Expert: Roger Lederer - 3/24/2010

Question
I live in upper east Tennessee.  For the past several days a male robin has been flying at windows and doors.  At first I thought he was seeing his reflection; however, he flys toward not only clear glass doors, but also windows with screens and glass that is not clear.  He perseveres for an hour or more at a time and returns every day.  What could be causing this behavior?

Answer
He is seeing his reflection - that's the only explanation, and it's a very common behavior this time of year. Robins and many other birds are territorial and when they establish territories in the spring they become aggressive and chase off intruders. Unfortunately, they don't distinguish between their own reflection in a window (or car mirror) and try to chase that off. The solution to the problem is to eliminate the reflection. Misting the outside of the window with a very weak detergent or soda solution will eliminate the reflection but will also impair visibility for you. Awnings, eave extensions, and window screens will eliminate all reflection and stop the collision problem. Hanging ornaments such as wind chimes, wind socks, and potted plants also help. The behavior will stop when nesting begins.