A record high 21 endangered California condors were treated at the Los Angeles Zoo and Botanical Gardens for
Adam Keats, senior counsel and urban wildlands program director for the Center of Biological Diversity, attributed the high quantity of condor poisonings to hunting activity.
"There's a wide use of lead ammunition in condor habitats. The availability of leads needs to be reduced by sale and stocking," Keats said.
Lead toxicity is the leading cause of death in juvenile and adult condors, according to Curtis Eng, chief veterinarian at the L.A. Zoo and manager of the California Condor Program. He confirmed that one bird had died of lead toxicity earlier this year.
By the 1980s, they were nearly driven to extinction, prompting an aggressive preservation plan. As a result, there are now about 231 condors in the wild, according to the Ventana Wildlife Society.
Wildlife biologists try to trap the endangered birds twice a year, from June until the end of hunting season in November or December, to test their blood for lead.
When treated at the L.A. Zoo, condors receive chelation, which pulls the lead out of the body. Those treatments are followed by supplemental fluids to minimize effects from lead toxicity and the chelation.
Most condors don’t show signs of illness after treatment, which could take as little as three weeks, according to the zoo. Sometimes, lead removal requires surgery if a bird can’t pass it through vomiting or defecation.
Keats said the statewide ban on lead ammunition -- to be phased in by 2019 -- should result in fewer condors getting poisoned in the coming years.