Condors' comeback imperiled by lead poisoning

The California condor's return from near extinction is threatened by persistent exposure to lead-based bullets, despite intensive efforts to treat and care for poisoned birds each year, scientists say. Lead poisoning in the condors is now "of epidemic proportions," said Myra Finkelstein, a research toxicologist at UC Santa Cruz and the principal author of a report on the condor problem in this week's issue of the Proceedings of the National Academy of Sciences. The condors' feeding habits seem Greece Soccer Jerseys to be a large contributor to the problem. The likelihood is 85 to 98 percent that a condor will feed on a carcass contaminated with lead during its lifetime, Finkelstein's colleagues calculated. "We will never have a self-sustaining wild condor population if we don't solve this problem," Finkelstein said. The huge black birds with their 10-foot wingspans once soared by the thousands over the mountains and deserts of California and the Southwest, but their numbers declined rapidly when hunters and trappers killed them off as the West was settled. They were listed on the federal endangered species list in 1967, and only 22 remained 30 years ago. Today, recovery efforts by determined conservationists have returned the condor population to more than 400. Captive breeding programs, hatcheries for eggs gathered from abandoned nests in the wild and many other conservation efforts have been hailed as great successes in saving the condor from extinction. But the analysis by Finkelstein and her team shows that nearly half the California free-flying condors have suffered from chronic lead poisoning in the past 10 years - many of them poisoned repeatedly during that time. Blood tests show that 20 percent are exposed to lead each year, but few die. The apparent recovery of the birds in their range in the Los Padres National Forest, the Big Sur coast and the Pinnacles National Monument is "deceptive," Finkelstein said. Carrion - wild animals shot by poachers inside the range or Wholesale Soccer Jerseys by licensed hunters near the range boundaries - has often been killed by lead-based bullets, and the bullets or traces of lead are swallowed by the condors. Each year the free-flying California condors are captured, held briefly and tested. When blood tests show lead poisoning, the birds are treated at the Los Angeles Zoo with chelation therapy - the same treatment used for children with lead poisoning, Finkelstein said. Finkelstein and her colleagues have made a population study of California's remaining wild condors and found that without continued treatment for lead poisoning, the population will never increase, and probably even decline. She noted that her analysis of lead-poisoned condors covered only birds within the state and did not include the condor population in Baja California or Arizona.