For the first time, the deadly new strain of avian influenza virus that has caused an unprecedented outbreak among birds in the Bay Area and statewide has been detected in a wild mammal in California, state wildlife officials announced.

Federal veterinary officials in January detected the highly pathogenic avian influenza strain, H5N1, in a bobcat after its remains were collected in Butte County in December and submitted for testing, the California Department of Fish and Wildlife said in a news release Wednesday.

“This is the first detection of the virus in a wild mammal in the state,” state officials said, adding that the deadly virus had been found in mammals — including foxes, raccoons and skunks — in other states and Canada.

Until now, only wild birds had been infected with the virus in California. H5N1 was first identified in wild birds in July 2022 and has been found in wild birds in 44 counties and domestic birds from 18 counties, officials said.

Avian influenza typically circulates among wild water birds and domestic poultry, and transmits to other birds through feces, saliva and respiratory droplets, according to the wildlife department.

Avian influenza typically circulates among wild water birds and domestic poultry, and transmits to other birds through feces, saliva and respiratory droplets, according to the wildlife department.But the current H5N1 strain has been infecting and killing a greater diversity of wild bird species than in past outbreaks, affecting raptors and scavengers such as turkey vultures and ravens, the release said. 

Both mammalian and avian predators and scavengers may be exposed when they feed on infected birds, officials said.

The infected bobcat was wearing a GPS collar that alerts state officials when an animal stops moving, officials said. State biologists found it in an area where the virus had been recently detected in a turkey vulture, and began investigating the cause of death.

The disease causes neurological symptoms including tremors and seizures in birds. People who see a bird exhibiting strange behavior, experiencing tremors or appearing weak and lethargic should call a local animal control or wildlife center, officials say.

Because no vaccine or treatment exists, a bird that shows symptoms will not survive, experts say.

Transmission to people is considered low, but wildlife officials say people should not touch injured or dead birds or allow children or pets near them. Dead birds should be reported to the Department of Fish and Wildlife.

The Centers for Disease Control and Prevention urges people who are in contact with wildlife to take basic protective measures, such as wearing gloves and face masks, and washing their hands.