Last updated: July 8, 2022
Article
White-nose Syndrome FAQs
NPS photo/von Linden
WNS is a fungal disease that affects hibernating, insect-eating bats. It's killed millions of bats in the US and Canada, up to 99% of some populations. Scientists first discovered WNS in NY in the witner of 2006-2007. They have evidence that the causal fungus is from Europe, but the bats there do not suffer the same mortality.
In addition to the white muzzles and wings, bats acting strangely could indicate WNS. This includes bats flying outside during the day in freezing temperatures during winter. Another sign is bats clustering around entrances of hibernacula (places where they hibernate) or dead or dying bats on the ground in winter.
A fungus called Pseudogymnoascus destructans causes WNS. It is often displayed as a powdery white substance around infected bats’ muzzles and wings.
Researchers have learned WNS is spread from bat to bat when they touch and also from cave surfaces to bats. Scientists also think that humans have the potential to carry the fungus from cave to cave, increasing the rate of spread.
Many things! Park personnel are busy monitoring bats, educating visitors about WNS, and protecting bat habitats. Our scientists work with researchers from other agencies to learn more about WNS and its effects on bats. Management has made decisions to close certain caves to protect hibernacula and maternity roosts. Management also varies from park to park, so some parks may offer to decontaminate shoes, while others may require you to leave any clothing or items that have been underground behind before entering a cave. Visitors may be required to walk across decontamination mats when exiting a cave.
Current evidence indicates that WNS is not transmissible from bats to humans. Studies have shown that the fungus grows only at cold temperatures (41-68 degrees F) that are much lower than that of the human body. Also, no human infections have ever been documented after exposure to WNS-infected bats or caves.
Although WNS does not cause illness in humans, a small percentage of bats can be infected with other dangerous diseases, such as rabies. Bats infected with either WNS or rabies may exhibit unusual behavior (e.g. erratic flying), which increases the risk for bat-human contact and exposure. Additionally, declines in bat populations can impact human health indirectly since humans depend on bats for important ecosystem services such as controlling pest insects.
Although WNS does not cause illness in humans, a small percentage of bats can be infected with other dangerous diseases, such as rabies. Bats infected with either WNS or rabies may exhibit unusual behavior (e.g. erratic flying), which increases the risk for bat-human contact and exposure. Additionally, declines in bat populations can impact human health indirectly since humans depend on bats for important ecosystem services such as controlling pest insects.
Do not touch the bat, but be sure to tell a Park Ranger.
Decontamination simply means disinfecting gear or shoes that have been in another cave. It reduces the risk of humans spreading the WNS-causing fungus from cave to cave when done properly. Some parks may offer the option to decontaminate shoes or other items. Not all parks offer decontamination, and some parks may require clothing or items that have been underground to be left behind. Washing your clothes does not decontaminate them and does not kill the fungus. Cavers should be come familiar with current decontamination procedures. Please not that some parks may not allow decontaminated caving gear or other items into caves or mines.
The best practice is to wear completely different clothes for each visit to a cave or mine. The fungus can remain on clothing and other surfaces for many years and still be transferred into a new place. Washing your clothes does not decontaminate them and does not kill the fungus. Please be sure to check with the cave or mine you are visiting ahead of time to learn about its regulations and see if there are any restrictions. Screening for WNS varies at each park, and rules are different park to park and can change any time. Cavers should become familiar with current decontamination procedures. Cave visitors can also follow these decontamination procedures after visiting a cave or mine, but some parks may not allow decontaminated clothing and items in caves.
Yes! It is important that humans do not accidentally help spread WNS. Scientists are still learning about the disease and how it’s spread, but properly cleaning shoes and gear that may have been exposed is a way to keep humans from moving the fungus from one cave or region to another. However, because decontamination may not kill the fungus that causes WNS, it's best not to bring or wear anything from one underground space into another even if it has been properly decontaminated. Please note that some parks may not allow decontaminated gear or other items into caves or mines.
Millions of bats have died, but it's difficult for scientists to accurately estimate the number of bats we've lost. In some hibernacula, 90-100% of the bat populations have been destroyed.
Bats are important native species. The insectivorous bats most at risk for WNS are quite busy when they’re out at night. They help control insect pest populations by eating large amounts of moths, mosquitos, and other insects that damage crops. Additionally, bats serve as prey for other animals are the inspiration behind technology we use everyday, like radar.
WNS mainly affects hibernating, cave-dwelling bats, so particular species are more at risk than others.
Throughout our national parks, more than 50 species of bats live in trees, in old buildings, in caves, in old mines. Some bats migrate during the winter, while some hibernate in caves or mines. Many parks have habitats that support different kinds of bats.
No. Bats actually live 10-15 years naturally, and they usually have only one pup per year. With that slow rate of reproduction, it is important to keep their hibernacula and maternity roosts undisturbed and free of the fungus.