A disease that is deadly to bats and caused by a fungal infection has its first confirmed cases in Oregon.
Two Columbia County bats and one Benton County bat have tested positive for white-nose syndrome, an invasive fungus thought to have come from Europe.
Once infected, bats will begin acting erratically and sometimes exhibit namesake spots on their noses, though that has not been a common trait in bats in the Western U.S., according to Emily Armstrong Buck, the white-nose surveillance coordinator for the Oregon Department of Fish and Wildlife.
"What we’re more likely to see is, right around this time of year or earlier, bats flying around at strange times, bats that are not able to fly very well or doing some strange things with some wing damage," she said.
Among the erratic behaviors is activity during times that a bat would normally hibernate. That causes the bat to burn through fat stores and water that would normally allow it to survive hibernation.
White-nose syndrome does not necessarily mean doom for the local bat population, though.
“There are signs that the fungus works a little differently here in the west, or our bats have different life histories, so we’re learning a lot right now about how things are going to play out,” said Armstrong Buck. “And we also have a lot more tools at our disposal now than we did when it first showed up.”
She encourages those who frequent areas where the fungus may be present, such as caves and mines, to clean their shoes after exiting using rubbing alcohol, and to wash their clothes before entering another area where the fungus might thrive.
Anyone who spots unusual behavior in bats can call ODFW’s health lab at 866-968-2600 or use the reporting tool on its website.
White-nose syndrome is caused by the fungus Pseudogymnoascus destructans, and was first detected in Oregon in September 2025, placing it among at least 40 states where the fungus has been found. It was first found in the United States in 2006 in New York.
It grows best in cool, dark places such as caves, where it spreads on to cool bat skin. Populations of bats in places like Europe appear to have acclimatized to the fungus, as it does not cause mass mortality there.
