White-nose syndrome confirmed in Tennessee's endangered gray bats

White-nose syndrome confirmed in Tennessee's endangered gray bats

May 30th, 2012 by Pam Sohn in News

In a Dec. 16, 2011 photograph, a little brown bat is swabbed during a white nose syndrome study at New Mammoth Cave near LaFollette, Tenn. (AP Photo/Amy Smotherman Burgess, Knoxville News Sentinel)

Photo by Associated Press/Times Free Press.

The confirmation of white-nose syndrome in endangered gray bats in upper East Tennessee is "great cause for concern," officials say.

The U.S. Fish and Wildlife Service has confirmed the presence of white-nose syndrome in very rare bats that wintered in caves in Hawkins and Montgomery counties.

"The documented spread of [white-nose syndrome] on gray bats is devastating news," said Paul McKenzie, a Fish and Wildlife Service endangered species coordinator, in a prepared statement. "This species was well on the road to recovery, and confirmation of the disease is great cause for concern."

White-nose syndrome previously had been documented in six hibernating bat species, including the federally endangered Indiana bat.

Significant mortality has been documented in many colonies of hibernating Indiana bats in the Northeast and mid-Atlantic states.

While no mortality has been observed in gray bats that can be linked to white-nose, the confirmation that gray bats can be infected is a worry. The gray bat, federally listed as an endangered species in 1976, occupies a limited geographic range in the Southeast.

Gray bats are endangered largely because of their habit of living in very large numbers in only a few caves where they live year round. That habit makes them extremely vulnerable to be disrupted by such factors as disease.

Conservation measures to prevent the spread of disease, such as restricting human access to those caves, has been successful in helping gray bat populations recover in many areas.

The diseased gray bats were discovered on two surveillance trips conducted by the Tennessee Wildlife Resources Agency and The Nature Conservancy. Biologists observed white fungus on the muzzles, wing and tail membranes of several bats.

Specimens were collected, and the disease was diagnosed at the Southeastern Cooperative Wildlife Disease Study at the University of Georgia, and later confirmed at the U.S. Geological Survey's National Wildlife Health Center in Madison, Wis.

White-nose syndrome has decimated bat populations across eastern North America, with mortality rates reaching 100 percent at some sites. First documented in New York in 2006, the disease has spread into 19 states and four Canadian provinces.

Bats with white-nose may exhibit unusual behavior during cold winter months, including flying outside during the day and clustering near the entrances of caves and mines where they hibernate.

U.S. Fish and Wildlife Service Director Dan Ashe said the agency will continue to research the disease to try to minimize it.

"Bats provide tremendous value to the U.S. economy as natural pest control for American farms and forests every year. Research and management of this disease remains a priority," he said.

Contact staff writer Pam Sohn a 423-757-6346 or psohn@timesfreepress.com.