The U.S. Fish and Wildlife Service (USFWS) announced last week that an estimated 5.7 million to 6.7 million bats have died from White Nose Syndrome (WNS) in 16 states and Canada. The estimate, which USFWS biologists based on data extracted from mines and caves through December 2011, far surpasses the previous 2009 estimate that calculated 1 million bats to have died from WNS.
“This startling new information illustrates the severity of the threat that white-nose syndrome poses for bats, as well as the scope of the problem facing our nation,” said USFWS Director Dan Ashe. “We are working closely with our partners to understand the spread of this deadly disease and minimize its impacts to affected bat species.”
WNS is caused by a skin-eating, cold-growing fungus and acquired its name from the distinct white powder-like marking it leaves on infected bats’ muzzles, wings and ears. In addition to the markings, it is often identified by the unusual behavior it triggers in bats, like flying outside during the day and clustering near entrances of caves and mines during winter hibernation. The infectious bat disease was first detected at Howes Cave near Albany, NY, in 2006 and since that discovery, has quickly decimated entire bat species across the Northeast, including the little brown bat, which has seen a 99% population reduction in Pennsylvania. “The worry is great, tremendous,” said Greg Turner, a specialist in endangered mammals who works for the Pennsylvania Game Commission.
And with WNS spreading farther west every year, disaster may be on the horizon for the agricultural and paper industries. The paper products industry could suffer economic losses if pests such as the emerald ash borer are no longer consumed by bats. And farmers will suffer from bat loss, too. Since bats eat pests and insects (as much as their entire body weight’s worth every night), farmers rely on them heavily as a natural pesticide, so much so that their services to the agricultural industry are projected to be worth roughly $22.9 billion per year. If WNS spreads in the west and exterminates bats in agricultural states, the price of food may soar to account for the rising use of pesticides.
“If WNS continues to take such a huge toll, the environmental and economic costs will be enormous,” noted Nina Fascione, executive director of Bat Conservation International.
As another winter hibernation season commences, biologists anticipate the continued spread of WNS as they struggle to improve their understanding of the disease. USFWS and the U.S Geological Survery (USGS) are working to reduce the risk of accidental transmission of WNS by humans by advising the implementation of effective decontamination procedures prior to leaving potentially diseased caves as well as by prohibiting movement of clothing and equipment between contaminated and unaffected locations and restricting unnecessary human access to sensitive habitats.
“Modifying human activity by implementing decontamination procedures, equipment restrictions, and site closures are the options currently available for managing the spread of WNS,” said Dr. Jonathan Sleeman, center director for the USGS National Wildlife Health Center. “These procedures will be reviewed as indicated by additional scientific findings.”