As you probably know, bats migrate and like to hang out in caves. In Austin, we had a large population of Mexican Freetail bats that would come north in the Winter to be pregnant and give birth sometime in the Summer. There are bats all over North America, hibernating before heading back south, and they're catching a nasty flu. White-nose syndrome (WNS) is named for a white fungus found on the muzzles and wings of affected bats. It was first documented in New York during the winter of 2006-07. WNS has spent the past few years rapidly spreading throughout the east and north into Canada. The damaging fungus (Geomyces destructans) thrives in cold and humid conditions: can we say caves? The nasty fungus is transmitted from bat to bat, but it is very likely that some of the spores are coming from human beings and their gear when they move from cave to cave.
WNS is a pretty nasty ailment and kills over 90% of its victims. The most common bat in the US is being threatened with extinction due to this disease. Because the syndrome often affects the bats while they're hibernating, it packs a powerful punch. Bats need to sleep and conserve their energy. When it's too cold for bugs, it's too cold for the bats to hunt enough to feed themselves: bats use a lot of energy to fly around looking for food and need a lot of bugs at a time. When their hibernation is disturbed, their bodies warm up and they burn the fat reserves crucial for their survival in the winter. The growing fungus irritates the bats' breathing and causes them to wake up, often leaving their caves. The skinny, cold bats then die. As the fungus progresses to the wings, the bats are no longer able to fly, and thus starve. To this date, WNS has been confirmed as far west as Missouri and Oklahoma. Signs of WNS include:
- White fungus around the nose, wings, ears or tail
- Bats seen flying outside during the day and in temps at or below freezing
- Bats clustered around the entrance of a cave/ hibernating area
- Dead or dying bats on the ground or on buildings, trees, etc
I know i have several readers in the affected area of WNS and many more west of its spread. I hope that this article has informed you of this potentially devastating effects of this nasty fungus and that you will reconsider caving in areas occupied by bats. If you do enjoy caving, please be sure that you thoroughly sanitize all your gear and clothing before moving to another cave. The health of north American bats is essential to natural control of disease spreading (and itchy!) mosquitos and other insects. Consider providing bat houses for your local bats and please leave a cave immediately and quietly if you see bats inside, and contact a local ranger or animal control professional if you notice any signs of disease.
More information about WNS can be found at the Fish and Wildlife website. You can also report unusual bat behavior at that same website. Sometimes observing little critters is fun and entertaining, and sometimes that observation is crucial to the survival of an entire species. If you love nature and animals as my husband and I do, please take precautions not to spread WNS and report any signs of bat disease immediately. Thanks!
* Information about WNS sourced from Lava Beds National Monument, part of the US Department of the Interior. Photos are from the Fish and Wildlife website.