Lead poisoning and the reintroduction of the California condor in northern Arizona.

Abstract

Since 1996, The Peregrine Fund has released California condors (Gymnogyps californianus) in the Grand Canyon region of northern Arizona with the goal of establishing a self-sustaining population, disjunct from other released populations in California and Baja California. A free-ranging population of more than 60 individuals now ranges within northern Arizona and southern Utah and has produced 9 wild young. The most frequent cause of death is lead poisoning from the ingestion of lead bullet fragments and shotgun pellets in the remains of gun-killed animals. In response, the Arizona Game and Fish Department has effectively reduced lead occurrence within the foraging range of the condors through hunter education and the promotion of nonlead ammunition. Most hunters have participated in the program. Throughout the course of the reintroduction effort, veterinary science and application have played essential roles in diagnosing fatalities and treating lead-exposed condors, a species with such a low natural reproductive rate that every adult is significant to the population.