Endangered California condors have been infected and died from avian influenza, also known as bird flu, according to the U.S. Fish and Wildlife Service.
The agency reported this month that it's aware of 20 condors that have died in the Arizona-Utah flock. Ten of them were confirmed to have had bird flu.
The first case was detected in March, officials with Fish and Wildlife said. That's when the Peregrine Fund, which manages the Arizona-Utah condor flock, reportedly observed birds showing signs of illness that was suspected to be lead poisoning. However, after a female condor died, officials confirmed that it had contracted bird flu.
There is concern that exposure to the avian flu will rise in the wild as birds migrate north in the spring.
What's the risk of bird flu spilling over to larger human populations?
Despite the continued spread of the avian flu, the WHO says the overall pandemic risk has "not significantly changed in comparison to previous years."
"California condor recovery partners are mobilizing resources and taking preemptive steps to protect wild birds from HPAI (Highly Pathogenic Avian Influenza)," the Fish and Wildlife Service said.
The California condor used to live anywhere from Canada to Mexico. However, experts say the population decreased dramatically partly due to habitat degradation.
Their population dropped to a low of 22 individual birds in 1982, according to the Park Service. They were trapped and placed into breeding programs to save them from extinction.
According to the National Park Service, there are now just over 500 California condors in the world, with about 300 flying free in the wild.
