Martin Davis turns onto a logging road and heads up, his Pathfinder jostling, toward the cave. It’s an overcast day in June, the kind when the mountaintops surrounding his home of Tahsis, B.C., are hidden among misty rain clouds. He has to ascend 650 metres above sea level, plus another 200 on foot. As the truck jerks, a little rubber bat — black wings extended, mouth open in a shout — falls off the dashboard.
British Columbia is home to Canada’s most diverse collection of bats, but surprisingly little is known about these 16 species, including exactly where many of them spend their time. Most hibernate for the winter, tucking away inside mines or caves with names like Deer Hell, featuring the skeletons of 11 animals who fell into the entrance; Labyrinth, a twisty maze; or today’s destination, Fracture Cave. Last December, Davis left equipment there to check for the presence of bats.
As he nears the highest stretch of the road, he quickly steps on the brakes. A tree has fallen from the right side, entirely blocking any further motion. “Oh no!” he says. “I usually throw my chainsaw in the back.” Instead, he turns the vehicle around, hops out and prepares his bag for the hike ahead. He tosses the pack under the fallen log, crawls after it and sets on his way. A mangled sign, bent over and chewed on by black bears, announces this as Weymer Creek Provincial Park. He’s been coming here since he helped create the park in 1996 to protect a rare species of bat from commercial logging. Cavers maintain the trails, purposely keeping some of the way hidden to stop unprepared visitors from doing damage to sensitive caves and themselves.
Davis crosses the creek twice, trudges over mounds of late-spring snow and, more than an hour later, arrives at the entrance to the cave. When he first started exploring it over two decades ago, he thought the entrance, tucked at the base of an old-growth tree and ringed by unstable-looking boulders, would quickly collapse and disappear. But it’s still here, exactly the same.
The bats of Western Canada might not have that kind of longevity. A disease called white-nose syndrome, named for the white fungal spores that grow on the snouts and wings of infected individuals as they sleep through the winter, has decimated populations in the eastern parts of Canada and the United States. And it’s closing in.
A lot of people don’t like bats, but they’re often misunderstood. They’re not blind, though they are good at getting around in dark places, producing high-frequency shouts that reflect back and help them perceive their environment. They won’t suck your blood — the bats in Canada feed on insects. And for that reason, they’re incredibly important. The web of life is fragile. Remove one component, and the ripple-down effects can be drastic. A little brown bat, of which there were millions in Canada before the disease arrived, can eat between four and eight grams of insects each night. Collectively, a million little browns clear up to 1,300 metric tons of insects from the night sky each year. Many of those insects are pests that would otherwise destroy farmers’ crops — losing all of North America’s bats would cost the agriculture industry more than $3.7 billion each year. Others are mosquitoes that could pass diseases between humans.
Researchers in the United States estimate that the American population of little browns, among the first to be hit with the fungus, will be extirpated — extinct within the region — in less than 10 years. In Canada, white-nose syndrome has already infected multiple species in Ontario, Quebec, New Brunswick, Nova Scotia and Prince Edward Island, killing more than 90 percent of known little brown populations. As the disease spreads, observers in Western Canada are rushing to gather what data they can about their still-healthy bat populations. They’re facing mountainous odds, and sometimes great physical challenges, to give the bats a sliver of a chance at survival.
In March 2007, biologists in New York state were getting ready to survey the population of the mouse-eared Myotis sodalis bat in Hailes Cave, near Albany. The species has been listed as federally endangered since 1967, but the most recent survey had counted 685 of them hibernating among the more than 15,000 bats that used the cave. Almost immediately, it was clear that something was wrong.
The cave floor was covered in bones, bits of wings, entire bat bodies. Thousands of bats were missing, though raccoon and mink droppings surrounding the piles of body parts suggested that they ended up as a scavenged meal. Seven thousand living bats remained, none of them Myotis sodalis. About half had a fuzzy white substance on their faces, the only clue to what had happened. Three other caves in the state also had signs of the mysterious sickness, which scientists started calling white-nose syndrome after the strange look of the surviving bats. “None of the many bat researchers we contacted in the Eastern United States had ever seen it,” read a poster presented at a bat research conference in Mexico that August, “despite having collectively observed millions of hibernating bats.”
