White-nose syndrome (WNS) is a disease that affects hibernating bats. It was first detected in New York State in 2007–08. By 2016, it was confirmed in 26 U.S. states and five Canadian provinces, had killed an estimated 5.5 million bats and caused up to 100% mortality in some bat hibernacula.
In March 2016, WNS was detected in bats in Washington state. That was the first detection of the disease west of the Rocky Mountains. See a map of the current distribution of WNS.
The disease is caused by the cold-loving fungus Pseudogymnoascus destructans. The fungus invades the skin of hibernating bats, causing tissue damage. It can be visible on the nose, ears and wings as a white, fuzzy coating. Infected bats exhibit higher levels of activity during hibernation which leads to a premature expenditure of winter fat reserves and causes the bat to leave the hibernacula early in search of food. The bats ultimately starve or freeze to death.
Many species of North American bats are highly vulnerable to this lethal fungus. Seven species have been affected in the eastern North America. A large decline in Northern long-eared bat (M. septentrionalis) populations led to its beign listed as threatened under the Endangered Species Act.
White-nose syndrome has not been detected in Utah to date and there are many unknowns about how the disease would affect our bat populations. Potentially, all hibernating bat species in Utah could be susceptible to WNS. The big brown bat (Eptesicus fuscus) and little brown bat (Myotis lucifugus) which are common in Utah, have been infected elsewhere. Also of concern are the Yuma myotis (Myotis yumanensis), long-eared myotis (Myotis evotis), fringed myotis (Myotis thysanodes), long-legged myotis (Myotis volans), California myotis (Myotis californicus), western small-footed myotis (Myotis ciliolabrum), canyon bat (Parastrellus hesperus), and Townsend's big-eared bat (Tadarida brasiliensis).
Bat-to-bat and bat-to-environment-to-bat transmission are believed to be the primary ways the fungus is spread, but human-assisted transmission is also possible. The fungus can be transported on boots, clothes and other gear. Pets can also transport the fungus on their fur. The severe effects of WNS on bat populations justifies taking precautions to reduce the risk of human-assisted transmission and minimize any disturbance to hibernating bats.
Multiple efforts are underway to determine how the spread of WNS can be prevented and the disease treated or cured. These efforts involve states, provinces, tribes, federal agencies, universities, conservation organizations and local communities. Those collaborative efforts are essential to bat and cave conservation. Reducing the risk of human-assisted spread of the fungus and avoiding activities that disturb bats during their critical hibernation periods are key to this effort. Within Utah, the Division of Wildlife Resources is collaborating with its federal partners to monitor subterranean bat roosts for WNS during the winter months.
What can you do?
- If you find a dead or sick bat between January and April, please contact the Utah Division of Wildlife Resources.
- Avoid entering caves, mines and other areas that are used by bats to prevent the spread of WNS and to avoid disturbing roosting bats.
- If you used any gear or equipment in a mine or cave in a WNS affected area, do not use it in Utah or any other unaffected areas.
- If you visit a subterranean bat roost, you should clean and treat your clothing and gear regardless of the season or the time of year following the National WNS Decontamination Protocol.