Condor 375, a female, was released May 1 and is doing well, according to society president Kelly Sorenson.
In March, biologists discovered that Condor 375 and a male flock-mate, Condor 286, had suffered gunshot wounds. Sorenson said the situation was a first in his organization's 11-year history of releasing the highly endangered birds in Central California.
However, the bird spent the past weeks being treated not for her wounds, he said, but for lead poisoning.
While the two conditions could appear related, Sorenson said the falcons more likely ingested lead from spent ammunition in their habitat.
"When you get shot and you don't die from it your muscle tissues actually encapsulate the metal," he said. "It no longer is available to the blood stream."
While it's impossible to determine exactly how the birds came in contact with the lead, Sorenson said spent ammunition is "the predominant, if not the only source" of lead poisoning cases he's seen.
In 2008, California outlawed the use of lead shot in condor habitat areas. Exposure to lead is particularly harmful for the birds, Sorenson said, especially when left untreated. Lead can shut down birds' digestive systems, he said, so they cannot get nutrients. Left untreated, the birds can die.
Condor 375 received daily injections to remove the lead from her bloodstream, according to a release from Ventana.
However biologists have not confirmed whether the pellets lodged in condors 375 and 286 contained any lead. The three shotgun pellets in Condor 375's wing and thigh and the 15 in Condor 286's wing and body were viewed only by X-ray.
"It would have been worse to try to surgically remove them," he said of the pellets. "The birds are still flying around with them."
Unfortunately, Condor 286's conditions are more severe, and Sorenson is unsure whether he will be able to return to the wild.
Biologists suspected lead poisoning when they noticed a marked change in Condor 286's behavior, Sorenson said.
"All of a sudden this bird went from one of the dominant birds in the flock one day to the next day showing up and getting whupped on by some of the youngest birds," he said.