White-Nose Syndrome

​Protect your family and animals as well as bats - contact your local wildlife authority or health department if you find a bat that is sick, injured, or in a place it doesn’t belong. Bats, just like people, are susceptible to a variety of illnesses. While the prevalence of rabies in bats is very low (around 1% according to researchi), testing bats involved in human or pet exposures is critical to protect those exposed as well as public health in general. A bat must be euthanized to be tested, and about 6% of bats tested had rabies according to the Centers for Disease Control and Prevention (CDC).

Bats are fascinating mammals that are vital for healthy ecosystems. They also benefit us, our crops, and our forests. The species that feed on nectar and fruit are key pollinators and seed-dispersers for many plants, and those that eat insects are our primary predators of nighttime insects, eating up to half of their body weight in insects in one night. Collectively, bats eat tons of insects nightly, drastically reducing the need for pest control. This not only reduces the amount of pesticides introduced into the environment, but also saves society billions of dollars each year. Bats’ economic value to agriculture alone is estimated by some to be more than $3 billionii a year. Furthermore, studying bats has led to advances in science and medicine, (e.g., echolocation, ultrasound, and drug and vaccine development).

The threat of WNS

little brown bat
Photo courtesy USGS. A little brown bat found in a New York cave exhibits fungal growth on its muzzle, ears and wings. Photo by Al Hicks, NY Dept of Environ. Conservation.

Approximately 1,240 bat species make up about 20% of all mammal species worldwide. But we are rapidly losing millions of individual bats (6 million in 6 years) to a disease called white-nose syndrome (WNS), which is caused by Pseudogymnoascus destructans, a fungus not native to North America. According to the U.S. Geological Survey (USGS) National Wildlife Health Center, bat populations have declined approximately 80% in the northeastern U.S. since the emergence of WNS. Furthermore, the disease seems to be marching across the U.S., and experts fear that some bats are becoming extinct in certain regions.

Bat population dynamics and stressors are complicated. Some of the threatening stressors include WNS, habitat loss, pesticide use, hibernation disturbance, and human interactions. As an organization that advocates for animals and animal health, the AVMA is concerned about the possible extinction of many animal species, including bats, and supports establishment and maintenance of effective conservation of these wild animals in their native habitats. Stopping the spread of WNS and protecting bat populations from other threats is important.

lab workers
Photo Courtesy USGS

Scientists from around the world are working together to better understand bats, WNS, and how WNS affects bats. In efforts to enhance WNS surveillance, mitigation, and control, researchers are monitoring bat populations, creating and testing artificial hibernation sites, and reducing impacts of the disease through treatment and biological control (e.g., using live bacteria or fungi to reduce the fungus that causes WNS). Through efforts such as marking bats to track individuals over time and exploring differences in survival, researchers are also investigating why some bats survive WNS but others don’t. Learn more by watching the video below.

You can help!

  • If you find a bat that is sick, injured or in a place it doesn’t belong, contact your local wildlife authority or health department immediately and avoid contact with the animal.

  • Stay out of sites where bats are hibernating. This will reduce disturbance to bats and unintentional spread of the fungus. Bats that wake from hibernation too early may use up their energy stores before enough food to sustain them becomes available in their environment. When this happens, bats die.

  • Decontaminate your gear and clothes whenever you do go underground. Although the fungus is primarily spread by bats, people entering caves and mines should follow standard decontamination guidelines to clean the disease-causing fungus off clothing and gear and not to move gear from sites with the fungus to sites without it.

  • Learn more about bats – including their value and risks – and share what you know with others. Visit www.whitenosesyndrome.org for more information.

  • Contact your local wildlife agency to learn more about:

    • Bat-friendly practices

    • Bat-friendly best management practices for the type(s) of land and land use you have

    • Volunteering to find and count bats

  • Contact your state or federal legislators to increase funding for WNS work.


Additional Resources



i. Brandon J. Klug, Amy S. Turmelle, James A. Ellison, Erin F. Baerwald, and Robert M. R. Barclay. 2011. Rabies Prevalence in Migratory Tree-Bats in Alberta and the Influence ff Roosting Ecology and Sampling method on Reported Prevalence of Rabies in Bats. Journal of Wildlife Diseases: January 2011, Vol. 47, No. 1, pp. 64-77.

ii. Boyles, J.G., P.M. Cryan, G.F. McCracken, and T.H. Kunz. 2011. . Boyles, J.G., P.M. Cryan, G.F. McCracken, and T.H. Kunz. 2011. Economic importance of bats in agriculture. Science. 332(6025): 41-42.