White-nose syndrome, a deadly disease that's spreading through bat colonies in the eastern half of the United States, has been detected in Kentucky, prompting officials at Mammoth Cave National Park to step up their safeguards against the disease.
The Kentucky Department of Fish and Wildlife Resources and the U.S. Fish and Wildlife Service on Wednesday announced that a little brown bat from a cave in Trigg County, in southwestern Kentucky near Paducah, was found to have the disease.
White-nose syndrome was first detected in New York state in 2006 and has killed more than one million cave-dwelling bats in eastern North America. Mortality rates of bats have reached almost 100 percent in multi-year infected caves, according to the Fish and Wildlife Service. With confirmation of WNS in Kentucky, a total of 16 states, mostly in the eastern United States, and three Canadian provinces have now been confirmed infected.
“This is likely the most significant disease threat to wildlife Kentucky has ever seen,” said KDFWR Commissioner, Dr. Jonathan Gassett. “It would be professionally irresponsible to take no action to stop or slow this disease. Bats are an important part of our natural environment, acting as pollinators and consuming mosquitoes and other insect pests across the landscape. We plan to aggressively manage this threat of WNS as it occurs in Kentucky in order to protect and conserve our bat populations.”
Kentucky is home to Mammoth Cave National Park, which has many bat colonies. So far WNS has not been detected in the park, which is roughly 180 miles east of the Trigg County cave. However, in response to the case confirmed in Trigg County, park officials said Wednesday that they "are initiating all the measures called for in our WNS Response Plan; measures to minimize the spread of WNS to Mammoth Cave, and measures to minimize the spread of WNS from Mammoth Cave."
"Mammoth Cave will continue to offer cave tours, but visitors will now be required to walk through bio-mats as they exit their tour; the mats will be deployed tomorrow (Thursday)," said park spokeswoman Vickie Carson. "We will still screen visitors prior to tours and decontaminate their shoes if necessary."
While it's not considered a health threat to humans, white-nose syndrome is deadly to bats, and there are fears that entire species could be eradicated by it. As the disease spreads, its impacts could ripple through ecosystems. Not only are bats efficient predators when it comes to insect control -- some bats can eat up to 2,000 mosquito-sized insects in a single night -- but they in turn are prey for hawks, owls, and skunks, just to name some predators.
At Great Smoky Mountains National Park, park officials shut off human access to all their caves back in April 2009. While Mammoth Cave still leads about 400,000 visitors a year through about 10 miles of the nearly 400 miles of passages interlaced within the park's massive cave systems, officials last year began developing protocols for dealing with WNS, both to keep it from entering the cave system or being carried out of the system on visitors' feet or clothing if it ever does show up there.
Those protocols range from addressing the issue on the park's website to discussing it with visitors before they go underground on cave tours. About 15 minutes before each tour leaves, an announcement concerning WNS is made. In it visitors are asked if they have been in a cave in the past five years and, if so, are they wearing any footwear or clothing, or carrying any items, such as a camera, that they had with them on those previous caving experiences.
If visitors are wearing footwear that has been in another cave, the shoes are treated with a concentration of an industrially concentrated solution of Lysol that testing at Northern Kentucky University has shown to be effective at killing the fungus. In the case of items such as jewelry or cameras, Lysol wipes are used to clean the items. Jewelry also can be placed in Ziplock baggies.
At the time, researchers were working to devise another decontamination system for footwear, one, for instance, that might entail simply walking across a pad or mat treated with a decontaminant. Since then the "bio mats" have been approved for use at Mammoth Cave.
"We have been screening visitors before they go in the cave since June 2009, and treating their shoes if they wore them in another cave previously," said Ms. Carson. "Last summer we began issuing coveralls and gear on all our crawling tours, decontaminating the coveralls and gear following every trip. (Thursday) we will deploy the bio-mats. Our cave guides speak to their groups about WNS -- about 400,000 people go through Mammoth Cave every year -- so it's a good opportunity for WNS education."
Wildlife officials in Kentucky were the first in the nation to develop a statewide response plan for addressing WNS, according to a FWS release. Part of that plan was regular monitoring of caves for the disease. Almost 100 hibernacula -- winter bat roosts -- were checked throughout Kentucky during the winter, according to state officials.
The Trigg County cave was one of five revisited by scientists upon confirmation of WNS in Ohio. These hibernacula were rechecked due to their known proximity to infected sites in adjacent states, the state said. The privately-owned Trigg County cave is used as a hibernaculum by six bat species, including the endangered Indiana bat, and is a summer roost for the endangered gray bats. Surrounding caves were checked within a 16-mile radius and no additional infected sites were found, the FWS said Wednesday.
Measures were taken to limit the spread of WNS beyond the Trigg County cave, which is regularly used as a hibernaculum by more than 2,000 bats. These included removing and euthanizing 60 highly suspect little brown bats and tri-colored bats as they were not expected to survive, the federal wildlife agency said.