The U.S. Fish & Wildlife Service says about half of the roughly 130 condors released since 1996 along the Arizona/Utah border have died or vanished.
Officials say the No. 1 cause of death for condors is poisoning from lead fragments left by bullets in animal carcasses.
Still, the birds are gaining a foothold. About 70 condors range from Arizona's Grand Canyon to southern Utah's Zion National Park.
California, which bans lead bullets in condor territory, has an additional 111 of the birds in the wild.
The total population in the wild is nearly 400, including some in Mexico.
