A woman who runs a wildlife rehabilitation centre in Powell River, B.C., says concussions are very common among local birds, even woodpeckers who are known for their brain-rattling high-speed pecking.
Merrilee Prior, president of the Powell River Orphaned Wildlife Society or PROWLS, says she recently had to rehabilitate a young pileated woodpecker.
The culprit? A window.
"This pileated [woodpecker] was a fledgling, it was a very young bird ... and it smoked into the window and just lay on the deck for almost 20 minutes," Prior said.
Birds show similar symptoms as humans when they get a concussion.
"They're stunned. They droop. They've clearly got a headache. If it's a bad one, there are coordination issues and they just want to be in a dark place," she said. "It's one of the biggest factors in birds coming in for rehabilitation."
Prior says she's seen all sorts of birds that have flown into windows, including hummingbirds, owls, hawks, and even a Canada goose. Many of them end up dying.
Researchers have estimated up to one billion birds die from window collisions every year in North America.
"They just don't understand glass," she said.
Many businesses and individuals have sought solutions to preventing birds from colliding into windows by installing screens and shades, pulling down indoor blinds, or applying stickers.
Prior, who has run PROWLS out of her home since 2010, says an easy cheap solution is to coat the outside of your window in warm soapy water and let it dry.
"People on the inside will barely notice it but the birds on the outside see a solid surface," she said.
And if a bird does end up hitting your window, Prior says there are a few steps to take.
"You should pick it up. You should put it in a dark box with a lid because birds do fly and call a local rehabilitation facility. They will have the medications and the knowledge just to feed it and give it some time."