Record number of endangered California condors treated for lead poisoning

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When Jenny Schmidt began working as an animal keeper at the Los Angeles Zoo, she expected to work with large mammals. She didn't want to work with birds, but after seeing how gentle the massive California condor was with its young, she fell in love with the bald-headed vulture. 

"A lot of people say, ‘Oh, that’s a face only a mother would love,’ but anyone that’s spent more than a day here, watching the birds, they leave here just saying how beautiful they are and that condors are their favorite bird," Schmidt said.

That's why Schmidt and her coworkers were troubled when 21 wild condors were brought in to be treated for lead poisoning. 

"It’s the highest number of condors that we’ve had to treat for lead toxicity at one time," said Dr. Curtis Eng, chief veterinarian and manager of the California Condor Program at the zoo. 

The Gottlieb Animal Health and Conservation Center is one of three clinics in the nation that treat the California condor, and it handles all of the condors that live in the state. The center has been able to treat and release most of the birds it takes in. Only six remained at the facilities earlier in the week, and Eng said he was hopeful that each would recover. 

Hunting's indirect impact

The California condor - once plentiful across the United States - soared perilously close to extinction. At one point, only 22 birds were left. An intensive conservation effort has increased that number to nearly 500, with roughly half the population living in captivity and the other half living in the wild. 

Eng said that these days, lead is the leading cause of death among adult and juvenile condors. The birds ingest the metal when they scavenge carcasses that were shot by hunters using lead ammunition. 

"When what is eaten by the condor goes into the digestive system, the birds’ digestive juices essentially extract that lead, and then that becomes toxic," Eng said. "Let’s say some hunter mistakes this bird and actually puts birdshot into the bird. These birds do not suffer as much lead toxicity - and rarely do they suffer any lead toxicity, because it’s not in the digestive system"

Measures have been implemented that aim to remove lead from the condors' food streams. In 2007, the Ridley-Tree Condor Preservation Act banned California hunters from using lead ammunition in condor areas. However, the law only applied to hunting big game or coyotes and didn't include shotgun shells. Last month, Governor Brown signed a bill closing those loopholes and expanding the ban across the entire state. The law is set to take effect in 2019. 

Some groups have criticized the bill as being against hunting. But Eng said that condor advocates also tend to be hunting advocates.

"We actually support hunting quite a bit, because it actually does produce food items for condors to scavenge on. And actually, quite a few of our condor biologists are actually very avid hunters," he said. "We just want to get rid of lead in the environment and in condors.”

Treatment

Fortunately, lead toxicity is largely treatable in California condors. One morning earlier this week, Michael Clark, a zookeeper with 24 years of experience working with condors, separately netted two of the remaining condors in his care and held them securely while his colleagues injected each bird with medicine that leaches lead from their systems. 

The condors receive daily treatments for five consecutive days, with a two-day break to monitor remaining lead levels. The process was quick and painless, but Clark said that having had to treat so many in the past few years has hurt his team's ability to focus on breeding the birds. 

"That's why it was such a push to get that bill passed," Clark said. "“We can’t sustain this. The birds can’t be recovered in the current situation.”

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