Expert: Roger Lederer - 1/20/2009

Question
we feed the birds year round here in WA state.  This year the winter has been quite cold and we have had a lot of birds.  I have one chickadee that for the past few days has gone around two sides of my house pecking at my windows and landing on the screens then back to the trees.  We have no idea why this bird is acting this way.  Any ideas?

Answer
Chickadees, cardinals, and many other birds are territorial and when they establish territories in the
spring or winter 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.