California’s Yurok tribe has secured federal and state support to locate new reintroduction sites for the critically endangered California condor. The alliance comes on the heels of a historic state law banning the use of lead bullets, the main cause of the birds’ high mortality in the wild.

After 22 years of struggling recovery programs to help California condors reclaim their habitats, California’s Yurok tribe has secured the cooperation of state agencies to determine whether the huge bird can be released into the northern Redwood Coast, an area they disappeared from 100 years ago due to human activity.

Condors may soon have a shot at surviving in these ancestral habitats unaided, thanks to a new California law banning the use of lead bullets, which is their primary killer.

Condors are obligate scavengers who have lived off the carcasses of mammals ever since the Pleistocene Era served up decaying mastodons. But 150 years ago their populations began to decline quickly, as European settlers in the Western US began killing the giant birds, gathering their infrequently-laid eggs, and littering their habitat with scraps of lead ammunition.

By 1982 only 21 California condors remained, and the US Fish and Wildlife Service recovered the carcasses of three birds, two of whom had died from lead, according to John McCamman, the agency’s California Condor Recovery Coordinator. At the time, scientists weren’t sure what had lead to the species’ precipitous decline, but, says Mr. McCamman, “It has become increasingly clear.”

The vast majority of rifle ammunition used in the US is made of lead, and when a hunter shoots a deer or a rancher shoots a coyote, one bullet can split into as many as 500 fragments, according to Kelly Sorenson, executive director of central California’s Ventana Wildlife Society, a conservation organization that works to reduce the prevalence of lead-riddled carrion in condor habitats. Consumed in carcasses or entrails, these lead fragments paralyze the birds’ digestive systems, causing them to starve.

In 1987 the entire existing condor population of 27 was captured for protection and breeding, writes Michael Wallace, in a 2012 history of the subsequent recovery efforts. Biologists succeeded in helping the population grow, and in 1992 they reintroduced the first condors into Los Padres National Forest. With careful management their numbers have risen past 400, between two wild populations and the ongoing captive breeding program.

But the California condor is still classified as critically endangered. Recovery programs provide the wild birds with stillborn calves as a source of lead-free carrion, and they capture lead-sick birds and treat them, when they can.

Despite this extra help, says Mr. Sorenson, their human-scale rate of reproduction – one offspring every two years – is no match for the high annual mortality rate of the wild populations. Condors naturally live to be 50-70 years old, says Sorenson, yet in 2013 10 adults died in California alone.

According to McCamman, the leading causes of death are lead poisoning, at 35 percent, and predation, at 15 percent.

“If we stopped managing the birds today, the species would once again decline anywhere, because of the extent of lead ammunition use,” says Sorenson.

To give the condor a fighting chance, the California legislature and governor passed A.B.711 in October 2013, a bill that bans the use of lead ammunition from 2019. A federal ban on shooting waterfowl with lead shot was enacted in 1991, but California is the first state to pass a total ban, despite intense opposition from the National Rifle Association.

Copper bullets, an alternative to lead, cost about $15 more per box, says Sorenson, whose group plans to distribute $25,000 of leadless ammunition free of charge this year, to people hunting or ranching near condor habitats.

The Yurok tribe, for whom the California condor has long been a sacred animal, is leading the charge to create a new reintroduction site near their reservation, which is based at the mouth of the Klamath River. For five years a team of Yurok wildlife biologists have used federal tribal grant funding to study the feasibility of various sites, by releasing and studying vultures. Like the condors, vultures are obligate scavengers vulnerable to lead poisoning, but unlike them, they are not critically endangered.

None of the tribe’s staff were available for comment, but tribal microbiologist Tiana Williams told Associated Press, “When a species like condor or eagle gives you material for your regalia, it is considered their spirit is in that, too. They are singing with you, and praying with you. We can get feathers from the US Fish and Wildlife Service, but it’s not the same thing as being able to go out there and collect the feathers we need from condors flying over our own skies.”

This week’s memorandum of agreement, between the Yurok tribe, the Fish and Wildlife Service, the state’s National Park Service, the California Department of Parks and Recreation, and the Ventana Wildlife Society, signals a shift in momentum which Sorenson says the new anti-lead law sparked.

“The intent is that we will drive this to conclusion,” he says.