CAMP EDWARDS — If you see the blades of wind turbines stopped at Joint Base Cape Cod, it could be a maintenance issue.
It could be weather. Or it could be bats.
Northern long-eared bats, which once thrived locally and throughout most of the Northeast, are federally listed as a threatened species and are on the state’s endangered list because of a fungal disease known as white-nose syndrome that’s wiped out an estimated 95 percent of the population, according the U.S. Fish and Wildlife Service.
Studies are underway at Camp Edwards, at the Cape Cod National Seashore and on Martha’s Vineyard to learn more about the bats and what it is about coastal areas that’s allowing the species to hang on, Jacob McCumber, natural resources manager for the Massachusetts National Guard, said.
“It was once our predominant (bat) species here on base,” McCumber said, referring to a study done about 15 years ago.
Over the summer, the National Guard’s natural resource department did acoustic surveys using sonar to determine if there was still a population of the northern long-eared bats on the base. Once they determined there was, they were able to capture two females in mist nets, install radio transmitters and track them using telemetry.
“We didn’t find any suggestion of active maternal colonies,” McCumber said.
Because the bats are a federally-listed threatened species, McCumber said investigations are done to make sure military training doesn’t interfere with the habitat. It doesn’t, he said. Natural resource employees also make sure that any prescribed burns or tree removal on the base won’t interfere with the bats, he said.
As for the wind turbines, any federally run turbines are required to shut down when the bats are migrating in the spring or fall, McCumber said. The base has three wind turbines that provide power to its groundwater treatment plants and two for the PAVE PAWS radar station. Typically, it’s on nights when the winds are light or nonexistent that the turbines stop spinning because the bats are likely on the move, he said.
The plight of northern long-eared bats was first identified for classification in 2013, but it wasn't until this May that the tiny winged mammals were listed as threatened.
“We used to have millions of bats on the landscape,” Susi von Oettingen, endangered species biologist with the New England office of the U.S. Fish and Wildlife Service, said. “We’ve lost a large source of insect control.”
Northern long-eared bats feast on moths, beetles and dreaded mosquitoes, eating as many as 1,000 in an hour.
“The little ray of hope we have is here on Cape Cod and Martha’s Vineyard,” von Oettingen said, where research is showing these bats are still present.
The going theory is the bats don’t migrate very far and so those on the Cape, islands and other coastal communities aren’t traveling to bat caves in places like Vermont and New York state where white-nose syndrome infects and ultimately kills bats by the hundreds because of the close quarters.
“I don’t know of a cave or mine within 40 miles of Cape Cod or Martha’s Vineyard,” von Oettingen said.
They could be hibernating in the foundations of older homes, cisterns, cinder block foundations, root cellars or the crevices of rock deposits, she said. Researchers hope to track the migrating bats next fall, though it can be difficult because the radio transmitters are very small and have only a short range.
A two-year study is underway on Martha's Vineyard by biologists Liz Baldwin and Luanne Johnson with BiodiversityWorks, a non-profit group funded by Martha’s Vineyard Vision Fellowship. Three breeding colonies were found on the island last summer, and the female bats were tracked moving their pups from various roosting spots, Johnson said. The bats use trees and utility poles, and sometimes nestle into the spot between trim board and roof on a house, she said. These are not the type of bats you might find causing havoc in an attic, Johnson said.
Baldwin and Johnson were able to tag nine females and watch as they moved from one roosting spot to the next.
Healthy northern long-earned bats live long lives — up to 20 years — and the females give birth to only one pup per year.
“Trying to replace one pup per year per female will take a long time,” Johnson said. “Every bat is important because reproduction so slow.”
Investigations are also underway at the Cape Cod National Seashore, Robert Cook, a wildlife ecologist, said. Funding is available through next summer and Seashore officials are looking to extend that through 2018.
Results from research over the past summer has not yet been analyzed, Cook said. Like research being done on the base and the Vineyard, the National Seashore is hoping to find out where the bats are going to hibernate.
“We don’t know where they are spending the winter. If they’re here, or leaving Cape Cod,” Cook said. “We want to find out what’s happening in the fall and winter months, which is a critical time of year for these animals.”