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Eagle-Eye View on Potomac Riverbank

Potomac Pathways: Since 1986, bald eagles have nested on Conn Island, minutes from Great Falls Tavern.

The nesting pair of bald eagles on Conn Island keep busy hunting for fish along their stretch of the Potomac and incubating their eggs through the winter in hopes of hatching a successful chick. It’s unlikely that they ever pause to reflect on what they symbolize.

They are among the most easily spotted living examples of our national symbol that feels diluted in a city where it is embossed on every coin, chair, T-shirt and podium. For C&O Canal National Historical Park visitors, seeing them entails a kind of redemptive thrill.

THE EAGLES also represent an ecological success story. Beginning in the late 1960s, bald eagles became gravely endangered due to use of the pesticide DDT. By the early 1970s, there were fewer than 500 pairs of bald eagles in the continental United States. DDT was banned in 1972, and following decades of conservation efforts, the bald eagle population has rebounded to more than 4,500 pairs in the lower 48 states.

In Maryland, the Department of Natural Resources identified 41 nesting pairs in 1977 and more than 400 pairs in 2004, a resurgence that has “far exceeded recovery goals” according to Glenn Therres, bald eagle biologist for the department’s wildlife and heritage service.

And the Conn Island birds are a symbol of backyard ecology at its best — a species usually identified with Alaskan wildlands that can be found minutes from the Beltway. They are the only nesting pair in Montgomery County and one of the only nesting pairs in Maryland along non-tidal waters — and few people know that they’re there.

MID-WINTER IS an important time in the bald eagle life cycle and a great time to see the Conn Island eagles, according to Rod Sauter, a park ranger at the Great Falls Tavern.

“Typically bald eagles in this area will have eggs on their nest somewhere around Valentine’s Day and then they usually hatch … around St. Patrick’s Day,” Sauter said.

That means that one eagle will almost always be on the nest incubating and protecting the eggs, while the other makes frequent trips up and downriver to hunt for food. Both activities provide good viewing opportunities for patient spotters and the nest is easier to see in winter when the surrounding trees are bare.

“Being patient is the key to all birding activities,” said John Bjerke, an amateur ornithologist who leads birding trips for the Audubon Naturalist Society. The other key, he said, is a good pair of binoculars or a mounted spotting scope.

The Conn Island nest is roughly the size and weight of a small car and is easy to see with the naked eye, especially when viewed from the spot on the River Trail directly across from it. But watching a soaring eagle will require binoculars, and a mounted scope is the best option for seeing the eagle in the nest, whose white head is often visible above its front edge.

Of course, some visitors are lucky enough to see one of the eagles make a low pass along the river. Bjerke said inexperienced birdwatchers sometimes confuse turkey vultures for the bald eagles. The trick to distinguishing them is paying attention to their posture in flight, Bjerke said.

“When [bald eagles] are soaring, they often soar with their wings perfectly level. When you see turkey vultures soaring along, they tend to wobble … and they tend to have their wings up in at least a shallow V,” he said.

THE CONN ISLAND pair first nested in there in 1986 and have returned nearly every year since then. In 1988 the nest tree fell over but in 1989, the eagle pair built a replacement nest in the current location and fledged two young.

Therres started surveying Maryland eagle nests by airplane in 1984 and took charge of Natural Resources’ eagle program in 1986, the same year that Conn Island eagles arrived. Since then, Therres has lived and breathed eagles, but one doesn’t have to be an eagle expert to appreciate the birds.

For one thing, they’re both long-lived and monogamous.

“In all likelihood they mate for life. They don’t necessarily stay together year round, but they are faithful,” Therres said.

For another, they’re an example of federal and state environmental policy working effectively. The federal ban on DDT and the protections conferred by the eagles’ endangered species status were the foundation for their resurgence. Maryland programs to restore the Chesapeake and establish a 1,000-foot shoreline protection zone cemented it.

