Falconers have begun a push to be allowed once again to catch peregrine falcons, which nearly became extinct in the 1970s but are thriving to the point where two pairs have been seen fighting for the privilege of nesting next spring in San Francisco.
A number of predatory bird species, including bald eagles and peregrine falcons, neared extinction in the late 1960s and early 1970s as the DDT insecticide moved up the food chain and into their diets, causing eggshells to crack before the chicks were ready to hatch — a phenomenon famously documented by biologist Rachel Carson in 1962. The insecticide was banned nationwide in 1972, and many of the raptor species have since recovered.
Peregrine falcons were taken off the federal endangered list in 1999, but they remained on the state list. California Department of Fish and Game commissioners in October directed department staff to investigate, within a year, whether the bird should be removed from the state’s list of endangered species.
“The peregrine’s breeding range has recovered beyond most researchers wildest expectations,” falconer Gary Alten, who submitted the application to delist the birds as endangered, said. “We have peregrines nesting in cities all up and down the coast.”
Delisting the peregrines would allow falconers to catch up to 11 peregrines a year from the wild, Alten told The Examiner, and to train them to hunt for ducks and other birds.
More than 150 pairs of peregrine falcons are believed to breed annually in California, and five pairs were believed to have nested in California in the early 1970s, Alten said.
Peregrine falcons, which have pointy heads, large feet and gray wings with spans as long as 3 feet, feed mainly on pigeons in San Francisco and nest on tall buildings.
A pair of falcons that bred last year on the eastern span of the Bay Bridge have begun to swoop between buildings in the Financial District. The City is big enough for just one pair, biologist Glenn Stewart of the Santa Cruz Predatory Bird Research Group said, and the birds were recently seen dueling over Treasure Island with another pair that bred in the Financial District in recent years.
“They’ll go out together like a couple of F-16s,” Stewart said, “and fight with other peregrines that come into their territory.”