Effectiveness of Action to Reduce Exposure of Free-Ranging California Condors in Arizona and Utah to Lead from Spent Ammunition
2008

Reducing Lead Exposure in California Condors

Sample size: 60 publication Evidence: high

Author Information

Author(s): Green Rhys E., Hunt W. Grainger, Parish Christopher N., Newton Ian

Primary Institution: Department of Zoology, Conservation Science Group, University of Cambridge

Hypothesis

What would be the effect of reducing exposure to spent lead ammunition throughout the range of the California condor population?

Conclusion

The extension of the existing lead reduction program to cover additional areas would significantly reduce mortality caused by lead and help the condor population to increase.

Supporting Evidence

  • Condors that spent time in areas where deer were shot with lead ammunition were more likely to have high blood lead levels.
  • High blood lead levels over a long period significantly increased the likelihood of death from lead poisoning.
  • Ending lead exposure reduction measures would lead to a rapid decline in the condor population.

Takeaway

California condors can get sick and die from eating lead from bullets in animal carcasses. By using non-lead bullets, we can help keep them safe.

Methodology

The study used tracking data and blood lead concentration measurements from free-ranging condors to model blood lead levels and mortality rates.

Limitations

The study was limited by the small number of condor deaths from lead poisoning observed during the study period.

Participant Demographics

The study focused on free-ranging California condors in Arizona and Utah.

Statistical Information

Confidence Interval

95% confidence limits for parameters were provided.

Digital Object Identifier (DOI)

10.1371/journal.pone.0004022

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