Night Moves: Following The Flight Of Ontario’s Bats

Wingspan. Nocturnal. Echolocation. These words sound more like superhero slang than bat-related biology terminology. Why then, have we given bats such a bad rep? If we can appreciate their aerial mosquito-gobbling moves above the dock at night, then why are bats met with horror-movie screams when we find one indoors? The world’s only flying mammal, a bat is an unlikely hero and a creature whose existence is under threat.


Bats are aerial acrobats who control pests and pollinate plants worldwide. Above: big brown bat. COURTESY MICHIGAN DNR

words: Carmen Kuntz

Having a bat in your cottage may be a minor inconvenience, but having them around your home or cottage is a good thing. As primary predators of night-flying insects, some claim they help control pest populations. But do bats have to provide us a service to be valued?

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“Humans are prone to thinking something is only important if it does something for us,” says Dr. Brock Fenton, specialist in the behavior and ecology of bats and Biology professor at Western University, Ontario. “Wildlife is important even if it’s not directly serving us.”

Using their highly accurate echolocation bats can eat their body weight in bugs in one night, but insect populations are so large and reproduce so quickly, bats barely make a dent. “There is no evidence that predators can influence the insect populations. It’s wishful thinking,” says Fenton. There is undoubtedly a relationship between bats and insects, but it’s not going to affect your evening bonfire. And that’s OK. Bats are also biodiversity indicator species, meaning their sensitivity to the environment—especially to changes in land use, like development and habitat fragmentation— provides important info about the greater health of an ecosystem.

Bats are fighting more than just stereotypes. Populations across North America, including Ontario, are in decline due to the rapid spread of a fungus called Pseudogymnoascus destructans, commonly known as white-nose syndrome (WNS). Hibernating bats contract and spread WNS while waiting out the winter in dark, moist areas. The fungus is not visible to the naked eye and occurs mostly on the nose and other hairless parts of a bat’s body including wings where it digests their wing membrane.

“Humans are prone to thinking something is only important if it does something for us … Wildlife is important even if it’s not directly serving us.”

“What we know from eastern Canada is that where there used to be thousands of little brown bats hibernating in caves and mines, there is now more than a 90 percent decline,” says Fenton.

Not all the news is bad, Fenton adds. “Animals are adaptive. When given the chance, they try to adjust.”

Research shows some bats are adapting by putting on more weight before hibernation. Chubbier bats are better able to deal with the energy zap that comes from fighting WNS. However, “bats are in the slow lane when it comes to reproduction,” Fenton continues, explaining that bats only have one offspring a year but have long life-spans.

“The Ontario record is over 30 years in the wild,” he says.  “When you live that long and you reproduce that slowly, you learn the landscape very well. That makes them very vulnerable. For instance, if someone calls an exterminator because they have bats in their attic, they could be killing 30-40-year-old bats and eliminating a longtime breeding area.”

Big brown and little brown bats have been hit hardest by WNS, but four of Ontario’s eight native bat species are now endangered because of wind turbines and human persecution. According to Fenton, if turbines were reduced by just 10 metres per second, the number of bat causalities would be reduced by 90 percent.

“We need to look at the big picture,” Fenton adds. “These incredible little animals are up against a tough fight.” Bats may not be cute or cuddly, but they are crucial to our ecosystems, from pollination to pest control. So open the window and let the little nocturnal acrobat back outside where it can do its work. Take pleasure watching these night hunters from your deck and appreciate them as a sign you are in a healthy ecosystem, bugs and all. Ask not what bats can do for you—ask what you can do for bats.

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