White Nose Syndrome Decimating Bat Populations in North America

Across North America, several species of bats are in precipitous decline. The culprit, White Nose Syndrome, first discovered in a New York state cave in 2006, and has spread rapidly since then, having been confirmed in an Oklahoma cave last winter.

While there is much that is still unknown about WNS, it is typically characterized by a white fungus that forms on bats’ noses, and also on the wings, ears and tails. It is suspected that the fungus irritates bats in their hibernation period, forcing them to awaken during this critical time. Waking up too frequently exhausts fat reserves that are needed to survive the winter. Awakened bats are often seen behaving erratically, flying outside during the day or flying in below freezing temperatures during times of little insect gathering potential. These bats usually freeze or starve to death.

WNS has killed more than one million bats in the US and Canada between 2006 and 2010. In some bat hibernation zones, mortality rates have been as high as 90% to 100%. Agency responses to the spread of WNS have typically been through partial, total, or voluntary cave closures. While it is thought that most transmission of WNS is bat-to-bat, the rapid spread has many scientists suspecting that human contact could be a vector of transmission as well.

In August 2010 NOLS Southwest proactively decided to cancel its fall 2010 and spring 2011 caving sections. This was due to the rapid spread of WNS, sincere concern that humans might be a vector for the disease, and a desire to ensure that NOLS activities were not having adverse affects on bat populations. Currently, the U.S. Fish and Wildlife Service is developing a National Plan for Assisting States, Federal Agencies, and Tribes in Managing White-Nose Syndrome in Bats.

We encourage you to explore The Fish and Wildlife Service web page dedicated to WNS. To see NOLS’ new curriculum on White Nose Syndrome contact [email protected].

Photo: Little brown bat with white-nose syndrome, New York Credit: Al Hicks, NY Dept. of Environmental Conservation.