Migrating birds are struggling with the expansion of mass development in built, urban environments. Besides the loss of critical habitat to nest and rest, they face death and injury due to collisions with buildings. This happens at night, caused by disorienting light pollution from skyscrapers, especially during spring and fall migration. Bird-building collisions also occur during the day as birds have no natural sense to perceive highly reflective and transparent glass so adored by architects as a solid object. Birds will strike clear glass while attempting to reach habitat and sky seen through corridors.

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?

Workplace windows are everywhere: on walkways, entranceways, skyways, skyscrapers, atriums, and even transit stations and bus shelters. Below are applications of visual markers and other bird-friendly glass innovations known by FLAP Canada to be effective.

Window Markers

Make all windows visible to birds. Provide birds with visual cues or markers alerting them to the presence of glass. Below are the FLAP Canada standards for visual markers:

    Separate visual markers by spaces 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, windows should not have reflective openings larger than 5 x 5 cm (2 x 2 inches).
    Apply visual markers to exterior surface (first surface) of glass to disrupt the illusion of a safe, natural environment reflected in the glass.
    Make markers stand out in contrast to transparent or reflective exterior surfaces under varying daylight conditions.
    The dimension of a marker is be no less than .64 cm (1/4 inch).
    Markers are to cover entire exterior glass surfaces up to 20 metres above grade or to the top of the mature tree canopy, whichever is greater.

To learn more, visit flap.org/commercial.

About Marker Spacing

FLAP Canada’s research into designing bird deterrent marker patterns determined that markers spaced evenly apart both vertically and horizontally tend to be less noticeable to the human eye. In an effort to ensure that marker spacing meets what research confirms as the maximum horizontal spacing of 5cm (2″), FLAP reduced the 10cm (4″) vertical gap to match 5cm. In doing so, FLAP Canada believes the markers to be more effective as a deterrent for smaller species like the golden-crowned kinglet, ruby-throated hummingbird and the brown creeper…some of the most frequently encountered species known to collide with windows during the day.

Photo credit: © Walker Textures

Acid-Etched Glass

Patterns etched on outside surface of glass offer optimal viewing areas and attractive bird-safe designs meeting 5 cm (2 inches horizontal) x 10 cm (4 inches vertical) expert rule.

Walker Textures® AviProtek® Bird Friendly Acid-etched Glass

Acid-Etched Glass

Photo credit: © Goldray Glass

First Surface Ceramic Frit

First Surface Ceramic Frit can be applied to glass for a cost-effective, low-maintenance solution to design needs; available in many standard or patterns and colours.

Goldray Glass

First Surface Ceramic Frit

Photo credit: © ORNILUX

UV Glass

Most birds can see ultraviolet (UV) light, a part of the spectrum of natural sunlight that humans cannot see. Some glass fabricators offer UV patterned glass as a bird deterrent. To ensure efficacy of this technology be sure these patterns reflect 20-40% over the 300-400 nm wavelength and that the UV coating be applied to the first surface of glass.

UV Glass

Photo credit: © Viracon


While further testing is necessary to review various silk-screen patterns, coatings and colours—with low, medium and high levels of reflectivity—silk-screen patterns can be an effective way to reduce bird collisions with glass in building design.
Viracon ®


Photo credit: © Feather Friendly®

Window Film

Feather Friendly is an easy-to-use and unobtrusive external vinyl window application that is barely noticeable to humans but highly effective in allowing birds to ‘see’ the windows, allowing them to avoid deadly collisions with windows typically on lower 3-5 floors.
Feather Friendly® Commercial, The Convenience Group

Window Film

Photo credit: © Bendheim

Channel Glass

Channel glass is a modular, U-shaped, machine rolled architectural glass from up to 60 per cent recycled material. Its opaque appearance, combined with low-emissivity coatings, makes for an effective bird deterrent solution.

Channel Glass

Netting, Screens, Grilles, Shutters, Exterior Shades

Netting, screens, grilles, shutters and exterior shades are common elements that can make glass safe for birds on buildings; whether in retrofit or integrated into an original design.

Netting, Screens, Grilles, Shutters, Exterior Shades

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.

6 Best Practices for Bird-Safe Buildings

  1. Request a BirdSafe® building risk assessment from trained FLAP Canada consultants to determine threat levels and priority solutions.
  2. Apply visual markers such as frit, film or acid-etched patterns or other bird-friendly glass innovations.
  3. Reduce intensity and direction of night lighting, or turn off lights at night.
  4. Treat interiors with time-automated blinds, and keep plants away from windows.
  5. Involve tenants, staff or security in monitoring and reporting efforts during migration.
  6. Be bird-safe ready. Sign up for spring and fall migration alerts from FLAP Canada to help prepare your facilities or staff.

Commercial Resources

Bird-Friendly Practices - Toronto

Bird-Friendly Practices

Bird Friendly Guidelines - Markham

Bird Friendly Guidelines

Bird-Friendly Landscape Design Guidelines - Vancouver

Bird-Friendly Landscape Design Guidelines – Vancouver