Chamberlain sees three options for Condor Recovery Program: "They could feed them 100 percent on calves, then they're less likely to get lead poisoning. They could eliminate lead from the ammunition, which would require legislation or a major change in hunting practices. Third, and this is what we're suggesting, you could train them on another food source that reduces their chances of lead contamination, and that would be the marine mammals."
At least one group of condors appears to be heeding that advice on its own, says Kelly Sorenson, executive director of the Ventana Wildlife Society (VWS) and co-author of the PNAS study. Since 1998, VWS has released more than 30 captive-bred condors in Big Sur, a remote mountainous region overlooking California's central coast. "We believe that marine mammals--primarily sea lion carcasses that wash up on the beach--now represent about 50 percent of the Big Sur population's diet," Sorenson says. "That's really exciting, because it means a much lower lead exposure for the condors."
He says that plans are under way to build a new holding pen along the coast south of Big Sur where seals frequently haul out. "Free-flying condors are just not finding these areas yet so we need to encourage them to do so," he adds. Other major haul-outs can be found from Baja California to British Columbia.
"If we can train condors to find sites along the beach where there are seals and sea lions all the time, then they'll frequent those spots and it will get them off some of the terrestrial sources with lead poisoning," Chamberlain concludes. "It would be fabulous some day to see condors feeding all along the coast, from Mexico to Canada, the way they did when the Europeans arrived here three centuries ago."