Once Sisquoc, seen here, hatched at the San Diego Zoo's Avian Propagation Center, he was taken to the Wild Animal Park and raised at the Condorminium. Because the long-term goal was reintroduction, it was important to keep the condor chicks from imprinting on humans—but how could they feed the chicks without letting them see people? Enter the now-famous condor puppet! The keepers worked with a local artist to create a lifelike hand puppet with condor features, which could feed and interact with the chicks like a parent condor would. The keepers remained behind a black curtain or other obstacle so that the chicks only interacted with the puppet. This technique was actually first tried by bird keeper Bill Toone when he hand-raised two Andean condors in 1981, with great results.