Can They Go Home Again?

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Its majestic wings once cast large shadows all over North America. The bird was a survivor. When saber-toothed cats and other big animals died off about 10,000 years ago, the California condor retreated to the carrion-rich Pacific coast and survived. A Spanish priest recorded seeing one in 1602; Lewis and Clark spotted another in 1805.

But a 20th century plague of hunting and lead poisoning brought Gymnogyps californianus to near extinction. Biologists trapped the last wild California condor in 1987, and 27 birds remained as genetic "founders" for a breeding program that has produced 25 additional birds, including the two freed last week.

Since a condor's wings are too large for much flapping, it soars skyward by jumping from its mountaintop nest into an updraft. On the ground, the birds need a spiraling thermal air current to take off. Says the Los Angeles Zoo's Michael Wallace: "I've seen Andean condors walk half a mile for a launch point."

Condors find food in open flatlands where shrubbery will not hamper takeoffs. They used to live on cliff tops around California's Central Valley and fly to lowlands where hunters shot deer and left "gut piles" full of bullet fragments of toxic lead.

Chicks raised in captivity have prospered at the San Diego and Los Angeles zoos, but returning to the wild is another matter. At least 30 of the 49 black-footed ferrets released in a Wyoming wilderness last fall have died. In Texas, reintroduced northern aplomado falcons were killed off by great horned owls that had moved into the falcons' old territory.

Captive breeding may destroy behaviors needed for survival. Zoo-bred golden lion tamarins dropped out of trees and ignored natural food after going back to the Brazilian jungle. The first red wolves reintroduced to a North Carolina refuge wandered out into residential neighborhoods.

In California the lives of the freed condors will be "managed." Stillborn calves left on mountains might keep the birds from flying to flatland sources of toxic food, and moving the carrion around will force natural foraging behavior. Biologists assume that intensive care is temporary. "Right now, we are this species' surrogate parents," says Robert Measta, head of U.S. Fish and Wildlife condor operations. "In the old days, adult condors did this job." With luck, someday they will again.