Spring is finally here. And with spring comes loads and loads of birds. However, as you may know, glass windows pose a risk because they are essentially invisible; by reflecting foliage or sky, they look like inviting places to fly into. According to a 2014 study, about 1 billion birds die from window strikes in the U.S. each year.
“There are two main types of window collisions: daytime and nighttime. In daylight, birds crash into windows because they see reflections of vegetation or see through the glass to potted plants or vegetation on the other side. At night, nocturnal migrants (including most songbirds) crash because they fly into lighted windows. Some of these nighttime collisions are due to chance, but much more often the nocturnal migrants are lured to their deaths by the lights. For reasons not entirely understood, lights divert nocturnal migrants from their original path, especially in low-ceiling or foggy conditions. In the lighted area, they mill about, sometimes colliding with one another or the lighted structure.”1
(Birds often see their reflection in a window and attack it, too. This happens most often in the spring when territoriality is high. Thankfully, while it is annoying to us, it is seldom dangerous to birds. Check out the video below for some tips to help deter window attacks.)
The good news is you can help save your neighborhood songbirds with some simple remedies. But first, you’ll need to identify dangerous windows. Large picture windows, paired windows at right angles to each other, or windows with feeders outside all need to be examined from a bird’s point of view; if you see branches or sky reflected in or visible through the glass, that’s what the birds will see, too.
Once you’ve identified the windows you need to make safer, you have a couple of options. Thanks to All About Birds for the following suggestions:1
- To deter small birds, vertical markings on windows need to be spaced no more than 4 inches apart and horizontal markings no more than 2 inches apart across the entire window. All marking techniques should be applied to the outside of the window.
- Tempera paint or soap. Mark the outside of the window with soap or tempera paint, which is inexpensive and long-lasting. You can use either a grid pattern no more than 4 inches by 2 inches or get creative and paint patterns or artwork on your window.
- Put decals, stickers, sun catchers, mylar strips, masking tape, or other objects (even sticky notes) on the outside surface of the window. These are only effective when spaced very closely.
- Acopian Bird Savers, also known as “zen curtains,” hang down over windows and do the work of tape or decals but are easier to install and can be aesthetically pleasing. You can order them to fit your windows or make your own.
- Installing mosquito screens over your windows is very effective, as long as they are on the outside of the window and cover the entire surface.
- Cover the glass on the outside with netting at least 3 inches from the glass, taut enough to bounce birds off before they hit. Small-mesh netting (around 5/8″ or 1.6 cm) is best so that birds don’t get their heads or bodies entangled but will bounce off unharmed. You can mount the netting on a frame, such as a storm-window frame, for easy installation and removal.
- One-way transparent film permit people on the inside to see out but makes the window appear opaque on the outside. They can reduce the amount of light that comes in your window (this can also reduce your cooling costs).
- Install external shutters and keep them closed when you’re not in the room or taking advantage of the light or view.
- Install external sun shades or awnings on windows, to block the reflection of sunlight.
- Add interior vertical blinds and keep the slats only half open.
- Avoid visual paths to sky and greenery. Bright windows on the opposite wall from your picture window may give the illusion of an open path to the other side. Closing a window shade or a door between rooms can sometimes solve this situation.
And finally, if you do find a bird dazed after a window collision, you’ll need to figure out how extensive its injuries are. If both wings hold together properly (neither dangling) and the eyes seem normal, check to see if it can perch in a branch unassisted. If so, leave it to recover on its own. However, if the bird has a noticeable injury, please take it to a wildlife rehabilitator as quickly as possible.
If you have to do that you can put the animal in a dark container and leave it somewhere quiet. Do not try to give it food or water and don’t handle it because technically, it is illegal to handle a migratory bird without a permit (and you aren’t an expert anyway)!