PHOENIX - They are among the rarest birds on earth, rescued from the brink of extinction in the late 1980s. Now, biologists are turning back the clock for the California condor.
Fifteen of the giant birds with the nearly 10-foot wingspans are roaming the cliffs near the Grand Canyon with 13 more scheduled to join them by late next month.
Ultimately, biologists hope to have a population of 150 condors in the Arizona wilds along with 150 more off California's mountainous northern coast and 150 others in captivity.
''Maybe in 10 to 20 years. That is the goal,'' Jeff Cilek, vice president for the Idaho-based Peregrine Fund that is heading the condor reintroduction program, said Thursday.
If reached, that goal would almost triple the current condor count of 164, which includes 40 in the wild plus 124 in breeding facilities in California and Idaho.
The world's population of the California condor - North America's largest flying bird - was down to 27 when the federally funded, $1 million per year program began in 1987 with help from the U.S. Fish and Wildlife Service.
The vulture-like scavenger was once abundant from Texas to British Columbia. But by 1849, in the California gold rush, miners discovered that condor quills - light, hollow and nearly half an inch in diameter - were ideal containers for gold dust.
The birds also were shot because they preyed on hunters' kills, and still more died when they injested shotgun pellets and got lead poisoning or flew into high-tension electrical wires.
By 1924, there were no wild condors left outside California. It was named an endangered species in 1967.
Enter the Peregrine Fund, a nonprofit conservation group that helped bring the peregrine falcon back from near-extinction in the 1970s. The reintroduction program for the condors began in December 1996 with the first release of captive birds back into the wild from the towering Vermilion Cliffs, 60 miles northeast of the Grand Canyon.
In November 1998, more condors were released from holding pens atop Hurricane Cliffs near the Arizona-Utah border. The condors were first reintroduced to the California wild, near Big Sur, in 1998.
Of the 13 condors awaiting release in Arizona over the next six weeks, eight were hatched at the Peregrine Fund's breeding facility in Boise, four were hatched in California zoos and another - labeled ''Condor 186'' - was originally released in 1998 as a 1-year-old and then recaptured in April 1999 after exhibiting no fear of humans.
''It went through a human aversion program in Boise,'' said Jeff Humphrey of the U.S. Fish and Wildlife Service in Phoenix. ''It displayed the curiosity that makes scavengers successful. We had to shape its behavior so it didn't associate humans with positive activity.''
The four California-born birds are between 8 and 9 years old. Scientists believe the two male-female pairs are prime candidates to be the first condors to breed in the wild since the start of the reintroduction program.
''The wild birds we started releasing in 1996 are starting to exhibit some nesting behavior, but they're still too young - perhaps a year or two away,'' Cilek said. ''Maybe being around the older birds will help accelerate that.''
A female condor in the wild usually lays one egg every other year, according to biologists.
''We're hoping this pair will act as good mentors for the other birds,'' Humphrey said. ''This has not been done yet in the California program. It's going to be a great year to watch in Arizona.''
But of the 35 condors released so far into southwestern Utah and northern Arizona, 15 have died - many from lead poisoning. Four birds also have been recaptured after they had difficulty adapting and a fifth is presumed dead although its carcass has never been found.
''We expected to have a tremendous mortality rate because these birds have never been in the wild,'' Humphrey said. ''We're had a couple good years where we only lost one or two.
''It's the second-generation birds that we're looking at now. Those are the precursors to success.''
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