All backyard birders are familiar with the occasional window strike when a bird inadvertently hits a window, but when a bird repeatedly and deliberately attacks a window, mirror or other reflective surface, unique steps may need to be taken to protect the bird from itself.
Why Birds Attack Windows
Some bird species are very aggressive and territorial, and during the breeding season when they notice their reflection in a window, mirror, chrome bumper or similar shiny surface, they assume it is a rival bird and will attack the reflection in an attempt to drive it away. They may fly against the reflection, peck at it, rake it with their talons or beat it with their wings, and while these actions do not generally cause severe injuries, they can lead to exhaustion that will make the bird more vulnerable to disease, malnutrition and predators.
Bird species that are known to attack themselves as reflections include:
- American goldfinch
- American robin
- California towhee
- Chipping sparrow
- Eastern towhee
- European robin
- Gray jay
- Northern cardinal
- Northern mockingbird
- Song sparrow
- Wild turkey
The degree of aggression and duration of the attacks will vary for each bird species, but attacks may begin as early as February or March and could continue until late summer if the species raises multiple broods during the breeding season. Only after the breeding season has ended will the aggression wane unless birders take steps to discourage these misled birds.
How to Stop Bird Window Attacks
Many of the best ways to stop birds from attacking windows are the same methods used to prevent bird window collisions. The key is to break up the reflection that the bird sees so it does not feel threatened by a non-existent competitor. Options include:
- Decals placed inside or outside the window
- Strips of tape, plastic or paper arranged in an irregular pattern
- Soaping the outside of the windows
- Placing non-reflective screen outside the window 2-3 inches from the glass
- Adding one-way transparent film or opaque plastic to windows
If the bird is attacking a vehicle reflection such as a car mirror or chrome bumper, moving the vehicle to a different area may solve the problem because it will be outside the bird's territory. Watching the birds carefully can also help create solutions – perhaps the bird only spots its reflection from a particular perch, and removing that perch may keep it from noticing the reflection and feeling threatened.
Another temporary solution to birds attacking windows is to make the area less bird-friendly to encourage them to find a less apparently hostile territory for nesting. Removing bird houses or several bird feeders, for example, may encourage aggressive birds to find a different area for raising their families, and while the birders may miss their company, the birds will feel safer in an area away from harassing reflections.
NOTE: It is illegal to capture or harm a bird, its nest or its eggs, even with the best intentions. The bird should never be harmed in order to stop it attacking its own reflection.
Watching a bird fruitlessly attack its own reflection over and over can be distressing for a backyard birder, and doing so is exhausting and stressful for the bird. Knowing why birds attack windows and how to stop them can help backyard birders provide a safe, hospitable environment for their backyard birds to enjoy.
Photo – Gray Jay © Gerry