How polkadot windows now protect birds at Pinery Provincial Park

Staff at Pinery Provincial Park, on the shores of Lake Huron, are applying thousands of tiny vinyl squares on the windows of the park's visitor centre in hopes that it will reduce bird strikes — which kill 25 million birds annually.

Window strikes second only to cats for bird kills

The vinyl squares are spaced no more than 5 cm (two inches) apart — the 'magic number' according to Pinery Provincial Park's Tanya Berkers. Berkers and staff, including Alistair MacKenzie, have been meticulously applying the dots on the park's visitor centre windows to prevent bird strikes. (Jackie Sharkey/CBC)

Thousands of tiny dots are being meticulously applied to the windows of the visitor's centre at Pinery Provincial Park.

The building, just 800 meters from Lake Huron, is nestled among the trees in a natural area that's home to 319 different bird species. Hardly a week goes by without a bird mistaking the reflections in the window glass for open skies, says Tanya Berkers, resource management group leader at Pinery Provincial Park.

"A number of the birds, they'd be stunned and would fly away afterwards," said Berkers. "As for bird deaths? Probably during the peak seasons — two or three a week. Since we've put up these dots, even though we haven't done it on all of the windows yet, the incidence has gone way down."

"There's been maybe one or two for the entire season."

Window strikes are a leading cause of death for birds. According to research done by Environment Canada, 25 million birds are killed every year from colliding with houses or buildings. Only domestic and feral cats are more dangerous to wild birds, killing 200 million birds annually.

"A lot of people are worried about windmills and impacts like that but research shows that windmills have a relatively small impact — the biggest is cats and second is windows,"  said Berkers.

Plants, windows at home

Bird population health is top of mind after a report published in Science showed North America lost three billion birds since 1970 — across all species, not just endangered ones.

It cost Pinery Provincial Park about $800 to outfit its visitor centre windows — a home treatment would cost much less, said Berkers, and it's not the only way to support bird populations.

"I think the biggest thing people can do is to plant native species — plants and trees — around thier yard," suggested Alistair MacKenzie the park's resource management and discovery supervisor.

MacKenzie, who has been a birder since age six, said native plants not only revitalize vanishing bird habitats but are a food source as well.

"When we think of a bird like the black capped chickadee, when a pair of them are raising their young they need high-protein, high-fat food to feed their babies and that usually comes in the form of caterpillars. Caterpillars feed on plants."

"So when we plant non-native species in our environment, it's essentially like putting styrofoam out there."

An unreliable food supply, said MacKenzie, can have a ripple-down impact and affect reproduction rates.

Ontario Parks says the area surrounding Pinery Provincial Park is home to 319 bird species and is a popular spot for birders. (Jackie Sharkey/CBC)

People can also use blinds or curtains to darken windows at night — birds are drawn to the light.

The trick to applying window treatments, like the ones at the park visitor centre, is to space the pattern no more than 5 cm (two inches) apart.

"Two inches is kind of the magic number. Whenever there's more space than that between the visible portion, then many species of bird think they can fly through it," said Berkers.

And, she said, the pattern doesn't need to be vinyl dots; lines or stripes work equally well, as do window paints and white-out pens.


Jackie Sharkey


Jackie Sharkey is currently a multimedia journalist with CBC News in P.E.I. She has spent the last decade working as a producer and guest host in Kitchener, Ont. and helped launch the station when it was created in 2013. She has also worked for CBC in Kelowna, B.C., Quebec City and Rankin Inlet, Nunavut.