A peregrine falcon shrieked in vain Friday as scientists snatched three eggs from his precarious perch beneath the Bay Bridge in an attempt to save the chicks from a deadly fall or car collision when they hatch.
"It's the most dangerous place in the world for them," said Brian Latta, a University of California, Santa Cruz, biologist who removed the eggs from a narrow beam about 200 feet above San Francisco Bay.
The parents, dubbed George and Gracie, had nested for years on the 33rd floor ledge of a downtown skyscraper, where they raised several clutches of chicks. The pair relocated to the bridge this year at the same spot where George hatched in 1999 and was rescued in a similar operation before he was old enough to fly.
If the eggs were allowed to hatch under the bridge, crosswinds could send the fledglings plummeting into the bay or hurtle them under the wheels of passing cars when they left the nest for their first flights.
Latta moved in Friday after Gracie left George alone to defend the nest, a two-inch depression in a wind-blown pile of dirt. Peregrines are known for their ferocity when their nests are invaded, and George swooped and circled as the eggs were taken.
"When the female comes back, he's going to have a lot of explaining to do," Latta said.
The couple are celebrities among San Francisco bird watchers, who have followed their progress in past years via a Web camera near the previous nest at Pacific Gas and Electric Co.'s city headquarters.
The peregrine falcon, which can reach speeds of more than 200 mph in its hunting dive, has taken up residence in many U.S. cities. Tall buildings mimic the steep cliffs that are the birds' natural habitat, and pigeons provide a plentiful source of food.
By removing the eggs from the nest, scientists hope George and Gracie return to their old nesting site and lay new eggs within a few weeks.
A digital monitor detected a heartbeat in two of the three eggs, which were packed in foam in separate plastic tubes after the rescue.
Biologists at the university's Predatory Bird Research Group planned to incubate the eggs and turn the hatchlings over to adoptive peregrine parents until they are ready to return to the wild.
While the raptor was removed from the federal government's endangered species list several years ago, it remains fully protected under California law.