Why Is a Bird Pecking at My Window and Car Mirror?
Birding experts Kenn and Kimberly Kaufman explain why a bird is pecking at a window or a car mirror and how you can stop this behavior.
How to Stop a Bird From Pecking at a Window

Question: “A cardinal bird is pecking at my window constantly. How do I make it stop?” asks Kay Baker of Mercer, Pennsylvania.
Kenn and Kimberly: 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. Try rubbing a bar of soap on the outside of your windows in all the spots that the bird visits regularly.
The cardinal should lose its drive to defend its territory after the breeding season wanes, so even if you can’t block all the reflections, this behavior should end after a few weeks.
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Birds Pecking at Car Mirrors

Question: “Why do cardinals peck at my vehicle’s side mirror?” asks Patricia Ekakiadis of Avonmore, Pennsylvania.
Kenn and Kimberly: 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.
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Each month, Birds & Blooms readers send in their questions to birding experts, Kenn and Kimberly Kaufman, who are the duo behind the Kaufman Field Guide series (which is one of our favorite field guides for birders) 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.