White-nose Syndrome

White-nose Syndrome (WNS) is a fungal disease that has been continually responsible for the death of millions of bats in North America since it was first discovered in a single cave in New York in 2006. The condition is causing massive population declines for multiple hibernating bat species – resulting in one of the most significant losses to wildlife in the past century. Named for the telltale white fuzzy growth on the nose, ears, and wings of infected bats, WNS repeatedly rouses bats from hibernation, causing them to consume their winter fat stores — which often can result in starvation before spring.

Bats with the disease symptoms of WNS are found in 34 U.S. states and 7 Canadian provinces. To date, 13 bat species have been found with WNS disease symptoms, including two federally endangered species, the gray bat and Indiana bat. The Northern long-eared bat was listed as federally threatened due to the rapid decline of this species from WNS. Thankfully, not all species are impacted the same way by WNS, with some appearing more resistant to the disease than others. Scientists are working to determine the conditions that contribute to a bat’s susceptibility and for potential treatments.

Bats affected with WNS do not always have visible fungal growth. Sometimes, they simply display unusual behavior such as flying outside during the day in near-freezing weather. As a result, in winter, you may see dead or dying bats on the ground or in buildings or other structures. If you encounter one, do not handle it!