Home Away From Home : Condors: A helicopter Thursday is to take four chicks to a custom-built cave in the cliffs. They may fly free in January.

A team of biologists is putting the final touches on a custom-built cave high in the cliffs above Fillmore before a pair of California condor chicks and two South American cousins move in on Thursday.

The four condor chicks, which were raised at the Los Angeles Zoo in an effort to preserve the nearly extinct California condor species, are scheduled to be flown up to the mountaintop in a Ventura County Sheriff’s Department helicopter Thursday morning.

The birds, aged 4 1/2 to 5 1/2 months, will be held at least until January at the cave, which is made of plywood with an arched simulated-rock opening designed to imitate their natural nest sites among the rocky cliffs of the wild. Brush will camouflage the flat lines of the roof.

A net over the birds’ sunny front porch--which boasts a stunning ocean view--will allow the California and Andean condors to hop around outdoors until biologists feel the chicks are ready to live on their own.

The chicks will be under near-constant daytime watch, as a hidden camera records their moves and scientists in a nearby camouflaged surveillance station record their behavior and watch for signs of problems. At night, the biologists will retire to a 4-by-8-foot A-frame hut they have built nearby.

Then, probably sometime in January, the netting will be removed one night as the birds sleep, leaving them free to soar into the wild.

That day will mark the culmination of a 10-year program to perpetuate the species of majestic birds, said David Clendenen, the lead U.S. Fish and Wildlife Service biologist on the condor recovery project.

The months leading up to the transfer of the birds have been nerve-racking, he said, but the payoff will come when the nets are removed.

“It’s a feeling of tremendous elation (when he thinks of) California condors soaring in the wild again,” Clendenen said.

Clendenen, a 10-year veteran of the program, said he will ask to be reassigned once the birds are set free.

“I feel that I will have come full circle,” he said. “I remember when we captured the last wild condor on April 19, 1987, Easter Sunday. I knew it had to be done, but it was a sad and empty feeling to be in those places afterward and know that there was no chance of seeing them soaring.”

If the first two California condor chicks do well in the wild, six more will be released next year. Before then, the two Andean birds that arrive Thursday and four others released earlier will be captured and returned to their native Colombia, where they are also considered an endangered species.

Until that time, scientists hope the four older Andean birds will act as surrogate parents to the chicks, showing them the best places to roost and find water.

The last wild California condors were captured after scientists determined that they were destined to become extinct if left in the wild. The birds, which once roamed across North America, were suffering from lead poisoning both from hunters’ bullets and from feeding on game that had been killed with lead ammunition.

In addition, scientists said that in order to have a successful captive breeding program, they needed as much genetic diversity in the species as possible.

“There is still a lingering question of genetics,” Clendenen said. “There is not a lot of diversity, and that can wait to show up for a few generations down the line.”

Through breeding at the Los Angeles and San Diego zoos, the condors’ numbers have grown to 52. The scientists in the Condor Recovery Team ultimately want to establish two separate condor populations of 100 birds each in the wild with another 100 birds in captivity, a goal that could take another 20 years.

Condors in the wild, which are dependent on their parents for their first year, learn habits from their elders before they settle down to mate for life at about seven years old. California condors have lived as long as 45 years in captivity.

Their tremendous sense of curiosity sometimes drew them into populated areas, where the contact with humans or their leavings often proved fatal, biologists said.

Now, the scientists hope to teach the birds to keep to the back country among the caves, cliffs, streams and protection of the 54,000-acre Sespe Condor Sanctuary and the neighboring 1,800-acre Hopper Mountain National Wildlife Refuge in the Los Padres National Forest.

The scientists know from watching California condors before their capture and the four Andean condors that were previously released at the Sespe sanctuary that condors can range 100 miles in a day and often roam for two or three days at a time.

On a recent afternoon, the Andean birds, which all have radios, were tracked in the San Gabriel mountains, 60 miles to the south as the condor flies.

But the biologists hope to entice all the birds back to the Sespe sanctuary with food, every few days setting out the carcass of a stillborn calf for them to feed on.

In addition, scientists are going to extremes to ensure that the birds do not associate people with food. Instead, they want them to fear people.

“It could very well save their lives one day,” said biologist David Ledig, who helped Clendenen design the condor cave.

Birds that become accustomed to people are doomed in the wild, Clendenen said.

During the birds’ captivity at the zoo, their helicopter journey and their confinement at the cave through January, biologists are scrupulously staying out of sight of their charges. At the zoo, a puppet condor head disguises a biologist’s arm as it reaches into small compartments to mother the chicks.

The mother puppet will be on hand at the mountaintop site for the first few days to “preen the chicks and calm them down,” Ledig said.

Chopped rats will be delivered while the animals sleep at night when they are young. Once they are on their own in the wild, the condors will be provided with calf carcasses, which will be set out in the backcountry every few days while the big birds are off soaring the Southern California hillsides.

The biologists have not yet decided how long they will continue feeding the birds once they are in the wild.

But they have lofty hopes for the fate of the condor and other wildlife species threatened with extinction.

“Hopefully, we can turn around the idea that a species will become extinct,” Ledig said.