Urban Wilderness: Birding in a National Airport’s Shadow

You may not think of the booming Washington, D.C. metro area, with its population of 5 million, as part of the Appalachian wilderness experience. Think again. If business or political activity takes you to the capital, be sure to seek out one of the most satisfying wildlife experiences possible: observing hundreds of bird species, including the bald eagle, at a protected birding area called Dyke Marsh.

The mighty Potomac River rolls out of the Appalachian Mountain foothills about 60 miles west of the city and as it approaches Washington it churns over the Great Falls within hollering distance of suburban housing estates. The river defines the southwestern edge of the District proper, widening as it reaches the great public monuments and Ronald Reagan Washington National Airport.

The George Washington Memorial Parkway rolls out of the colonial port city of Alexandria, Virginia, just south and west of the airport, and at a roadside pullout that’s marked on hardly any map sits 380 acres of unspoiled tidal marsh and swamp forest. Managed by the National Park Service and tended also by the Friends of Dyke
Marsh organization, Dyke Marsh is home to an astonishing range of bird life even as the metropolis grows all around it. A generation ago the health of the Potomac River was faltering; the river was red-brown, opaque, stinking and greasy, dangerous. Today, after years of restorative work, the Potomac runs relatively fresh and clear and once again supports a rich mix of vegetation and animal life. It’s a success story worth experiencing up close.

I first saw Dyke Marsh one cold winter dawn. It was the end of December 2002 and the sun, a shimmering orange disk, had just cleared the misty horizon. The city lay silent, sleeping, and the Potomac was as smooth as a mirror. I had gone to join the weekly bird watching group that meets for three hours each Sunday at 8 a.m., hoping to see a bald eagle in the wild…or rather, in the city. When I had first stumbled across the Friends of Dyke Marsh web site (www.fodm.org) the most impressive aspect was the bird list: more than 40 years of observation have yielded 296 species, from the ruby-throated hummingbird to the red-throated loon, from the yellow-crowned night heron to the yellow-rumped warbler. Double-crested cormorants, snowy egrets, peregrine falcons, great horned owls. The bald eagle was listed as “very common” in winter, so there I was. (Besides birds, the marsh supports snapping turtles, leopard frogs, red fox, river otters, beaver and muskrat.)

On that morning, ironically, the bird walk was cancelled because the big end-of-year bird count was taking place elsewhere, but a friendly regular — an elderly lady harnessed to a powerful pair of binoculars — pointed out several good spots to try and then gestured to the trail head.

Before exploring the trail, I spent nearly half an hour just beyond the parking lot, where a calm inlet was dotted with hundreds of big birds. Could those be whistling swans? And the great blue herons were notable for their impressive numbers and for their seeming fearlessness as they stalked their prey within a few feet of the shore. Never had I seen these magnificent birds this close. The water was so still that the tiniest ripples reflected little diamonds of sunlight onto the necks of three mallards as they paddled by. Golden-crowned kinglets flitted overhead. And in the distance, to the south, stood a stout pole in the water, topped with the unmistakable form of an eagle’s nest; the old lady had said one usually sits there.

Dyke Marsh is named for the earthen dikes that were constructed on these lowlands in the early 1800s, the better to create additional agricultural fields and grazing land in the tidal flats. Over nearly two centuries this raised land has become forested with sycamores, poplars and other deciduous trees that provide perches and nesting space. Now that farmers no longer use the fields, a tangled undergrowth has grown up, sheltering countless bird species, and the wetlands at the edge have become perfect habitat for waterfowl. For part of the 20th century the marsh was used as a construction dump, although that insult has been erased. Wildlife experts say this place is the “largest remaining piece of freshwater tidal wetlands in the Washington Metropolitan area.” Hard to believe it sits almost directly in the flight path of a major airport; the birds don’t seem to mind.

The footpath — once the “haul road” for crops and supplies — meanders through the forest before opening up to a wide swath of marshland where cattails glowed golden in the early morning light and songbirds filled the air with music. A new boardwalk takes birders out over the marsh, where wood ducks and mallards dabbled. A kingfisher surveyed the scene as I kept my eyes open for a bald eagle. No luck.

By the time I returned to the parking lot, the sun had warmed the old road through the forest and birds were busy feeding high overhead. A downy woodpecker was hard at work. Even a common backyard bird like the cardinal became exotic in this new setting; I watched one as it pulled chunks of seeds from the flower-like pods of the tall tulip poplar. Vines and berries everywhere also contribute to the abundant winter food supply.

Now a fellow birder walked past and quietly mentioned that he had just seen the bald eagle nearby: it had flown to the top of a tall tree clutching a fish. A few more steps…and there it was! The eagle faced out toward the river, hunched over as it tore at the big fish laid across a branch.

Winter, spring, summer, fall. Dyke Marsh always provides a memorable stop for nature lovers visiting the nation’s capital.