White Nose Syndrome in Bats

What is it?

  • White Nose syndrome (WNS) is a serious disease affecting bats.
  • Named for the white fungus that often appears on the muzzles (noses) of hibernating bats, WNS has caused the deaths of an estimated 1 million bats in the northeast and mid-Atlantic over the last 4 years.
  • First seen in early 2006 in a cave in NY it has since spread to 11 states, including WV.
  • Once a cave is infected the disease appears to spread quickly throughout the bats in the cave and mortality may exceed 90%.

How is it spread?

  • WNS is spread bat-to-bat as they cluster in caves and mines.
  • Scientists suspect it is also accidentally transferred from one cave to another on the footwear, clothing, and gear of humans visiting caves.

What happens to affected bats?

  • Bats with WNS use up their winter fat stores too quickly and do not have enough energy reserves to hibernate the entire winter.
  • Affected bats exhibit unusual behaviors such as flying out of caves in the winter, even in the middle of the day.
  • Because there are few insects available for them to feed on, bats leaving caves prior to the normal end of hibernation period eventually starve or freeze to death.

Can WNS affect humans?

  • There is no evidence that the disease is harmful to any animals other than bats.

Why should people care about losing bats?

  • Bats play a key role in keeping insect populations in check.
  • Between April and October, when most bats are active, they can eat their own body weight in insects each night.
  • The insects they eat include those such as mosquitoes which carry human diseases, as well as insects which impact agriculture and forest health.
  • Bats are a critical component of cave ecosystems.

What is being done?

  • Scientists are searching for causes of the disease and methods to treat it.
  • Public land managers and many private cave owners have temporarily closed caves to entry to prevent the accidental human-caused spread of the disease while long-term solutions are sought.
  • At this time all Forest Service caves in the Monongahela National Forest are closed to public entry.
  • Land managers are implementing actions to sustain the health of remaining bats, such as developing water sources and improving habitat for feeding and roosting.

What should a person do if they observe unusual bat behavior or find dead bats?

  • An occasional bat flying on a warm day is not unusual, but it is unusual to see large numbers flying in daylight, in the winter, or in inclement weather.
  • Dead bats outside caves are also unusual.
  • The US Forest Service, US Fish and Wildlife Service and WV DNR all note that they do not need dead bats to be collected at this time.
  • Dead bats are unlikely to carry diseases transmissible to humans, but if they are removed from around homes or barns it is always a good idea to wear disposable gloves while handling them (or any other dead animal.)
  • Report unusual behavior or dead bats by providing detailed information such as location, time of day, observed behavior, number of bats, weather conditions, photographs of dead bats, and your name and phone number to:

The Monongahela National Forest wildlife program manager, Dan Arling at 304-636-1800 extension 202; e-mail at darling@fs.fed.us, or at Monongahela National Forest, 200 Sycamore Street, Elkins, WV 26241. Information will be shared with the Fish and Wildlife Service, and the WV DNR.