Arriving by utility task vehicles and on foot, the team of wildlife biologists, scientists, scholars and technicians converge at the end of a twisty, steep logging road this unseasonably warm and dry late October afternoon. Hauling backpacks filled with research gear and tools, they trek through a dry stoney creek bed to the base of a sheer mountain bluff littered with massive boulders, artifacts from ancient Ozarks landslides.
Gazing upward, the men and women slowly ascend, navigating brambly perilous ledge trails. Their mission: to survey and assess bats engaged in autumn swarm mating season. One group sets up on a steep dirt slope beneath a tumbled cavern where bats are known to summer. A second group climbs on to survey a known hibernaculum or bat hibernation cave up the mountain.
Ozark Highlands Biologist Pedro Ardapple, U.S. Fish and Wildlife Service recovery lead for federally endangered and threatened bats in Arkansas, along with Crystal Griffin, a scientist with Environmental Solutions & Innovations, Inc. in Fayetteville, assemble a harp trap to place over the cavern opening.
"It's called a harp trap," Ardapple said, "because of the way it's built with basically parallel fishing lines [strung] like a harp," drawn tight around a large white plastic pipe frame. "The bats fly into them and drop down into a bag where we can fish 'em out."
"And since we don’t have the whole entrance covered," Griffin said, "we are setting up tarps around the trap to ensure that we funnel the bats into our little harp so we can catch them."
"We'll position one or two people next to the harp trap to extract bats from the bag," Ardapple said, "which never get tangled up compared to mist nets, and then we'll process them, take measurements, collect species information and morphometrics, to get a count and species diversity, both."
Bats will begin to emerge from the cavern at dusk, in an hour, to feed on flying insects. That gives the team time for a quick bite, unpacking foil-wrapped sandwiches and snacks. Amanda Foust, a wildlife technician with the U.S. Forest Service Big Piney Ranger District, reclines against a log, crunching on potato chips before setting to work.
At twilight, the team don headlamps, face masks and gloves, to protect themselves as well as the bats, grabbing data clipboards, pens and measuring devices. Crickets softly trill as sounds of fluttering soon rouse the team into action. A Gray Bat suddenly emerges from the cavern, wings spread, flying straight into the soft harp trap strings, fluttering down into the containment bag, unharmed.
Matthew Anderson, a U.S. Forest Service Fish and Wildlife biologist stationed on the Ozark-St. Francis National Forest along with Ardapple and Griffin carefully examine the endangered bat. The tiny furry creature growls with displeasure. Once the physical is complete, the bat is banded then released, soaring off into pitch darkness.
Amanda Foust,
Wildlife scholar, Doug Barron, examines the wings of a captured Ozark Big-eared Bat, also federally listed as endangered.
"I know, you are so unhappy," he said speaking softly. Barron is an Associate Professor of Wildlife Science at Arkansas Tech University in Russellville who specializes in birds but has recently become interested in bats.
"It's a fantastic opportunity to come out and actually handle these bats," he said. "Bats that are cryptic and hard to find. I'm pretty excited to actually get to hold them in hand."
Barron is accompanied by Arkansas Tech University graduate student Lark Sybrant. Her research focus happens to be Ozark Big-eared Bats.
"I'm so excited to be here tonight because this is the first time I've ever held an Ozark Big-eared Bat, and it was kind of a magical experience," Sybrant said. "They're a subspecies of bat and they have very small ranges. They were once found in Missouri, Arkansas, and Oklahoma but now they're just found in a few counties in Arkansas and even fewer in Oklahoma, so they have small ranges and because of that, their populations are at greater risk of going extinct."
During intermittent lulls, team members switch off their headlamps and sit in complete darkness, listening and chatting softly.
Hours later, when no more bats emerge, the team packs up their gear and disassembles the harp trap.
"So this was just the first night," said Matt Anderson. "We're planning to come back tomorrow. We caught 20 Gray Bats and seven Ozark Big-eared Bats."
On the the second night, a total of 27 Gray Bats and 10 Ozark big-eared Bats were trapped, examined and released. Pedro Ardapple, who later broke away from the team, used a night-vision unit counting 872 mostly Grayy Bats flying out of a crevice just around the mountain.
Anderson says this place is prime bat habitat, which state and federal scientists have long been monitoring.
"This site is unique, because all of the endangered bat species on the Ozark-Saint Francis Forest have been found here historically," he said. "Ozark Big-eared Bat, Indiana Bat, Gray Bat, and Northern Long-eared Bat. We've also found Tricolored Bats here which are currently proposed endangered."
