Lead Poisoning ‘Epidemic’ Preventing Condor Recovery
California condors are in the midst of a lead poisoning "epidemic" according to a new study, published in the Proceedings of the National Academy of Sciences on Monday. Researchers found that condors are exposed to dangerous levels of lead and it's preventing the condor population from recovering.
"We will never have a self-sustaining wild condor population if we don't solve this problem," Myra Finkelstein, study coauthor and a research toxicologist at the University of California, Santa Cruz, said in a statement. "Currently, California condors are tagged and monitored, trapped twice a year for blood tests, and when necessary treated for lead poisoning in veterinary hospitals, and they still die from lead poisoning on a regular basis."
Like Us on Facebook
Condors are scavengers and typically feed on the carcasses of animals, such as deer. Hunters use lead bullets, and when the condors feed on the remains, they ingest bullet fragments and develop lead poisoning.
Between 1997 and 2010, researchers tested lead levels in 150 condors and found that close to 50 percent had lead levels that would require medical treatment. Over that same time span, there was no reduction in the number condors testing positive for lead, despite a partial ban on lead bullets in California.
"The levels of lead are completely mind-boggling," Donald Smith, study coauthor and an environmental toxicologist at UC Santa Cruz, told the Los Angeles Times. "Usually, in people, if we see an incidence of 1% we call it an epidemic - and this is 20%."
Researchers said that a total ban in necessary, because even if only 1 in 200 carcasses were shot with lead bullets, the majority of the wild condor population would develop lead poisoning.
"Unfortunately, even if only a few people are still using lead ammunition, there will be enough contaminated carcasses to cause lead poisoning in a significant number of condors," Finkelstein said. "We found that over the course of 10 years, if just one half of one percent of carcasses have lead in them, the probability that each free-flying condor will be exposed is 85 to 98 percent, and one exposure event could kill a condor."
At their lowest point, only 22 condors remained. Now, the species is up to over 400 thanks to a captive breeding population. Over half of the condors on the planet live in captivity. J. Michael Scott, a zoologist at the University of Idaho, who was not involved in the study, said experts have to weigh the benefits of supporting the condor species.
"If we were to walk away from the condor, it would quickly go extinct," he said. "So how long do we want to do this for - and what's the cost to other endangered species?"
© 2012 iScience Times All rights reserved. Do not reproduce without permission.