The California condor population fell through the twentieth century until only 22 birds remained. The decision to capture the last free-flying individuals in 1987 was fiercely contested; the alternative was watching the wild population reach zero. Captive breeding at zoos, including double-clutching to raise output, allowed releases to begin in the early 1990s, and the total population has since passed several hundred with a majority flying free.
The cause of death has not changed. Condors feeding on carcasses and gut piles ingest fragments of lead ammunition, and lead poisoning is repeatedly identified as the leading mortality factor in released birds. Free-flying condors are routinely trapped for blood testing and chelation treatment.
That dependence is what keeps the species Critically Endangered rather than recovered. The population is numerically larger but not yet self-sustaining, and the genetic base of 22 founders leaves little room for further loss.