Staff at the Calgary Wildlife Rehabilitation Society have their hands full this December.
Among their tiny patients is a saw-whet owl that is recovering from a near-death experience. The bird suffered a severe head injury after slamming into a home in southeast Calgary in November. Saw-whet owls are one of the smallest owl species in North America.
“Every year, we see about 2,300 animals come through the facility. Many come from window strikes,” said Melanie Whalen, the director of animal care at CWRS.
She treats injured bats and birds that have collided with windows but there is nothing she can do for the dozens of dead birds brought to her.
Volunteers with the Calgary Migratory Species Response Team have been busy this fall collecting birds and bats that have flown into buildings.
“I think it’s very important because window strikes kill a significant number of birds and bats, so the more education we can bring to people… to be able to prevent window strikes from happening is positive,” said Whalen, who is also a co-founder of CMSRT.
CMSRT was co-founded by Kathleen Johnson this fall. A group of about 40 volunteers woke up at the crack of dawn every day for two months to scour the exteriors of downtown buildings, looking for evidence of animal strikes.
“I was sitting in my own living room and I had a bird strike my own window, and that’s the moment I knew we cannot blame and we cannot judge,” Johnson said.
“We all have this problem in our own homes. It gives us the basis to work together to improve things ourselves. Even homeowners can do things and businesses as well. We can all work together to help with the situation.”
A field study from the response team found 107 animal strikes during September and October 2019; 88 of those died but researchers believe that is just a portion of the total.
They also found significant variation in the types of birds that were dying. Migratory birds are hitting the buildings more frequently than resident birds.
“Migratory birds are probably fairly naïve when it comes to migrating through a downtown urban centre,” said Scott Lovell, assistant professor of biology at St. Mary’s University in Calgary and co-founder of CMSRT.
“Maybe those are the ones getting confused by light and striking the building whereas the residents are here year-round and just get used to moving around the city.”
There was also variation in buildings; some had dozens of hits while others had none. Researchers think the type of glass has something to do with it and the amount of foliage.
“Eighty per cent of the strikes are occurring where we have vegetation very close to the buildings, so the birds are sitting in the vegetation napping, feeding, and they get startled and hit the building,” Lovell said.
CMSRT volunteers say the program’s surveillance has paid off already. Out of the 17 live animals that were brought in to the CWRS, 16 have been released.
“I believe a lot of that success has to do with the quick response of volunteers getting to those animals and bringing them into rehab quickly,” Whalen said.
CMSRT is planning a spring count and getting more citizen scientists and building owners on board to help keep the winged creatures alive.
There are many things homeowners can do to prevent bird and bat deaths such as taping fishing line or old CDs to the inside of windows.
CWRS has volunteers that respond to wildlife rescue and pickups in the city and surrounding areas throughout the year.