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How to Stop Birds Attacking Windows (Why Do Robins Knock on Glass?)

I have "green-fingers," and love my garden. I enjoy watching wildlife and being outdoors.

Ways to Stop a Bird From Attacking or Pecking at Your Window

The best way to prevent a bird from attacking or going crazy at your window is to break up the reflection of its image so it doesn't think its reflection is a competitor.

  1. Use highlighters to draw a grid on your window: This is the best method. It works immediately and is recommended by the Texas Parks and Wildlife Service. Birds can see the highlighting, but it is barely visible to humans.
  2. Cover up the window: You could break up reflections by leaving the window dirty or by using decals. This doesn't really work and stops light from entering the room.
  3. Use stick-on deflectors or shiny objects (old CDs) to break up reflection and distract: Shiny hanging objects aren't very effective, but stick-on deflectors can work and are easy to apply.
  4. Close exterior shades and blinds: This is not really an effective solution as you are sacrificing daylight and views for the sake of preventing birds pecking at the windows.
  5. Shade the window with an awning: This may work as it breaks up reflections, but can be an expensive option.
  6. Install wind-chimes or water-fountain as a distraction: These are fun to have but are not an effective bird deterrent.
A young Gray Jay attacks its own image in a car's wing mirror.

A young Gray Jay attacks its own image in a car's wing mirror.

Stop Pecking by Removing Reflections

Some people try to prevent birds attacking panes of glass by covering the outside of targeted windows with non-reflective cellophane. The problem with this is that wind and rain will quickly make the cellophane come adrift and ineffective.

A better alternative is to use a decal or an internal window deflector. I find that a Bird's Eye View window deflector works well. It breaks up the clear view of the glass for the birds and stops them striking at their own reflection. At the same time it's small enough not to obstruct your view of the outside. It's also easy to remove from the window if you should want to.

Draw Gridlines on Your Window Using Highlighters

The best solution I’ve found to this problem is one recommended by Texas Parks and Wildlife Service. It involves drawing grid lines on your windows using fluorescent marker pens (highlighters). It’s cheap and easy to do. It can be done from inside your property so there’s no need to worry about climbing ladders. Best of all, it works!

How It Works:

The pigment in the highlighters can be seen by birds but is difficult for humans to see, so it doesn’t interfere with your view out of the window too much. Drawing a grid of lines with a fluorescent marker breaks up a bird’s reflection, so the repetitive pecking behavior stops. The effect is virtually instant. I use Sharpie Tank Highlighter Marker Pens. Their tanks contain enough ink to draw a grid over the whole window, and their quick-drying ink means that smudging is minimized.

The video below was made by the Texas Parks and Wildlife Service and demonstrates the difference in bird behavior between a marked window and an unmarked one. It is remarkable the difference a few highlighter lines can make.

How to Keep Birds From Hitting Your Windows

Summary of Texas Parks and Wildlife Service Method

  1. Clean the inside of your windows using a propriety glass cleaner.
  2. Next, use a highlighter to draw a grid of lines on the inside of the affected window. (This is the one that the bird is using for its target practice.)
  3. The horizontal lines should be less than 2” (5 cm) apart. The vertical lines need to be no more than 4” (10cm) apart.
  4. You will need to reapply the grid every week or so as daylight will gradually fade the florescent ink.
  5. That’s it. The job is done. Problem Solved!
  6. Now you can sit back and enjoy birdwatching without the head-banging tactics.
The European Robin (Erithacus rubecula) often knocks on windows in the UK.

The European Robin (Erithacus rubecula) often knocks on windows in the UK.

Unusual, Aggressive Bird-Pecking Behavior

Have you ever been sitting quietly at home or in your car when a bird starts to attack the window? A robin recently used my living room window as a target and flew repeatedly at the glass. These demented attacks on their reflections on a window pane or car wing-mirror can last from 10 to 20 minutes. The same bird may repeat this action several times a day, and this strange behavior can last for several weeks.

Why Do Birds Fly Into Windows?

Birds fly into windows for three reasons:

  1. They fly into a reflection of a tree or plant thinking its real. When birds see reflection of vegetation or they see through the glass to indoor plants, they fly straight for it at full speed.
  2. Male birds attack their own reflections to defend their territory. These attacks take place most often in spring (the breeding season) and in the fall (when birds are newly arrived on migration from another country). Scientists believe that birds attack their reflection in the glass thinking it's a rival bird.
  3. Night-migrating birds become disoriented by lighted windows. Because these birds navigate by starlight, artificial building lights can confuse them and divert their migration patters. Birds either collide with the windows or they hover around lighted windows until they get exhausted. A single lit city building can kill thousands of migrating birds in just one night.

How to Stop Birds From Attacking Windows

Territorial Birds That Attack Windows

American goldfinch

American robin

California towhee

Chipping sparrow

Eastern bluebird

Eastern towhee

European robin

Gray jay

Gray wagtail

Laughing kookaburra

Magpie-lark

Northern cardinal

Northern mockingbird

Ruffed grouse

Song sparrow

Wild turkey

Yellow-rumped warbler

 

Do Shiny Balloons Scare Away Birds?

Some people think that hanging balloons in front of glass will frighten away wildlife, but they're not an effective deterrent. A good guide to bird behavior is What it's like to be a bird: It will help you understand the way birds see the world, from flying to nesting, eating, and singing. Hanging shiny items like CD discs can scare birds away, but you need to keep them constantly moving to have any real effect.

The American Robin (Turdus migratorius) may peck at windows in the US.

The American Robin (Turdus migratorius) may peck at windows in the US.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.