Steve Mellon, Post-Gazette photosThis Eastern pipistrelle bat was resting in Barton Cave, which will be closed to cavers from October through May.
This gate at the entrance of a popular Fayette County cave will protect hibernating bats from cavers, who interrupt their winter sleep, says wildlife biologist Aura Stauffer, of the Pennsylvania Department of Conservation and Natural Resources.
UNIONTOWN -- An Eastern pipistrelle bat was hanging out all alone on the low limestone ceiling, 50 yards into cool, dark-as-the-inside-of-your-coffin Barton Cave.
Smaller than a computer mouse and with red forearms and light brown belly fur, the bat was asleep just for the day. But several hundred other pipistrelles, along with little brown and big brown bats, will soon join him for a more prolonged stay, attaching themselves to the cave roof to hibernate until spring.
For the first time, their winter nap will not be interrupted by human visitors.
Barton Cave, in Fayette County, along with Coon and Lemon Hole caves in Westmoreland County, have been outfitted with specially constructed, heavy metal and concrete locking gates, with bars far enough apart to let bats in but small enough to keep cavers out. The three caves, which are in the Forbes State Forest, along the Laurel Ridge, will be closed from the beginning of October through the end of May.
The gated caves are the latest additions to a bat conservation program that, since the mid-1980s, has locked up and limited public access to more than 20 caves and twice as many abandoned mines around the state, said Aura Stauffer, a wildlife biologist and the state Department of Conservation and Natural Resources' resident bat expert. The caves are known bat hibernaculums, places where bats gather in colonies and hibernate through the late fall, winter and early spring.
The program, jointly run by the DCNR and the State Game Commission, aims to prevent people from hurting one of nature's most misunderstood creatures during its most vulnerable time.
Lemon Hole and Coon caves each house more than 1,000 bats for the winter months. About 400 use Barton Cave. Ms. Stauffer said the caves had been on her list for gating for several years. A joint federal and state grant of $7,500 provided the money to do all three.
"When bats are hibernating in a concentrated area like this cave, any disturbance can cause the bats to wake up," Ms. Stauffer said while leading a tour of Barton Cave last week. "When that happens, bats can die because they expend energy and use body fat they need to get them through the winter."
Helping bats survive
Bats are the only major predator of night-flying insect pests such as June bugs, cucumber beetles, leaf hoppers, tent caterpillar moths and mosquitoes. They need protection like cave gating because their populations are in decline across the United States and worldwide as a result of habitat loss. Their habitats are being lost to suburban sprawl, development, timbering and mine reclamation and pesticide use that eliminated many food sources.
Of the 45 species found in the United States, six are listed as endangered or threatened, and another 20 are listed as species of special concern by the U.S. Fish and Wildlife Service.
Nine species of bats are found in Pennsylvania, although two of those are extremely rare. The Indiana bat is on the federal and state endangered lists, and the small-footed bat is a state threatened species. Of the nine species, six hibernate in Pennsylvania and three -- the silver-haired, red and hoary bats -- migrate out of state for the winter..
All nine species belong to the family Vespertilionidae, also known as evening bats. And all are insect eaters and use a sound tracking system known as echolocation to find and take their prey on the wing.
On a good summer night, a bat will consume up to 25 percent of its body weight, about 1,000 insects, in an hour.
"To keep agriculture and forests healthy, we want to have these animals that eat insects survive and thrive," Ms. Stauffer said.
There's evidence to suggest they are doing that in Pennsylvania's gated hibernaculum communities. Cal Butchkoski, the State Game Commission's bat biologist, said Pennsylvania's bat populations suffered severe declines between 1950 and 1970, but were starting to bounce back.
"I think we're making some progress. Our annual monitoring of hibernaculums indicates a slight increase at some and others remaining stable," Mr. Butchkoski said. "We've seen no major declines in the last 10 years, and at some of our gated sites, we have found dramatic increases in numbers and species diversity."
He said the hibernaculum population in the gated mine in Canoe Creek State Park in Blair County had increased from 3,000 to 25,000 bats during the past 15 years. In a gated cave on state gamelands in Armstrong County, bat numbers increased from 4,000 to 10,000 in the past decade.