A biologist in Tresckow, Pa., holds the remains of bats with white-nose syndrome. Photo by Stephen Alvarez/National Geographic Creative
Cori Lausen, a recent PhD graduate from the University of Calgary, sat
in the conference’s audience as American biologists shared their alarm
and what little they knew. “Everybody was just dead silent and shocked,”
she says. Lausen remembers feeling powerless, though she soon turned
that into action. She had first studied the creatures for an
undergraduate research project, and had left a job teaching high school
to dedicate her life to learning more about them. A game-changing new
threat gave her another reason to continue that work. She moved to
British Columbia and dug in.
By the next year, it was clear that
white-nose syndrome was not going away. After the winter of 2008, the
situation at Hailes Cave had worsened: another 5,300 bats were dead, a
91 percent decline from the usual numbers. Other sites emptied out
completely. Almost every cave checked within 130 kilometres of the
original four was infected.
Here’s what we know now: a European
bat, carrying the spores of a white fungus called Pseudogymnoascus
destructans, likely hitched a ride on a container ship bound for New
York. (Another common theory is that the fungus arrived in the United
States on the clothes of a caver.) In Europe and Asia, hibernating bats
developed resistance to the fungus after evolving alongside it for
generations. But the North American bats that came in contact with
patient zero had no built-in defence. The fungus invades their skin
tissue, disrupting their water balance as they hibernate for the winter.
The thirsty bats rouse, drawing on the fat stores they need to survive
until spring. After this happens enough times, they need food — fast.
Since there aren’t any insects for them to eat out in the cold winter
landscape, the bats starve.
The fungus spread farther, reaching into central Canada by 2010. The federal government declared three of the hardest-hit species “endangered” in 2014. At least 5.7 million bats died between 2006 and 2012 in Canada and the United States. The disease was expected to spread across the continent, infecting the West Coast as early as 2025.
Lausen, who now works for Wildlife Conservation Society Canada, wanted to make the most of that time. First, she had to know where the
bats were. In the East, bats congregated in groups of hundreds or
thousands in giant hibernation sites. No such locations were documented
in British Columbia or Alberta, and Lausen knew she didn’t have the
skill set to scour deep, sometimes dangerous cave systems in search of
them. Martin Davis, however, did.
When he was eight years old,
Davis toured a cave in Virginia with his parents. “I was hooked
immediately,” he says. At 13, he convinced the McMaster University
caving club in Hamilton, where he grew up, to let him join in on their
expeditions. He overcame a childhood fear of small spaces and was
exploring caves as far as Mexico by 18. Caving brought him into contact
with bats, and he did some work protecting and researching them in the
1990s. Now 60, he has the skills to get into hard-to-reach places,
decades of experience and an extensive network in the caving community.
approached him with an idea that eventually turned into a program
called BatCaver: if Davis and a team of volunteers across British
Columbia and Alberta left data collectors inside caves over the winter,
they could start to find and map the West’s bat populations.
BatCaver co-ordinator Martin Davis prepares to enter Fracture Cave in the mountains near Tahsis, B.C. Photo by Elena Gritzan
rain is still holding off as Davis reaches the mouth of the cave. The
entrance slopes down and bends to the left before a two-and-a-half-metre
drop, which he’ll travel through by rope. He turns on his helmet light,
slips on his harness and gets ready to descend. If he’s not back within
an hour, I’m to retrace our steps down the mountain, retrieve his
hidden spare keys for the truck, drive back to the village, call for
help. A minor injury could become fatal for cavers, who rely on their
strength to bring themselves safely back to the surface. Get stuck, and
it could be days before anyone finds you. Davis says that Canada hasn’t
had a caving fatality since 1992, but it doesn’t hurt to be careful.
backs into the cave, holding on to the rope. His view of the surface
disappears as he makes the drop into the large underground passage. He
often loses track of time in caves; calm and dark, they feel like a
whole other world. About 50 metres away, he finds it: the acoustic data
collector. He waves a small magnet in front, and it flashes red. This
means it’s still working, recording nearby sounds, like the echolocation
shouting of a bat flying by. He takes it and continues down the passage
to grab the second collector, a small white cylinder at the end of a
metal coil that’s tracking the temperature and humidity.
back out is a little trickier. Metal pieces that can slide up but not
down attach to the rope to support his feet and hands. He climbs
inchworm-style up the rope until he reaches the initial slope. Pushing
against it with his feet, he ascends the last few metres and emerges out
of the hole.
