Window Collisions: A Major Threat to Wild Bird Populations

This information was obtained from a CBC News Article posted on May 26, 2026 by Aastha Shetty.

Warning: This post contains information that some readers may find distressing.

A new project in Kitchener, Ontario, called Bird Friendly Kitchener is monitoring birds that die after window collisions in urban centres. The leader of the group, Meredith Blunt, has been monitoring the number of window collision bird deaths since August 2025, and since then, she has collected 234 birds in Kitchener alone. The project was inspired by the organization FLAP Canada, based in the Toronto region, that collects data on the number of birds who have died after hitting windows across Canada. According to FLAP's data, over 3,200 birds have died from window collisions since the beginning of 2026.

Patricia Seaton Homonylo won 2024's Bird Photographer of the Year for this photo of 4,000 dead birds, all killed by colliding with glass in Toronto.

What can you do to help?

Blunt says that single-family homes with more than two stories are the most harmful for birds. The best thing to do is break up the reflections of their windows through the use of anti-collision stickers. The stickers are decals specifically made to prevent birds fro crashing into the window.

FLAP Canada outlines some guidelines for bird-safe window markers:

1. Glass Surface

   • Markers must be on the exterior (outer) surface of the window

2. Density of Marker Pattern

   • There must be no more than 50 mm between markers

3. Marker Coverage

   • The marker patterns must cover the entire surface of the window

4. Marker Contrast

   • Markers must be high contrast to the window surface under varying daylight conditions (sun, overcast, shading, etc.)

5. Size of Marker

   • Visual markers must be at least 4 mm in diameter for individual elements or at least 2 mm wide by 8 mm long for linear elements

Check out some examples of window decals below!