Wind turbines have scary impacts on bats. Here's what can be done

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Hey, it's Emily. Last week, I went to the Electricity Transformation Canada conference in Toronto, and one of the talks that jumped out at me was about protecting bats from wind turbines. 

This week:

• Wind turbines have scary impacts on bats. Here's what can be done
• The Big Picture: Creepy crawlies up close
• 'Second-hand fashion at its best': Thrift store holds charity fashion show

The eastern red bat is one of three migratory bat species in Canada that have a high risk of mortality from wind turbines. The one in the photo has a tracking transmitter and antenna attached. (Brock Fenton)

Wind turbines are considered an environmentally friendly way to generate electricity. But they are often deadly for bats — a new study this week estimated wind turbines killed 18.7 million bats in the U.S. alone between 1981 and 2024, and the death toll had grown, with the expansion of wind energy, to about 1.5 million bats per year by 2021.

In Canada, the evidence is also scary, especially for our three migratory bat species: A 2023 scientific assessment of the hoary bat, eastern red bat and silver-haired bat found they all face "high risk of mortality at wind energy facilities."

The main source of evidence? Declining numbers of dead bats found under wind turbines, killed by either collisions or the dramatic pressure changes near the blades.

Dana Green, a biologist who co-authored the assessment, said the bats don't seem to be learning to stay away, so the fact that there are fewer dead bats points to a plummeting population — the report recommended they be federally listed as endangered. 

Scientific models suggest "fatalities associated with wind energy facilities" could lead to a 90 per cent population decline over 50 years for the hoary bat and a 22 per cent probability of extinction over 100 years.

Wind turbines don't kill all bats equally. Most species of Canada are small, brown bats that hibernate in Canada and face little risk from turbines (although they've been decimated by a deadly disease called white-nose syndrome).

Biologist Dana Green holds a hoary bat during field research in Saskatchewan. (Submitted by Dana Green)

It's the three more colourful migratory species that tend to die from wind turbines during their fall migration to hibernate in the southern U.S. and Mexico.

That's when they fly through the wide open migratory pathways where wind turbines are often located.

Green, a postdoctoral researcher at the University of Northern British Columbia, said hoary bats, Canada's largest bat species, seem to be attracted to turbines, although researchers don't know why.

So what can be done?

The main strategy for protecting bats is "curtailment," which means shutting off wind turbines during certain times if bats are at risk. 

In Ontario, such rules apply to a wind farm if bat mortality is more than 10 bats per turbine per year.

Normally, wind turbines start operating at wind speeds of three or four metres per second. But between sunrise and sunset between July 15 and Sept. 30, the rules ban operation if the wind speed is below 5.5 metres per second, since bats tend to fly when it's less windy.

Because this "blanket" curtailment reduces the amount of power and revenue a wind farm can generate, more targeted solutions have also been developed.

Wind turbines in Elmira, P.E.I. A number of strategies can help protect bats from dying due to wind turbines, such as shutting them off at night during fall migration. (Aaron Adetuyi/CBC )

"Smart" curtailment uses ultrasonic microphones to detect bats and automatically shut off one or more nearby turbines.

At the Electricity Transformation Canada conference in Toronto last week, Andrew Taylor, a senior ecologist at Stantec Consulting, said smart curtailment can be expensive because it requires a lot of detectors. Depending on the range of the detectors, the bat could be at risk before the curtailment kicks in — something that also concerns Green. 

Taylor said smart curtailment can also make it hard for wind companies to predict how much energy and revenue they could lose due to temporary shutdowns.

He presented a solution developed by his company that involves using fewer detectors to monitor bats for a year, relating the number of bats wind and weather patterns, and then using that information to fine-tune when to shut off the turbines.

"We do like to think that we're letting the bats tell us when it's best to curtail," he said.

Ian Maynard, a research engineer at a Natural Resources Canada lab focused on renewable energy, did a recent analysis of 51 scientific studies on mitigating bat deaths from wind turbines as well as some of his own modelling in Ontario.

Maynard said the difference in annual electricity generation and revenues between smart and blanket curtailment is only about two to three per cent, so the higher-tech solution may not always be worth it.

Some studies looked at sounds, colours or lighting to deter bats. Maynard said that's "where a lot of people want to go," but their effectiveness depends on the location and bat species.

He found that many studies mitigating bat deaths from turbines weren't large or transparent enough to be reproducible.

"There needs to be options available," he said. But he added that good scientific evidence is needed before policies can allow them. "That's kind of the next step."

For now, Green thinks a federal, Canada-wide blanket curtailment policy is needed. 

She thinks green energy is "fantastic" and "absolutely" believes wind energy and migratory bats can coexist, but wind developers need to do more to protect bats. "If green energy wants to advertise itself as green, then put your money where your mouth is."

—Emily Chung

Old issues of What on Earth? are here. The CBC News climate page is here. 

Check our podcast and radio show.  In our latest episode: Sixty-five bats dropped dead inside a home custom-built to protect them. What went wrong? For bat moms looking for a place to raise their pups, it’s not the rent that’s through the roof, it’s the temperature. But bat people are busy building them safer homes, from tiny condos with emergency exits to mini bark roosts stuck to trees. 

What On Earth? drops new podcast episodes every Wednesday and Saturday. You can find them on your favourite podcast app or on demand at CBC Listen. The radio show airs Sundays at 11 a.m., 11:30 a.m. in Newfoundland and Labrador.

