Three California vultures have died from bird flu in northern Arizona, and authorities are trying to determine what killed the other five in the flock, the National Park Service announced this week.
The Park Service said a female with suspected lead poisoning was found dead on March 20 and testing revealed she had Highly pathogenic Avian Influenza (HPAI).
Two other birds later found dead also tested positive, while the test results of the other five were still incomplete, the park service said.
The park service says the birds are part of a population that moves throughout northern Arizona and southern Utah, including Grand Canyon National Park.
The Peregrine Foundation, which manages the Arizona-Utah poultry flock, also captured five other birds that appeared to be sick and sent them to a wildlife rescue center in Phoenix. Officials say one bird has died and the other four have been quarantined.
Exposure to the virus is expected to increase during the osprey’s spring northward migration.
The park service says HPAI has not been detected in other populations in California or Mexico’s Baja California.
Avian influenza occurs mainly in birds including domestic chickens, but it is also found in other animals, wild and domestic, in all states of the United States except Hawaii.
Humans are considered to be at low risk for HPAI infection, although cases of infection have been reported.
The California Falcon is one of the largest birds in the world with a wingspan of up to 10 feet. The birds once patrolled the skies from Mexico to British Columbia. Conductors can live for 60 years and fly great distances, which is why their range can extend to several states.
The population plummeted to the brink of extinction in the 1970s because of hunting, habitat destruction, and lead poisoning from eating animals shot with lead bullets.
In the 1980s, wildlife officials captured the last 22 vultures left and took them to the San Diego and Los Angeles zoos to be protected and bred in captivity. The birds are then released into reserves and national parks where they can be monitored.
The birds have been protected as an endangered species under federal law since 1967 and California state law since 1971.
The California Falcon is back in the wild and currently occupies parts of the Central Coast of California, Arizona, Utah and Baja California, Mexico. The total wild population now has more than 300 birds.