A fungus that is destroying bat populations in eastern North America has made its first appearance on the Canadian Prairies.
Researchers with the Wildlife Conservation Society report that they've found the fungus that causes white-nose syndrome in eastern Saskatchewan, despite hopes the western grasslands would prove a barrier.
"We have found the fungus," said Cory Olson, who discovered it while researching how bats use structures on the prairies such as bridges.
"It's easily in the millions of bats in North America that have already died from this fungus."
White-nose syndrome is caused by growth of the Pseudogymnoascus destructans fungus on the bodies of hibernating bats. Bats are able to fight off the fungus during the summer. But when they hibernate in winter, their immune systems slow down.
The fungus eats at the skin on their wings, which causes the bats to dehydrate and wake up to drink. When they do, they burn energy. If they wake up too many times, their fat reserves don't get them through the winter and they starve to death.
Bats typically hibernate in large groups. If the group gets infected, the destructans fungus can wipe it out, said Jordi Segers, the white-nose syndrome program coordinator with the Canadian Wildlife Health Cooperative.
"In the lucky scenarios, 85 per cent of bats disappeared. There's a really, really high mortality."
White-nose syndrome was first identified in North America in 2006. It's now throughout the eastern United States and Canada, as well as western states such as Washington.
"It's been spreading a few hundred kilometres every year," said Olson.
Scientists had hoped Prairie geology, which has few caves where bats gather in large numbers, might be a barrier. They still hope the more solitary hibernation of western bats will slow the syndrome's progress.
"The West is potentially different from the East," Segers said. "It might slow down the spread."
Although the fungus is now present in Saskatchewan, no bats have yet been diagnosed with the disease.
That's because it takes a hibernation season for symptoms of the syndrome to appear. As well, little is known about where and how Prairie bats hibernate, making it tough to find animals that don't survive.
The three species of bats native to the Prairies are already considered endangered. The threat of white-nose syndrome comes on top of challenges they already face from deforestation and the draining of wetlands that nurture the insects the bats live on.
"We know climate change is already having a big effect on bats," Segers said.
Bats play an important role in local ecosystems, he said.
They're also important to humans. Bats eat large amounts of insects that would otherwise damage crops.
U.S. studies have suggested that bats save American farmers billions of dollars a year in crop losses.
A Saskatchewan government zoologist said the province is aware the fungus has been found.
"The Ministry of Environment is working closely with local researchers and other agencies to ensure that appropriate protocols are followed by professionals when handling bats," said Erin Swerdfeger.
"(It) is forming a provincial working group to address many of the questions about our bat populations."
Segers and Olson point out that some bats survive white-nose syndrome. Finding out why might provide a clue to fighting the disease. One possibility is a probiotic "cocktail" that could help bats fight the fungus, said Olson.
Too little is known about Canada's bats, added Segers. More research will be needed to track the progress of the disease and how it can be fought.
"Through research, we're trying to find out how these bats survive and what we can do to help."
This report by The Canadian Press was first published Sept. 14, 2021.
Bob Weber, The Canadian Press