Expert: Roger Lederer - 3/13/2009

Question
QUESTION: over the past 30 YEARS, our kitchen window and the basement window of our immediate neighbour has been continually assaulted by a female cardinal, day in and day out. If I place a piece of paper in the window , she will not come for a week or two but then begins again. In the mean time , she attacks our side garage window. Why ? Thank you

ANSWER: Cardinals 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.


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QUESTION: Keeping in mind the long period of time this has been going on , it cannot be the same bird. The present bird is at this time, assaulting the window while carrying nesting material in her beak. Could it be that this particular family of cardinals has something in it's memory from before this subdivision was built and the area was all trees? 30 years is a long time. She does this all winter,spring, summer and winter. What do you think? Thank you.

Answer
I didn't mean to imply that this is the sam bird; certainly not. ALL Cardinals are prone to do this, as are Robins, Bluebirds, Mockingbirds, and others. It's not this particular family of Cardinals, its something that lots of birds do, all over the world. It is just common territorial behavior and has nothing to do with your subdivision or Cardinal memory. I get hundreds of questions each year and this "crazy cardinal" question is the most common one, so you are not the only one to have observed or dealt with this.