About 2,000 migrating snow geese died recently in Idaho from a disease that could kill birds in mid-flight, wildlife officials say.
Staff and volunteers from the Idaho Department of Fish and Game picked up dead birds over the last several days at wildlife management areas near the towns of Terreton and Roberts.
The agency said the cause of death is likely from avian cholera, which can cause convulsions and erratic flight.
Authorities said the snow geese, which are known for their white bodies and black wingtips, were migrating from the Southwest and Mexico to their breeding grounds in Alaska.
It's unclear where they picked up the bacteria, said Steve Schmidt, a regional Fish and Game supervisor. "Outbreaks of avian cholera have occurred sporadically in the region over the past few decades," he said in a news release.
"The important thing is to quickly collect as many of the carcasses as possible, to prevent other birds from feeding on the infected birds," Schmidt said.
There were also about 20 eagles in the Terreton area as well, Mud Lake Wildlife Management Area biologists said. However, it was unclear if they were exposed.
According to the U.S. Geological Survey's National Wildlife Health Center, avian cholera spreads so quickly in infected birds that some with no previous signs of illness can die while in flight and fall out of the sky.
Health experts say humans are not at a high risk of infection from the bacteria that causes avian cholera.
Nearly 10,000 snow geese pass through Idaho each March to rest at the state’s wildlife areas, Schmidt said. They usually spend 2-3 weeks to feed on waste grain at nearby wheat fields.
He said Tuesday he had no reports of deaths of other snow geese from similar areas in other states.
Schmidt said among the dead birds was a dead trumpeter swan, which he said likely also died of avian cholera.
The Associated Press contributed to this report