A deadly, unstoppable fungus is likely to decimate Alberta's bat population. Here's what we know

Alberta bat researchers knew this day would come: a fungus responsible for the deaths of millions of bats in North America has arrived in the province.

And nothing can be done to stop the spread, meaning it is likely to wipe out a large percentage of the bat population.

Media reported earlier this month that Pseudogymnoascus destructans — the fungus that causes white-nose syndrome in bats — had been detected in guano in southern Alberta.

The fungus causes white-nose syndrome in bats, a disease that interrupts a bat's winter hibernation, prompting the animal to waste its energy and die of starvation.

How did we get here?

The fungus was first discovered in New York in 2006 and has wiped out millions of bats in eastern Canada and the U.S., spreading through the eastern seaboard and decimating populations and working its way west. 

Lisa Wilkinson, senior species-at-risk biologist and provincial bat specialist, said the province expected the fungus would come to Alberta.

"We've been watching the spread since it was first discovered in 2006 and it was getting closer and closer in 2021," she said.

"The discovery of the fungus was made in Saskatchewan in 2021, and about that time or just earlier, the fungus was detected in Montana. So we knew it was only a matter of time before we were going to find it in the southeast corner of Alberta."

The province listed two species of bat —  the northern myotis and little brown myotis — as endangered in 2021 and closed the most accessible bat cave hibernation sites, including Cadomin cave and Wapiabi cave — both in west-central Alberta.

Wilkinson said the move was done as a preemptive effort to keep the deadly fungus out of Alberta caves.

"We know that once the fungus gets here and they develop the disease, there are going to be population declines. In some areas, it's been 90 per cent population decline, so it's huge," she said. 

The pending arrival of white-nose syndrome prompted the formation of the Alberta Community Bat Program, said Cory Olson, program co-ordinator for ACBP, which is a project of Wildlife Conservation Society Canada that started around 2016.

"Our objective was to prepare Alberta for the arrival of white-nose syndrome, which we knew from eastern Canada was likely to decimate our populations once it arrived here in Alberta," Olson said. 

Olson says the spread of the fungus was detected by collecting and testing bat guano from roost locations. Two samples from along the southern stretch of the Red Deer River were positive for the fungus.

The arrival of the fungus most likely means white-nose syndrome is not far behind, but so far it hasn't been found in Alberta.

Wilkinson and Olson both told CBC News they would expected bats to be found to have died from white-nose syndrome within the next year or two.

Where are we headed?

One challenge facing researchers in western Canada is that little is known about where bats spend the winter.

"We know a few of the caves where bats hibernate, it actually doesn't account for very much of the population," said Olson.

"If you were to add all the caves in western Canada where we know these species occur, it would only account for a few thousand individuals out of the probably millions of bats we have."

The fungus that causes white-nose syndrome grows over the winter, noted Olson, making it harder to monitor the spread. 

"There's really no hope for getting rid of the fungus now that it's established. ​​​​​​"​- Cory Olson, Alberta Community Bat Program

You can't put heavy trackers on bats because they are so small, said Olson, and the animals tend to winter underground where signals can't penetrate. 

Another challenge facing most bats in Canada is that they only give birth to about one pup per year, so if a major threat like white-nose syndrome wipes out a huge proportion, it can take a long time to recover. 

What do bats add to the ecosystem?

While the average Albertan may not have much direct interaction with bats, they do reap the benefits of their natural pest control.

"They are the largest primary consumer of nocturnal insects," said Wilkinson.

Research shows that a bat can eat more than 1,000 insects in a single night.

Wilkinson said that studies in the U.S. have found that bats are responsible for saving billions of dollars because they act as a natural pesticide, and Alberta farmers have also benefited tremendously from the flying mammals. 

If white-nose syndrome wipes out a huge percentage of bats in the province, the effect will be noticeable on people, crops and the ecosystem. 

Can anything be done? 

B.C. researchers have been working on a probiotic powder that could help prevent white-nose syndrome in bats, but it isn't likely to be used in Alberta any time soon, Olson said. 

The treatment is designed for B.C. and the probiotic would need to be developed from local strains of microbes to ensure they don't introduce new species in an area they don't belong.  

Wilkinson said Alberta is closely monitoring the probiotic treatment in B.C. She said there are other options like fungicides could work in some settings, but they might not be the solution for Alberta.

"There's a lot of caution because especially in caves that are a little bit warmer, they're their own thriving ecosystem with lots of other organisms in them, so you have to be really careful … there's nothing right now that's going to be a silver bullet."

Wilkinson noted that UV light has been shown to be effective in killing Pseudogymnoascus destructans, but with most bats hibernating underground in Alberta, it's not a practical solution for bats in the province.

The hope, Olson said, is that if white-nose syndrome wipes out a large percentage of the population, some bats are able to survive alongside the fungus and eventually develop immunity at a population level. 

"We're not going to stop this fungus," he said.

"There's really no hope for getting rid of the fungus now that it's established. But hopefully with proper management we can at least get through this and help our bats recover."

Some experts have suggested that the spread of white-nose syndrome may be slower in western Canada, because bats in the west don't gather in large numbers in caves the way eastern bats do. 

Olson said the best way to help Alberta bats is to create an environment where they can succeed and not interfering with roosting.

"If they're allowed to survive and successfully reproduce, the hope is that they can eventually recover."