GRANDVIEW, W.Va. -- As a birthplace for peregrine falcons, Virginia's Robert O. Norris Bridge, arching 110 feet over the mouth of the Rappahannock River and crossed by 11,000 vehicles a day, is often a deathtrap.
The bridge offers adult peregrines a good vantage point from which to prey on a wide variety of birds drawn to the western shore of Chesapeake Bay.
"But for young peregrines learning to fly, the bridge has a very high mortality rate," said Wendy Perrone, director of the Three Rivers Avian Center and project coordinator for the New River Gorge's peregrine falcon restoration program. "Many of them are hit by cars and trucks."
A brother and sister peregrine falcon, collected from a nest on the Virginia bridge earlier this week by Virginia wildlife personnel, have been relocated to a cliff along the rim of the New River Gorge, where they will be released in two or three weeks, after acclimating to their new, more peaceful, home.
Three other peregrine chicks from Finney's Island in Chesapeake Bay were initially scheduled to arrive Tuesday with the bridge-born pair, but high winds and choppy water made their pickup and delivery too hazardous.
"They'll have a much easier time learning to fly and hunt here," Perrone said.
Last week's arrival of the two young Virginia falcons marked the start of the sixth year of a National Park Service peregrine restoration program at the New River Gorge National River.
Funding cutbacks left the program's future uncertain until mid-April, when Perrone got the green light to proceed with another year of peregrine releases -- with a pared-down budget.
"Whether or not there would be a program at all this year went back and forth for months," said Perrone. "We took a small cut, but we're glad to be adding a sixth year."
"We realize now that we can't take this program for granted," said National Park Service wildlife biologist Mark Graham.
Since 2006, 100 young peregrines have been released in the New River Gorge, and survived at least long enough to learn to fly and hunt. The project is the largest in terms of numbers, and most successful, in terms of birds surviving past the fledgling stage, in the Eastern United States.
Peregrine falcons were listed as an endangered species prior to 1999, due primarily to widespread use of the insecticide DDT, which entered the food chain and caused the falcons to produce abnormally fragile eggshells and fewer offspring.
After DDT was banned in the United States in the early 1970s, peregrine numbers began to rebound, boosted by reintroduction efforts across the nation. While no longer considered endangered, the falcons have still not repopulated all of their native range, particularly in the East.
Peregrines are the world's fastest animal, capable of diving for prey at speeds of 260 mph. They feed primarily on other birds.
Surveys by wildlife biologists have identified the New River Gorge, with its abundance of cliffs, as some of the best habitats in the Eastern United States for re-establishing a small peregrine falcon population.
While a population has yet to be re-established in the New River Gorge, a breeding pair of peregrines was observed nesting on a cliff within the Gorge in Fayette County in 2009. Bands on the male identified it as a New Jersey-born peregrine released in the Gorge in 2007.