White-nose Syndrome

little brown bat with white-nose syndrome (Photo credit: USFWS Headquarters)

With the recent announcement that white-nose syndrome has been discovered in Alabama, I thought I should write a little on this incredible threat to bat health. White-nose syndrome (WNS) is a fungal disease that is associated with high numbers of bat deaths. For the species affected (small brown bats are particularly devastated by this disease), the death toll can be enormous (in some hibernacula the die off is 90%).

Bats and Reproduction

Bat deaths are a key concern because bats don’t have a high reproductive rate. Unlike rats and mice whose numbers can bounce back very quickly, bat populations can take years to recover from a significant die-off. The reason is simple. Bats have only 1 or 2 young per year depending on the species. So if a thousand bats die (assuming 50% of the deaths are female), it can take decades for reproduction to replace the losses.

The Fungus

A photographer took a picture of a bat that had a white looking nose in New York in 2006. Scientists later learned that the white was actually a cold-loving fungus called, Geomyces destructans. It invades the skin of bats and is associated with bats with low body fat and death. It is unclear whether the fungus is causing the illness or whether the fungus is taking advantage of weakened bats.

Bats and You

The bottom-line for you the homeowner is to avoid adding to the destruction of bats. While I do not recommend that bats be allowed to stay in your home, I do think that most homeowners can wait to have the bats excluded after August 15 to reduce the possibility of killing young. Homeowners should also ensure that bats are not poisoned, or killed unnecessarily. Finally, be sure to hire a reputable wildlife control firm, one that follows the Bat Control Guidelines established by the National Wildlife Control Operators Association (http://www.nwcoa.com) (Disclosure: I am a member of NWCOA and am the editor of the NWCOA Newsletter). Don’t forget to always follow bat rabies protocols established by the CDC when a bat is discovered in your living space.

Further Information

If you want to learn more about this disease and the threat it poses to bats, visit http://www.fws.gov/WhiteNoseSyndrome/

About the Author

Stephen M. Vantassel is a certified wildlife control professional who specializes in wildlife damage management issues and identification. His latest book is The Wildlife Damage Inspection Handbook, 3rd edition. Stephen is available for speaking, research, writing, and consultation.