Finding a Killer: On the Trail of White-nose Syndrome
Finding a Killer: On the Trail of White-nose Syndrome
A disease deadly to bats reaches its long arm south, threatening Georgia cave systems
By Pete Pattavina
Chronically misunderstood, fictionalized, feared, reviled and vilified, the modest bat, the diminutive ruler of darkness, finds itself beleaguered by an incurable disease that is spreading swiftly through the eastern United States and Canada. Although its arrival in Georgia in 2013 seemed inevitable, white-nose syndrome was an unwelcome visitor. The ravaging disease caused by an aggressive European fungus has killed an estimated 6 million cave-dwelling bats since its discovery in New York State in 2006.
Bat experts Trina Morris of the Georgia Department of Natural Resources and Nikki Castleberry of the Georgia Museum of Natural History confirmed the presence of white-nose in three North Georgia caves this winter. I followed the team and saw what it was like to be in the exciting, largely-unseen world of the cave ecosystem and then witness something that threatens to destroy the very keystone of this fragile community.
Feb. 19: White River Cave
Just outside Rockmart, the teeth-clenching sound of grinding, rusted iron marks our arrival at White River Cave as owners Mason and Ana Rountree slide open the heavy, angle-iron ribs that bar the cave entrance. The Rountrees, both attorneys in nearby Dallas, bought and gated White River Cave with the sole purpose of protecting it; they spent years hauling out bags of beer cans and trash, and chaperoning school groups on tours inside.
The integrity of the cave is steadily improving. Cave crickets are coming back, and salamanders. Spray paint on the walls is fading and flaking away, revealing smooth, limestone contours.
A huddle of big brown bats squats near the cave entrance, their stout heads and bulldog-like noses jammed tight together. Northern long-eared bats, a species considered for protection under the Endangered Species Act, poke downy heads from nooks and crevices. Diminutive tri-colored bats dangle by toenails from the walls and ceiling, sleeping in deep torpor. Thousands of minute water droplets coalesce on their fur, casting over them a jeweled prominence.
For a newbie like me, it is a seldom-seen world of wonder and quiet. Even in a cave along a busy highway, a cave with walls smeared with decades of spray paint, with only a few rock formations and with walls mud-caked from the dirty hands of hundreds, maybe thousands, of visitors, the experience stirs in me a boyhood feeling of private discovery.
In the deeper corners of the cave, Mr. Rountree shows me scooped marks in the walls made by workmen’s mattocks 150 years ago, when the cave was mined for saltpeter, an essential component of gunpowder.
Wearing white, Tyvek suits and sterilized clothing, we scramble over mud and boulders, swabbing bats and cave walls to test for white-nose. Jackie Jeffrey, a DNR intern, studies the cave map with Mr. Rountree, divides the cave into sections and keeps count of the bats in each section. Tiny vials, half-filled and carefully labeled, hold the snapped-off heads of cotton swabs that will be sent to a lab for testing.
All of the bats we see appear relaxed and healthy, continuing in their torpid state and only briefly troubled only by our visit. If a deadly fungus is hiding in this cave, it is well-hidden.
Our eyes adjust as, one by one, we walk up through the twilight zone of the cave and duck through the cave gate and back into the open air. It is cold and starting to rain but the team is in high spirits as we peel off white suits, boots and helmets, storing them carefully in plastic bags to avoid potentially contaminating the truck with unseen fungal spores.
Feb. 26: Black Diamond Tunnel
It seems as if the rain will never stop. Cold and wet at 6 a.m., our team drags itself into the truck. Trina and Nikki, already awake for hours, had loaded an aluminum john boat packed with supplies earlier that morning. We drive north through the steady rain to Rabun County, heading to Black Diamond Tunnel.
The tunnel is named for a failed railroad that ran out of funding in 1860, when South Carolina seceded from the Union. When the smoke cleared from the Civil War five years later, Black Diamond Tunnel, a half-finished, 1400-foot railroad passage blasted into a solid granite mountain, is one of the few, permanent remainders of the Black Diamond Railroad Co.
We meet Black Diamond Tunnel’s owner, Regina, at her house. She hugs Trina, talking excitedly about Trina’s recent travels, having read her Facebook posts. Regina throws on a heavy raincoat and black felt Stetson: She’s kind and caring and not about to let us go into that tunnel without watching over us, especially since a relative drowned in Black Diamond years before.
Trina negotiates the truck up the wet, dirt road and we park by an ancient, belt-driven sawmill once powered by a Ford Model-T with wooden cogs affixed to its axles. The rain continues, steady and cold.