Check the CBC News Climate Dashboard for live updates on record-breaking weather and current conditions across the country. Set your location to find out how today's temperatures compare to historical trends.

(CBC)

Reader feedback

What are you doing to be greener this fall and Halloween? We'd love to hear your tips and see your photos.

Got questions, comments or just want to share something? Write us at whatonearth@cbc.ca (and send photos there, too!)

The Big Picture: Creepy crawlies up close

(Dara Ojo)

This astonishing green and orange creature is a huntsman spider in Jiaxing, Zhejiang Province, China, captured by Edmonton-based photographer Dara Ojo.

He says his images of spiders often provoke the strongest reactions in people, especially those who fear them. But he hopes a closer look will change their perspective. 

"Being able to see what their faces look like gives them personality," he said. 

At Halloween, giant spiders and webs adorn neighbourhoods to creep out passing trick-or-treaters. Ojo thinks these decorations reinforce the idea that spiders are scary — something he aims to counteract with his new book, Tiny Titans. 

"I'm always trying to get the fear out of people," said Ojo, whose book features 120 close-up portraits of insects and spiders in Canada, China, Costa Rica and Nigeria, where he is originally from. He hopes seeing them up close will inspire empathy instead, and a desire to help them, by doing things like planting native flowers.

The book hits bookstores across Canada on Nov. 10. 

— Emily Chung

Hot and bothered: Provocative ideas from around the web

• The first climate lawsuit to go to a full trial in Canada began its hearings in Vancouver this week. The outcome could set new constitutional precedents in Canada and inspire climate litigation worldwide.

• The re-election of Luiz Inácio Lula da Silva as Brazil's president comes as a huge relief for the Amazon rainforest. Lula has cracked down on deforestation in the Amazon, which was otherwise at risk of severe collapse.

• On Haida Gwaii, logging took the trees that bears called home. Now, the Haida Nation is building them new dens, The Narwhal reports.

• The world's largest electric ferry is now in service, taking up to 225 cars and 2,100 passengers at a time between Buenos Aires, Argentina, and Colonia, Uruguay. You can read more about electric ferries in Canada in a CBC article from April.

'Second-hand fashion at its best': Thrift store holds charity fashion show

The fashion show was jointly organized by the Dawson City Thrift Store and the Willow Foundation Dawson City to raise funds for the community. (Hyunjung Kim/CBC)

If you've ever struggled to style thrifted clothes, an event in Dawson City, Yukon, might inspire you.

The town's thrift store held the first fashion show last Friday in its more than 40-year history.

About 20 volunteer models — including kids — walked the runway showcasing dozens of creative second-hand outfits.

The event was jointly organized by the Dawson City Thrift Store and the Willow Foundation Dawson City to raise funds for the community.

Gaby Sgaga says she decided to volunteer as a model to support the organizers she knows — but also for the opportunity it presented.

“Who doesn't want to be a runway model?" Sgaga said. "And it's for a good cause. So it's a double win.”

Gaby Sgaga showcased two sets of the outfit. Her second outfit combines glitter with a lumberjack jacket under the theme 'glitz and casual.' (Hyunjung Kim/CBC)

Most of Sgaga’s clothes are second-hand, as she believes in the importance of recycling.

"You could really find some good-quality clothes second-hand, and you're also helping people and the planet," Sgaga said.

For Sandy Jung, whose hobby is cosplay, the runway was familiar. But for Amandeep Kaur, it was a nerve-wracking stage. Still, she enjoyed a rare chance to show off her fashion in Dawson.

"I feel afraid to wear the high heels outside on the road … but here is the chance that you can wear these shoes. I like my dress and I feel pretty," Kaur said.

Amandeep Kaur, left, and Sandy Jung pose at the Dawson City Thrift Store Fashion Show. Jung says she will participate next year as well, if she has a chance. (Hyunjung Kim/CBC)

Nine-year-old Esmé Winton and eight-year-old Olive Dewell dominated the show, although they said they felt scared at first.

The two friends picked their own outfits from the thrift store and have already established their own styles.

"When my mom chooses my outfit, I always change it," Winton said.

Olive Dewell, left, and Esmé Winton, right, pose at the fashion show. Winton found the moment exciting, adding that she always welcomes the chance to perform due to her love of acting. (Hyunjung Kim/CBC)

One of the event's co-ordinators, River Doucette, says the show empowered the models.

"And that's just what we wanted, right?" Doucette said.

"We want the community to get together and just have a great night, especially when the weather's getting cold."

A live auction

The fashion show included live auctions where people raised paddles while the models walked the runway.

Leah Payne was one of the most active bidders.

"I don’t make it to the thrift store a lot, actually, because I happen to not be around during the hours it’s open. So this is a really fun way to see some of the things that they have," Payne said.

Natasha Henderson won a leopard print jacket. She's excited to see what she can do with “this amazing vintage piece of clothing from Canadian history.”

A crowd of about 100 people raised auction paddles for the models' outfits. (Hyunjung Kim/CBC)

To Henderson, the deacon of St. Paul's Church, to which the thrift store is closely connected, each garment has a history.

"They’re all worn by someone else somewhere else, and they made their way here," she said.

"It’s just wonderful to be part of that garment's life."

— Hyunjung Kim 

Thanks for reading. If you have questions, criticisms or story tips, please send them to whatonearth@cbc.ca.