By Alana Power
Wind turbines in Ontario have the potential to kill thousands of bats every spring and fall.
Bat biologist Juliet Nagal is studying the migration patterns of bats along Ontario’s shores so that she can suggest locations for turbines that would be less harmful to the nocturnal creatures.
Nagal, 28, works for EchoTrack Inc., a company that tracks migrating birds and bats using radar which detects height, speed and direction. Microphones allow for species identification. The focus of Nagal’s research is to find out if bats are migrating in the same pattern as birds along Ontario’s shores.
Birds will follow the shoreline, and only cross it when it is totally dark, said Rhonda Millikin, president of EchoTrack.
“We don’t know if the bats are doing the same thing, but that’s one of the questions we want to find out,” she said. If the province allows wind farms off the shores of Lake Erie, EchoTrack’s research will provide insight into how far off the shore they should be, Millikin said.
Depending on the placement, some wind farms can kill thousands of bats in the fall season and some will only kill a handful. “It really comes down to how the wind turbines are placed,” Nagal said.
“Unfortunately for wildlife we like to put wind turbines where there’s lots of wind and lots of wind is what animals use to migrate,” she said.
The overall effect of one wind farm killing up to a thousand bats is not known. This is because the total population of a species is impossible to determine, since bats don’t hibernate in clusters. “No one can say for sure how many it’s okay to kill,” Nagal said, adding that it is even more important to try to protect the bats because their population is unknown. “Because we don’t know how many of them there are we should be extra careful to kill as few of them as possible,” she said.
Nagal set up her radar and microphones at Port Burwell on Wednesday just before sunset on Lake Erie. After dark, bats could be seen flying over the lake and shore on the radar screen.
Nagal began tracking the bats in August. Wednesday was day 62 of work in a row for the biologist. She usually goes out in the spring and fall to track migration patterns. She finds a site, sets up the trailer with the radar and equipment, faces it north and sets up the acoustic system to track the bats. Now that the weather is colder, Nagal’s field work is coming to an end and she will begin analyzing the data she collected.
Nagal also does mobile acoustics, where she drives every road in a project area, stopping every kilometre to record, listening for bats, she said. The goal of the mobile acoustic system is to see if she can pick up any species that are not found in the set radar positions.
If there are any known caves in an area, Nagal gets to go visit them. “That’s the fun part because we actually get to handle (the bats),” she said.
The danger to bats from wind turbines is different than for birds. To be killed, birds actually have to be hit by the blade of the turbine, while bats do not, Nagal said. Some are hit by the blade, but because bats’ lungs are highly pressurized in order to perform echo-location, they implode when they fly close enough to the blades of the turbine, Nagal said. “They just have to fly through something that’s invisible to them and they’ll die,” she said.
It is important to know the impact of windmills because bats are extremely important ecologically, Nagal said. “They eat huge numbers of crop pests every year, moths and beetles especially,” she said. Without bats crops would require a lot more pesticides, she added.
Nagal said she thinks windmills are great if they are placed in good locations. “The best thing is that if there are any windmills in your area, ask the company if they’ve thought of this,” she said. Some companies will use acoustics to determine the number of bat activity, but that doesn’t show how many bats are in that area exactly, Nagal said. “It could only be five bats that happened to be feeding in that spot all night long,” she said.
“With radar you know a wider area than just acoustics,” she said. Through radar technology they are able to determine where there are high concentrations of bats and recommend placing the turbines in locations away from those areas.
“If we understand what the animal needs in the environment then we can help the company mitigate for that risk,” said Millikin.
Nagal is hopeful that these efforts will help decrease the rate of bat mortality due to wind farms. “The forest would be a sadder place without bats,” Nagal said.