Alberta is forging ahead with efforts to protect bats now endangered by a deadly fungus expected to devastate colonies across the province.
The little brown myotis and northern myotis are under threat due to white-nose syndrome, a disease that has killed millions of bats in North America and put infested populations on the brink.
Three years after the fungus that causes the disease was first detected in Alberta, the provincial government has published a draft recovery plan that aims to minimize losses and help the species eventually rebound from the severe population declines the syndrome is expected to bring.
With no known cure for the disease, government conservationists hope to make colonies as resilient as possible before it takes hold.
‘No magic bullet’
“We’re not going to completely destroy the fungus,” said Lisa Wilkinson, a bat specialist and senior species-at-risk biologist with Alberta Environment and Protected Areas.
“We’re not going to completely cure white-nose syndrome.
“There is no magic bullet.”
A small number of bats have shown a natural resistance to the fungus. The hope is that those survivors can eventually rebuild the population, Wilkinson said.
Recovery is expected to take decades, the government document cautions.
“All we’re trying to do is give bats a helping hand so that populations can slowly recover,” Wilkinson said.
A probiotic treatment that inoculates bats against the fungus has shown promise but more research is needed before it can be applied in Alberta, she said. In the meantime, protecting bat territory from development or human disturbance is critical.
“Like any species, it’s not going to recover if we can’t give it the habitat it needs,” she said.
The draft recovery plan, prepared by the Ministry of Environment and Protected Areas, aims to mitigate the disease with new protections for critical habitat, extensive tracking of infections, and enhanced research on Alberta’s elusive bat population.
Habitat protections would focus on conserving “essential roots,” including hibernacula — cracks, crevices and caves used for winter hibernation — and maternity roosts, sites used as nurseries by females rearing their young.
The plan calls for “buffer zones” around bat caves, roosting sites and landscapes most often used by the animals to forage, drink and commute.
Guidelines will be developed to ensure land-use activities maintain bat habitat. “Bat-friendly” management practices for land development will be promoted.
The plan also calls for more research to track the spread of the syndrome and the population itself. If approved, a provincial disease surveillance and monitoring plan would include cave surveys, capture programs and bat counts.
Public consultation on the document closed last week.
Kennedy Halvorson, a conservation specialist with the Alberta Wilderness Association, said the recovery plan should be implemented as soon as possible but needs to include more enforceable limits on industry.
The association has called for stricter limits on pesticide use to bolster insect populations that bats rely on for food, and for binding restrictions on the forestry sector to better safeguard bat habitats.
“We saw how devastating it was to the eastern bat populations,” Halvorson said. “We need to treat it like it’s going to be just as devastating here.
“It needs to be implemented quickly and in all honesty, it probably should have been implemented before the fungus and the disease even arrived.”
The fungus has been spreading westward for decades and Alberta has been bracing for its arrival.
In 2021, the provincial government classified the little brown myotis and northern myotis as endangered in a pre-emptive effort to stave off outbreaks.
This spring, the first cases of white-nose syndrome in the province were confirmed in two bats in the badlands along the Red Deer River in southeastern Alberta. The fungus had been detected in 2022 in guano collected in the same area.
Known as Pseudogymnoascus destructans, the fungus thrives in cool, damp conditions found in the caves bats prefer.
It spreads most often from bat to bat. The fungus invades their skin during hibernation, causing lesions and coating their muzzles in a powder of spores.
Infected bats wake early from hibernation and ultimately starve to death.
Biologists first saw bats dying from the disease in 2007 in New York state. The disease surfaced in Canada in 2010. In some infected caves, 90 to 100 per cent of bats have died.
Cory Olson, a bat expert and wildlife biologist, said understanding where bats are hunting, hibernating and rearing their young is critical to minimizing the death toll.
Identifying habitat, however, is a challenge due the species’ nocturnal and elusive nature.
Only eight hibernacula have been identified in Alberta and just a handful of roost sites are known.
“We think we have millions of bats,” Olson said. “But most of them, we have no idea where they hibernate.
“And that means we can’t protect their habitat, we can’t ensure that they’re not disturbed during the winter. And we also can’t monitor, in most situations, whether this fungus is growing.”
Olson, who lent his expertise to the drafting of the recovery strategy, is the program co-ordinator for the Alberta Community Bat Program, a project of Wildlife Conservation Society Canada.
The pending arrival of white-nose syndrome prompted the program to be formed in 2016.
Olson said the recovery plan will lean on technology to glean more information on Alberta’s hard-to-track bat population. Much of the work has already begun.
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Ongoing echolocation research that captures the chirping sounds bats make to navigate is helping researchers pinpoint critical habitats. DNA studies are providing new insight on the demographics of local populations.
Olson’s group began a guano research program in 2021, extracting DNA from bat droppings collected from hundreds of bridges where the tiny mammals rest at night.
Expanded population monitoring will also help conservationists understand how the disease might play out in Alberta, he said.
Hibernacula in Eastern Canada house tens of thousands of bats. In Alberta, the populations are patchy, with smaller groups taking refuge in cracks and crevices across the landscape. This, along with Alberta’s icy winter temperatures, may help slow the spread.
“We’re very concerned. That doesn’t mean that our bats are doomed,” Olson said. “What we’re really hoping for is that, with sound management, we can get bats through this.”
2 species at risk
Only some species of bat become sick from the fungus. Of nine species in Alberta, the northern myotis and little brown myotis — both mouse-eared microbats — are most under threat.
Animals of both species produce few young, making them particularly vulnerable to decline. Females give birth to no more than one pup per year, and many don’t survive the winter.
The little brown myotis, also known as the little brown bat, weighs seven to 10 grams at adulthood. Found throughout Alberta, they roost in buildings, old trees or rocky crevices, and hunt at night, capturing inspects on the fly.
The outlook looks particularly bleak for the northern myotis, whose populations are already precarious. Similar in size to their more urban cousins, they prefer to roost in trees. Better adapted for foraging in the woods, they have long ears and slightly longer wing spans.
Previously, the status of the little brown myotis in Alberta was secure. The less-common northern myotis was previously listed as potentially at risk because of its reliance on forest habitats.
Friend, not foe
Alberta’s recovery plan emphasizes co-operation with conservation partners, citizen science programs and all Albertans.
The strategy says Alberta needs to help improve the species’ troubled reputation and reduce bad, sometimes deadly, encounters with humans.
Wilkinson said people need to remember that the flying mammals are not a foe and that we reap many benefits from the pest-eaters.
“They are friends,” she said.