Why Is a Bird Pecking at My Window and Car Mirror?

Updated: Feb. 06, 2024

Experts explain why a bird is pecking at its reflection in a window or mirror and how you can stop this breeding season behavior.

How to Stop a Bird From Pecking at a Window

house finch pecking at windowCourtesy Lori Vanover
House finch pecking on a window

“A cardinal is pecking at my window constantly. How do I make it stop?” asks Birds & Blooms reader Kay Baker of Mercer, Pennsylvania.

Birding experts Kenn and Kimberly Kaufman say, “When a bird starts pecking at a window like that, it has mistaken its own reflection for another bird and is trying to drive it away. Some individuals become obsessed with these phantom rivals and may attack them for weeks.

The only real solution is to do away with the reflection itself. You need to block the reflection on the outside of the glass. Putting an exterior screen on the window is one simple solution. If that isn’t possible, try rubbing a bar of soap on the outside of your windows in all the spots that the bird visits regularly. Or tape a piece of paper or plastic over those areas. If none of those options are feasible, you can just wait.

The cardinal should lose its drive to defend its territory after the breeding season wanes. Even if you can’t block all the reflections, this behavior should end after a few weeks.”

Find out why woodpeckers peck and how to stop it.

Birds Pecking at Car Mirrors

A male cardinal attacking the side mirror of a car.Getty Images / Jeff R Clow
A male cardinal attacking the side mirror of a car.

“Why do cardinals peck at my vehicle’s side mirror?” asks reader Patricia Ekakiadis of Avonmore, Pennsylvania.

Kenn and Kimberly say, “Cardinals, like many other birds, defend a territory during the nesting season to make sure they have enough space and food for themselves, their mate and their young. If a male cardinal sees another male cardinal in his territory, he chases the trespasser away.

Unfortunately, he can’t tell the difference between a real cardinal and a reflection in a mirror. So he might spend hours trying to chase away this false intruder that can’t be intimidated. You might try covering the mirror when you’re not driving your car so this defensive cardinal can go about his business.”

Are hummingbirds territorial at feeders and flowers?

About the Experts

Birding experts Kenn and Kimberly Kaufman are the duo behind the Kaufman Field Guide series and speak and lead bird trips all over the world. If you have a bird-related question for them, submit it here! It could appear here or in a future issue of the magazine.

Why Trust Us

For nearly 30 years, Birds & Blooms, a Trusted Media Brandhas been inspiring readers to have a lifelong love of birding, gardening and nature. We are the #1 bird and garden magazine in North America and a trusted online resource for over 15 million outdoor enthusiasts annually. Our library of thousands of informative articles and how-tos has been written by trusted journalists and fact-checked by bird and garden experts for accuracy. In addition to our staff of experienced gardeners and bird-watchers, we hire individuals who have years of education and hands-on experience with birding, bird feeding, gardening, butterflies, bugs and more. Learn more about Birds & Blooms, our field editor program, and our submission guidelines.