Bats and caves go together. So many popular images of bats involved swarms of them hanging upside down onto the roofs of caves, and then swarming out at night to feed.
Batman has his bat cave for a reason.
In Glacier National Park, bats have been spotted in the Cougar Valley but what isn’t known is whether or not bats live in the Nakimu Caves, which are located several kilometres up the valley from the Trans-Canada Highway.
The issue is of particular interest because of the spread of white nose syndrome (WNS) in bats throughout eastern North America. The disease was introduced to North American from Europe in a cave in New York State and has since spread in all directions through 21 U.S. states and five provinces. In Canada, it is found as far west as northern Ontario and in the United States, west of the Mississippi River.
WNS is caused by geomyces destructans, a fungus that thrives in cool environments like caves. It mostly affects bats while they’re hibernating, and eats away at a bat’s fat reserves, causing it to wake up from hibernation and then starve to death from excess winter activity. The mortality rate in bat populations affected by WNS is about 75-95 per cent.
There are nine species of bats found in Glacier National Park. Of three species of bats that are being recommended for placement on the Species at Risk Act, two are found in Glacier – the little brown bat and the northern bat. WNS is estimated to have killed from 5.7—6.7 million bats in North America so far.
“The bat species who are hit hardest right now are really commonly found bat species,” said Sarah Boyle, an ecologist in Glacier National Park. “Their populations, when they’re hit, particularly in the winter when they’re hibernating, it will wipe the entire colony out.”
WNS is believed to have been brought over from Europe, where bats are immune to the disease, and spread to North America, possibly by a spelunker who transported the fungus that causes the disease overseas. Since 2006, when it was first detected, it has spread rapidly.
Bats play a very important role in an eco-system. They eat more than their weight in insects every day and pollinate crops. A report published in Science magazine estimated their economic value to U.S. agriculture as being in the billions of dollars. With populations being decimated by WNS, there has been a renewed interest in bat research. Sarah Boyle showed us a map produced by the website whitenosesyndrome.org that shows the spread of the disease.
“I’ve been told from other wildlife health surveillance operations that it’s not a matter of if it comes westward, but when,” said Boyle. “We’re trying find out if that fungus is here and we’re also trying to get a really good handle on the bat population in the caves, if we have bat populations in the caves and if so, if they use the caves, and when.”
Last Thursday several members of the media were flown into the Cougar Valley in Glacier National Park to visit the site where researchers are conducting bat studies in the Nakimu Caves. The caves were a major tourist attraction in the park in the early 20th century, but access has been very limited in recent decades after the valley was closed in order to protect bear habitat. Due to the difficult access through Balu Pass, and the need for special permits, only a few dozen people access the caves every year.
We flew in by helicopter, landing in a clearing high up the Cougar Valley, beneath towering cliffs and steep, alder-filled avalanche slopes. Silas Patterson, a resource conservation technician was there to greet us. He brought us down a short path to the staging area, where we met Sarah Boyle, the Glacier National Park ecologist. She was sporting a little baby bump and wearing a green Parks Canada skirt. “Like Mary Vaux,” she joked later, referring to one of Glacier National Park’s pioneering female mountaineer.
A few more Parks’ staff and contractors joined us. Eric Dafoe, the long-time public safety manager, was there serving as the guide to the caves – he has been in them about 50 times over his long career in the park. We also met Mandy Kellner, a wildlife biologist who has been contracted to study the bats in the cave and Baylee Out, a fourth year microbiology student at Thomson Rivers University.
Our tour started with a visit to a nearby cave entrance so we could get a glimpse of the caves while Parks’ staff enjoyed their lunch. Then, we regrouped and made our way down to the main entrance of the cave. We switchbacked through the Cougar Valley until we came upon a culvert inserted into the side of the mountain. It led into the cave, where a cool air blasted out like natural air conditioning.
One-by-one we entered the cave and stepped gingerly down a loose cable ladder. The cave was cool and damp, the roof was coated in water droplets and the ground was slick and muddy. Dafoe led the way into the cave while the scientists went about their work. We didn’t get too far in before we reached a point where the cave dropped off sharply.
Myself and Calgary Herald reporter Colette Derworiz joined Out where she was crouched over, collecting fungal samples from some small pieces of wood that had found their way into the cave. As she explained, little bits of wood are the best place to find living organisms because they cling to the few bits of organic material that make their way into the otherwise bleak cave environment.
She grabbed a sample using a sterile swab and then quickly sealed it in a test tube. Later, it will be brought to a lab, placed on a petri dish and refrigerated, while researchers wait for spores to form so they can identify what species it is.
“My major project is to clear the cave, that it’s got no geomyces destructans in it, which is the fungus that causes white nose syndrome,” she told us. “If I do culture it and I do find it, then they’ll have to close the caves and try to prevent people from spreading it out. If it’s not here, they can focus on protecting the caves from people bringing it in.”
As a side project, her professor will also be testing the spores to see if they contain any novel anti-microbial agents that can be used in antibiotics. “And it all starts by collecting dirt in the cave,” said Out.
Closer to the entrance, Kellner and Patterson were setting up some bat detection equipment. There were two pieces of sampling equipment they are using to detect bats. One is an AnaBat – a specialized machine that can detect the eco-location signals sent out by bats and determine their species based on the signals sent out. The other was a song metre, which can detect high frequency sounds. They will also be monitoring the climate in the cave.
Kellner and Patterson had a large box filled with D-cell batteries, a microchip, and a number of SD cards to store data. Outside the box, Kellner affixed two microphones. The box was set to turn on at night for 30 minutes every half-hour; bats are most likely expected to roost in the caves at night.
“They will sleep all night in their day roosts, but if they are using this as a swarming site, they will come in at night,” said Kellner.
So far, she hadn’t noticed any signs of bats in the caves. There were none of the usual signs of guano in the cave. “Often if bats are roosting somewhere there will be guano either on the floor or stuck to the walls,” she said. “When they’re hibernating they’re not eating, so you’re not getting a bunch of guano, and then there’s fact the floors are really wet. I haven’t given up.”
There has also been no anecdotal reports of bats in the caves, but visits are so sporadic and the bats so small (they weight only about 10 grams) that it would be easy to miss them.
Patterson and Kellner wrapped a red rope around the box and tied it to an overhanging rock – the better to keep away pack rats that have a tendency of interfering with the equipment. They will return in October to collect the data and install new batteries and then continue collecting data through the winter and next spring and summer.
“The thing with bats, is there’s bats everywhere, it’s just that you never see them,” said Kellner. “We know so little about them. Unless you specifically set out – It’s not like pack rats. You use such specialized equipment for the bats that you just never know.”
The goal of the study is to establish a baseline on bat use of the Nakimu caves. When all is said and done, Parks Canada will have 18 months of data to sort through. It’s a novel study in Glacier National Park, where bats have never been researched before.
“It’s an awesome project,” Kellner said. “It’s a very exciting thing to come work in a cave. It’s the first chance to really check out if there are any bats in Nakimu.”
There is little ability to stop the spread of WNS. The best way, said Boyle, is to make sure cavers don’t spread the disease through their equipment. Some cavers are using entirely different equipment for each cave they enter, she added. She sprayed the soles of our shoes with disinfectant before we entered the caves. The results of the study will help determine access to the caves in the future
“If we can still allow people in our caves in Parks Canada but get them to disinfect their equipment that will go a long way to stop the spread,” she said. “We’re trying to get ahead of the curve.”