Most people have experienced the heartbreaking thud of a bird hitting a window. Or maybe we’ve observed a territorial bird pecking at its reflection in glass or a mirror.

Why does this happen?  Unfortunately, birds have no concept of glass. They may see their reflection and fight with the image they see.  Or, reflected trees and sky, a tempting potted plant seen through glass, or a view straight through the building or glass balcony railing can trick birds into thinking that they can sail through to the other side. Birds that do not die on impact can go into shock, become easy prey for predators such as cats.

Canadian research¹ estimates 25 million birds fatally collide with windows at low, mid and high-rise buildings annually.

¹Quantifying Human-related Mortality of Birds in Canada, September 2013

What can you do to help keep birds safe?

Windows are everywhere: in our houses, cottages, condos, apartments and even balconies.

For spring and fall migrating birds, glass can be deadly.

Guidelines for Window Visual Markers and Bird Feeder Placement

Markers were applied using a oil-based window Sharpie and a cardboard stencil of a maple leaf.

To effectively reduce bird collisions with your windows, you will need to make your glass look like a barrier for birds to avoid by using visual markers. A visual marker is a pattern of any shape that is applied to or hung in front of your window. Be creative, treat your windows like a canvas. Please follow these 5 guidelines when applying markers:

    Separate markers by spaces no more than 5 x 5 cm (2 X 2 inches).
    Apply markers to the exterior surface of glass.
    Make sure the markers stand out in contrast to the transparent or reflective glass surface under varying daylight conditions.
  • SIZE
    A marker should be no less than 6 mm (1/4 inch) in diameter.
    Cover the entire glass surface.
    When applying UV treatments, ensure these patterns reflect 20-40% over the 300-400 nanometer wavelength.
    Place bird feeders less than 3 ft (1 metre) away from windows.

Thank you for protecting birds in your neighbourhood! Please share your creations with us at

Download the Guidelines for Bird-Safe Window Visual Markers

Helpful Visual Guide

Use this visual as a guide. Place over various areas of your treated window. If no markers can be seen, the spacing is too big.

Window Treatment 2x2 cutout

D-I-Y Bird-Safe Design

Uniformly cover the outside of windows with a contrasting pattern of any shape, keeping these visual markers no more than 10 cm (4 inches) apart vertically or 5 cm (2 inches) horizontally. To help make your marker pattern less visible to people, while perhaps helping to keep smaller birds safe, such as hummingbirds and kinglets, a window must have no reflective openings larger than 5 x 5 cm (2 x 2 inches).

D-I-Y Bird-Safe Design

Photo credit: © Screenscapes

Window Shades

There are a variety of exterior shades to choose from including patterned ones made of mesh mounted on the outside of your window with strong hold suction-cups that allows you to to have a clear view out and total daytime privacy.

Window Shades

Bird feeders / Bird baths

Position your bird feeders and bird baths half a metre (1.5 feet) or less from your windows. Over this short distance, birds cannot build up enough momentum to injure themselves should they hit your window. The closer the feeder to your window, the better for the birds and your viewing.

Bird feeders / Bird baths

Photo credit: © Dr. Ellen K. Rudolph

Bird / Window Screen

Install externally mounted window screens using window mounts or suction cups.
The Bird Screen Company

Bird / Window Screen

Prefabricated Decals


Prefabricated decals can be used as bird deterrents, however, to be effective, any decal must be spaced as described in our handy visual guide.

Prefabricated Decals

Photo credit: © Acopian BirdSavers

Window Curtain

Hang ribbons or strings on the outside of your windows 10 cm (4 inches) apart.
Acopian BirdSavers

Window Curtain

Photo credit: © Feather Friendly®

Window Pattern

Apply effective patterns on the outside of your windows.
Feather Friendly® residential tape

Window Patterns

Photo credit: © CollidEscape™

Window Film

Perforated window film provides some of the best results for reducing collisions. From the outside this film looks opaque and dramatically reduces window reflection and transparency. From the inside, this film looks like a window screen. This preserves your view and the flow of natural light into your home.

Window Film

Photo credit: © ABC Bird Tape

Window Tape

Use tape to create patterns. Any opaque tape can work, but translucent ABC Bird Tape transmits light and is made to last outdoors.
ABC Bird Tape

Window Tape

Note: BirdSafe and FLAP Canada do not endorse or recommend any commercial glass product or manufacturer, therefore, mention of commercial products on this website cannot be construed as an endorsement or recommendation. BirdSafe recommends consultation with glass manufacturer representatives for answers to your specific questions on price, quality, etc. or to request a quote for any window treatment.

Disclaimer: Results may vary depending on conditions such as landscaping, topography, building design, lighting, local bird populations and the condition of the product itself. No window solution can guarantee elimination of bird-window collisions. Reference Terms of Use.

Additional Ways to Keep Birds Safe

  1. Think bird safe with birdfeeders and birdbaths
    To help prevent injury or risk of collision, place birdfeeders and/or birdbaths less than a half metre (< 1.5’) or closer from your windows. Over this short distance, birds cannot build up enough momentum to injure themselves should they hit a window. The closer to your window, the better it is for the birds and your viewing.
  2. Place houseplants away from windows
    Interior houseplants attract birds and may deceive a bird into flying into the plants. Instead, it flies into the glass. Move houseplants away from windows, and install blinds to be drawn during the day with slats turned open.
  3. Plant Native Plants
    Plant native trees, shrubs and flowering plants in your yard to provide food, shelter and nesting areas for birds. Visit the North American Native Plant Society ( for tips.
  4. Leave window screens in front of windows
    Exterior screens in front of windows help reduce the risk of birds colliding with windows by muting the reflective qualities of glass. This is only effective for those windows with screens. All uncovered glass remains a threat.
  5. Refrain from cleaning your windows
    Bird collisions increase dramatically when windows are sparkly clean. Even minute dust particles on windows help reduce the reflective qualities of glass.
  6. When you find an injured bird
    Should a bird hit your window, gently place it inside an unwaxed paper bag or cardboard box firmly secured. Place it 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, or visit for more information.
  7. When you find a baby bird
    Visit for more information.
  8. Be a Community Scientist
    Grim, we know. But if you should find a bird injured or dead by a window collision, you can contribute to bird behaviour and species research by reporting the incident on our mapper, a global mapping database. As we collect data, eventually, we’ll be able to determine where there is a concentration of collisions (a “hot zone”) and what makes a building, corner or intersection particularly deadly.