Bird-friendly glass windows are critical to the well-being of birds, especially if they are situated in their migratory path. This article focuses on why it’s important to consider the birds when designing buildings and what to do about it.

A few weeks ago, I was sitting on a panel at an integrated design charette in Ottawa, given by Enbridge Gas Distribution through their Savings By Design program. Sustainable Buildings Canada organizes the sessions and provides the expertise. We work as a team to help developers understand how to make their buildings at least 25% more energy efficient than the Ontario Building Code. In addition to that, we provide information on how to make buildings more sustainable in general. I am invited to talk about indoor air quality and construction and demolition waste management, while others are there to discuss other sustainability subjects.

Last week was the first time I was introduced to  Safe Wings Ottawa, an organization whose mission is to educate the public and prevent bird-building collisions. It was an eye-opening presentation for me, and I am now a convert. In fact, since then, I have been evaluating buildings on whether or not they are bird-friendly.  Anouk Hoedeman from Safe Wings gave a straightforward and enlightening presentation on birds and buildings.

Bird killed by collision with window

To begin with, in the anti-wind turbine group, there are many naysayers who contend that wind turbines are bad for the birds. And while they’re not wrong, wind turbines cause about 600,000 bird deaths per year in North America. However, buildings cause approximately one billion bird deaths (Note that Anouk also commented that cats are estimated to cause 1.4 billion bird deaths, however, the caveat is that many of those birds counted may have already hit a building and were already dead or at least vulnerable).

Birds are nice, but why is it such a big deal?

You might be wondering, aside from the tragedy of that many deaths caused by buildings, why it’s a problem we should be concerned about given all the other issues we have in the world right now. Well, as it turns out, birds play a significant part of any ecosystem. A few of the key benefits they bring to any area are:

  • They are predators of insects and help keep populations in check,
  • They spread seeds and pollinate plants.

Anouk told us about a documentary called The Messenger (check the website for screenings dates and times) that gives an excellent and disturbing example of what happens when bird populations decline. In China in the 1950s, sparrows were a nuisance for farmers so the government decided to help by having the citizens destroy the sparrow population. Eventually, their tactics succeeded and the sparrows disappeared. The following year there was a mass invasion of locusts destroying crops and killing millions of people through starvation.

The bottom line: Birds are important!

What does an unsafe bird building look like?

Transparent passageway linking buildings

Buildings that are considered “bird unfriendly” have a few different characteristics, but all involve windows. Any sort of glass passageway  where the bird can see right through to the other side is dangerous to a bird. They cannot distinguish glass from no glass and will crash head first into it.

Kanata Research Park - reflecting trees in mirrored glass
Kanata Research Park – reflecting trees in mirrored glass

Buildings that reflect trees, shrubs and plants are dangerous to birds because they see them as real.

Indoor plants next to windows
Indoor plants next to windows

Plants on the inside of buildings next to the window are dangerous because the bird won’t see the glass and think they can land on them.

Glass balconies are dangerous as well; birds don’t see the glass.

Glass buildings next to glass buildings, beside glass buildings, all reflecting each other can confuse birds. They can fly around between those buildings and never find a way out and die of exhaustion.

More than 70% of birds that hit a building die on impact, and  of those that get up and fly away, there is only a 50% chance of survival.

Bird-friendly glass and other solutions

Fortunately, there are solutions to helping birds avoid crashing into buildings.

The safest and most effective solution is to address the issue in the design phase of the building. There are several cities that have now developed bird-safe guidelines to help make buildings safer for birds. Safe Wings’ website has links to those guidelines for Toronto, Vancouver, Chicago, San Francisco and more. There are many sorts of glass that are made to be bird friendly.

If you understand what the issues might be, if, for example, you are designing a buildings that will be next to a park, or next to other glass buildings, there will likely be a bird problem. There are several Canadian and American companies that make bird-friendly glass. Anouk mentioned that the glass need only be incorporated up to about 16 meters, or, the height of most trees, to prevent the majority of collisions.

Window Film by Feather Friendly bird safe glass:
Window Film by Feather Friendly bird safe glass:

 Window film: In the event that the building is already built and is a problem for birds, there are a variety of window films available that can be applied to the outside of windows (more effective than from the inside).

Acopian Bird Savers
Acopian Bird Savers

Cord: parachute cord is another treatment that can help birds avoid buildings, such as that made by Acopian.

The right bird-friendly glass is one of the best ways to reduce the number of collisions.

What doesn’t work:

Bird sillouette decals
Bird silhouette decals are not effective at preventing bird collisions

Falcon and other bird decals (that is an indication that the building has a bird problem)

  • Fake owls
  • Highlighters and bingo daubers (good for drawing grid patterns but will wash off in the rain)
  •  Residential bird fatalities:

    Surprisingly (at least to me), detached homes cause up to 44% of all bird-building collisions. If you have a bird collision problem, visit Safe Wings Ottawa’s website for tips on how to help birds avoid your windows.

    For more information on preventing birds from crashing into buildings, visit Safe Wings Ottawa.

    Many thanks to Safe Wings Ottawa for providing the photos for this post.

    BEC Green

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