How many birds are killed by collisions with windows? It’s hard to say exactly but it is conservatively estimated that one billion birds are killed by whacking window glass just in North America alone. That’s about 5% of the total number of birds (20 million) estimated to be alive in North America at the end of the breeding season in early fall, when bird populations are greatest.
Why birds fly into glass
After studying this problem for many years ornithologists have shown conclusively that birds simply don’t recognize window glass as a barrier. During the day birds fly straight into windows because they are confused by reflections of the sky, trees or other objects. Most of the birds that hit windows die of head trauma. This happens not only in our homes, but also in larger buildings like office towers.
And at night, especially during foggy or rainy weather, birds become confused by the bright lights left on in office towers and are apparently lured into deadly collisions by them. Sometimes hundreds are killed in one fell swoop as they circle and repeatedly batter the lit windows and/or the ornamental lights on top of buildings. This phenomenon occurs most often during spring and fall migrations.
What you can do
Nobody wants to kill birds, but windows are everywhere and more are being to the landscape every day. Besides, humans need windows for all kinds of reasons. Nevertheless, each of us can do our part and together we can make a big difference towards reducing the number of birds killed.
Here’s a compendium of tips to keep birds from hitting the windows in your home. While it might not be practical to “bird-proof” every window you’ve got, you might want to try some of these on your “problem” window(s):
* One of the best -- and least obtrusive -- things you can dow is cover the window with CollidEscape performated film to make the surface visible to birds while allowing you an unobstructed view outside. For more information see: view link
* Hang stuff closely spaced in front of the glass on the inside, like strips of tinsel, cloth ribbons, paper mobiles, netting or even feathers on strings.
* Put decals (simple dots and similar patterns seem to work best) on the outer glass surface. To be effective the decals need to be evenly spaced and close together (2-4 inches) across the majority of the window surface. This makes the window look like the deadly obstacle it is. Here’s a website that sells cute decals you might not mind using: view link The popular practice of putting just one or two stickers, like those falcon silhouettes, on a window has been proven to be pretty much useless.
* Frost or etch the glass using decorating-type techniques to make it opaque. You can likewise spray the glass with veggie oil or fake snow, or just let it get dirty. Products used by greenhouses to diffuse and soften the sunlight, as well as various plastic wraps, can also accomplish this.
* Buy special, see-through screens; these also make the window opaque.
* Sponge or stamp a consistent pattern on the window with soap or thinned window paint.
* Move house plants out of windows.
* Close curtains, install outdoor blinds, or install indoor blinds (the kind with slats) and leave them partly closed.
* At night use only low-intensity lighting and/or keep window coverings closed. Use task lighting, lamp shades, etc. to direct light away from windows. Turn off lights you’re not using or dim them as much as possible.
Regarding feeders:
* Move feeders, baths, edible vegetation, and other things that attract birds 30 feet or more from any glass.
* If you want to keep feeders in proximity to windows move them in even closer -- to within three feet of the window. At such close range the birds approaching the feeder are slowing down for a landing and, while they might still hit the window, they’re less likely to get hurt.
Faulty towers
What to do about reducing the hordes of birds killed by lights in office towers. Let’s get them dimmed or turned off! It’ll save not only birds but also energy.
Simple ignorance is a huge part of the problem here. If you work in an office building talk to its owners, managers, maintenance contractors, etc. directly. You can even give them written information such as this fact sheet from the bird conservation network: view link
You can get more information (and even a Tool Kit) about saving birds from striking buildings from the Lights Out web page: view link
This organization, along with Chicago Bird Collision Monitors, have been highly successfully in educating the public and working with building managers in the Chicago area to creatively find solutions to window strike problems.
More good news
Thanks to grass-roots efforts, conservationists and architects are increasingly aware of the window kill problem and are implementing solutions in new construction projects and evolving guidelines for “bird friendly” buildings. New technologies, such as glass that looks opaque on the outside, or that has particles within it that allow it to “switch” from opaque to translucent, are also in the offing.
But as consumers we need to demand these products in public structures and choose to purchase them for our homes if they are to do any good.
Obviously window kills are a big problem with no single easy fix. But if each of us does his or her part we can reduce the death toll significantly. Please do what you can where you live and work. It will make a difference!
More links
The Bird Conservation Network’s Bright Lights, Big Cities: Lights and Windows are the Deadliest Hazards for Birds: view link
An informative article from the oft-terrific Audubon Magazine: view link
Tips from the Cornell Lab of Ornithology: view link
A “project” suggestion for making objects to help birds avoid windows: view link
+ Janie Johns photo, source NPR.org
Peace and good birding,
Scott Cronenweth
www.naturalpathwalks.com
