#07-116 April 16, 2007
Avoid bird, window collisions with these simple tips from DNR
Ornithologists estimate that up to 100 million birds are killed each year by collisions with windows. These collisions usually involve small songbirds, such as finches, that may fall unnoticed to the ground. Sometimes the birds are merely stunned and recover in a few moments. Often, though, window hits lead to severe internal injuries and death.
It's thought that birds hit windows because they see the landscape reflected on the glass surface, but do not realize that a hard, transparent surface lies between them and that apparent open space. Panicking birds, fleeing for cover to escape predators, are even more likely to fly into windows.
“If you find a bird dazed from a window hit, place it in a dark container with a lid such as a shoebox, and leave it somewhere warm and quiet, out of reach of pets and other predators,” said Laurel Barnhill, wildlife biologist with the S.C. Department of Natural Resources (DNR). “If the weather is extremely cold, you may need to take it inside. Do not try to give it food and water, and resist handling it as much as possible. The darkness will calm the bird while it revives, which should occur within a few minutes, unless it is seriously injured. Release it outside as soon as it appears awake and alert. If the bird doesn't recover in a couple of hours, you should take it to a veterinarian or wildlife rehabilitator. Remember it is illegal to hold a migratory bird without a permit.”
Some ideas to make your windows safer:
- Relocate feeders and other attractants. You can start by simply moving your feeders and birdbaths to new locations. Bird strikes usually occur at particular windows, so moving feeders farther away from them may solve the problem entirely. You can also try placing your feeders much closer to the glass—if a feeder is just a foot or two from a window, birds may still fly into it, but not with enough force to injure themselves.
- Avoid apparent visual tunnels. Bright windows on the opposite wall from your picture window may give the illusion of a visual tunnel through which birds may try to fly. Try making one window less transparent by keeping a shade drawn or a door closed, or by altering the lighting inside the house.
- Commercially available hawk silhouettes are effective at deterring window strikes, as long as you use several. They work not because they look like hawks, but because they break up the window’s appearance. Do not attach objects directly to thermopane windows without consulting the manufacturer. Get a silhouette at the Cornell Lab of Ornithology site (PDF required).
- Attach branches in front of windows. For a more natural look, attach dead tree branches in front of your window. They may cause the birds to slow down and avoid the window as they fly toward it. You can arrange the branches so they don't obscure your view.
- Attach hanging objects to deter birds. Hang lightweight, shiny items in front of the window so they move in the breeze and dissuade birds from approaching. Try strips of shiny, reflective plastic (hung a few inches apart), old aluminum pie plates, or unwanted compact discs.
- Reduce reflections with trees or awnings. Reduce the amount of light reaching a problem window by planting shade trees close to it. This will help prevent reflections. However, it will also obstruct your view. Trees take time to grow, so consider shading your window with an awning instead. Either one may help birds by reducing the amount of sky reflected in windows.
- Cover windows with netting. Place netting over the window. It provides a physical barrier to birds flying into the glass, yet won't obstruct your view. Small-mesh netting is best, so if birds do fly into it they won'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. You could also try insect screening material.