Alberta’s bat population facing decline due to human activity and spread of disease

·3 min read

While bats don’t have the best reputation, they are absolutely vital to keeping insect populations in check. While some feed on fruit, all bats that live in Canada feed on insects. One small brown bat can consume as much as four to eight grams of insects in a single night during summer.

Unfortunately, there are two significant threats to bat populations in Alberta – wind farms and White Nose Syndrome.

There have been many studies on worldwide mortalities of bats due to wind farms. A study published by Nature in 2021 ( states that environmental impact assessments are poor predictors of actual fatality rates, and minimizing blade rotation at periods of high collision risk is likely the best method of mitigation.

WNS is a fungal disease that has caused 90% loss in bat populations across the U.S. and Canada. Most devastating in the winter months, WNS causes a white fungal growth around the muzzle of affected bats. It also causes them to wake during hibernation, which increases their activity and can lead to starvations and dehydration.

A Beyond Pesticides ( daily news blog for May 18, 2022, discusses the economic impact to farmers from declining bat populations. Without bats to naturally keep insect populations in check, crop yields decrease and input costs rise, a ripple effect that continues down the line to consumers.

From there, the ripple effect continues as farmers need to use more pesticides that further harm bats along with other species that provide ecosystem services.

The blog states, “As declines in bird and bat populations continue to occur, it is becoming increasingly clear that just like the loss of pollinators, ecosystem services provided by bats cannot be adequately replaced by human activities.”

First discovered in the mid-2000s in New York, WNS was brought into North America by humans, likely on the gear of hikers and spelunkers. The disease has been spreading since then and was found in Alberta last year.

Agrologist Paul Muyres is concerned about the effects to agriculture with WNS now arriving in Alberta. He believes more education is needed, on the importance of bats, the reasons for a decline in their population and what the average person can do about it. One important fact is bats are protected and it is illegal to kill them.

“In terms of pest control,” stated Muyres, “the little brown bat, especially in southern Alberta, could help control things like wheat midge and diamond backed moths. Those are detrimental pests in the agricultural world and they can have severe economic impacts.”

Providing good summer habitat is essential to help bats rear their pups and provide them with insects to eat. Old deadfall and wooded areas need to be conserved, explained Muyres. While bat houses help, studies suggest natural habitat is more beneficial. A bat-friendly farming fact sheet, along with other information about bats in Alberta and the threats against them, can be found at

SAMANTHA JOHNSON, Local Journalism Initiative Reporter, Medicine Hat News