As deadly fungus spreads, Alberta turns to probiotics to save dwindling bat population

CBC

2 days ago

As a deadly fungus threatens to devastate bat colonies across Alberta, the provincial government is trying to save what's left of the population with a new probiotic treatment.
Across two sites in southern Alberta, 18 bat houses have been sprayed with the probiotic cocktail, aimed at preventing white-nose syndrome — a disease that's killed millions of bats across North America.
White-nose syndrome is caused by a fungus that invades the winged mammals' skin during hibernation, causing them to wake early and ultimately starve to death.
"We think it's a big deal. It's the first time outside of B.C. and Washington, that Lower Mainland area, that this probiotic's been used in North America," said Lisa Wilkinson, provincial bat specialist with Alberta Environment and Protected Areas.
The treatment has been in the works for years by scientists at Wildlife Conservation Society Canada, McMaster University and Thompson Rivers University. It contains four bacterial strains, found in some bats' wings in western Canada, that have been shown to inhibit the disease-causing fungus.
The freeze-dried probiotic cocktail is mixed with water and sprayed into bat houses when the animals are out foraging. When they return, their wings get coated with the treatment. The goal is that the fungus won't be able to penetrate their wing tissues and wake them up during hibernation.
While it has been tested across 11 sites in B.C. and Washington, researchers behind the concoction say this is the first time it's actually being used as treatment.
They say it was a good opportunity to expand their work, but also a necessary move after learning about the poor conditions of some bats in southern Alberta.
White-nose syndrome in Alberta
The fungus that causes white-nose syndrome was detected in Alberta for the first time in 2022, along the Red Deer River.
By 2024, symptoms of the disease were confirmed in the province for the first time. Those symptoms became "very severe" by this spring, according to the coordinator of Alberta's bat program with Wildlife Conservation Society Canada.
"Lots of bats had pretty sizeable holes in their wings. There was substantial evidence of this fungus invading their skin tissues. Under UV light where this fungus fluoresces, you could easily see that large portions of the bat body have been infected with this fungus," said Cory Olson.
Olson said the bats were also weak and underweight, and it seemed very likely that those that survived through the winter wouldn't be able to raise offspring.
"When animals can't raise offspring, that is inevitably going to lead to population declines."
There's already evidence that Alberta's bat populations are declining, Olson said. In 2023, his team counted over 2,000 bats at one specific site in the province. This year, they only found between 200 and 400 of them.
Wilkinson has found similar trends in other areas in southeastern Alberta as well. But she cautions that bats do move around and are notoriously difficult to monitor, especially because no one knows where they hibernate.
Bats spreading the probiotics
There is also a vaccine being developed in the U.S. to combat white-nose syndrome.
Cori Lausen, director of bat conservation with the Wildlife Conservation Society of Canada, said the U.S. treatment sounds promising. But she said there is one thing that could put the probiotic ahead of a vaccine.
Researchers have noticed some probiotics showing up in their control sites, where they deliberately do not apply the probiotics, she said.
"We didn't know if the bats would actually spread the probiotic amongst themselves, and it turns out, it looks like they are," said Lausen, who's been leading this work across the country.
"That's actually very good news…. We may not know about some of the other colonies in the area, and they might also be benefiting."
Lausen stresses they made sure not to introduce anything novel to the bats' environment that could put them at risk down the road.
Biologists sent wing swabs from southern Alberta bats to a lab at McMaster University to ensure the bacteria was already found here.
'No silver bullet'
The team will head back to the sites next spring to see how the bats survive the winter and whether the white-nose syndrome has improved.
They'll also catch bats, swab their wings and test how much more of the beneficial bacteria they're finding.
Wilkinson, with Alberta Environment, hopes to spray the treatment in other areas next year, too.
"There's no silver bullet. We're not going to get rid of it. It's basically giving the bats a helping hand," she said.