Expert: Roger Lederer - 3/13/2010

Question
For the second year in a row, a robin sits on a branch in the front of our house and for as long as an hour will fly, always hitting the same place,to the top corner of the window.  What is interesting, is that from her vantage point she cannot see a reflection.  There are not any plants in the window. Last year, this continued for about a week.
Any thoughts?

Thank you in advance.

John

Answer
It seems clear that he/she DOES see her reflection. (Although the the other possibility is that there are a bunch of insects gathered in that corner of the window she is feeding on, but you'd notice that.)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.