Environment |

In Bay Area, bald eagles breed and soar once more

From a giant nest perched above the clamor of a Milpitas school playground, there’s a chilling high-pitched peal. It’s the call of the unwild.

Spring has sprung a beautiful surprise in the urban Bay Area: a bumper crop of breeding bald eagles. Long endangered, this powerful symbol of American strength and solitude is making a remarkable comeback in our crowded metropolis, with 19 reported nests in eight counties.

Creatures once seen mostly on the Discovery Channel are being sighted in a place better known for semiconductors, shopping centers and subdivisions. They’re soaring over Stanford’s Inner Quad, San Jose’s Westfield Oakridge mall, the levees of Alviso. One eagle recently perched on a pine tree near Raging Waters aquatic park in San Jose. Another was mobbed by crows on the runway at Palo Alto Airport.

The eagle boom here and across country is the pay-off for decades of environmental investment. Fifty years ago, the bird seemed destined to become a memory — seen only on coins and flagpoles — until official protection and pesticide restrictions changed its fate.

Like paparazzi, Milpitas parents and children gathered last week to gaze up at a redwood tree on the front lawn of Curtner Elementary School, swapping predictions about when eggs might hatch. They cheered when a bald eagle soared off the branch, its wings spread 6 feet wide, flashing its white tail like a winning hand of cards.

“They’re real majestic. Talons big as my hands,” said Ruben Delgadillo, who watches every afternoon when picking up his grandson.

Marveled another parent: “You could go your whole life without seeing this, or only see them in a zoo.”

In choosing a home, eagles look for the same things as people: plentiful food, a nice home and a little space, said Ralph Schardt, executive director of Santa Clara Valley Audubon Society. But just like millennials who get priced out of prime real estate markets, new pairs may be moving to more unconventional neighborhoods throughout the Bay Area.

“They fly right over our playground. Everybody’s like, ‘bald eagle, bald eagle! They yell it out,” said 11-year-old Ruben Delgadillo III, joining his grandfather after Curtner’s classes were dismissed. “It’s cool.”

The largest bird of prey in the United States, the bald eagle is one of the great success stories in wildlife conservation — proof that Mother Nature can bounce back, if only given a chance. Pumas, wolves and panthers are back on the prowl. So is the Yellowstone grizzly bear. Condors are recovering, as are gray whales. California sea otters, feared to be extinct until a small number, about 50, were discovered in remote coves off Big Sur in the 1930s, have rebounded to 3,272.

This spring, Bay Area raptors are particularly abundant. A new web camera in a Richmond shipyard is recording an osprey nest — one of 42 pairs producing 51 fledglings along the San Francisco Bay, numbers that have surged over the past five years, according to the Audubon Society.

Golden eagles are nesting in Cupertino’s Stevens Creek watershed. A long-gone Swainson’s Hawk returned to the Bay Area several years ago, nesting near the Coyote Creek Parkway. The white-tailed kite, almost extinct in California in the 1930s and 1940s due to shooting and egg-collecting, is common again.

There’s a peregrine falcon nest inside a hangar at San Francisco International Airport, said Glenn Stewart, director of the UC Santa Cruz Predatory Bird Research Group. Another pair is nesting on the counterweight of a Bay Area drawbridge, bobbing up and down every day.

Records are sparse about bald eagles’ early populations in the Bay Area. A nest in 1915 near the San Mateo County town of La Honda was the last evidence of local nesting until the current recovery, according to William Bousman’s “Breeding Bird Atlas.”

By the mid-1960s, fewer than 30 nesting pairs of bald eagles remained in the entire state of California — and they were all in the northern third of the state. Marshes were filled, and the pesticide DDT disrupted the eagles’ reproduction, thinning and crushing eggshells. Conservationist Rachel Carson warned in her book “Silent Spring” that the bird would soon be extinct.

The Endangered Species Preservation Act of 1966 helped reverse its fate. Penalties were imposed for shooting the birds. In 1972, DDT was banned.

The fish-loving birds were aided by the creation of many new man-made reservoirs, which were stocked with bass, catfish and trout.

To re-establish breeding populations in Central California, conservationists with the Ventana Wildlife Society in 1987 began importing chicks from Canada and Alaska, then released them into the Big Sur wilderness.

“That was our seed stock,” said UCSC’s Stewart. “We harvested 6- to 7-week-old eaglets and released them, 10 to 12 per year.”  Survivors of these 70 transplants began spreading, first to Lake Nacimiento in San Luis Obispo County..

Meanwhile, individuals began coming down from the north; the first modern nest record for the Bay Area was from Lake Berryessa in Napa County in 1989. In 1996, a pair of breeding eagles were found at Alameda County’s Del Valle Reservoir; the female was one of Stewart’s transplants from Alaska. The first nest in Santa Clara County was in 2006. Six years later, there was a nest in San Mateo County’s Crystal Springs Reservoir. One year after that, youngsters were born at Lake Chabot Regional Park in the Berkeley hills.

Now, with 40 known nests in Central California, Stewart said, “we have succeeded beyond our wildest dreams.”

There are now 371 recorded eagle breeding nests or “territories” in California, although they may not be used every year, according to Carie Battistone, statewide raptor coordinator at the California Department of Fish and Wildlife.

The federal protection effort has been so effective that the bird has been removed from the endangered species list. Last spring, two bald eagles — dubbed Mr. President and The First Lady — nested in a tulip poplar tree in Washington, D.C.

Our new generations of Bay Area eagles aren’t banded, which makes tracking and counting them a challenge. Juveniles are easily mistaken for other raptors because they don’t develop their distinctive white heads and tails for five years.

As their population expands, they’re moving out into new habitats, and perhaps habituating to human mayhem.

“Just look up,” joked Audubon’s Schardt, remembering a recent drive in rush hour along Interstate 280. “There they were, above all that traffic jammed along the Peninsula. I almost crashed my car.”

Eagle nest sites reported in the San Francisco Bay Area, by county: