Wind turbines keep killing bats in Canada. Advocates say this needs to change

Bats do not have a strong public image. After all, they are associated with blood-sucking vampires, dark caves and everything creepy.

But researchers say Canada's migratory bats are in desperate need of protection as wind turbines have been decimating their populations for decades.

“We're not talking about if these migratory bats will go extinct. We're just talking about when,” said Corey Lauzen, director of bat conservation for the British Columbia-based Wildlife Conservation Society.

Lauzen and other experts say there are solutions that can help prevent further destruction of bat populations, including reducing how often deadly turbine blades fire. And she says it's not just bat lovers who should pay attention.

Canada is home to three migratory bat species: the hoary bat, the eastern red bat and the hoary bat. All three species are considered endangered, according to the Committee on the Status of Endangered Wildlife. The federal government is considering adding them to the Species at Risk Act..

According to the document published in the journal Biological Conservation in 2017. The hoary bat population could decline by 50 to 90 percent over the next 50 years and could become extinct within a century.

Awareness of the problem

Lauzen first saw the danger wind turbines pose to bats back in the early 2000s, when she was studying bats at the University of Calgary.

TransAlta, a company implementing one of the first wind energy projects in Canada, asked its laboratory manager to investigate after dead bats were found around their turbines near Pincher Creek, 200 kilometers south of Calgary.

“Seeing dead bats is really difficult because they are long-lived mammals that cannot sustain such a high mortality rate. And you had this gut feeling that this was going to be a problem,” Lauzen said.

Although it was not precisely how many bats died at the time, most were killed by impacts from the blades, while others died due to changes in pressure near the turbines.

But it was unclear why they came so close to the turbines in the first place.

Lauzen said they may have been checking the turbines out of curiosity, or their echolocation was bouncing off the turbines in strange ways, sending them flying blind.

Their six-week migration also coincided with mating season, and the bats may have mistaken the tall turbines for trees where they could find mates.

Whatever the reason, one thing was clear: the bats were dying.

Why are bats important?

Bats are of great importance to farmers and ranchers. They eat all kinds of insects, giving farmers the opportunity to avoid using pesticides on crops and pastures.

“I can't imagine what the insect population would be like if we didn't have this bat population,” said Julia Palmer, a rancher in Pincher Creek, Alta.

According to research work published in the journal Science in 2024. Declining bat populations often resulted in farmers having to use more pesticides. Higher infant mortality rates followed.

Although paper studied deaths caused by white nose syndromeLauzen says the study provides a warning about what's at stake.

“This is the first piece of evidence that we've been able to point to and say, 'See, we told you bats were important for your health,'” Lauzen said.

What's being done

After a large number of bat deaths and an increase in the number of wind farms, Lauzen and her team proposed a solution that became known as curtailment, or wind turbine shutdown.

Bats often fly when it's not very windy, so turbines can be shut down during those times with little impact on profits, she said.

She also suggested turning off turbines when bats migrate and pass wind farms.

According to Alberta study published in 2022seasonal overnight stops would reduce profits by less than two percent but would prevent the death of many bats.

In 2013, Alberta published its first recommendations on wind energy projects and migratory bats, implementing reduction proposals made by Lauzen and her team. In 2017, another directive limited the number of bat deaths allowed on a wind turbine.

Some other provinces also have rules regarding the bat mortality threshold or minimum limit level, but these vary from place to place.

Currently, companies do not face any fines if they reach these thresholds, Lauzen said. Instead, they will have to step up reduction efforts to prevent future deaths.

Lauzen says that's not enough because there are many more wind turbines now than there were a couple of decades ago. Since the thresholds are specific to each turbine, this could still equate to a large number of deaths.

According to federal government reportWind power capacity in Canada has increased dramatically since 2007.

“To be honest, even setting these thresholds hasn’t worked because it doesn’t look at the big picture,” she said.

Smart reduction

Kent Russell says turbines could be designed to shut down only when bats are expected to be present, rather than shutting them down for long periods of time.

One way to do this is with a device that can hear bats when they are nearby and then turn off the turbines until they pass.

Russell is a senior wildlife biologist and project manager at Western Ecosystems Technology Inc., headquartered in Calgary and Wyoming.

His company works with wind energy companies to study bat activity throughout the year and then create models that predict the best time to shut down a turbine. 

“It will be a single set of rules that will be programmed into the turbine so that the turbines turn on and off at night as the schedule dictates,” Russell said.

Sarah Palmer, a former director of a wind project owned by Toronto-based renewable energy company Potentia, says smart curtailment is key to getting industry on board.

“With new technologies, the industry is looking to provinces to embrace these new types of technologies as an option rather than cutting them out completely,” said Sarah Palmer (no relation to Julia Palmer).

Smart reduction technologies are regulated from province to province, and existing research is conducted in the United States, so it may take time for regulators in each province to approve their use. And some turbines are too old to use this technology.

As more research is done to learn about bat migration and numbers, Lauzen says regulators should prohibit companies from building wind farms along migratory routes.

“The hope that we can prevent these bats from becoming extinct is what keeps me going,” she said.

“Hopefully we can keep these bats alive long enough to advance renewable energy technologies to the point where we may not be killing bats anymore.”