Biologists have confirmed what many Bay Area bird-lovers have suspected: This spring has sprung a bumper crop of breeding bald eagles, restoring populations of our powerful national symbol.

At least 30 breeding pairs of eagles have been counted this spring in central coastal California, from Marin to Santa Barbara County, according to the Ventana Wildlife Society. Their findings were reported in the latest issue of the Journal of Raptor Research. Related Articles Bald eagles settle into suburban life

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“The species almost went extinct but now we have a robust and growing population of bald eagles,” said lead author and the society’s Executive Director Kelly Sorenson, in a prepared statement. “For 60 years, bald eagles were absent from central California during the summer breeding season.”

A nest in a redwood tree on the front lawn of Curtner Elementary School in Milpitas has attracted so many people that the Milpitas Unified School District issued a protocol for visitors to keep their distance. A warden from the California Department of Fish and Wildlife patrols the area to ensure the safety of the eagles, particularly on weekends.

Nests also were reported near Santa Clara County’s Lexington Reservoir, Anderson Reservoir, Calaveras Reservoir and Arastradero Preserve; Alameda County’s Del Valle Reservoir; San Mateo County’s Crystal Springs Reservoir, Contra Costa County’s Sunol Regional Wilderness.

Now most or all of the Bay Area eaglets have begun exercising their wings near the nest, practicing short takeoffs and landings. Some have already fledged, leaving the nest.

Many of today’s eagles are thought to have originated from populations brought to Big Sur from Alaska, British Columbia and northern California.

Between 1986 and 1994, 66 young eagles were collected and released at the same site of the present-day Condor Sanctuary owned and managed by the Ventana Wilderness Society.

Breeding of these introduced birds was first documented in 1993.

By 2012, the central California population increased to 26 known occupied breeding territories, exceeding the recovery plan goal for central California.

This number likely underestimates the actual number in central California, because the large size of the region and limited access to private land prevents a thorough search, according to the report.

While not all Bald Eagle nesting in the region can be attributed to the project, the first seven nesting pairs each included at least one released eagle. So Sorenson believes that the project expedited the recovery of a Bald Eagle breeding population in central California.

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.

The bald eagle was chosen in 1782 as the symbol of the United States of America, because of its long life, great strength and majestic looks.

But by the 1900s, the species seemed slated for extinction. Habitat was lost, as marshes were filled. The pesticide DDT disrupted the eagles’ reproduction, thinning and crushing eggshells.

Although Bald Eagles historically nested statewide, most nesting had ceased in the southern Sierra Nevada

range and the central California coast by the 1930s, according to the new report. Thereafter, breeding Bald Eagles were almost entirely limited to the northern quarter of the state, although they sometimes visited lakes and reservoirs elsewhere during the winter.

Bald eagle populations have rebounded since the Endangered Species Preservation Act of 1966 helped reverse their 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.

Sorenson sees a parallel between bald eagle and California Condor recovery in central California.

Like the eagle, California Condors are now showing positive signs of recovery as well due to ongoing efforts to minimize the threat of lead poisoning from eating ammunition the primary obstacle to condor recovery.

“For both the California Condor and the Bald Eagle, their recovery is only made possible due to the passage of the Endangered Species Act and a whole lot of people who care enough to save them,” said Sorenson. “Both species give us hope for wildlife conservation and our ability to take care of the planet and the ecosystem.”

Tip Line for Protecting Bald Eagles

Eagles are protected by the federal Bald and Golden Eagle Protection Act.

To report someone harassing an eagle nest, call the toll free “CalTIP” number of the California Department of Fish and Wildlife at (888) 334-2258.