RODALE NEWS, EMMAUS, PA—White-nose syndrome (WNS), a condition that has been associated with the deaths of up to 200,000 hibernating bats in the northeastern United States, has been linked to a newly identified fungus, according to a U.S. Geological Survey study published in the October issue of the journal Science.
In early 2006, the mysterious disease started spreading through caves and killing off droves of bats in Connecticut, Massachusetts, New York, and Vermont. The white fungus is visually striking and often found on dead and dying bats’ noses, ears, and wing membranes.
THE DETAILS: USGS researchers examined 117 dead bats found at 18 sites in the Northeast between February and April 2008. They found the white fungus on 105 of the 117 bats. More than 65% of the fungus-infected bats that were analyzed had little or no fat reserves; stored fat is critical for the bats to survive winter hibernation in their caves. Apparently some of the emaciated bats wake from hibernation searching for food in winter, when there isn’t any available.
Lead author David Blehert, PhD, microbiologist at the USGS National Wildlife Health Center in Madison, Wisc., says researchers are trying to figure out whether WNS emerged because the fungus was recently introduced into caves by people or other animals, or if it was always present, but is now killing bats suffering from weakened immune systems due to some other cause.
WHAT IT MEANS: Although some people are spooked by bats, they are incredibly important creatures. Their appetite for insects helps keep mosquito levels low—they can eat up to 100% of their body weight in bugs in a single night. “In the northeastern United States, decreased bat numbers could lead to increased incidence of mosquito-born diseases, such as West Nile Virus,” says Blehert.
Bats also save farmers megabucks. “Worldwide, bats play critical roles in plant pollination, seed dissemination, and insect control,” Blehert adds. “In the United States, bats are important for insect control; insect control by bats has been valued at approximately $2,000,000 per year to Texas cotton farmers.”
Here’s what you can do to help nature's mosquito control force.
• Make your yard bat-friendly. Put up a bat house on your property. Consider adding a garden pond or bird bath in an open space so bats have access to fresh water. If you’re worried about bats and rabies, don’t be. The group Bat Conservation International reports that fewer than 10 people in over 50 years have contracted rabies from common North American bat species. Rabid bats rarely become aggressive, so if you encounter one that seems sick, avoid it and contact your local animal-control authority
• Cave carefully. If a cave known to harbor WNS is closed, honor the instructions. Cavers should especially exercise caution to avoid inadvertently transporting pathogens between caves.
• Give a little. Consider making a donation to help fund more research on WNS by the Indiana State University Bat Center or Bat Conservation International.
• Be kind to indoor bats. If a bat finds its way into your house, there’s no need to kill it. Stay calm and trap it in a room with an open window; eventually, it will fly outside. You can encourage it to leave by tossing some dirt or salt out the window; the bat may follow it, thinking it’s chasing some insects.