Slowing the Spread of White Nose Syndrome in Bats

Little brown bats hibernate together in caves. Most of these bats have fungal growth on their noses. Photo courtesy of Nancy Heaslip, NY Department of Environmental Conservation.

Since 2006, a newly discovered fungal disease referred to as white-nose syndrome has killed millions of North American bats. U.S. Forest Service researchers, along with researchers from other Federal and state agencies and universities have been investigating the fungus and its devastating effects on bats since the disease was first noticed.

Roger Perry, a research wildlife biologist with the Forest Service Southern Research Station (SRS) Southern Pine Ecology unit, recently summarized their findings in a new report, White-Nose Syndrome in Bats: An Overview of Current Knowledge for Land Managers.

“We’ve made significant strides towards understanding this new disease and its impacts on bats,” says Perry. “Unfortunately, information that can be used directly by managers to help control it is still lacking or speculative.” The primary management goal at this time is to slow the spread of the disease to give biologists time to find workable solutions for this disease crisis before it spreads throughout the continent. Already, the fungus is found in most eastern states, as well as several Canadian provinces and Midwestern states.

White-nose syndrome has spread at an average rate of 200 miles each year. Bats pass the disease among each other, and humans entering hibernation caves may inadvertently carry fungal spores on their clothing or equipment, potentially transferring the disease to new areas. Once an area is infected, the disease can kill up to 95 percent of susceptible bats. White-nose syndrome may place endangered species such as the Indiana bat at even greater risks of extinction, and could cause other species to become endangered or locally extinct.

To protect bats, managers are limiting access to caves and other hibernation sites, reducing disturbance around the areas where bats raise their young, and maintaining quality habitat. “Bats that are healthy and have accumulated plenty of fat when they begin hibernation could have better survival,” says Perry. “Every time a bat wakes up from hibernation in the winter, it uses up a great deal of stored energy.”

Part of the reason white-nose syndrome is so lethal is that it can rouse bats from hibernation during winter. Although most conspicuous when growing on bats’ noses, the fungus can grow anywhere on their skin, invading and irritating the tissues. It can grow on the wings, creating holes in them, which may impede a bat’s ability to fly and disrupt their physiological processes because of the vast amount of skin that covers their wings.  

Bats are important members of cave ecosystems, where they help maintain the food chain. Because caves are usually cut off from the sun’s energy supply, many animals and microbes that live exclusively in caves rely on cave-roosting bats to provide a constant influx of nutrients, in the form of guano or bat droppings.

Bats are also very important to farmers. Although tiny, they are big eaters. Each summer night, a bat can eat over half its own body weight in insects. All together, bats in the United States consume thousands of tons of insects each night. Without bats, insect populations could boom, costing billions of dollars in added pesticides and agricultural damages each year.

“Explaining how important bats are is critical to managing white-nose syndrome,” says Perry. “Everyone can help protect bats – by respecting cave and mine closures, decontaminating clothes and equipment before and after entering caves, letting state wildlife agencies know if they see dead bats, and by telling others about white-nose syndrome and the value of bats.”

Read the full text of the report.

For more information contact Roger Perry at

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