Bat survey seeks signs of life

Rich Fritsky, a wildlife diversity biologist for the Pennsylvania Game Commission, places a high-tech microphone on his vehicle's roof that can detect bat chirps.

HOP BOTTOM (AP) – Biologist Richard Fritsky drives at 20 miles per hour down a dark country road.

He’s listening.

With a $965 microphone, sophisticated computer programs and his biology training, he is searching for bats.

The Pennsylvania Game Commission, which employs Fritsky, studies the bat population in different ways. One way is to visit sites where bats are known to congregate. Another way is to listen for the creatures.

That’s what Fritsky was doing recently, and the reason he was driving from Hop Bottom in Susquehanna County to Falls in Wyoming County.

His route was random, originally created for another biological survey – the North American Breeding Bird Survey. From those paths, which have been used for decades, the game commission randomly selected routes for biologists to use for its own bat-surveying purposes.

As he drives, a faint buzz comes from his computer. A program called SPECT’R III is scanning the night skies for sounds that humans can’t hear. The computer mostly just buzzes, but occasionally he picks up something: a high-pitched chirp from a bat using echolocation to hunt insects in the night. The computer repeats the sound, the screen lights up and the software marks more data. After the drive is finished, he’ll use another software program to sort out the sounds of bats.

The equipment and the software is relatively new for the game commission. The state has performed years of bat surveys, but searches using this method are only four years old.

Humans are still an important part of the process.

Biologists go through the sound files to make a second check of the recordings the computer threw out as not containing bat noises.

The goal is to map the bats’ locations and better understand them. With that information, biologists can try to protect the animals, which are in an ongoing crisis.

Major decline

The software buzzes quietly inside Fritsky’s truck as he completes the survey.

A chirp is cause to take notice.

He points at the curves of data that appear on his computer screen. They are signs of bats.

Biologists are encountering far fewer bats these days.

The animals pollinate crops, disperse seeds and eat millions of insects, but some species in Pennsylvania and other eastern states have suffered major declines. A disease called white-nose syndrome is to blame.

A fungus invades the skin of bats suffering from white-nose syndrome, disrupting their hibernation cycle, according to Bat Conservation International. Instead of hibernating normally, infected bats repeatedly wake during the winter, burning up limited fat reserves. By the time they leave hibernation sites, they are hungry, thirsty and dying.

Scientists in New York State found bats with the disease in 2006. By 2008, it had spread to Pennsylvania – including Luzerne and Lackawanna counties.

One site Fritsky checks, on a river island in Northumberland County, used to have about 4,000 bats. On a recent check, he counted 35.

“That’s a good example of how devastated these bat populations are from white-nose syndrome. We’re talking 99 percent drops,” he said.

Even considering the population decline, the survey is a quiet one. Routes past an old barn and near wetlands produce few chirps from the computer speakers.

Imagine, he says, what a driving survey would have been like before the decline.

“It would have been crazy,” Fritsky said. “You would probably turn down the speaker so you could think straight.”

The survivors still show lesions on their wings and suffer from dehydration, which weakens the bats.

Biologists hope the survivors may have a natural resistance to the fungus that they can pass on to their offspring.

Even if that happens, though, it will take decades for the populations to recover to the numbers they had before the disease. Bats produce offspring when they are two or three years old, and only produce one child per year.

“We think it will take well beyond our lifetimes,” he said.

What is being done?

Piece by piece, the collection of data gathered by Fritsky and other biologists grows. What it says is part of what moves the state and federal governments to action.

The U.S. Fish and Wildlife Service leads a network of organizations, including the Pennsylvania Game Commission, that investigate the disease and try to manage it. Since 2008, the service has granted more than $24 million to institutions and federal and state agencies for white-nose syndrome research and mitigation.

“A lot of it is finding out what we know,” said Greg Turner, a game commission biologist.

That information is gathered through methods like the survey Fritsky employed and other research, such as by tagging and tracking bats on airplanes to find their new roosting sites.

Besides studying the animals, the game commission also protects them. That involves buying land to protect the sites where bats hibernate and the maternity colonies where many females give birth. Other methods include building bat boxes, where the animals can sleep, or constructing bat-friendly barriers at existing colonies that don’t disturb the hibernation conditions but still keep out humans.

Sometimes, the computer identifies a bat as an especially rare one for the state.

When that happens, biologists set traps in the area to see if they can confirm the species is there. If the computer detects a federally protected Indiana bat, for example, and state biologists find one, they submit a record to a database called the Pennsylvania Natural Diversity Inventory. When construction contractors seek permits for a project, they must check their project boundaries against the inventory, which can create regulations for the work.

Protecting an animal costs money – for researchers to study and interpret data, for land purchases that protect or develop suitable habitat, and for initiatives that educate the public about that particular part of the ecosystem.

The game commission’s research informs its own decisions and the policy of other states. White-nose syndrome hasn’t advanced to some of them, so the Pennsylvania data gives them an idea of what to expect and a warning to start preparing. If they survey now, before the disease advances, they’ll have a baseline idea of what the population looks like.

The commission has been a major player in white-nose research since 2008, Turner said, either by supporting other efforts or doing the actual research to understand the disease and the bats that suffer from it.

“I don’t think there’s ever been a wildlife disease taken care of without a vaccine, and you can’t vaccinate millions of bats,” Turner said. “It’s a tough one.”