WWF-Canada Blog:
Species


Collision Course

Across Canada, young birds are leaving forests, wetlands and shorelines for warmer climes.  The summer flush of insects is waning and shortening day-length sparks a trip southward for many birds.   On their way to the southern U.S., Mexico, the Caribbean or Central and South America, migrating birds often follow rivers and lakeshores, right where we humans have built skyscrapers and other buildings clothed in glass.  Often beautiful to our eye, glass lit at night or shiny by day is invisible to birds – invisible, and therefore, deadly.

Philadelphia Vireos are one of over 100 bird species known to collide with windows. (c) Tim Stewart / WWF-Canada

In 1996, WWF-Canada and FLAP (the Fatal Light Awareness Program) published Collision Course: The Hazards of Lighted Structures and Windows to Migrating Birds.  This was the first investigation across Canada by an ornithologist of the threat of bird collisions.  The report estimated that some 100 million birds collide with windows and buildings across North America each year, a number on the same order as estimates for bird mortality from each of pesticide use and cats ( both outdoor pets and those gone feral).

In Toronto, where FLAP has documented bird collisions and rescued injured birds for two decades, over 100 species of birds have been found.  Sparrows and warblers comprise 75% of those found, with White-throated Sparrows and Ovenbirds topping the list.  On some particularly foggy nights, where birds are low and confused during migration, hundreds may be found in a small commercial building district.

In principle, the solutions are easy:  turn off unnecessary lighting at night and make windows visible to birds by day.  In practice, these goals are difficult, but there is considerable hope and progress.

WWF and FLAP launched the Bird-Friendly Building Program in the late 90s, which saw over 100 commercial towers in Toronto commit to increasing awareness about bird collisions and reducing night-lighting in and around their buildings.  FLAP still promotes this today through a great website.  As participation grew and FLAP engaged other bird conservation groups in the issue, the City of Toronto co-ordinated the Lights Out Toronto! campaign, leading to adoption of Bird-friendly Development Guidelines for the municipality in 2007.

You can help by taking action at your home, office, school, cottage or cabin – wherever you have windows!

1. Turn off, lower the brightness or direct downward and away from windows any lights you can – this is probably wasted lighting and energy anyway.  Remember, if it’s in your eyes, you won’t see much better for the glare and it’s likely threatening birds.

2. While reflections occur on the outside of glass, it can help somewhat to close blinds on the inside.  I  set venetians to ½ or ¾ closed, helping to break up reflections on the outside and reduce collisions.

3. Urge your office building manager and management company to adopt Bird-friendly Building habits.  It’s an easy, positive step that saves money, reduces energy use, slows climate change and reduces bird collisions – something tenants, owners, employees and managers can all agree on and work toward, especially in spring and fall, but why not year-round?!

4. Visit FLAP – the Fatal Light Awareness Program – their excellent website www.flap.org is full of information, tips and techniques.

Enjoy fall migration, as sparrows, warblers, swallows, wrens and all migrating birds move through the backyards, ravines, city parks and rural regions all across Canada.  And please do your part to ease their journey by safeguarding them from windows and buildings in your home and work life.


  • Jessica Wuest

    Thank you Steven, is is an important topic as it is one of the top predators to migratory birds. I am a graduate student studying bird collisions with office tower buildings in the downtown core of Calgary, Alberta and am very interested in chatting with anyone who has knowledge to share in this area!

  • Sara Falconer

    Thanks, Steven. And what a beautiful photo!