California Condor: A Literature Synthesis of Primary Threats and Population Recovery Efforts

In 1988, the California condor (Gymnogyps californianus) was first listed on the International Union of Conservation of Nature and Natural Resources (IUCN) Red List of Threatened Species as Threatened. By 1994 the California condor thad been relisted as critically endangered. The Peregrine Fund (at the World Center for Birds of prey), the Los Angeles Zoo, the Oregon Zoo, and the San diego Wild Animal Park has been managing a large-scale integrated captive-breeding and reintroduction program that has been largely responsible for the current upward population trend of the California condor. The number one threat to the continued survival of the California condor is lead poisoning. In 2007 the Ridley-Tree Condor Preservation Act was signed which requires the use of non-lead ammunition within the species geographical range in California. As of 2018, due mostly to the efforts of the captive-breeding program across California and Arizona there are 106 mature wild birds only 44 of which are capable of successful reproduction. And while population size is currently increasing, future population size cannot be predicted because the many natural and man-made threats are too varied and uncontrollable. Students at Dominican University of California are conducting a literature synthesis involving detrimental effects of known toxins on the California condor focusing specifically on the impact of lead poisoning and legislation to control use of lead ammunition on the California condor. The decline of the California condor population during the 20th century is primarily due to the accidental ingestion of fragments of lead bullets and lead shot from carcasses which leads to fatal lead poisoning. Furthermore, the California condor population has also been greatly affected by the detrimental effects of poisoning by pesticides such DDT which caused reduced eggshell thickness in the condor eggs. Our findings through this literature synthesis show that while the current data shows a slight incline in population trends for the California condor, the future sustainability of the condor population remains dependent on strict monitoring, intensive conservation, and widespread species management efforts