Navigating downtown Calgary by car or on foot can be tricky. But for migratory birds, the lights and towers aren't just confusing — they can be deadly.

Volunteers with the Calgary Migratory Species Response Team are studying the impact of buildings in the downtown core on migrating species of birds and bats.

"It's estimated about 25 million birds a year die hitting buildings in Canada," said Dr. Scott Lovell, assistant professor of biology at St. Mary's University. "We have about 500 million birds that breed here in Canada … it seems like a small number compared to that but these are birds dying simply due to structures we have put up."

These birds all died due to striking buildings in Calgary's downtown core. A group of researchers is studying how buildings affect migratory species. (Helen Pike/CBC)

"I want to work with these buildings to try and reduce the number of strikes in Calgary," said Lovell. "What features of a building make it conducive to these strikes? Because some buildings had a very high number of strikes and some buildings had zero."

Lovell said migratory bird strike deaths haven't been studied in the city for decades, since a limited study was done in the late '90s. The city's downtown has changed a lot in the past 20 years, he said.

From Sept. 1 to Oct. 31, volunteers with the team scoured the downtown core just before dawn, at dawn and at night.

During those 157 shifts, they surveyed 1,297 buildings and found 107 animals that had struck buildings:

72 birds.

35 piles of feathers or other portions of deceased birds.

Five bats.

Nineteen of those found were alive and 88 were dead.

Living and injured animals were rescued and taken to Calgary Wildlife Rehabilitation Society (CWRS), while the deceased animals were collected and taken to St. Mary's University's biology department for further study.

Of the living animals delivered to CWRS, 94 per cent were successfully released back into the wild, according to society co-founder and animal care director Melanie Whalen.

Kathleen Johnson — another CWRS co-founder — said there's a variety of actions building owners can take to prevent bird strikes — even for small residential buildings.

"It could be related to turning lights down at a certain time, it may be something just on the glass that's not going to affect the appearance of the building but may help birds and bats to avoid collisions in the future … it'll be very much a case-by-case basis," she said.

The team plans to repeat their study during the spring migration period.