Artificial incubation of California condor Gymnogyps californianus eggs removed from the wild

The currrent California condor (Gymnogyps californianus) recovery plan entails increasing the reproductive rate via replacement‐clutch manipulation of eggs. During the period from 1983 to 1985, 15 eggs were removed from wild nesting pairs for artificial incubation. The eggs were incubated at a dry bulb temperature of 36.4°C in modified forced‐air Lyon Electric incubators. The incubation humidity was adjusted for individual eggs based on weight loss data (water = weight), 25.6–30.0°C wet bulb (41.0–63.0% Relative Humidity (RH)). The chicks were hatched initially under forced‐air conditions of 36.1°C dry bulb, 31.1–01.7°C wet bulb (70.0–73.0% RH). In 1984, hatching parameters were changed to still‐air conditions, 36.1°C dry bulb (top of the egg), 35.0°C dry bulb (bottom of the egg), 31.1–31.7°C wet bulb (70.0‐73.0% RH). Tactile and auditory stimulation was utilized during the pip‐to‐hatch interval. From among 15 eggs collected, 13 hatched, and 12 condor chicks were raised successfully (hatchability: 86.7%; survivability: 92.3%).