There aren’t many happy conservation stories these days.

The plot and players are familiar by now: a species on the verge of extinction and a swelling human population seemingly intent on pushing it over the edge, plus the ever-looming climate catastrophe that ratchets up the stakes in all wildlife protection narratives.

But in the case of the California condor — North America’s largest flying bird — those elements add up to something very different: good news.

In 1982, when just 22 California condors were left in the world and the species’ obituary was being written in advance, scientists captured the remaining population to breed the scavenger birds in captivity. Nearly four decades later, a consortium of government agencies and nonprofit groups announced a miraculous milestone: 1,000 California condor chicks hatched since the official rescue program began.

The 1,000th chick hatched at Zion National Park in Utah, probably in May. Officials confirmed its survival earlier this month, inspiring a symbolic cheer at a time when experts say Earth is experiencing its sixth mass extinction of plants and animals, the worst since dinosaurs died off 65 million years ago.

“We don’t celebrate the successes enough to remember what that feels like and get reinvigorated,” Chris Parish, director of conservation at the Peregrine Fund, a partner in the recovery program, told The Washington Post. “We’ve put a lot of effort into this. A lot of dollars, a lot of years of research. We are closer to recovery, and our ultimate goal is a self-sustaining population.”

Forty thousand years ago, condors prowled skies across North America, their nearly 10-foot wingspans cutting an impressive figure wherever the trail of mammoth and saber-toothed cat carcasses led them. Considered sacred by many Native American tribes in the west, the number of California condors began to dwindle as citizens of a young United States spread across the continent.

Researchers began studying the vultures in earnest in the 1940s and even then, the population was imperiled, Parish said. By the 1980s, with fewer than two dozen remaining, experts began the slow process of capturing, breeding and reintroducing the birds back into the wild.

The population has since grown to more than 500, with over half living outside of captivity. In 2016, the Los Angeles Times reported this progress represented “one of the most dramatic turnarounds ever for a species on the brink of extinction.”

But the species remains critically endangered, and the raptors are now found mainly in California, Arizona, southern Utah and Baja California, Mexico.

Experts have monitored the condors intensively, trying to determine what exactly leads to their demise. It’s not a lack of food, Parish said, and it doesn’t seem to be the always expanding human industrial complex, either, eliminating two of the most common species killers. Instead, scientists have found that the leading cause of California condor mortality — by far — is lead poisoning.

The birds often feast on the carrion of animals shot and left behind by hunters, and they sometimes swallow lead pellets, fragments or whole bullets while picking at the flesh. Scientists understand this relationship, between lead and animals that become part of the food chain, in large part because they were so fastidious in their study of the California condor.

It was among the research that prompted California’s ban on lead ammunition, which took effect this month and prohibits lead ammunition when shooting any wildlife anywhere in the state. But Parish and the North American Non-lead Partnership have avoided advocating bans and are instead pushing for increased education in the hunting community.

Parish pointed to a pilot program in Northern Arizona, where nearly 9 in 10 deer hunters have either switched to non-lead ammunition or agreed to haul away the remains of shot animals. It’s programs like that, he said, that must be expanded if the conservation community wants to continue the condor’s success story.

For Parish, the fight for the California condor is bigger than just the one species.

“It’s not the bird that’s worth it,” he said. “It’s successfully identifying the problem and solutions and acting on those solutions. That’s what we’re going to need. We’re going to need to have confidence in society that we can do it again.”

Because Parish, like most all conservationists, knows that the California condor is far from the final species to teeter on the precipice of extinction.

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