derick.net

The relationship between windows and birds comes in different degress of deadliness. Other times it is fast peck of bird running into glass. Others it is a tiny series of small crashes and a light flutter of many wings. The worst, however, are the jarring impacts that resonate throughout an entire house, leaving you and your family members startled and often crippling or killing the bird. Sadly, these impacts are far more common than you might think. In an article for Audubon magazine, David Malakoff cited that in North America, window strikes kill between 100 million and 1 billion birds annually. According to an NPR story, Professor Daniel Klem of Mulhenberg College things that Malakoff’s estimate is too conservative, and that the real number easily exceeds 1 billion birds in the United States alone.

Why Strikes on Windows Occur?

It’s hard to know for certain exactly why window strikes happen, but observation has granted some measure of insight. The first, and seemingly most common, rationale is that birds simply cannot see glass. The transparency of the glass makes the window look open, and this is often complicated further by a window on the opposite side of the house. This causes what is commonly referred to as the “tunnel effect,” meaning that the bird believes that the two windows lack glass and thus represent a clear tunnel to fly through.

The other primary reason for bird strikes seems to be reflections. Windows in homes and office buildings sometimes give a good reflection the area around them. So, while the house or building certainly appears to be a house or building, the windows look more like wooded areas which are perfectly safe for flying.

Ways to prevent window strikes

There are a range of possibilities for preventing window strikes. The most effective method is to remove a window, or to completely cover it with something opaque and non-reflective like wood or cardboard. Granted, this removing a window is a bit drastic and not practical for the vast majority of home owners. Thankfully, with a little understanding as to why birds strike windows, home owners can reduce bird strikes with more people-friendly methods.

Covering Windows

While boarding up windows is an extreme solution, it does prove a point. Putting something between the window’s glass and the outside world can both alert a bird to a physical object and prevent reflection. The line for most home owners seems to be when such a covering moves from the area of protecting birds and into the realm of obstructing views. Home owners have several options like summer storm screens, to heavier plastic “shade cloth” and even the commercial CollidEscape film, all of which help to remove transparency and restrict reflection to various extents.

Silhouettes and Obstacles

Another tactic is to prevent the bird from coming  near the window. Some homeowners put blockades, such as a tree or bird feeder, in front of a window, particularly windows that are struck with some frequency. If you notice that your bird feeder is causing birds to strike your window, then moving the feeder further from your house would be a prudent move. Another popular method, which works to varying degrees, is to intimidate birds away by way of statues and silhouettes. A statue of an owl, or a cut out made to resemble a flying hawk can cause an errant bird on a collision course with a window to change course.

The Happy Medium

For many home owners, window strikes are infrequent happenings and thus can easily be remedied by merely moving a bird feeder or placing a hawk silhouette in a tree. For others, other more permenant efforts must be used. Lucily, for most people in areas with a lot of bird traffic, there is a happy compromise. Make part of the window more obvious with the application of custom window decals or stickers. Placing stickers on a window makes the glass less transparent and can break up reflections, minimizing two of the most common reasons why birds strike windows in the first place. Special techniques can even make these decals nearly-invisible to us humans while staying perfectly visible to birds. Such stickers benefit birds while doing very little to detract from the value humans derive from said windows.

Custom Stickers used to prevent bird strikes can come in a variety of shapes and sizes. Homeowners can make use of seasonal varieties like flowers for spring, snowflakes for winter, and even holiday images. These stickers can even be made in the images of predatory birds, thus mimicking the silhouette effects and adding to the sticker’s effectiveness.

The real key to preventing bird strikes is to change the status quo. This can be done through changing the locations of physical things - like bird feeders and trees - thus forcing birds to alter their flight paths. Or, it can be done though intimidation, via silhouettes of predators. Or, a home owner can change the bird’s perception of the actual window. Stickers, whether they are human-visible or not, make windows more obvious to birds, while screens and covering cloths negate the qualities (reflections and transparency) that make windows harmful to birds in the first place. The home owner needs to determine which prevention method works best.