Lead poisoning and the deceptive recovery of the critically endangered California condor

摘要: Endangered species recovery programs seek to restore populations self-sustaining levels. Nonetheless, many recovering require continuing management compensate for persistent threats in their environment. Judging true the face of this is often difficult, impeding thorough analysis success conservation programs. We illustrate these challenges with a multidisciplinary study one world’s rarest birds—the California condor (Gymnogyps californianus). condors were brought brink extinction, part, because lead poisoning, and poisoning remains significant threat today. evaluated individual lead-related health effects, efficacy current efforts prevent lead-caused deaths, consequences any reduction currently intensive actions. Our results show that remain chronically exposed harmful levels lead; 30% annual blood samples collected from indicate exposure (blood ≥ 200 ng/mL) causes subclinical measured as >60% inhibition heme biosynthetic enzyme δ-aminolevulinic acid dehydratase. Furthermore, each year, ∼20% free-flying birds have (≥450 need clinical intervention avert morbidity mortality. Lead isotopic shows lead-based ammunition principle source condors. Finally, population models based on demographic data condor’s apparent solely ongoing management, only hope achieving dependent elimination or substantial rates.