Anderson, who coordinated the survey, says the aim of harp trapping is to safely capture, quickly study and then release bats in order to assess species diversity and threats — especially posed by white-nose syndrome. The highly contagious fungal disease, which thrives in cold, humid caves and mines, was first documented in upstate New York in 2006.
The white, fuzzy, irritating fungus sprouts on bats' muzzles, ears and wings during winter hibernation. Forced awake, confused bats exit protective warm caves and end up freezing to death or starving. Untold millions of bats have died due to white-nose syndrome with no known treatment or cure on the horizon.
Considered the worst wildlife disease outbreak in North American history, white-nose syndrome continues to spread and is now confirmed in nearly half of all hibernating bat species in North America, including Arkansas.
"That's a big reason why we are here tonight," Anderson said, "to monitor bats following the impacts from white-nose syndrome. Some species have been heavily affected, some species not so badly, and so we're trying to understand what those impacts are over time. One of the valuable reasons that bring us back to this spot is we had some researchers from Arkansas State University capture bats here in 2010 and 2011 prior to white-nose arriving in the Ozarks. When white-nose hit starting in 2012, our bats started to decline. And when we came back out here in 2017 and trapped again, we did see some big changes in our bat populations from that sampling. So here we are, now, ten years after, trying to get a time series data set to understand better what's trending in our bat species."
White-nose syndrome spreads bat to bat, as well as by people unwittingly carrying the fungus on boots and caving gear into bat hibernacula, forcing cave closures on federal and state lands across Arkansas.
Bats trapped by the team were inspected for signs of the disease, Anderson said, noting that Ozark Big-eared Bats and Gray Bats both appear to be less impacted, which is why they are now also monitoring for immunity -- as well as any early signs of recovery. Anderson said he expected to document more bat diversity on this site, trapping, for example, endangered Northern Long-eared Bats that once thrived on the Ozarks, but none were observed.
"Bats play a really important role in the food web, our forests and our surrounding ecosystems," Anderson said. "Bats are the only consumers of night flying insects and in turn can protect forests from insect and disease outbreaks. And in agricultural circumstances, bats save billions of dollars in the United States, reducing the need for pesticide use, saving costs at the grocery store."
Environmental Solutions and Innovations consultant Crystal Griffin works in the private sector, federally permitted to survey planned developments to locate and protect critical bat habitat. She was among those who surveyed this site back in 2017, in the aftermath of white-nose syndrome. She's made it her life's work to protect wild bats.
"I honestly just think bats are very misunderstood creatures," she said. "Their physiology, their ecology, they're just so different than any other mammal. I mean they're the only flying mammal so that makes them cool. I am super happy, because I am totally content, and completely love my job, love working with bats and I'm really excited to be here."
U.S. Fish and Wildlife biologist Pedro Ardapple works to protect Ozark bat hibernacula -- hibernation sites on federal forests like this one and state parks, most recently Devil's Den State Park. Bats are non-migratory species so depend on these places year-round.
"Devil's Den has one of the larger Ozark big-eared Bat populations in the state," he said, "historically around a hundred bats. But for a population that, worldwide, is 2,000 for the species in whole, it's a very significant portion. But the caves have gotten human disturbance for years, for generations at this point. There has been enforcement and cave closures. None of it has worked very well. There's still people disturbing them routinely."
So, Ardapple obtained grant funding to install gates and locks on bat caves in Devils Den State Park. An early result, he said, is that the population of endangered Ozark big-eared Bats over doubled, a significant increase.
Ozark big-eared Bats, Gray Bats, and other hibernating bat species raise their young, called pups, inside chosen maternity colony caves. So, last spring, Ardapple along with Arkansas Game and Fish Commission bat expert Blake Sasse, attached radio transmitters to a couple of mother bats to locate caves for protection.
"And I had a pilot fly and track them. Blake and I were both working from the ground. We located several new transient sites, caves where they were moving to, in between the hibernacula and maternity colony. And then eventually we located a maternity colony along the Oklahoma border."
Ardapple and Sasse also have used aerial telemetry to track maternity bat foraging sites while continually searching for and surveying bat caves on both federal — and private land.
"In total I think we're at 175 new sites we've documented," Ardapple said. "And I think 74 of those we have found proposed or listed bat species. And we've also found close to one of the largest Gray Bat maternity colonies in the state."
The team's two-night bat survey findings, once processed, will be shared with federal and state agencies and then archived on a biodiversity database housed by the Arkansas Natural Heritage Commission which maintains information on the location and status of species of conservation concern in Arkansas.
The end goal is to locate and protect diverse cave-dwelling bat habitat, no matter how remote, so that Ozarks bats may once again flourish.
