Directory of Illinois Wildlife


Prevent Collisions with Windows

According to published estimates, between 98 million to 980 million birds are killed in glass window collisions each year. The collisions occur when a bird sees a reflection of vegetation or sky in windows and tries to fly through the glass, not recognizing the glass as a barrier. In addition, birds will attempt to fly through two panes of glass parallel to one another. When they hit the glass, they can be killed or suffer serious injury. You can help reduce the possibility of bird window strikes. To help prevent birds from striking glass:

  1. The most effective way to reduce fatalities caused by strikes is to use window screens. Screens limit reflection, and they provide a softer material than glass if a bird does fly into the window.
  2. Break up the reflection in the window. If your windows do not have screens, plant shrubs or trees near the window to obstruct the bird’s view of the glass. Suspend branches or shiny objects over windows that are struck often or consider placing multiple decals on windows that are most problematic.
  3. Place bird feeders less than three feet or more than 30 feet from windows. By placing the feeder close to the window the bird does not have enough distance to build up speed if it gets startled at the feeder and accidentally hits the window, thus reducing the chance of injury or death. By placing the feeder farther out, the bird has more room to orient itself and will hopefully choose to fly away from the window.
  4. If you have sets of windows parallel to one another, consider keeping blinds down on one set so that birds cannot see through and try to fly to the other side.
A Bird Keeps Attacking My Window

Most window strikes are accidental. However, sometimes birds will purposefully fly at a window. During the breeding season birds, such as American robins and Northern cardinals, become territorial in areas surrounding their nest site. If a bird sees its own reflection in a nearby window, it may try to ‘drive off the intruder’ by attacking the window. Despite the bird’s best efforts, the ‘intruder’ just won’t go away. Repeated attempts by the bird to get rid of the ‘intruder’ can stress the bird and may result in bill injuries. This behavior is often seen in Illinois from late April through early August. After the nesting season is finished, the bird will stop “attacking” the window.

In the meantime, the best way to help these misguided birds is alter the reflective qualities of the window. This can be done by placing decals on the outside of the window (you will need to use multiple decals). Another option is to temporarily cover the outside of the window with a non-reflective surface. Bug screens are effective, or you can use a sheet of plastic that prevents the bird from seeing its reflection. Clear, plastic painter’s drop cloths work well at blocking the reflection while still allowing light into a room. Plastic netting (1/4-inch mesh) can also be suspended in front of the window to deter birds from hitting the glass.

For more information about bird-window strikes:

Protect Birds from Cats

Cats (<i>Felis catus</i>), both domestic and feral, kill millions of birds, snakes and small mammals annually. Keep cats indoors unless supervised.This simple step will protect your pet from accidents and disease, as well as providing a safer environment for wildlife.
Photo courtesy of Adele Hodde, Illinois Department of Natural Resources)

Both feral and house cats are known to have serious impacts on populations of small mammals and birds. Even well fed cats will hunt. Because cats often bring their kills home, they may bring you into unnecessary contact with wildlife. Putting a bell on your cat’s collar will not usually protect wildlife. Research has shown that cats can learn to stalk their prey silently even when wearing a bell. Additionally, birds and other wildlife do not associate the sound of a bell as a warning of danger. From a public health standpoint, cats that are allowed outside unsupervised may be exposed to diseases that are transmittable to humans such as rabies and toxoplasmosis. Keeping your family, your cat, and the birds in your neighborhood safe is easy: Keep cats indoors. The article Cats and Wildlife from Texas Parks and Wildlife provides more information about cats and wildlife.

Protect Birds from Pesticides

Birds can be killed if they eat pesticide granules or if they eat insects or other animals that have been poisoned by insecticides or pesticides. To help reduce the risk of poisoning:

  1. Use non-chemical controls if possible. Use mulch to avoid weed growth. Pull weeds by hand. Mow your lawn frequently with the mower set at two to three inches since this develops a thicker lawn that can shade out weeds.
  2. Use pesticides only when necessary. Always follow the package directions and use products in a controlled and localized manner to avoid contaminating surrounding areas. Cover or remove bird feeders and baths before applying chemicals to your yard.

Protect Birds from Disease

The five most common diseases found in backyard bird populations are salmonellosis, trichomoniasis, aspergillosis, avian pox, and mycoplasmosis. For more information about disease at bird feeders, read the fact sheet from the National Wildlife Health Center.

By thinking about feeder placement and maintenance, you can protect your family’s health while providing safer feeding stations for the birds.


Bird Species

Non-native species
Game Birds