Q: Where have the bats gone? My backyard has always had hundreds of bats circling high overhead in the evenings, however in the last two years I’ve noticed a significant decline in number. Along with that we have had a influx of moths. Is there a connection? And what can be done about moths if the bats aren’t around to feed on them?
Answer: “While I’m not sure the degree to which the reader’s bats are gone, it is well documented that many bat populations in the U.S. have been declining due to human disturbance of hibernacula (the places where bats seek refuge) and maternity colonies, but more recently and problematically due to an emergent fungal disease,” said James Tomberlin, a mountain region wildlife biologist with the N.C. Wildlife Resources Commission.
White nose syndrome is a disease named for the white fungus that appears on the muzzles of hibernating bats.
Other symptoms include bats flying outside during the day in cold temperatures; bats clustered near the entrance of the hibernacula; and dead or dying bats on the ground or on buildings, trees or other structures.
It was first discovered in New York back in 2006 and was detected in North Carolina during Wildlife Resource Commission bat monitoring work in 2011, he said.
“This disease is most prominent in our mountain counties and has resulted in some local bat populations declining by as much as 99 percent. Unfortunately, the first case of white nose syndrome was detected in Stokes County this past winter and marks the farthest east record in North Carolina.”
He said that the Wildlife Resource Commission, U.S. Fish and Wildlife Service, North Carolina State Parks and volunteers are partnering to expand monitoring efforts in the Piedmont and coastal counties to document and ascertain the scope of this disease across North Carolina.
“At this point, education is our best defense against the further spread of the disease, which can be exacerbated by human activity, as well as ways to manage bat habitat in your area,” he said.
More information on bats in NC is available at www.ncwildlife.org/Portals/0/Conserving/documents/Profiles/Bats_Species_Profile.pdf. And for more information on white nose syndrome and its symptoms, you can go to www.whitenosesyndrome.org/faqs.
As for moths, “Since bats are a key predator of moths, it’s possible there is a connection between the lack of bats in the area and increase in moths,” Tomberlin said. “Not sure much needs to be done about the moths, but that’s best handled by the homeowner and their pest control provider.”
Kendrick Weeks, western wildlife diversity supervisor with the Wildlife Resources Commission, added that bats are one of two types of “aerial insectivores” in the state, the others being nightjars such as whip-poor-wills, chuck-will’s-widows and nighthawks.
“Smaller owls, like eastern screech owls,” will also eat moths along with other insects and small mammals, but they are not significant predators of moths,” he said. “We have seen a decline of nightjars in the recent past, but not to the extent of those bat species affected by white nose syndrome.”