The Indiana bat, a "critter of concern," as Mr. Butchkoski put it, found at only one site in 1980, has now been identified at 16 sites, most of them gated caves or mines.
"They may not yet be on the road to recovery," he said, "but we've mapped out a route that will take them in that direction."
But not everyone is keen on taking that ride if it means losing access to some of the state's most popular caves.
Dave Ruth, chairman of Pittsburgh Grotto, the local chapter of the National Speleological Society, a caving organization, said the group had no official position on the cave-gating program. But many members are upset about losing access.
"These are some of the larger, more significant caves in Western Pennsylvania that are being gated, and the state wouldn't have had to gate them if people didn't go into the caves in the winter, when they shouldn't have," Mr. Ruth said.
"That was a caving rule. Certain caves were posted off limits on certain caving Web sites, but people who continued to go into them made the gating necessary."
Pennsylvania has more than 1,000 caves that have been identified as potential bat roosting locations. But wildlife officials gated the 20 the state did after surveys found they get high volumes of human traffic during the winter.
"People say they've been going into these caves since they were kids and they're not going to disturb the bats, but the lights and noise they make could cause the bats to come out of hibernation and stress them enough so they can't make it through the winter or reproduce," Mr. Butchkoski said.
"Some of these caves are just getting so much impact that we have to make provisions for the wildlife and there's no way we can keep people out without the gating. We can try to educate them about the need to conserve the resource but, if they're not interested, we won't be successful."
Exploring on hands and knees
Barton Cave is a case in point. A short drive east of Uniontown, it has long been a popular destination for caving clubs, college classes, scouting troops and the casual, recreational caver.
From the gravel road in Forbes State Forest, it's an easy quarter-mile hike down a sloping, well-worn trail that curls in front of an outcropping of Loyalhanna limestone. The mossy, lichen-flecked slabs of rock bracket the sliver of an entrance.
The gate was installed last week by Chris Sanders, who has worked on between 30 and 50 others at cave and mine entrances from Vermont to Illinois. It's made from reinforced, four-inch angle iron, three-eighths of an inch thick, anchored with rebar and 10 bags of Sakrete and bolted into the rocks.
It's positioned inside the entrance so that ice cannot form around it during the winter and block the flow of air.
Entering the cave requires a slither along the slanting rocks and a backward roll before reaching the gate, which has a small rectangular opening that won't be barred and locked until Oct. 1.
Ms. Stauffer squeezed through on hands and knees and turned on her headlamp and a flashlight before setting off in a low crouch. Inside the entrance, the cave walls are covered by a thin film of mud and a footwide stream of water trickles in a channel cut through centuries. The best footing is right in the stream.
There are deep, long crevices and fissures slicing into the ceiling and jutting rocks. It's a solution cave, formed by water, and drips echo steadily from nipple-like stalactites. Because the floor, walls and ceiling converge at irregular angles, perspectives are warped, like an amusement park funhouse.
The temperature is about 45 degrees. Because of the irregular rock formations and darkness, helmets prove their worth early.
For all of that, Barton is considered an easy cave to explore, Ms. Stauffer said, at least for the first 150 yards of its more than one mile of passageways.
"This cave gets a lot of use from a lot of different kinds of people, and it's good for beginners," she said. "Most recreational cavers and clubs know about the bats and stay away, but there's always some others that don't, and that's why we gated. Sometimes, it's hard to balance recreation with conservation."
After crawling and rolling through some tighter, low passages, she reached a room with a higher ceiling. Light beams scanned the ceiling like Hollywood movie premiere searchlights. A single bat was spotted and identified as an Eastern pipistrelle. Ms. Stauffer said he was sleeping, not hibernating.
He began to stir, and Ms. Stauffer pushed on, crab-scrambling, climbing and sliding over the wet and muddy rocks for another 100 yards. She found three more bats, all hanging alone, before coming to the part of the cave that narrowed enough to require a 10-minute crawl. There, a piece of plastic pipe containing a voluntary register of visitors was tethered to the wall.
"There were groups, seven, 12 and 15 people in here last November and December, according to this, all months that people should not be in here," she said, reading by her headlamp. "But some people just do not realize the danger they pose to bats."
Don Hopey can be reached at firstname.lastname@example.org or 412-263-1983.