Ventana Wildlife Society to test, treat wild birds for lead poisoning
High on a cliff face in Big Sur, condor No. 340 — the first of 26 Oregon Zoo-hatched California condors to be released in the wild since 2005 — perches with his wild-fledged mate. If the pair is successful, this will be the first year they raise a chick together.
They almost didn't get the chance. In January, the pair was at the Los Angeles Zoo undergoing chelation therapy — a chemo-like treatment for lead poisoning. It was the sixth lead-related hospital visit for No. 340, whose pre-release name, Kun-Wak-Shun, means thunder and lightning.
"Lead poisoning is the leading cause of death in free-flying condors."
—Kelley Sorenson, Ventana Wildlife Society
With an assist from the Oregon Zoo Foundation's Future for Wildlife grant program, Ventana Wildlife Society is gearing up for its 16th year of lead-testing California condors in Big Sur.
"Lead poisoning is the leading cause of death in free-flying condors," said Kelly Sorenson, Ventana Wildlife Society CEO. "It's an agonizing death often preceded by a loss of coordination and neurological impairment. It is heart-wrenching, especially since we've invested so many years in each of these birds."
Nearly every free-flying condor in California has been treated for lead poisoning at some point in its life, although not all victims survive, or are even found.
Since October 2012, lead poisoning has killed at least five condors in Big Sur and Pinnacles National Park, according to Sorenson.
A study released that year identified lead-based ammunition as the principle source of lead poisoning in condors. Although lead has been widely eliminated from paint, gasoline and water pipes, it remains the metal of choice for ammunition manufacturers. Like eagles and other scavengers, condors can ingest the toxin when they eat the remains of an animal that's been shot with lead ammunition.
"Recreational shooters, poachers — anybody who fires a gun outdoors — can inadvertently poison an animal," said David Shepherdson, Oregon Zoo deputy conservation director. "But it's hunters and ranchers who are best positioned to turn this crisis around. Many have already made the switch to lead-free ammunition."
Researchers with the Peregrine Fund credit a switch to non-lead ammo for a dramatic drop in the number of Arizona and Utah condors requiring lead-reducing therapy — 11 this year to last year's 28.
The story of lead poisoning is a major theme at the Oregon Zoo's new Condors of the Columbia habitat, opening in May. The exhibit's name is a nod to the condors that once soared above Oregon, although none have been seen in the state for more than a century.
"The Oregon Zoo would like to see California condors return to the Pacific Northwest," Shepherdson said. "But until the problem of lead poisoning is resolved, condors will never fully recover in the wild."
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