Scientists work to stay ahead of white nose syndrome, a deadly fungus that has killed millions of bats in the US and Canada

Nate Fuller was just starting out as a bat scientist nine years ago when he entered a massive cave in rural Pennsylvania to look for live animals. Instead, he found himself wading through a distressing muck, the decomposing bodies of thousands upon thousands of dead bats.

That was in the early years of white nose syndrome, the creeping, lethal fungus that has decimated North America’s bat population, killing millions of bats and sparking frantic research and conservation efforts across the United States and Canada.

In Fuller’s case, that traumatic discovery changed the trajectory of his career and led him here this month, to a remote cave site in central Montana, where he is part of a team of bat researchers led by the Wildlife Conservation Society studying the hibernation of western bat populations.

“It was one of the worst things I’ve ever seen,” Fuller remembered of his Pennsylvania experience.

Today, research related to white nose syndrome, one of the most devastating wildlife diseases of modern times, could be the only way to ensure that bats continue to survive.

Across the western United States and Canada, these scientists are nearing the end of one of the most comprehensive studies ever of the hibernation habits of bats. In three years, they have captured and studied 1,500 bats across seven US states and two Canadian provinces and several species. Most bat studies focus on small, specific populations in fixed areas but this one is tracking a whole region, trying to figure out which bats will make it through the coming plague.

Facebook Twitter Pinterest While eastern bat populations in the US and Canada have been devastated by white nose syndrome, those in the west remain relatively untouched. Photograph: Wildlife Conservation Society

White nose syndrome attacks bats during their winter hibernation, when the fungus, which thrives in cold weather, creeps and settles over the animals’ noses and wings. Hibernating animals affected by the fungus awaken sooner and more often than they should, deplete their valuable fat reserves and starve to death.

“This study could tell us who’s susceptible and who’s not susceptible, and it may depend on where these bats are choosing to roost and to hibernate,” explains Sarah Olson, principal investigator on the project for the WCS.

Since white nose syndrome was discovered in eastern bats in a cave in New York in 2006, Canada has added three species of bats to its endangered list; the United States has added one and is considering two others. The US population of little brown bats is down 90%, while 97% of northern long-eared bats have been eradicated.

Destruction of threatened species habitat taking place on 'scandalously huge scale' Read more

Even though it has wiped out whole bat populations in the east, white nose syndrome is only just beginning to sneak into the western United States. It has been found in limited spots in a few western states – Wyoming, Colorado, Washington and Texas – but researchers are braced for the certainty it will arrive here with force, just as deadly as it has been in the east. Before that happens, they are hoping to learn all they can about western bats and their most vulnerable state.

“I think we’re 100% sure it’s going to get here. It’s just a matter of time before it comes to all the states,” says Olson. “There’s nothing that’s going to stop it from spreading.”

In some ways, the killer plague has elevated the status of these often-unappreciated flying mammals. Public awareness about bats and their importance in the ecosystem has soared. Most people now know, at least, that bats are essential to keeping mosquitoes under control.

It's just a matter of time before it comes to all the states. There's nothing that's going to stop it from spreading. Sarah Olson

Olson explains the study while driving over a winding, rutted dirt road into national forest land, deep in a particularly sparsely populated part of central Montana. There, three field researchers including Fuller are camped out for work in rotating 24-hour shifts with a research trailer they will use once they capture bats just past sunset.

At dusk, near the entry of the cave the bats use for winter hibernation, the scientists unroll two delicate strands of netting and wait for feeding time. After dark, the bats swarm near the mouth of the cave to eat insects.

A colony of bats hibernate in this cave, a half-mile deep tunnel that opens into a massive cathedral far underground. Inside the cool quiet of its dark interior, the scope of the challenge of saving bats from white nose syndrome becomes clear.

Although the fungus is primarily transmitted from bat to bat, there is evidence to indicate that humans helped spread it far and wide. Old graffiti scrawled across the interior walls of this cave make it clear that it is a favorite spot for spelunkers. These days, people who scramble through caves and bat habitat are more careful about decontaminating their gear to kill the fungus, a necessary step to slow its spread.

The local bats have not moved into this cave for the season just yet; instead they are focused on getting fat for the winter.

Facebook Twitter Pinterest Katie Haase inspects the body and wings of a bat collected for research. Photograph: Wildlife Conservation Society

Outside the cave, the night’s bat capture work starts slow. The team is aiming to gather 30 bats of different species on this chilly night after the first fall snow; the animals are cooperating and only a few animals have straggled in. But after 90 minutes, a small swarm takes shape and the team begins to gently disengage bats from the nets and place them into individual cotton bags, calmed by the warm darkness inside.

Researcher Katie Haase carefully drapes the collection of bat-filled bags over her chest and hikes back down the mountain covered in bats. There, she and Fuller bring the bats inside their research trailer and, one by one, remove the annoyed, chattering mammals from their cocoons to be weighed and measured, with a dozen selected to stay for overnight monitoring. The team will check the bats’ body composition, metabolic rates, and other measurements involving temperature and humidity controls.

Olson explains: “We’re getting out there and measuring, how do all these factors play together, then combining all of this to make an assessment of risk for bats.

That will give us a better picture of which bats are susceptible, to tell us where to look where white nose syndrome will hit hard.”