But perhaps most importantly, the bald eagle’s symbolic cache has fueled public interest in conservation.

“I get excited about seeing them and I see them quite a bit,” Bjerke said. “They’re pretty majestic looking,” said Therres, which helps them generate far more public attention than, say, the several species of tiger beetles that are endangered in Maryland.

“It’s not the eagle’s fault,” Therres said. “It’s a bug. It’s not an eagle. It doesn’t carry the charisma.”

CONN ISLAND

Conn Island is a 35-acre oval running north-south from between one-fifth of a mile upstream of the Tavern. The island is completely forested and rarely visited: it is dangerous for even experienced boaters to access due to the Washington Suburban Sanitary Commission dam just downstream.

The land is owned by the Nature Conservancy, though the organization has plans to transfer it to the National Park Service according to Mary Travaglini, Potomac Gorge habitat restoration manager for the Conservancy’s Maryland/D.C. chapter.

The island is dominated by a floodplain forest, with low-lying plant life that can survive occasional flooding. It is home to several species of rare or threatened plants and to a large blue heron rookery, where the herons nest and raise their young.

The bald eagle nest on Conn Island is on the island’s eastern shoreline, facing the Maryland bank of the Potomac, about halfway up the island’s length.

BALD EAGLE LIFE CYCLE

Bald eagles do not develop their characteristic white head and white tail until they are sexually mature, about 4-5 years old. Prior to that their appearance varies greatly but is generally brown and mottled.

When bald eagles are 4-5 years old, they nest for the first time. Monogamous nesting pairs lay 1-3 eggs around February, which, if successful, hatch around early April each year. Young stay in the nest for about 12 weeks and typically start flying in mid-June. They stay nearby for several more weeks learning how to hunt and feed and then go off on their own, living nomadically for the first four years of life.

Bald eagles feed mostly on fish, and while they are skilled hunters, they are known equally as scavengers and even thieves. They often harass other birds, such as osprey, and claim their quarries. They also prey on waterfowl, turtles, muskrats, and carrion or roadkill.

LOCAL BIRDWATCHING

For more information about all kinds of birdwatching in the Washington area, contact local conservation and birding organizations like the Audubon Naturalist Society

“That’s really the best way — the only way that you’re ever going to actually learn how to bird and where to find them is to go on group trips with local organizations,” said John Bjerke, and amateur ornithologist who leads trips for the Society. He said that novices are always welcome.

* The Society conducts free bird walks, bird counts for research and bird watching events for charity. It also oversees three local nature sanctuaries, including Woodend Sanctuary in Chevy Chase. To participate in Audubon Naturalist Society birding events, visit www.audubonnaturalist.org and click "Birding" or call 301-652-1088 for recorded information, which is updated weekly. Woodend Sanctuary is located at 8940 Jones Mill Road, Chevy Chase.

* Locust Grove Nature Center in Cabin John Regional Park has naturalists who lead bird watches in the area. Locust Grove’s Web site, www.mc-mncppc.org/parks/nature_centers/locust, lists upcoming events.

* The Montgomery Bird Club is a chapter of the Maryland Ornithological Society that sponsors bird field trips and holds monthly meetings, on the third Wednesday of every month at Potomac Presbyterian Church, 10301 River Road, from 7:30-9:30 p.m. Everyone is welcome. Visit www.mdkinc.com/mccbird.

* The C&O Canal National Historical Park has river, forest, marsh and field habitats alongside the towpath, and Rileys Lock and Lock 7 (near Glen Echo at the intersection of Goldsboro Road and MacArthur Boulevard) are favorites of local birders. A local bird guide and a hike in C&O Canal National Historical Park is a great start for those who wish to go solo. The Lockhouse 8 River Center, located between Great Falls and Glen Echo on the C&O Canal operated jointly by the Potomac Conservancy and the National Park Service, holds regular nature programs, including bird walks. The Lockhouse 8 River Center Web site is www.potomac.org/action/ctg/lockhouse.