California condor poisoned by lead, not copper, when both are ingested: A case study

Lead poisoning from feeding on carcasses shot with lead-based ammunition is a well-known threat to wildlife. Thus, nonlead (e.g., copper-based) ammunition is promoted as a safe alternative. We present a unique situation of a male California condor (Gymnogyps californianus) discovered with both a lead fragment and a copper bullet in his digestive tract simultaneously. We show that ingestion of a copper bullet did not result in elevated blood copper concentrations, while ingestion of a lead fragment contributed to lead toxicity. Our findings can inform nonlead ammunition outreach efforts by demonstrating that ingestion of a copper-based bullet did not result in the poisoning of a California condor.

Automated summary

Lead poisoning is a known threat to wildlife that feed on carcasses shot with lead-based ammunition. Copper-based ammunition is promoted as a safe alternative, but our unique case study of a male California condor shows that ingestion of a copper bullet did not result in poisoning, while ingestion of a lead fragment did. This finding can inform outreach efforts promoting nonlead ammunition.