The California condor, rescued from extinction in an elaborate and expensive recovery effort, has become tantamount to a zoo animal in the wild and can't survive on its own without a ban on lead ammunition across its vast Western ranges, a scientific study has concluded.
The majestic scavengers, bred in captivity and released to nature in recent decades, require "constant and costly human assistance," a blue-ribbon panel of the American Ornithologists' Union reported this week.
They must be frequently trapped, tested and treated for lead poisoning. They depend on man-made "feeding stations," a buffet of lead-free carcasses of rats, deer, stillborn calves and other animals, a practice that has damaged their ability to forage.
As for natural reproduction, the yearlong study found that the condors' nesting success was "nil" before intense intervention last year to vaccinate chicks for West Nile virus and surgically remove ingested refuse such as rags, nuts, bolts, plastic and bottle caps.
Human aid has led to "inappropriate behavior" of the condors, which are attracted to people and man-made structures, the 57-page report found. The gregarious birds perch on utility poles, risking electrocution and, in Southern California, have taken to soaring with hang gliders and mingling with humans to pick through food wrappers.
So much effort is required to feed, nurse and protect wild condors, the scientists wrote, "that one might argue that they constitute little more than outdoor zoo populations."
Since the last wild condor was captured in 1987, federal and state agencies, zoos and conservation groups have spent tens of millions of dollars breeding more than 300 birds in captivity. About 150 have been released to fly free over forests and deserts in California, Arizona, Utah, New Mexico and Baja California.
Condors -- North America's largest soaring birds -- have survived on the continent since the Pleistocene epoch. With a wingspan of up to 9 feet, they fly as far as 150 miles a day to forage. But with the disappearance of large mammals, such as mountain lions, they tend to feed on carrion left by human hunters.
Last year, $5 million was spent on condor recovery efforts, including $1.2 million from the U.S. Fish and Wildlife Service. The San Diego Wild Animal Park and the Arizona-based Peregrine Fund spent more than $1 million each, and the Los Angeles Zoo, which operates on damaged birds, spent more than $500,000, according to the report.
Government and private wildlife groups "cannot be expected to expend funds indefinitely to maintain condors in nature," the study said. "Progress toward recovery is not sustainable under current conditions because reintroduction of more condors simply increases the costs required to keep wild birds alive."
The six scientists on the panel have not been involved in the condor recovery program. Led by biologist Jeffrey R. Walters of the Avian Ecology Group at Virginia Tech University, they called for "an extensive outreach effort to rally support for replacement of lead ammunition" in condor territory and nationally.
"Poisoning from ingestion of spent ammunition in carcasses is so severe and chronic," the panel concluded, "that condor recovery cannot be achieved so long as such lead exposure continues."
But they also noted that humans who ingest meat from deer and other game can suffer adverse effects from lead: "Removing lead ammunition is not only right for condors, it is right for other scavengers, and it is right for hunters and their families."
The report called on the Fish and Wildlife Service, which oversees the recovery program, to "increase the visibility of its leadership."
An agency spokeswoman concurred that lead has had "a significant impact on condors" and said the service has already begun to implement some of the report's recommendations, including outreach to hunters.
Also, the service supports adding more feeding stations, but farther afield so that birds will forage more widely.
The National Rifle Assn. and other hunting groups have fought restrictions on lead bullets, which are cheaper than copper varieties.
Last year California became the first state to pass a law prohibiting hunters from using lead ammunition within the condor's 2,385-square-mile range.
Lead is banned for shooting big game, such as deer, antelope, bear and non-game species, such as feral pigs and coyotes. Smaller game, such as birds and rabbits, can still be killed with lead bullets.
The law is "a huge step forward," Walters said. But the panel interviewed state officials, local conservationists and hunters, and found that enforcement "may be highly problematic. . . . California Fish and Game has done little to educate hunters . . . and [non-lead] ammunition is not readily available or identifiable in many retail outlets," according to the report.