Almost 40 years ago, the California condor – the largest soaring bird in North America, boasting a wingspan of nine to 10 feet – became extinct in the wild, as the 22 surviving birds were taken into captivity in a last attempt to save the species. Roughly half a century before that, condors had disappeared from the Bay Area altogether, decimated by lead poisoning and other threats.

But now, thanks to extensive conservation efforts, more than 300 condors fly free in the wild – and for the fourth year, they have returned to the East Bay on an “aerial tour.”

“The condor story has wings,” said Seth Adams, land conservation director at the environmental nonprofit Save Mount Diablo, based in Walnut Creek. “It’s soaring, it’s inspiring, it’s all kinds of things.”

On Aug. 18, 2024, seven condors from the central California flock soared north over Alameda and Contra Costa counties, circling Mount Diablo and nearby areas for three hours.

The group was a mix of three wild-hatched condors and four that were raised in zoos and conservation centers before being released. They ranged in age from three to eight years old, and like all condors, the colored and numbered tags on their wings identified them as individuals.

“I’ve been monitoring condors for nearly 20 years, and it’s wonderful to see groups of them exploring further north in the Diablo Range every summer for the past four years,” said Alacia Welch, the condor program manager at Pinnacles National Park, in a statement released by Save Mount Diablo.

Because condors are still critically endangered – Ventana Wildlife Society counts 561 living condors in the world, of which 344 are wild and 101 reside in central California – scientists have fitted each condor with a radio transmitter to allow location tracking. Some also have GPS tags, which allow for more precise tracking but require expensive subscriptions to operate.

“We would rarely know of these long-range flights if it weren’t for the GPS transmitters on some of the condors,” Welch added.

Adams said that Save Mount Diablo has helped fund GPS tags for condors partly to test a theory that condors would explore the vast open spaces of the Diablo Range.

“Condors prefer intact habitat,” said Adams, and the Diablo Range is rich with it, serving as a haven for many rare plants and animals.

He added that while mature condors tend to stick to an established territory, juveniles under eight years old are more likely to explore further.

That is especially encouraging because 2024 has been a “banner year” for condor nesting, so more young condors will be ready to fledge in the near future. As of September 2024, the central California flock has hatched a record nine wild-born nestlings according to the National Park Service, and on Nov. 6 an additional six captive-bred young birds were released into the wild by Ventana Wildlife Society (VWS).

“The oldest condors in the wild are approaching 30 years of age, and as the flock becomes more established and expands in size, we expect that they will inhabit new areas that are suitable for their needs,” said VWS Executive Director Kelly Sorenson. 

“The Diablo Mountains are quite suitable and it is not surprising that condors are now starting to frequent this area.”

But even with intact habitat to return to, conservation experts say other hardships make the species’ recovery a challenge. The biggest threat to California condors by far is lead poisoning: when hunters use lead bullets, lead fragments contaminate the carcasses that condors feed on, causing life-threatening heavy metal toxicity.

Although the use of lead ammunition for hunting was outlawed in California in 2019, lead bullets are still often cheaper and more easily accessible than alternatives, so lead poisoning remains a crucial threat to condor recovery. According to the National Park Service, almost all of the adult condors in the Pinnacles National Park flock have needed emergency chelation treatment at least once – some being found with blood lead levels high enough to kill a human.

In addition to rehabilitating poisoned condors, efforts to prevent lead toxicity include providing a “clean food subsidy” (uncontaminated meat) to wild populations and promoting access to non-lead ammunition.

“Hunters and ranchers are key to the success of the condor in the wild,” said Sorenson, and should not be “villainized” for their traditions. Instead, VWS works to make non-lead ammunition more readily available, especially in areas where wild condors forage.

The program has made promising progress. “Lead poisoning is still the number one cause of death, but for the first time since the reintroduced birds began getting lead poisoning, we have not recorded a single death from this cause this calendar year,” Sorenson said. “[But] we know that a lack of non-lead ammunition still hinders access and use.”

“In the long run, our goal is to establish a self-sustaining population where hatches exceed deaths,” and eliminating lead poisoning is key to that goal, Sorenson added.

Other conservation threats to the California condor include “micro-trash” pollution, collisions with power lines, climate change-fueled wildfires, and highly pathogenic avian influenza (HPAI). After HPAI killed at least 10 condors in the Arizona-Utah flock in 2023, a vaccine for the birds was given emergency approval, and as of October 16, 2024, over half of the central California flock has been immunized against the deadly virus.

Despite all the hardships, conservationists have hope that the California condor will continue to recover in population and range.

“I wouldn’t be surprised if these summer forays [to the Diablo Range] continue into the future,” said Welch, “so all you eagle-eyed condor enthusiasts should keep an eye to the sky!”