A fungus that could wipe out Island bat colonies detected in Metro Vancouver

For the second time ever, a fungus that could wipe out entire bat colonies has been detected in BC.

The fungus, Pseudogymnoascus destructans , causes white-nose syndrome (WNS) in bats, a condition that disturbs the hibernation patterns of the animals, leading to deadly consequences.

It doesn’t affect humans, but when bats come into contact with it, they can develop a layer of white fuzz on their noses and wings, causing them to wake up from their winter slumber to try to clean it off. By the time spring rolls around, the bats have exerted too much energy, leading to fatal starvation and dehydration.

BC has the most diverse bat population in Canada—and the Island is home to more than half of the province’s bat species. Nearby, a major roost in the attic of Metchosin’s community hall is home to more than 1,500 bats, including Yuma bats and little brown bats, two species that have had WNS detected in Washington state.

The fungus was recently found to be present in bat guano (droppings) in Metro Vancouver, according to the province.

The last and only other time it was detected in bat guano in BC was in Grand Forks in 2023. So far, there have been no confirmed cases of WNS in BC bats.

Still, the presence of the fungus in droppings is enough to cause concern—this is the closest Canadian detection to the Island yet.

Its gradual spread to the West Coast has long been a fear of local bat experts. In 2016, Island researchers sounded alarm bells when a little brown bat infected with WNS was detected near Seattle, within the migratory range of local species.

Paula Rodriguez de la Vega, provincial coordinator for Community Bat Programs of BC, says her organization is expecting WNS to eventually make its way here.

WNS was first detected in North America in 2006, found in a cave in New York state. It’s believed the fungus was brought here from Europe, where bat populations are better able to tolerate the fungus.

WNS has killed millions of bats in the eastern portions of North America, and affected colonies often have high mortality rates.

The fungus has put three species of bats on the endangered species list: 90% of long-eared, little brown, and tri-coloured bat populations were killed off in fewer than 10 years.

Scientific modelling has shown that little brown bats—once the most common species in North America—could be wiped out completely in the northeast as soon as this year.

Bats are essential to the ecosystems they inhabit, providing pest control, pollination, and a powerful fertilizer (their guano).

And finding the WNS fungus in nearby Vancouver is “not good news,” for BC or the Island, says Rodriguez. Her team has been coordinating with Island communities to ensure the illness is detected as quickly as possible if it arrives here.

“We work with homeowners and partners to collect spring bat guano at designated bat colonies, track when bats first return to their maternity colonies, and conduct annual bat counts at colony sites,” Rodriguez says. The Metchosin Community Hall is one of the sites where the count takes place each year.

The province and Rodriguez are asking the public to help with species monitoring by reporting any sightings of new roosts, dead bats, or unusual bat activity in winter to the BC Community Bat Program.