Photo © USFWS

White-Nose Syndrome

White-nose syndrome (WNS) is a disease of bats caused by the fungus Pseudogymnoascus destructans. The fungus is called Pd, an abbreviation of its scientific name. Pd infects the skin of hibernating bats, disrupts physiological processes, and causes dehydration. Hibernation is a strategy used by bats in cold climates to survive the winter months when insect prey is absent. Before hibernation, bats increase and store body fat to use as energy throughout the winter. Hibernating bats maximize these energy stores by lowering body temperature, reducing rates of circulation and respiration, and slowing metabolism. Bats infected by Pd arouse from hibernation more frequently, deplete finite energy stores and die of starvation before the weather warms and insect prey become available.

The first observation of WNS occurred in 2006 when a picture of bats with white fuzz on their muzzles was taken in a New York state cave. The disease is named for the white fuzz found on some infected individuals. The fungus was new to science and was not known to have previously occurred in North America. It has since been found in Europe and Asia. The fungus was first detected in South Dakota in May 2018.

Available management actions include monitoring for the progression of the fungus and disease, decontamination protocols for equipment used in cave or mines, closures of hibernacula and education on the importance of bats and the severity of the disease. Research into ways to control and recover from the disease is ongoing. The detection and spread of this deadly disease make protection of bats from other threats, such as disturbance during hibernation and loss of maternity and hibernation sites, even more critical.

For more information on the spread of this disease in the United States and information on research efforts, visit