Managing California Condor Health

Our work includes detection of West Nile Virus (WNV) and investigations into the potential cause of vaccine failure. Using this knowledge, we will develop improved vaccination models for WNV and avian influenza and strategies that will be effective under free-ranging conditions.

We are also documenting the effects of acute and chronic lead exposure, from which over 12 free-ranging California condors have died. We will correlate all available blood, lead, bone, and feather lead data with mortality data and field histories to assess the direct and indirect effects of acute and chronic lead exposure in California condors. 

We are also exploring the significance of elevated liver copper levels. Several California condors that have died in the field have had higher than expected hepatic copper levels, but the significance of this is unknown. We will compare hepatic copper levels in captive and free-ranging California condors, and correlate these findings with clinical, field, and management histories, and postmortem findings. 

Ongoing genomic analysis of the California condor is aimed at identifying candidate genes for the chondrodystrophy mutation and supporting breeding management. Sequencing and characterization of a candidate locus are underway that could enable us to identify carriers of the chondrodystrophy allele and provide tools for improved management of this disease and its impacts on the condor populations.

As an additional strategy, we are evaluating markers to construct a linkage map to identify regions on condor chromosomes associated with the disease condition. Sequencing the condor genome is an emerging possibility, utilizing the newly emerging DNA sequencing technologies.

Finally, environmental toxicology studies are addressing the potential problem of condors feeding on marine mammal carcasses that could contain high concentrations of persistent organic pollutants such as PCBs and pesticides. We are preparing condor tissues obtained from pathology for gene expression analysis and hormone receptor cloning. The goal is to evaluate the sensitivity of condors to contaminants found in these marine mammal carcasses and to compare that to other species of birds known to have high and low sensitivities to similar chemicals.