The September 2023 issue of The Wildlife Society’s Wildlife Society Bulletin contains a paper by Finkelstein et al. documenting the case of a California Condor that had ingested a lead fragment and copper bullet simultaneously. From the paper’s abstract:
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.
Of course, lead shot and its effects on non-target wildlife is a contentious issue. The paper is open access and I’ve included it for download here. You can also obtain it directly from the journal’s web page.
Map: California Condor Critical Habitat Designated Under the Federal Endangered Species Act