In this dissertation, I present two original research studies on the behavior and survival of the critically endangered California Condor ( Gymnogyps californianus). I also provide a comprehensive review of the role of captive-rearing to the conservation of birds.

The first study examined the behavioral differences of puppet- and parent-reared condor juveniles reared in captivity. This study further defined and examined the behaviors of adult conspecific mentors and their interactions with juveniles. Dominance hierarchy analyses for two cohorts of juveniles and their adult mentors indicated the establishment of a linear hierarchy. Although puppet-reared juveniles engaged in fewer social behaviors in captivity, they successfully integrated into a social hierarchy. The second study examined potential predictors of behavioral problems and survival outcome of released captive-reared California Condors using binary logistic regression and chi-square analyses. Predictors incorporated in this study included age at release, sex, mentoring, rearing facility, release site, and established population size. Results up to two years post-release indicated that sex, adult conspecific mentoring, and established population size were significant predictors of survival, whereas rearing facility and rearing method were significant predictors of behavioral problems. These results indicate that mentoring may be especially crucial to survival of captive-reared California Condors released to the wild, and that many puppet-reared birds successfully adapt to life in the wild.

The comprehensive review covered important methods used in avian captive-breeding and reintroduction programs. The strengths and weaknesses of various rearing methods are discussed, including the importance of raising birds in an atmosphere that most closely mimics their breeding preferences, developmental mode, and life-history traits. The need to understand a species before implementing a captive-breeding program is essential. Pre-release training is presented as a method to help prepare naive birds for release, with emphases given to mentoring, predator training, and obstruction avoidance. Comparisons between hard and soft releases and in situ and ex situ conservation are examined. By establishing guidelines for determining success, emphasizing the need to practice adaptive management, and implementing frequent independent reviews, avian conservation programs – including the California Condor recovery program – can become even more successful in the twenty-first century.