Homeowners have big windows that bring light, views and the outdoors into their homes or recreational properties. But all that glass can be a killer. Every year, millions of birds die when they fly into glass.

Commercial buildings were once thought to be the biggest culprit, with confused birds flying into windows at night. That still accounts for large numbers of bird deaths, but more recent research shows that one and two-storey homes and cottages are to blame for the majority of bird strikes. Most of those strikes happen during daylight hours.

"Most people have experienced the heartbreaking thud of a bird hitting a window. Environment Canada biologists have concluded that collisions with windows on small buildings are a leading cause of bird deaths, taking millions of lives every year," says a FLAP (Fatal Light Awareness Program) brochure. "Windows deceive birds: reflected trees or sky, a tempting potted plant seen through glass or a view straight through the building or glass balcony railing can trick birds into thinking they can sail right through to the other side."

FLAP Canada is a registered Canadian charity that safeguards migratory birds in the built environment through policy development, research, education, prevention, rescue and rehabilitation. It partners with governments, businesses and communities to promote bird-safe practices.

One of the most dangerous residential designs, whether in a new or renovated home, is the "through and through," where you can look in one window and see through the house and out a window on the other side, says Paloma Plant, program co-ordinator of FLAP Canada.

Along with large windows used to provide lake views at cottages, the popularity of transparent balcony railings has also proven to be deadly. In cottage country, along with tiny humming birds, larger birds are falling victim. Pileated woodpeckers and grouse can break windows when they hit, she says.

To see for yourself just how reflective the glass on your house is, Plant says to go out six or seven times in a day, on the hour, and take a picture of the window to see what different environments are reflected as the sun moves.

There are simple steps homeowners can take to make their homes safer for birds. "Create visual noise," says Plant, by using decals and dots on the exterior glass surfaces to make it more visible to birds. You can hang ribbons or strings outside the window, draw patterns on your windows with a bar of soap, install externally mounted window screens or apply a special film on the outside of your windows.

Putting visual markers on the exterior of the glass is more effective than pulling down blinds or closing curtains but they have to be installed correctly. Many people put up hawk silhouettes, but they don't work well. Plant says they tend to be placed at the top left or top right of a big window. "Birds aren't stupid. They know it's not a real hawk, she says. Birds may avoid the immediate area where the silhouette is because they see something is there, but the rest of the window is still exposed.

Residential tape or dots placed on the outside surface of windows is more effective. Spacing dots in 2x2-inch or 2x4 inch patterns is enough of a visual cue, Plant says, adding that from inside the dots aren't noticeable.

Pick a contrasting colour, for example white dots on a window shaded by overhangs.

Being bird friendly may even be an excuse to get out of a household chore. "We had a call from a woman who had lived in her home for 30 years and had feeders but no bird strikes. Then birds started to continuously hit the window. We asked, what changed? Did you get a new feeder? A new landscape? She said no. She thought about it for two days before she realized she had had her windows professionally cleaned for the first time," Plant says.

During mating season, aggressive male robins and jays tend to bump against the window, thinking their own reflection is another bird.

Applying soap to the windows will help. On the bright side, when it rains you'll have clean windows, but the downside is that you'll have to reapply, she says.

An exterior mounted bird screen is another option. If birds do hit it, they'll bounce off like a trampoline. Plant does not recommend the use of netting, which can become loose and entangle birds. "It may do more harm," she says.

Winter is also a bad time for bird strikes, as more people put bird feeders in their yards. Position bird feeders less than 1.5 feet from your windows, or more than 30 feet away, to prevent birds from flying into bird feeder reflections. Having the feeder more than 30 feet away reduces the chance of a feeder being reflected in the window and having it closer than 1.5 feet away means birds have already started to slow down and if they do hit the window may not be as badly injured, Plant says. "They're already applying the brakes so hopefully the strike will not be as lethal."

If you find an injured bird, FLAP says to place the bird gently inside an unwaxed paper bag or cardboard box firmly secured. Place the bag or box in a quiet location away from people and pets. Do not give the bird food or water. Contact your local wildlife rehabilitator for further instructions.

FLAP has a reporting bird/window collisions program where the public can record an incident of a bird injured or killed in a window collision. FLAP Mapper, a citizen-science global mapping database, is Here.

Here is a link to FLAP's website for collision prevention strategies for both residential and commercial buildings: http://www.flap.org/bird-safe- buildings.php.

For more information about how you can help the birds, visit www.flap.org.