In order to ensure bald eagles and other wildlife will continue to thrive in their natural habitat in the Woodrow Wilson Bridge Project Area, a permanent 84-acre bald eagle sanctuary was created on March 2001on Rosalie Island in Prince George’s County, Maryland.  The sanctuary is more than eight times larger than was required by the US Fish and Wildlife Service, underscoring the project’s commitment to build the new facility in an environmentally friendly manner.  Just the fact that the bald eagles have decided to nest so close to the 200,000 vehicles that travel the Capital Beltway each day suggests that they may have developed a higher tolerance for human activity.

Female, Martha, perched at Rosalie Island, 2004

In June 1998, the U.S. Fish and Wildlife Service, during a routine regional flyover, identified a Bald Eagle nest in Betty Blume Park which is a Maryland – National Capital Park and Planning (M-NCPPC) – owned park, located in Prince George’s County, Maryland south of the Beltway near the National Harbor property.  This pair has affectionately come to be known as George and Martha Wilson, the first family of eagles located at the Woodrow Wilson Bridge. 

The Project’s Environmental Team has taken a great interest in both the resident and wintering eagle activities in an effort to avoid conflict with construction activities.  Well before construction started, in 1999, the Woodrow Wilson Bridge Project Environmental Team began field observations of the resident pair.  Between January and June of each year of active construction, bird specialists, called ornithologists, observed the eagles regularly from a boat in Smoot’s Cove and Oxon Cove, or from a parking lot when the nest was moved to Park property.

Wintering bald eagles at Smoot’s Cove, 2003  

Oxon Cove is on the north side of the Beltway and is a likely location for birds to perch while they are fishing in the cove.  The old bridge deck after it was demolished, was placed into the cove to create nooks and crannies for fish to swim through.   Smoot’s Cove is on the south side of the Beltway where the deep water that was mined many years ago allows for other deep-water fish to live.  Each year the Team has been fortunate to see this pair’s young.  They also report on the number of eggs hatched and have determined the number of young fledged from the nest (first flight).  They recorded the eaglets as they learn the basic skills they need to survive to adulthood and become active breeders like their parents.  From the first tentative flights out of the nest, to the parents teaching the young how to hunt, fly, and well, just how to be an eagle the birders have watched every move.

The bird specialists can recognize the eagles by distinctive colors of their feathers, patches of colorings about their faces, beak characteristics, similar to the way that you might see differences in other like creatures such as dogs or cats.

Adult male and female eagles look exactly the same with a body length of 30-31" long (76-79 cm) and an amazing wingspan of 6-7' 6" (1.8-2.3 m)

Martha in full flight, 2004

Because we have spent so many hours observing this resident pair, several physical differences are apparent.  When the birds are in the same physical location, it’s easy to see which is the female, she’s bigger.  Her body is bigger to accommodate egg laying. Martha also had something else which made her easier to spot, her tail feathers had a reddish tint to them. When she soared overhead, with sunlight streaming from above, her tail feathers looked almost like a red-tailed hawks'!  We are not certain if she got into something that left a lasting stain on those feathers, or whether it’s a result of her genes, but she also had some reddish feathers on the right side of her white head.

Incubation shift change, George on right, 2004

George is comparatively smaller and has a different dark brown tint on his chest and wing feathers.  He’s more milk chocolate colored compared to Martha’s dark chocolate.  George has also had some additional scarring on his beak, which makes it easier to tell them apart.

George at the nest, 2004

Eagles are known to be builders of the largest single pair nests in the world, reaching up to 12 feet in diameter and weighing up to 1,000 pounds.  The fact that eagles will use the same nest year after year, building upon the previous season like a foundation, allows for a significantly larger nest in the coming years.  In addition to gathering fallen branches and small limbs from the shoreline and woodland interiors, the adults break large branches off live trees!  The eagles would circle around the tree tops, eyeing a particular branch, start into a dive, talons lunging forward, and hit the branch with such force they would snap the branch off.  The entire tree trunk would sway from the force of the strike!

In their first 3 years in Betty Blume Park, George and Martha successfully fledged 8 eaglets: 3 in 1998, 2 in 1999 and another 3 in 2000.  They were in the nest in Betty Blume Park until a strong windstorm in Fall 2000 blew down their nest. In 2001, they built a nest farther south along the Maryland shoreline adjacent to Smoot’s Cove, closer to the Woodrow Wilson Bridge construction, and again fledged 2 eaglets.  George and Martha faced further challenges when the second nest blew down after another windstorm.

Subsequently, the resident eagle pair selected a location along the southern tip of Rosalie Island, approximately 75 feet from the edge of the active work zone.  Since they selected a site so close to the active work zone, they were watched as they built their nest.  The pair stayed in this nest for 4 breeding years with 2 eaglets fledging in 2003, 3 eaglets fledging in 2004, followed by two nest failures in 2005 and 2006 for an estimated total of 15 fledged young.   

One of two eaglets that fledged in 2003. Woody first flight weekend

After sustaining injuries previously in April by a competing female, Martha was euthanized in October 2006 after a dislocation of her right elbow.  George remained in the project area, unmated until the end of the 2007 breeding season.  With the aid of a new female, a new nest was built along Harborview Avenue adjacent to Oxon Hill Manor where 2 eaglets fledged in July 2008 and 2 eaglets fledged in July 2009.

