So Many Bald Eagles, So Little Room Left to Nest

In Virginia, the 2005 bald eagle survey by the Center for Conservation Biology said the number of breeding pairs grew 5.8 percent from the year before. The average annual rate of growth has been 10 to 12 percent in recent years.

"Growth in the Virginia breeding population appears to be slowing in recent years, possibly reflecting some threshold in capacity within the lower Chesapeake Bay," said the survey report, funded in part by state and federal wildlife agencies.

A record number of chicks were born in Virginia last year, though Watts predicted that this, too, could level off. Virginia bald eagles also are ranging into new inland territories as the prime coastal habitats fill up.

The one known eagle nest in the District, located on National Park Service land, did not produce chicks this year for the second year in a row, said Park Service resource management official Susan Rudy. The reason is unknown but could be related to parasites in the nest, she said.

The April 5 fight between two eagles near Washington began near a nest on the Maryland shore of the Potomac River that has produced chicks since the late 1990s. The pair occupying the nest were nicknamed George and Martha by construction workers on the nearby Woodrow Wilson Bridge along Interstate 95. Martha was attacked by another eagle, believed to be a female seeking to take over her territory, and is recuperating at Tri-State Bird Rescue.

The fight and its aftermath made news reports nationwide, in part because bridge construction workers see the nest every day. But Craig Koppie, a Fish and Wildlife Service biologist, said there is no doubt there are many more fights out of public view.

The male, George, guarded the nest for three days after the attack, but the eggs in it did not survive. Koppie said that a decade or two ago, biologists would have dismissed the idea that bald eagles would be willing to nest within earshot of a construction project, as these two did.

"Isn't it ironic," Koppie said, "that they could handle the man-made features and not the rivalry of their own species?"