We work fast to pull on Tyvek suits, and Regina unhooks three strands of a barbed wire gate that block her cows from going near the tunnel. We haul the john boat over the roughly-graded railroad bed, toward the yawning tunnel mouth. We set the boat down periodically to straighten our cramped fingers or get a better grip on the gunwale. A waterfall spills over the entrance, and cold water pelts our gear and suits as we get in the boat. Regina snaps a few pictures as we enter the darkness, the boat moving into deeper and deeper water.
It seems odd that Black Diamond Tunnel was built on a downward slant. I suppose it wouldn’t have been a problem had those 19th century workmen blasted the tunnel clear through the mountain to let the water drain out the low side, but they didn’t. Instead, the tunnel remains flooded from the back and when filled, flows out a small stream at the entrance. In other words, as the tunnel digs deeper into the mountain’s heart, the water depth increases, while the ceiling gets lower and the wallows walls become narrower. Yes, going into the tunnel … well, it feels as if you are entering a trap.
Tri-colored bats are everywhere; more than 5,000 bats roost here each winter, making Black Diamond Tunnel one of the largest, documented hibernacula for tricolored bats. They pepper the walls and high ceiling. Some cling inches from the water’s surface. Today, my job is to paddle the boat slowly and steadily while Trina and Nikki count bats with hand-held clicker-counters.
Jackie sits beside me, keeping notes and keeping the samples organized and labeled. I can sense the water is getting deeper – it’s cold and crystal-clear – but my head lamp isn’t strong enough for me to see the bottom. Trina and Nikki each have spotlights with enough candlepower to illuminate bats on the lofty ceiling and in the cave’s deep nooks and crannies.
“Trina,” I say, “shine that spotlight of yours down there so I can see how deep this water is.”
“Uh-uh,” Trina says, shaking her head.
“What? Why not?”
Trina doesn’t answer at first, then says absently, “Nope, not doing it.”
I’m perplexed. I try again. “I can’t see anything with this dinky, little light. Lemme see down there.”
I pull off my helmet, with the headlamp attached, and hold it to the water’s surface to see if I can get a better look and gauge the depth, but the effort is in vain. The three girls, steadily working, are clearly enjoying my frustration. A quiet giggle or two breaks out as they continue working. I’m so outnumbered, I think.
Trina’s spotlight shines on the walls and ceiling. I can’t let the matter rest. “Are you really telling me that I’m going to leave this tunnel today without knowing how deep this water is?”
Trina stares at me briefly, “Yep, because I don’t want to see what’s down there,” she says. “Have you ever seen that movie What Lies Beneath? I just know that if I shine this light,” she says, wagging the spotlight back and forth in front of my face, “down there to the bottom ... I just know … there’s going to be a body or something even worse staring back at me!”
All of us laugh and we get back to our respective jobs, but we’re going farther into the tunnel and Trina’s seemingly irrational fear of the lurking unknown seems has an unanticipated effect on me. The walls start to close in and the ceiling, once high, begins to bear down on us. What’s more, I keep getting this impression that someone is murmuring intermittently in the darkness ahead. When I train my ears to the sound, what it could be or where it is coming from, I find I can’t hear it any longer.
I laugh a little uneasily. “Does anyone else, uh, hear that?”
Trina nods her head knowingly. “I told you it was freaky in here,” she says, “and you have to be always be messing around. I told you.”
As we go deeper, the murmuring transitions into what sounds like a pack of yappy dogs barking at a great distance, and I then realize it is the sound of dripping water that, as the tunnel continues to constrict, produces sound that reverberates in seemingly endless waves and echoes from all directions.
We go deeper still in silence. The only sound now is the counters ticking away rhythmically as Nikki and Trina count bats. The ceiling is so low we have to lie down on our backs in the boat. Our helmets nearly skim the ceiling and we are careful not to let the hull touch the tunnel walls, lest we knock off hibernating bats that would instantly drown in the ice-cold water. We touch our fingertips lightly to the ceiling and silently pull our boat cautiously forward through the small space. Tricolored bats hanging from the ceiling and covered in condensation brush by within an inch or two of our faces.
It is a surreal feeling and none of us speaks as we reach the back of the tunnel and then, slowly, reverse our motion and pull ourselves out the same way we came in.
As we exit Black Diamond, we see the small, backlit profile of a human figure grow larger in the distance. A woman with long, curled hair … a raincoat … a Stetson … materializes at the mouth of the tunnel. For hours in the gray, steady rain, Regina has waited for us. We’re barely out of the boat before she wants to know if her bats are healthy, did we see any disease?
“No, we didn’t see any evidence of white-nose syndrome,” Trina says, smiling. “Lots of fat, healthy bats.”
March 5: Sitton’s Cave
Lookout Mountain sits as a giant, sandstone-capped wrinkle of monolithic limestone in northwest Georgia. On State Route 136, we climb the mountain’s 2,000-foot summit and seem to fall straight into Dade County, weaving down sharp switchbacks on the west side of the mountain. Our team knows that the farther our surveys take us to the northwest, the closer we come to the advancing edge of white-nose syndrome.
