Audubon’s ‘Batman’ studies elusive mammals 

WELLFLEET – They call him the Batman, but he’s not Bruce Wayne by day, he’s Mark Faherty.

This Cape crusader came about his title accidentally. He’d recently started working as the science coordinator at Mass Audubon’s Wellfleet Bay Wildlife Sanctuary. The sanctuary was contemplating putting up a wind turbine. There are reports that turbines and bats don’t get along.

“I wanted to do a study so I got a bat detector to see what kind of bats we had at the sanctuary,” Faherty recalled. “That generated a lot of data.”

You won’t be able to buy a bat detector at the local hardware store, or even at Walmart, but there are such things. Faherty purchased an AR-125 ultrasonic receiver from Binary Acoustic Technology.

The AR-125 looks kind of like the radar guns baseball scouts use to measure the speed of fastballs at Cape League games. But this machine detects and records the sounds of bats.

“It’s tuned to the frequencies bats use, 10 to 120 kilohertz, above the frequencies we can hear,” Faherty explained. “The sounds are fed into a laptop where the calls are recorded by specific software. Then you use software for analyzing the bat calls and see a sonogram and the frequencies and you can determine what the species is, for the most part.”

Some species that share a genus, such as the little brown bat and northern long-eared bat, are difficult to tell apart but most bats can be sorted out.
That was four or five years ago and since Faherty still has all the equipment when there are questions about bats, the call goes out to The Batman. Faherty’s interest remains piqued as well.

“A lot of the new interest in bats comes from wind turbines. Studies showed bats were killed at an alarming rate, particularly along ridge tops and even in treeless places in Alberta where the forest bats were killed as they migrate through the turbines,” he explained.

The bats have their own sonar system to navigate at night, and catch insects, so they can avoid the blades, but that isn’t enough.

“They’re not striking the blades but the (low pressure) shockwave ahead of the rotating blade can collapse their lungs,” Faherty said.

A study by Jason Horner in the Journal of Wildlife Management revealed that rather than flying through the turbines the bats hung around to forage. The study in Alberta revealed that 90 percent of the dead bats at the base of the turbines had severe lung damage with no external injuries. They were killed by the whoosh of the blades.

Bats in the Northeast have an even bigger problem – the fungal disease known as white nose syndrome.

“Our most common bat, the little brown bat, could go extinct in 20 to 30 years,” Faherty said. “It is killing 90 percent of the bats in some big communal caves in New York and Vermont.”

Those caves supply Cape Cod’s bat population. Our little brown bats fly north to the caves for the winter. The big brown bat, which is more likely to winter in your attic, is already more common on Cape Cod.

“It is a cold loving fungus (possibly imported from Europe) that saps the reserves of the hibernating bat during the winter. When they wake up they don’t have the energy to fly around so they don’t survive,” Faherty said.

There are other bats on the Cape as well. The eastern pipistrelle bat is quite rare. Northern long-eared bats are more common. There are red bats that breed in the forest.

“They seem to be around the Cape Cod National Seashore. I detected them this summer,” Faherty recalled. “They migrate south in the winter. Hoary bats and silver-haired bats also migrate through and we have records of all of them. But bats are still very mysterious. It’s amazing what we don’t know about them.”

We know they eat mosquitoes, often just after dusk or near dawn, swooping through back yards or over ponds. Moths and flying beetles are the favorite prey.

During the day bats will hide in holes in dead trees, attics and barns and often in the rake boards of houses. That’s the trim board right under the roofline.

“They can compress into such a tight space you can’t imagine how they fit themselves up there,” Faherty marveled. “People have told me they roost under their patio umbrellas.”

Faherty hopes to do more bat detecting this fall, to have data to compare with past years. He’ll use the detector on the bridge over Silver Springs at the sanctuary.

“They’re everywhere,” he declared. “We have found them around houses and they’re common around wetlands. I did driving surveys thus summer on a 30-mile route with the bat detector taped to the roof of the car and I would find them around houses rather than large stands of woods.”

Solitary woodland bats, like the red bat, are the hardest to locate.

“The more I learned, the more interested I became,” he reflected. “And once you do it with the bat detector, you become ‘the bat guy.’”