California Condor HPAI Response Update - August 18, 2023

The U.S. Fish and Wildlife Service’s Incident Command Team, in collaboration with partner agencies, continues to develop and implement conservation strategies to help California condors considering Highly Pathogenic Avian Influenza (HPAI). Strategies include implementation of vaccine trials, field monitoring, and adaptation of current management practices to be increasingly nimble and flexible in response to future HPAI outbreaks.  

Incident Update

Black Vulture Vaccination Trial Results  

Final analysis for the samples from the black vulture portion of the vaccine trial are complete. USDA conducted hemagglutination inhibition tests on serum samples collected 42 days after the vaccination. The samples were evaluated for antibody titers that are commonly used as surrogate markers against influenza and other pathogens. Results are as follows for the 10 birds in each group: 

  • Group 1 received a vaccination of 0.5ml on two occasions (initial injection and booster). Results show that 90% of the birds showed titers expected to provide protection.  

  • Group 2 received a single 1 ml dose vaccine. Results show that 70% of the birds showed titers expected to provide protection. 

The birds in Group 1 that received the booster generally showed higher titer levels.  

California Condor Vaccination Trial 

Vaccination of condors in managed care continues. Blood samples from the birds will be collected at 21-days and 42-days following vaccination to evaluate the immune response from the two different vaccination approaches, mimicking the black vulture trial. Ten condors will participate in each group for a total of 20 condors receiving the vaccine, and five condors will serve as a control group. Trials will run into October. 

  • Group 1 received a vaccination of 0.5ml on two occasions (initial injection and booster). 10 condors completed vaccine administration. Samples collected on day 21 are pending analysis. 

  • Group 2 received a single 1 ml dose vaccine.  Six condors administered single dose of 1ml vaccine. 21-day samples collected on 3 birds (first to receive the 1 ml dose vaccine). Samples are pending analysis. Four birds yet to be vaccinated. 

  • Group 3 includes control birds. They will not receive vaccines, but blood samples will be collected.  


Ongoing Field Operations  

Construction of new condor pens at Bureau of Land Management’s Vermillion Cliffs and Liberty Wildlife are underway. New infrastructure will improve biosecurity and capacity for the program to respond to any future disease outbreak.  

Story Tags

Endangered and/or Threatened species
Migratory birds
Wildlife management