuaries that create their own problems. At Valley Forge National Historical Park, efforts to control a booming population of white-tailed deer have spurred a lawsuit from a group that believes a prey-predator relationship should be allowed to play out. But how realistic is that?
No longer the sleepy, bucolic landscape that existed when General George Washington and his troops wintered here in eastern Pennsylvania in 1777-78, Valley Forge today is surrounded by development, not the least of which is the King of Prussia Mall, one of the largest malls in the country in terms of commercial space.
With its 3,500 acres, many lush and green with vegetation, the park has become a magnet for white-tailed deer, which officials say are overrunning the vegetation.
The issue of too many deer did not arise overnight. While in 1983 there were an estimated 165-185 deer at Valley Forge, according to park research, by 2000 the herd had grown large enough that Congress directed the National Park Service to begin assessing the problem. Three years ago the park launched efforts to develop a deer-management plan, an effort that recently led the park officials to decide to employ sharpshooters and birth controls to cull and contain the herd, which peaked at 1,647 animals in 2008 before dipping to 1,277 this year, at 165-185 animals, according to Kristina Heister, the park's natural resource manager.
"We've said many times that this park is really a refuge in the middle of suburban Philadelphia," she said Friday afternoon during a phone conversation. "And as such it becomes even more important that the habitat that we have here is in good condition. ... We have to strike that balance. We know that we can't achieve that with the number of deer that we have today."
The culling decision hinged in part on over-browsing of vegetation in the park and associated concerns for the park's overall habitat and impacts to other animals. And while it has not yet been detected in the park, the threat of Chronic Wasting Disease, a contagious neurological disease, reaching Valley Forge also contributed to the decision. Though not directly tied to the park's decision-making, deer-vehicle collisions -- of which there are nearly 90 every year within the park's borders -- also are a concern.
Members of the surrounding community also have voiced concerns over deer devouring their gardens, the possible spread of Lyme Disease, and deer droppings. But they also have mentioned how nice it is to have such highly visible wildlife. In 2007, a study performed for the park by Cornell University researchers touched on the issue of urbanization of the area and its impact on wildlife.
Anthropogenic factors such as human population growth and land development often were described as the ultimate source of deer issues. Many interviewees perceived human-deer interactions as a symptom of broader ecological disruption (e.g. habitat loss, fragmentation) that concentrated deer in undesirable locations:
“Development has created the problem, we, mankind has (sic) developed the problem. The deer are doing their best to survive, they’re coming back at us and eating our shrubbery. What are they supposed to do, lay down and die?”
“We’re choking out the whole landscape by building up developments. There’s nowhere for them to go.”
“I usually see herds. It wasn’t like that when I was a kid. A couple of new developments were built, that’s when I noticed the difference. I attribute it to human encroachment. The zoning around here is out of control. There’s too much development bordering the park.”
While park managers believe culling and using birth control are the best approaches to managing the deer, two animal advocacy groups filed a lawsuit this week to stop that plan. In their filing, the Friends of Animals and Compassion for Animals, Respect for the Environment argued that the Park Service's approach violates the National Environmental Policy Act, as well as the National Park Service Organic Act, and even the Valley Forge National Historical Park's enabling legislation.
“Decisions under the National Environmental Policy Act cannot be based simply on seizing upon the apparently easiest answer to a perceived problem,” said Lee Hall, legal director for Friends of Animals. “Killing deer is not the answer to the decline of plant life in a sprawling, concrete-covered suburb.”
Allison Memmo Geiger, president of CARE, added that she didn't know what was worse, “shooting deer or compromising their social and reproductive interactions by imposing birth control on them.”
And Michael Harris, a law professor at the University of Denver's Environmental Law Clinic that filed the lawsuit, said the decision runs counter to the National Park Service's preservation mission.
“For the National Park Service to enter Valley Forge National Historical Park in the cover of winter to slay white-tailed deer is not only an appalling twist on the park’s history, it is another sign that the Service has abandoned its century-old mission to strive for parks in which conservation of nature is paramount,” he said in a release.
What those groups would like to see, according to Ms. Hall, is for the park to allow coyotes to control the deer population.
"The coyotes are making a comeback in the park. It seems to us that the biologist who put the papers together, who put the proposal together, would want to cultivate more respect for the coyotes," Ms. Hall told the Traveler on Friday. "You might know that the Pennsylvania Game Commission basically treats them as vermin ... I think that just makes people feel that there is something wrong with them, they are dangerous. They do live in the park, and they do have the capability of being able predators, particularly against the sick and the young deer."
In arriving at their preferred solution, Valley Forge officials did in fact consider using predators to control the deer numbers, but discarded it as unrealistic, said Ms. Heister, who added that past research has demonstrated that predators are not capable of controlling suburban deer populations.
"There is no expectation that a coyote population would be capable of regulating deer populations at this level," she said Friday. "We'd have a lot of fat, happy coyotes, but we'd probably have a similar number of deer."
While Ms. Hall was unfamiliar with a recent incident in a Canadian national park in which coyotes were said to have fatally mauled a young woman, she didn't think a coyote population in Valley Forge would pose a serious threat to visitors.
"They’re in our area. I think you have to be careful with your animals, if you have cats and dogs you have to be careful," she said. "But they’re indigenous to this area, and they belong here.”
Ms. Hall also said Valley Forge's deer population has stabilized -- a contention Ms. Heister disputed -- and that the animals are really not a problem, "other than eating people’s flowers in the area."
"I jog and hike in there and I don’t see them as a problem," she said.
Some problems created by the deer might not be obvious to all observers, though. According to Ms. Heister, the heavy foraging by deer impact ground- and shrub-nesting bird species such as black-and-white warblers and thrushes, which, she said, are in decline. And when oaks lose their acorns in fall, voracious deer eat them with relish, depriving squirrels and other ground foragers, she said.
The park is suffering "not only the indirect effects of complete removal of habitat, but direct competition for resources," said Ms. Heister. "The butterfly can't have the flower if the deer ate it already, and the squirrel can't have the acorn if the deer ate it already."