A few days earlier, Trina received reports from National Park biologists who observed bats with white-nose symptoms in a cave at Lookout Mountain Battlefield, just eight miles north of the cave we are visiting. Last year, biologists confirmed the disease just over the state line in Tennessee. So white-nose syndrome’s slow creep into Georgia was not surprising. Still, our team hasn’t seen evidence of the disease.
We check in at the Cloudland Canyon State Park office and let park manager Bobby Wilson know we are headed to the northern tip of the park to survey Sitton’s Cave, where 1,600 tricolored bats roost each winter along with a few dozen endangered gray bats. Jerry Wallace meets us there. A lifelong caver and artist, Jerry is tall and sinewy, with long, grayish hair that pokes out the sides of his caving helmet. He helps with bat surveys at Sitton’s each year, showing us different rooms off the main passage where bats are roosting. This year, Trina contracted Jerry to survey other caves in north Georgia to get counts of hibernating bat populations.
Sitton’s is a river cave, meaning that we will be trudging through a fast-flowing stream of 50-degree water in the main passage. Tyvek suits, which can quickly fill with water, are too dangerous for today, so we opt for sterilized clothing, ensuring we don’t introduce any viable fungal spores from other caves we’ve surveyed.
The cave portal is enormous, a huge, sloping funnel studded with Volkswagen-sized boulders that have fallen from the sheer limestone cliffs that sit sentinel over the cave entrance. As it begins to rain, we skitter down the muddy slope and just within the shadow of the cave entrance we begin to see tricolored bats in the half-light. We see a lot of tricolored bats. Too many tricolored bats.
“This is not a good sign,” Trina says. This many bats roosting close to the entrance is a sign the bats were roused too early from hibernation, a sign they could be starving and need to forage for insects, a sign of white-nose syndrome. A bat’s life is all about balance, a balance of frenetic foraging activity during the summer months to catch enough insects to feed their young and build fat reserves to last them through the winter, when no food is available. The fungus that causes white-nose syndrome causes so much irritation to hibernating bats they are roused too often, depleting these critical fat reserves.
In desperation, afflicted bats leave their caves looking for food, only to find the harsh cold of winter outside, where they freeze or starve to death.
Trina spots our first dead bat. The tricolored’s desiccated body hangs from its toenails in the cave entrance. A cave cricket sits on the exposed rib cage, making a meal of the bat’s misfortune. Still, none of the live bats we see at the entrance show typical signs of white-nose – the fuzzy, fungal growth that attacks the nose, ears, wings and other areas of exposed skin.
We crawl through the first muddy passage and encounter another sick bat, distressed and wings partially outstretched, floundering in the mud. Trina gently places it the side of the passageway, hoping it can climb onto the dry cave wall. The passage opens into a large, cold chamber formed by the swift-flowing stream rushing through it. It’s here that we first see it, bat after bat with signs of fungal infection, lesions on their wings and ears.
There is no mistaking white-nose syndrome when you see it, but as scientists, we can’t just rely on hunches, we need data. Trina and Nikki look sickened by the sight of the disease in so many of these bats that, last season, showed no outward signs of sickness. We begin swabbing bats and collect a freshly dead specimen to take to Athens for testing. We all know what the results will say, and a pall is cast over our group as we press on, deeper into the cave.
This is what an extinction event looks like, I think. The passenger pigeon, Carolina parakeet, ivory-billed woodpeckers and even the decimation of American chestnut forests – these were textbook abstractions of extinction that biologists shake their heads over. Mistakes, accidents or misfortunes of past generations, dusty specimens that sit untouched in display cases and museum drawers. Seeing how this aggressive, exotic fungus is attacking these small animals is not some quiet suggestion of a problem, but possible extinction in its rawest and ugliest form screaming in our faces.
About 30 or 40 percent of the bats we see at Sitton’s show severe symptoms of infection from white-nose syndrome. More than a mile underground, Jerry climbs into one of the cave’s upper rooms, a place where gypsum formations abound: rimstone and shallow pools, draperies, flowstone, and columns extending from floor to ceiling. He looks at the concentration of sick bats around him and breaks down in tears.
“I don’t think have the heart for this work,” he says.
Nikki offers the most comforting words she can. She tallies the number of bats in the room and says, “We’ve got a job to do, Jerry, and we need you.”
As of April 2013, white-nose syndrome had also been documented in two caves in adjacent Walker County and a mine in Gilmer County, marking five sites confirmed with the disease in Georgia. Learn more about bat conservation in Georgia, Georgia’s white-nose syndrome plan and the disease itself.
Pete Pattavina is a U.S. Fish and Wildlife Service biologist stationed in Athens, Ga. He also provided the photographs used here.