A recovery program aimed at restoring the California condor to much of its historic range across the Southwest has been hampered by dozens of deaths linked to lead from the remnants of hunters' bullets, wildlife officials say.
About half of the roughly 130 condors released since 1996 along the Arizona/Utah border have died or vanished, said Steve Spangle of the U.S. Fish and Wildlife Service.
"Lead is the No. 1 problem with the program," Spangle said. "We would have been wildly successful without the lead."
California has an additional 111 of the birds in the wild largely due to a separate recovery program there, said Susan Whaley of The Peregrine Fund, which raises condors at the World Center for Birds of Prey outside Boise, Idaho.
The San Diego Zoo was the first facility in the world to successfully hatch a California Condor. The Zoo also contributes to the endangered bird’s repopulation.
As scavengers, North America's largest land bird feasts on carcasses such as deer and coyotes left behind by hunters.
Spangle said hunters generally prefer lead bullets because they are heavier and shoot straighter than other types of ammunition. But they break into hundreds of fragments when they hit an animal, then get ingested by scavengers like the condor.
"Most biologists believe we'll never have a sustaining population unless we remove the lead from the environment," Spangle said.
The California Department of Fish and Game in 2008 banned the use of lead ammunition in the 15 counties considered condor territory, but many ranch owners ignore the directive, and some have said it's because they believe the ammo ban subjugates their rights. Lead consumed is the No. 1 cause of death in condors in California and remains the biggest obstacle to their recovery there, as well, biologists say.
A condor died near Pinnacles National Monument in 2009 after it was tracked with GPS to an area where a landowner had shot dozens of ground squirrels with lead ammo and left them for scavengers. It was especially devastating because the condor was part of the first cohort released at the national park in Central California and was just reaching breeding age
The total population in the wild is nearly 400, including some in Mexico.