A little brown bat (Myotis lucifugus) with white-nose syndrome
in Greeley Mine, Vt.
Photo by Marvin Moriarty/USFWS
The Interior Department's U.S. Fish and Wildlife Service in May unveiled a national management plan addressing the threat posed by white-nose syndrome, which has killed more than a million hibernating bats in eastern North America since the disease was discovered five years ago.
"Having spread to 18 states and four Canadian provinces, white-nose syndrome threatens far-reaching ecological and economic impacts," Interior Secretary Ken Salazar said. "We've learned a lot in the past few years about the disease, but there is much more work to be done to contain it."
White-nose syndrome is the first epizootic documented in bats. Researchers have identified the recently discovered Geomyces destructans fungus as the presumed causative agent of the disease, named for a white fungus visible around the muzzles, ears, and wing membranes of affected bats.
As of April 2011, WNS had been detected in six of the nine species of hibernating bats in the affected region. Species known to be susceptible to the disease are the little brown bat (Myotis lucifugus), Indiana bat (M sodalis), northern long-eared bat (M septentrionalis), eastern small-footed bat (M leibii), tricolored bat (Perimyotis subflavus), and big brown bat (Eptesicus fuscus). G destructans infections have also been confirmed in several bat species in Europe.
The rapid and widespread deaths associated with WNS is unprecedented in hibernating bats. It is theorized the fungus disrupts the bat's normal hibernation patterns, causing the animal to display uncharacteristic behavior during the winter months. Infected bats have been seen flying outside in the daytime or clustering near the entrance of the caves where they hibernate, called hibernacula.
The USFWS' "National Plan for Assisting States, Tribes and Federal Agencies in Managing White-Nose Syndrome in Bats" lays out a coordinated national management strategy for investigating the cause of the syndrome and finding ways of preventing the disease from spreading.
Bat remains are now a common sight in caves throughout
eastern North America on account of the white-nose syndrome
epizootic that has killed more than a million bats since 2006.
Photo by Ann Froschauer/USFWS
Since the syndrome was first documented near Albany, N.Y., in 2006, the service has been heading up a national response that now includes more than 100 state and federal agencies, tribes, organizations, and individuals. Interior Department agencies have invested more than $10.8 million in this effort since 2007, including more than $3 million in funding in support of ongoing research looking for methods to control or cure the disease.
In addition to research, the national response has also developed decontamination protocols to reduce the transmission of the fungus, surveillance strategies, and technical diagnostic procedures.
Little is known about how the disease is spreading so quickly among bat colonies. The government has closed numerous hibernacula to prevent humans from inadvertently carrying the fungus to other caves.
Hibernating bats typically have only one offspring per year, so population growth depends on high rates of adult survival. These naturally low reproductive rates, combined with the high mortality rate observed in populations with white-nose syndrome, will likely prevent affected bat populations from recovering quickly.
Ecologists and natural resource managers worry about the broader impact of WNS, considering how essential bats are to healthy ecosystems and agricultural systems. An analysis published in the April 1 issue of the journal Science showed that pest-control services provided by insect-eating bats save the U.S. agricultural industry $3.7 billion annually.
The U.S. Fish and Wildlife Service plan for dealing with white-nose syndrome is available online at www.fws.gov/WhiteNoseSyndrome/ along with maps and additional information about the disease.