A captive-bred California condor recently released into the wild was found dead Wednesday after it crashed into a power line in the Ventura County back country near Fillmore.
It was the second condor death in four days.
"Some weeks are positive, some are not so positive," said Mike Wallace, recovery team leader and biologist with the Zoological Society of San Diego.
The 1-year-old bird found near the Sespe Condor Sanctuary in Los Padres National Forest was the seventh to be killed by power lines since the condor release program began in 1992.
A 2-year-old bird that was also released last month is missing, officials said. All the released condors have radio transmitters attached to their wings, but biologists lost the signal from the 2-year-old about a week ago. They believe it may have flown out of the search area or into a canyon, blocking the signals.
A former researcher for the $25-million condor recovery program suggested Thursday that other problems should be ironed out before more of the endangered birds are placed in the wild in Southern California.
Pete Bloom, a research associate with the Western Foundation of Vertebrate Zoology, said that lead poisoning from bullets is the primary problem for birds released near populated areas. The condors often eat carrion that has been shot, ingesting the lead. Thought should be given to suspending releases at the Sespe site until this is resolved, Bloom said.
"It hasn't been dealt with because of the political difficulties," he said, referring to opposition from such organizations as the National Rifle Assn. to banning lead bullets.
After the initial releases in 1992, until 1999, there were no releases at the Sespe Condor Sanctuary in Ventura County because too many of the birds were electrocuted.
Since the program began, about 40 birds have died of various causes, which include poisoning by antifreeze and lead.
The discovery of the latest death came two days after a chick was found dead at the bottom of a cliff in Los Padres National Forest in Santa Barbara County. The chick is believed to have been killed by an adult condor that biologists had hoped would nurture it.
Despite such problems, Bloom said he believes the condor recovery program is worthwhile.
"I wouldn't call it a losing battle," he said, "but it's a long education process for both the biologists involved and the condors. We're at the steep end of the learning curve."
During the 1990s, scientists developed ways to scare condors from power poles, with some success. In this case, however, the young condor probably was not able to control his flight well enough and couldn't veer away once he got too close to the wires, officials said.
"Once they get to be good fliers, lines aren't a problem," said John Brooks, a U.S. Fish and Wildlife Service spokesman. "But it takes a while for them to get the skills."
Biologists said it was too soon to talk about suspending releases from the Ventura County site. But they are pursuing remote release sites in New Mexico and Baja California, where there are far fewer power lines and probably fewer opportunities for lead ingestion.
Wallace said the release program was bound to run into bumps at the beginning.
"Look at how we've been able to basically save a species from extinction," Wallace said. "That took a long time to do, and we had deaths along the way. . . . We'll adjust to this."