Bat conservationists in Washington state also
thought they had about 10 years to prepare for the arrival of the
disease. On March 11, 2016, a little brown bat, near death, was found 48
kilometres from Seattle and sent to a local wildlife rehabilitation
centre. Two days later, it was dead. It tested positive for white-nose
At first, Lausen wondered if the news was a false
alarm; there had been one before. As she listened in on a conference
call about the new discovery, she couldn’t deny it: white-nose syndrome
had jumped to the West Coast, and it was at her doorstep. “I was feeling
pretty desperate,” she says. “We thought we had so much more time.” She
called an emergency meeting of the BC Bat Action Team, a group
dedicated to bat conservation. It had never met in person before.
biologists gathered at a hostel near Chase, B.C., last September and
spent two days discussing potential actions. “It definitely galvanized
us as a group,” says Leigh Anne Isaac, the team’s co-ordinator. “It
helped us understand what needed to happen immediately.” They released a
plan, stuffed with 83 actions grouped into categories and prioritized
into three levels. Lausen says that a few things rose to the top.
one: find the bats. Along with BatCaver, the action team decided it was
important to strengthen the recently launched North American Bat
Monitoring Program, which uses sound detectors to track population
numbers in the summer. The hope is to build a database record of
different bat species over time.
The province’s community bat
programs, another initiative prioritized at the emergency meeting,
recruit local volunteers to add to that data set. Observers sit outside
known colonies in the summer, counting each bat as it flies by. The
original purpose of the regional programs was to give information to
people who find bats living on their property, but they’ve also evolved
into vital soldiers on the front line of white-nose syndrome, taking
calls from the public about dead bats that are then tested for the
Step two: figure out some way to help the bats survive.
There’s promising research into compounds that could be sprayed on a bat
to slow the progression of the disease. But the timeline for getting
the remedy field tested and approved is long, to make sure it isn’t
harmful for other parts of the ecosystem — and the bats in the East are
“People are thinking it will eventually help
the West, but I really don’t think it’s going to,” says Lausen.
BatCaver hasn’t found the “motherlode of bats” that she was originally
hoping to uncover. Save for a couple of sites with hundreds of bats in
Alberta, most of the bats they’ve located hibernate in smaller, more
spread-out clusters. It would have been easy to go into a cave filled
with thousands of bats in Eastern Canada and spray them with a substance
to help them survive; not so in the West, where you’d have to track
them down one by one. There’s some hope that white-nose syndrome might
not spread as quickly among bats that rest farther apart, but there’s no
way to know until it arrives.
Lausen’s exploring other
options. With a cave microbiologist, she’s identified some bacteria and
fungi that naturally occur on bats’ wings and slow the growth of the
white-nose fungus. These could be added in high concentrations to summer
colony entrances, which bats would rub against on the way in and out,
picking up the helpful microorganisms. The pair has applied for funding
to test the idea.
In New York, 10 years after the disease first
appeared, a few colonies have survived, persisting at five to 30 percent
of their original size. They seem to have found some way to fight the
fungus. If so, it’s possible a small number of bats could survive across
the continent. But they breed slowly, one pup a year. It would take
generations upon generations to get back to their original levels, in a
time when they’re facing other threats from climate change, industry and
wind power. Even the most hopeful admit that it’s going to be a rough
The day after Davis returns from the cave, he pops open
the case of the acoustic data logger, puts its memory card into his
laptop and looks at the graph. The frequencies plotted on his screen,
brief bursts of sound repeating every second, look like bat calls. But
as he flips through the rest of the winter’s data, he starts to
second-guess himself. The data points aren’t linear enough, the shapes
not cohesive. “I wonder if I’m wrong about this and if it’s a drip or
something,” he says.
A couple of minutes later, he’s decided:
they probably aren’t bat calls at all. The local bat populations don’t
use Fracture Cave every year, and it looks like they went elsewhere this
Data sets like this, empty of bat voices, could become all
too common in a year or two if the white-nose fungus hits the West.
Until then, all Davis can do is soldier forward. Soon, he’ll embark on
another hike, descend into another cave, retrieve another bat logger and
share the data with Lausen and her team. Maybe this time they’ll find
some bats. “I just have to have hope,” Lausen says, “that we’re going to
be able to do something.”
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