|Wildlife biologists Nikki Castleberry (left) and Trina |
Morris prepare to take spore samples at Sitton’s Cave
at Cloudland Canyon.
We were standing in the parking lot of the Sitton’s Gulch trail at Cloudland Canyon one sunny day last month and Ms. Morris, a wildlife biologist, was talking about bats.
As most readers know by now, these flying mammals are threatened by a mysterious fungal infection called White Nose Syndrome, and Ms. Morris and her fellow biologist, Nikki Castleberry, both employed by the Georgia Department of Natural Resources in Social Circle near the University of Georgia, were here to test the bats of Cloudland Canyon’s Sitton’s Cave for WNS as well as to count them.
The biologists were accompanied by two Georgia public information employees, Rick Lavender and David Allen, who need to know as much as they could about WNS since they are responsible for disseminating news about it; and by my husband, Jerry Wallace, who as a local hobbyist familiar with Sitton’s Cave was invited to go along, take pictures and help count. His photographs accompany this article.
So your humble narrator had latched on in a spousal as well as a reportorial capacity, and the biologists were kind enough to allow me to interview them before and after they performed their study in the cave, though I did not go in.
“We don’t have White Nose Syndrome in Georgia yet, as far as we know,” said Ms. Morris. “We want to know when it shows up in Georgia.“
DNR had decided in 2010 to keep Sitton’s and Case, the other Cloudland Canyon cave, open to park guests even in the face of rapidly spreading WNS, not just because scientists were – and are – unsure whether human visitation has anything to do with spreading the infection, but also because it was considered there weren’t that many bats living there.
But whatever the population, Sitton’s is a known bat hibernaculum, a place where the fuzzy fliers hang upside down for their long winter’s nap, and that’s why Ms. Morris and crew had chosen February for their study. “In the middle of the winter, they’re in torpor so they don’t respond very quickly to disturbance,” she said.
The job today for all the cavers was to count bats, but Nikki Castleberry was the chief swabber. Her job was to sneak up on a small, random selection of sleeping bats and, while disturbing them as little as possible, take a quick swipe at their noses and forearms with a Q-tip. These samples were then to be carefully packaged and sent to a lab to be tested for WNS spores.
Ms. Morris explained that though WNS hasn’t showed itself in Georgia yet, it’s almost certainly a matter of time. “It’s in Tennessee in the Smokies, and it’s in North Carolina. It’s not right in any of the border counties yet, but it’s pretty close,” she said. “I would say it’s definitely less than 100 miles, so reasonably close as the bat flies.”
“We don’t know whether it’s actually spreading this year,” added Ms. Castleberry. That, she said, was because of the unseasonably warm winter, which kept bats awake and active longer. “We just might not see the bats being symptomatic like we normally would, because they’re going to groom the fungus off.”
In the United States, explained the biologists, the White Nose Syndrome epidemic started up North in 2006, and in fact it is a cold-weather affliction affecting cave-hibernating bats. “When they get the fungus in the winter it irritates them,” said Ms. Morris. “They wake up and burn all those fat reserves that they need to spend the winter in caves. They also sometimes get dehydrated and malnourished during the process.”
Geomyces destructans, the fungus that makes bats’ noses appear white, also causes lesions and holes in their wings, but Ms. Morris said what bats with WNS actually die of is starvation and infections.
“Or hypothermia,” interjected Ms. Castleberry. “Sometimes they just freeze to death because they fly out and it’s, you know two degrees in New York in January.”
Once WNS infects a bat population, mortality can approach 100 percent. “Within a year or two, over 90 percent of the bats die,” said Ms. Morris. “That’s pretty common in the Northeast. Not in the Southeast yet. We don’t know if it’ll just take more time or if we won’t see that level of mortality.”
So far, she said, about 5.5 to 6 million bats in the U.S.A. have died of WNS, according to the latest scientific opinion. “That was a big change, because for the last couple of years they’ve said ‘over a million,’” said Ms. Morris.
She said the fungus is thought to have arrived in the States from Europe, where bats test positive for the fungus but don’t die of it. This may simply be a matter of bats that have built up a resistance to the infection. “We do have bats that aren’t dying in the Northeast that we hope will eventually reproduce and build back up the population,” she said.
Again, it is not known whether humans are disease vectors in WNS, but DNR is taking no chances, and the cavers showed me the precautions they take –clothing and equipment are disinfected before and after cave trips, equipment and samples sealed in sterile plastic bags.
Finally, swathed in layers of outerwear against not just spores but also mud and water – Sitton’s is as wet as can be imagined without requiring actual scuba gear – the five cavers disappeared into the depths of the earth, where no air-breathing lady journalist has any business this side of the grave. I went on my way in the beautiful sunlight.
But I checked with Ms. Morris later, and she reported her group’s findings: No WNS so far, but a lot more bats than they expected. “Overall, we had 1740 bats, and they all looked healthy, the best we could tell,” she said.
Most of them were tricolored bats, formerly called Eastern Pipistrelles, she said, but there were also a couple of brown bats and 26 gray bats, which are endangered. “That’s a good handful of them,” said Ms. Morris.
What does any of this mean for Cloudland Canyon’s caves? Probably, said Ms. Morris, it will strengthen the argument she and other biologists have already proposed for changing the times the park allows visitors in the caves. “It will definitely give us more of a reason not to have it open in the winter,” said Ms. Morris. “That’s what we’re proposing. It will be open all summer, but not in the winter, because that’s when it’s most disturbing for the bats to have people coming in and out.”
Currently, Cloudland Canyon closes the caves every third month. November and February were closed, and so will be May. Under the proposal, the winter would be off-limits but the warm months would be open season. “I think that having it open more in the summer will give more people an opportunity to visit,” said Ms. Morris.
As for what will happen if or when the epidemic does show its white-nosed head, Ms. Morris has no idea. “Basically, our White Nose plan says once it’s found, we just kind regroup and look at the situation and make a decision with the park or whatever landowner it is what we do at the site.”
That day may arrive sooner than later. This month, only a few weeks after the Sitton’s trip, White Nose Syndrome was confirmed in Russell Cave in neighboring Alabama.
Meanwhile, Ms. Morris wants the public to understand why bats deserve our concern. “Some people think, in the past especially, that bats are just a nuisance,” she said. “They get in your house, they’re flying around, they’re dangerous, they carry rabies. In reality, all our bats in Georgia eat exclusively insects. That’s the main reason they’re beneficial here.”
Besides their bug-eating capacity, said Ms. Morris, bats are also useful as plant pollinators.
“They’re kind of like the birds of night,” she said.
Source: The Dade County Sentinel