Threats to Bats


A Little Brown Bat with
White nosed syndrome, Myotis lucifugus
Photo: U.S. Fish and Wildlife Service

Bats are in decline nearly everywhere they are found. These amazing animals face a multitude of threats including habitat loss, pesticide use, destruction of roost sites, overharvesting for bush-meat, climate change; and much more. Worldwide, about 24% of bats are considered critically endangered, endangered, or vulnerable. Bat numbers in the United States and Canada have declined dramatically as a new disease, White-Nose Syndrome (WNS), has killed over six million bats in just eight years.

What is White-Nose Syndrome?

White-Nose Syndrome is one of the greatest threats to bats in North America and is killing bats as they hibernate in caves and mines. The disease is named for the white fungus that appears on the nose, ears, and other body parts of hibernating bats. First documented in New York in the winter of 2006-2007, WNS has spread rapidly. Today, nine bat species in 31 states and 5 Canadian provinces have been diagnosed with this devastating disease.

Scientists identified a previously unknown species of cold-loving fungus, Pseudogymnoascus destructans, as the cause of WNS. White-Nose Syndrome causes bats to awaken more often during hibernation and use up the stored fat reserves they need to survive the winter. Infected bats often emerge early from hibernation and are seen flying around in near-freezing weather. These bats usually freeze or starve to death.


Multiple Bats With White-nose Syndrome, Photo: U.S. Forest Service

Alarming Death Rate

The impact of WNS is frightening! Death rates can reach 100% at some sites within just a few years. More than half of the species of bats that live in America hibernate in caves and mines and are at risk to this disease.

What is being done?


Dead Bats — Winter 2009, Photo:

Scientists around the world are working together to understand this disease, how it is transmitted, and how to protect our bats. Both the United States and Canada have a National Plan in response to WNS. States, provinces, territorial, federal, and tribal wildlife management agencies, as well as academic institutions and other organizations are collaborating to:

  • monitor survival and mortality of bat populations;
  • research the most effective methods for decontamination of gear used in bat habitat;
  • provide public outreach to advocate the importance of bats and address common misconceptions;
  • develop and execute recovery plans;
  • develop and test experimental treatments on bats in the laboratory and field.

What can you do to help?

  • Stay out of caves and mines where bats are hibernating.
  • Always decontaminate your gear after entering a cave or mine to prevent the spread of the fungus.
  • Be observant for unusual bat behavior such as bats flying during the day or in the winter or bats struggling to get off the ground. Report these sightings to your state or provincial natural resource agency.
  • If you find a dead bat, contact your state or provincial natural resource agency.
  • Help spread the word about the importance of our bats and the threat of WNS.

Learn More about WNS