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White Nose Syndrome

Why are America’s Bats Dying?

Since the winter of 2006-2007, at least one million insect-eating bats from at least nine states have died from White Nose Syndrome (WNS). This disease, named for the white fungus often seen on the muzzles, ears, and wings of infected bats, poses a threat to cave hibernating bats of the United States and potentially all temperate regions of the world.   The fungus, scientifically called Geomyces destructans, invades the skin of bats, producing ulcers and often altering bats’ hibernation arousal patterns, making them leave their hibernation before they are ready and causing them to starve. 

WNS has been detected in fourteen states: New Hampshire, Vermont, New York, Massachusetts, Connecticut, New Jersey, Pennsylvania, Delaware, Maryland, West Virginia, Virginia, Tennessee, Missouri, and Oklahoma, and in the Canadian provinces of Quebec and Ontario.  

BLM Reminder: Abandoned mines are closed to all access

brown bat with white nose syndrome 
A brown bat with white nose syndrome
Credit: Marvin Moriarty/USFWS

What is causing this?

Scientists are still studying the fungus, trying to determine how it is transmitted, how quickly it affects bats and why it affects them. Researchers do not yet know if WNS emerged because the fungus was introduced into caves or if the fungus already existed in caves and began infecting bats for some other reason. WNS is likely spread by contacts among bats and with other environments. However, movements of humans and other animals between caves could also promote the spread of WNS. Scientists are currently working to determine if fungal infection is the sole cause of WNS-associated bat mortality. 

What does this all mean? 

Bats are important plant pollinators. By eating the nectar from agricultural plants, such as fruit trees, bats help flowering plants reproduce. Most flowering plants cannot produce seeds and fruit without pollination – the process of moving pollen grains from the male part of the flower to the female part. Over 300 species of fruit depend on bats for pollination. These fruits include mangoes, bananas, and guavas. If bats disappear, the fruits you love may become scarce.    

 little brown bat with white nose syndrome
This little brown bat has white nose syndrome. 
You can see the white substance on his face.
Photo courtesy Al Hicks, New York Department of Environmental Conservation

Bats also help control nocturnal insects, some of which are agricultural pests or vectors for human disease. Almost any insect that is active at night can be food for a bat, including moths, beetles, flies, crickets, gnats, mayflies, wasps, and mosquitoes. An individual bat can eat its body weight or more in insects every night. It is estimated that the one million bats killed by WNS to date would have eaten more than 5.5 tons of insects per night or 2.4 million pounds of insects per year. Bats are an important element in the ecology of caves. Many forms of cave life depend upon the nutrients brought in by bats and released from their guano (feces).

Bats are adapted to high rates of survival (many of them live beyond ten years of age); so many bats only have a single “pup” each year, which prevents overpopulation in healthy bat species. Scientists are worried bat populations will not quickly recover from such devastating losses, which means an ecological balance will be altered in the wake of their absence.

Bats are an important part of our natural system. There are over 1,000 species of bats worldwide and they make up about a quarter of all mammal species. Bat populations all over the world are declining for various reasons. 

Does WNS pose a risk to human health?

WNS is in caves and mines that have been visited by hundreds of people during the past three years, yet there have been no reported illnesses attributable to it. However, because scientists are still learning about WNS, we do not know if there is a risk to humans from contact with affected bats, and we cannot advise you about human health risk. 

How can I help?

Public land agencies across the country are working together to help prevent the spread of the fungus. Scientific evidence suggests that humans spread it from one cave to another with their boots, clothing and anything they bring into the cave. Some caves have been closed to human access, and still others may be closed to prevent the fungus from spreading further.

-If a cave is closed in your area, do not enter the cave. 

Download this brochure about White Nose Syndrome and take it with you!
Going to enter a cave?  Learn how you can decontaminate yourself and your gear after entering a cave, so you can help save America's bats!
Download our Decontamination Procedures brochure and take it with you, so you can avoid contaminating Idaho's caves.







It is very important to follow decontamination procedures if you are entering caves!  Follow these procedures from the U.S. Fish and Wildlife Service:

Decontamination Procedures

Other useful links:
biologist entering cave
A biologist enters a cave wearing protective gear.  
He will make sure he changes and/or disinfects his clothing, footwear and gear using proper procedures before entering another cave.


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