Deadly bat ‘White Nose Syndrome’ spreading across USA

Little brown bats with White nose syndrome. Credit Credit: Nancy Heaslip, New York Dept. of Environmental Conservation

This is the first record of White Nose Syndrome in Tennessee. Three tri-coloured bats were collected by the Tennessee Wildlife Resources Agency (TWRA) and submitted to the National Wildlife Health Center (NWHC) in Wisconsin for testing.

Last spring the state of Tennessee, National Park Service, and USDA Forest Service and Tennessee Valley Authority closed caves on public lands in Tennessee in an attempt to slow the spread of the fungus. The Nature Conservancy also closed caves located on their lands in Tennessee.

95% mortality
Scientists are trying to determine the cause of WNS and its effects. Once a colony is affected, the fungus spreads rapidly and has killed at least 95 percent of bats at one New York hibernation site in two years. Other northeastern U.S. monitored bat colonies affected by WNS are experiencing similar large fatalities. There have been no reported human illnesses attributed to WNS and there is currently no evidence to suggest that WNS is harmful to humans or other organisms.

This is one of two two-colored bats collected last week showing signs of White Nose Syndrome. (Photo by Sterling Daniels, TWRA)

Preliminary research results recently released by the United States Geological Survey indicates that the potential exists for WNS to be transmitted between bat hibernation caves as an unwanted hitch-hiker upon humans, their clothing, or other caving gear.

Stay away from caves
"Temporarily staying out of caves and mines is the one thing we can do right now to slow the transmission of White Nose Syndrome," said Cory Holliday, Cave and Karst Manager for The Nature Conservancy in Tennessee.

Endangered bats
"We knew the bat deaths in the Eastern United States were large. Here in Tennessee we stand to lose the last stronghold of bats like the endangered Indiana and grays. We have hundreds of thousands of bats hibernating in our caves each winter. With a 95 percent mortality rate the loss is catastrophic."

Biologists are concerned that WNS could devastate populations of endangered Indiana and gray bats. Bats play a key role in keeping insects such as agricultural pests, mosquitoes and forest pests under control.

Natural pest control
"Bats provide a tremendous public service in terms of pest control, said Richard Kirk, Nongame and Endangered Species Coordinator for the Tennessee Wildlife Resources Agency. If we lose 500,000 bats, we'll lose the benefits from that service and millions of pounds of insects will still be flying around our neighborhoods, agricultural fields and forests."

The disease causes bats to use up their fat reserves rapidly during hibernation. This causes the bats to fly out of caves during the winter in a desperate attempt to find food, but since the insects they eat are also seasonally dormant, the bats soon die of starvation.

State and federal agency biologists and non-governmental organizations are currently surveying caves in east Tennessee and other portions of the state. These surveys are being conducted as annual bat population surveys and to monitor for WNS.