In early April 2004 we eagerly watched as George and Martha incubated their newly laid eggs.  Eagles usually lay 2 or 3 white eggs in late February to early March.  In 2004 we confirmed incubation (or care of the eggs) began on March 3, 2004.  Eggs began hatching out on April 8 and by April 10 the adults were seen feeding the young eaglets.  Eggs may not hatch out at the same time, so there may be several days time between the first eaglet birth and any others.

Martha incubating eggs, March 2004

Incubation behavior is easily monitored.  At least one of the adults is almost always in the nest.  On extremely warm days, the adult can come out of the nest for up to 20 minutes without harming the young inside.  At times like these, it is not unusual to observe the eagles flying down to the water surface, skimming their breast feathers along the water and flying back to the eggs, cooling the eggs with the wet feathers.  Both adults take turns incubating the eggs.  Typically, the female remains in the nest overnight while the male roosts nearby.  After eating in the morning, he will take over the incubation duties for the day leaving the female free to feed, preen (or groom), and monitor their territory by flying high above the Capital Beltway.  By late afternoon, usually between 4:00 and 4:30 pm the second shift change of the day occurs, and the male is once again free to eat, soar, preen, and roost and in general just be an eagle.

Two young eaglets in nest, 3 weeks old, 2004

When the eggs hatch out after a 34-36 day incubation period, food will be brought back to the nest by both parents, where pieces are torn off and offered to the chicks.  After several weeks, food will be left in the nest with the young responsible for feeding themselves.  Fish comprises 80% of the eagles’ diet, however, eagles are great scavengers and will harass other birds (especially Osprey), and will often also feed on road kill, small rodents, waterfowl and eel.

And just what will the young eagles do for their first several weeks of life? Everything is new and interesting, so they will be learning and watching.  They will learn eagle behavior from their parents, what foods to eat, how to catch their food, what vocalizations and expressions mean to each other and to other species of wildlife.  They will learn what predators are and where they fit into the food chain.  They will watch young goslings and ducklings underneath their nest tree.  They will learn about fox and deer.  They will learn how to fly, how to lift off and how to land, how to turn and what they can do with their talons.  They will exercise their wings; they will preen their feathers. And occasionally, they will have little tiffs with their siblings in the nest.  By the time fledging  occurs in early July, the eaglets will be about the same size as the adults.  We can identify females, which can weigh up to 12 pounds, even when young, based on their size.

eNature's Wildlife Audio: Bald Eagle

Their parents will tempt them to leave the nest and begin flight training by bringing food back near the nest, but not right to the nest.

Even though they will receive the best of care from their parents, the first year of these new eagles lives are full of danger.  Around mid fall, the adults will drive their offspring from the area.  Where these juveniles fly to and what they do is something we don’t know.  None of the eagles are tagged or radio collared.  It is suspected that offspring of the bridge pair may visit occasionally during the migration south in the winter or when looking for territory. 

George with newly hatched eaglet at 3 weeks old, 2004

We know that only 10% of eagles survive to adulthood, most dying from starvation.  When they reach sexual maturity, the female will select a nesting area and a mate. The females control Bald Eagle territory.  Consequently, if something should happen to the male and she remains in her breeding years, she may select another mate.  Eagle pairs will stop breeding between 10 and 12 years of age and then relinquish their territory to a younger mated pair.  The breeding cycle will then start all over.  We can identify wintering birds and guess their approximate age, even before they develop the distinctive white head and tail feathers marking maturity.  Differences in the chest and breast feathers provide easy identification features.

Martha at the nest, 2004

Because of the endangered/threatened status of eagles, the project, in compliance with federal regulations consulted with the U. S. Fish and Wildlife Service to determine how best to protect these birds while simultaneously constructing a new bridge.  In April 2000, the project produced a listing of reasonable and prudent minimization measures to the resident eagles when they are at the nest, as part of a formal technical document called an Environmental Assessment.  The regulatory agency (United States Fish and Wildlife Service or USFWS) then concurred with a formal document called a Biological Opinion, each in accordance with the Endangered Species Act.  These documents are updated as new information evolves.

George in flight, 2004

The policies and recommendations are strictly adhered to and have resulted in the re-alignment of a major construction haul road on the Project in Maryland, restricted areas around the nest, time of year restrictions for certain activities in locations around the bald eagle use area, and purchase of 84 acres now being used for a Bald Eagle sanctuary on the north side of the Beltway, in Maryland.

George, 2004

On August 8, 2007 the Bald Eagle was removed from the Federal List of Endangered and Threatened Wildlife for all the lower 48 states of America.  Due to environmental diligence nation wide, the reported number of mature reproductive pairs increased from 487 in 1963 to a reported 9,789 in 2007 resulting in the delisting.  Unfortunately, May 1, 2008 the Bald Eagle was re-listed as threatened but, only in the Sonoran Desert, Arizona. 

• FINAL SUPPLEMENTAL BIOLOGICAL ASSESSMENT, Woodrow Wilson Bridge Project, Federal Highways, April 2000
• www.enature.com, website
• Baltimore Sun, Page 1, August 4, 2003 “Eagle eyes watch over Wilson Bridge Project”, Stephen Kiehl
• Field observations, Woodrow Wilson Bridge Project, Bald Eagle Status, various dates through August 2009
• Washington Post, May 11, 2003, Update: Bald Eagle Provide Noisy Nursery for Offspring Amid Bridge Construction
• Lives of North American Birds, Kenn Kaufman, 1996.
• www.fws.gov/Endangered/wildlife.html, website