Researchers associate WNS with a newly identified fungus (Pseduogymnoascus destructans) that thrives in cold, humid conditions found in caves and mines used by bats. The fungus could be responsible for the bat deaths, or it could be secondary to the cause. Bats affected with WNS do not always have obvious fungal growth, but they may display abnormal behavior. Biologists found evidence of this fungus in two northern Arkansas caves in January 2013. As of March 2015, WNS or the fungus associated with it has been found in five Arkansas counties.
How is WNS is transmitted?
We believe WNS is transmitted primarily from bat to bat. There is a strong possibility it can be transmitted by humans inadvertently carrying the fungus or its spores from cave to cave on their clothing and gear.
What are signs of WNS?
Bats may lose their fat reserves, which they need to survive hibernation. They may leave their hibernacula during winter and die. The number of bats dying in infected areas increases as winter progresses. WNS may be associated with some or all of the following unusual behaviors:
- White fungus, especially on the bat’s nose, but also on the wings, ears or tail
- Bats flying outside during the day in temperatures at or below freezing
- Bats clustered near the entrance of a hibernacula
- Dead or dying bats on the ground or on buildings, trees or other structures in winter
Hibernating bats may have other white fungus not associated with WNS.
What should I do if I see bats that might have WNS?
If you see bats with signs of WNS in winter, contact Blake Sasse at the Arkansas Game and Fish Commission, 877-470-3650.
What species of bats are affected?
Tri-colored, little brown, northern long-eared, big brown, small-footed bats, gray, and Indiana bats have been found with WNS symptoms or have died from the disease. Five other species – eastern red bat, silver-haired bats, southeastern bats, Rafinesque’s big-eared bats, and Virginia big-eared bats have been found with the fungus, but have not been confirmed with WNS.
What should cavers know and do?
Cavers should observe all cave closures and advisories and avoid caves, mines or passages containing hibernating bats. If cavers decide to go in a cave, they should decontaminate their clothing and gear in accordance with U.S. Fish and Wildlife Service guidelines. To learn more, visit www.whitenosesyndrome.org.
Does WNS pose a risk to human health?
There is no evidence that WNS can affect humans. However, take precautions and do not expose yourself unnecessarily to WNS. Biologists and researchers use protective clothing when entering caves or handling bats.
What is the effect of WNS on bats?
More than 5 million bats have died from WNS, and there seems to be no end in sight. There have been cases of 90-100 percent mortality of bats (primarily little brown bats) at several hibernacula in New York, Massachusetts, Connecticut and Vermont. However, there may be differences in mortality by site and species.
What should owners of caves on private lands do?
The AGFC recommends private landowners prohibit access to their caves for the time being to help slow the spread of WNS by humans. If they do decide to allow access, they should require cavers to follow the guidelines above for decontamination of gear before and after going in the cave: If your cave has significant numbers of bats and you have had problems with illegal trespassing in the cave, please contact the AGFC as there may be programs available to fund cave protection measures at such sites.