Bird flu confirmed in California Condors
Bird flu (Highly Pathogenic Avian Influenza; HPAI) has been confirmed as the cause of mortality for six California Condors found in northern Arizona, according to wildlife officials.
The news is of deep concern to conservationists, given the precarious state of the bird's recovering population in North America. California Condor does not reach sexual maturity until it is six years old and birds lay only a single egg every two years, meaning population growth is very slow.
At least six California Condors have died of bird flu in recent weeks (Alexander Viduetsky).
The Arizona-Utah population of California Condor moves throughout northern Arizona and southern Utah, using the landscape within Grand Canyon National Park, Zion National Park, Vermillion Cliffs National Monument, the Kaibab Plateau, and surrounding areas.
On 9 March 2023, The Peregrine Fund, which manages the Arizona-Utah condor flock, first observed a bird in the wild exhibiting signs of illness, initially suspected to be lead poisoning. Crews continued to monitor this bird and others showing similar behaviour. On 20 March, they collected the deceased female below its nest, which was the first bird confirmed positive with HPAI.
Upon collection, the bird was went to a US Fish and Wildlife Service (USFWS) forensics laboratory for necropsy to determine the cause of death. Oregon Veterinary Diagnostic Lab analyzed samples, and preliminary results indicated the bird tested positive for HPAI subtype H5N1. The positive result was confirmed by the US Department of Agriculture's National Veterinary Service Laboratory on 30 March.
As of 4 April, a total of three deceased condors had been retrieved and confirmed as HPAI victims. The number of confirmed cases had jumped to six by 12 April.
A USFWS statement on 12 April read: "Until further notice, we will report all deceased condors in the Southwest Flock found on or after 30 March 2023 as 'suspect HPAI'. As results are confirmed at the US Department of Agriculture's National Veterinary Service Laboratory we will confirm the suspect case and report them as 'confirmed HPAI'.
"As of 12 April 2023, 12 condors have died from 'suspect HPAI' and six condors have died from 'confirmed HPAI'."
To date, the virus has not been detected in the other condor populations in California, USA, or Baja California, Mexico.
California Condor populations face multiple stressors, such as exposure to lead shot and habitat degradation, that have reduced the resilience of the population. To address the unfolding threat of HPAI, coordination is ongoing with avian influenza experts, veterinarians, and Tribal, state and federal partners across the species' range. California Condor recovery partners are mobilising resources and taking preemptive steps to protect wild birds from HPAI. Across the condor's range, daily activities continue, such as captive breeding and the monitoring of breeding and nesting sites.
Potential exposure of HPAI is expected to rise during the spring migration of birds north to their breeding grounds. HPAI has been detected in all US states except Hawaii, and has been found in both wild and domestic animals.
