White-Nose Syndrome: The Growing Threat to Washington Bats

What is White-Nose Syndrome and how is it killing Washington's bats?

White-Nose Syndrome Expands in Washington: Eleven New Counties Affected

White-nose syndrome, a lethal disease impacting hibernating bats, has continued its troubling spread across Washington state. In 2024, the Washington Department of Fish and Wildlife (WDFW) and its research partners have documented new cases in eleven counties, highlighting the ongoing challenge of this devastating fungal infection. This disease first appeared in Washington around 2016 but is now obviously growing and spreading inside local bat populations.

The disease, caused by the fungus Pseudogymnoascus Destructans, was detected for the first time this year in Clallam, Clark, Grant, Grays Harbor, Island, Kitsap, Klickitat, Okanogan, and Whatcom counties. Benton and Thurston counties also have confirmed cases of the syndrome. Abby Tobin, the bat species lead for WDFW, emphasized the significance of these new findings, noting, “The fungus that causes white-nose syndrome was detected in nine new counties, and the disease itself was confirmed in two additional counties this year. Our efforts to survey for and respond to the disease continue, including testing emerging treatments.”

White-Nose syndrome causes severe harm to hibernating bats by attacking their skin and causing holes in their wings, which disrupts their ability to fly and leads to premature arousal from hibernation. This disruption causes bats to burn through their fat reserves, leading to dehydration or starvation. The disease has caused significant declines in bat populations across North America. Although white-nose syndrome is fatal to bats, it poses no threat to humans, livestock, or other wildlife.

Since the disease was first detected in King County in 2016, WDFW has confirmed over 280 cases in Washington. White-Nose syndrome has been confirmed in nine counties, and the fungus has been detected in 21 counties. Four bat species in Washington have been confirmed with the disease, while four additional species carry the fungus without showing symptoms. A detailed map of the detections is available on WDFW’s white-nose syndrome webpage.

Since the disease was first detected in King County in 2016, WDFW has confirmed over 280 cases in Washington. White-nose syndrome has been confirmed in nine counties, and the fungus has been detected in 21 counties. Four bat species in Washington have been confirmed with the disease, while four additional species carry the fungus without showing symptoms. A detailed map of the detections is available on WDFW’s white-nose syndrome webpage.

WDFW is urging the public to avoid handling wildlife, particularly bats that appear sick or are found dead. Sightings of unusual bat behavior, like flying or roosting outside during winter, should be reported to WDFW through their website. Fungal spores can cling to clothing, shoes, or recreational equipment, unintentionally spread by humans.

Washington, home to 15 bat species vital to its ecosystems, is actively working with state, federal, tribal, and non-government organizations to monitor bat populations and explore preventative treatments. For more information about white-nose syndrome and Washington's bat conservation efforts, visit WDFW’s Living with Bats webpage.