|Song sparrows are among the birds that commonly attack their reflections. Photo by J.J. Meyer|
Audubon volunteers and staff members cover the side mirrors on their cars with plastic grocery bags when they park at the San Joaquin Wildlife Sanctuary in Irvine this time of year.
“Every spring we get California towhees and song sparrows attacking the side mirrors on our cars,” said Trude Hurd, project director of education for Sea and Sage Audubon. “Males are feeling very territorial, so they try to drive the intruder in the mirror away.”
It’s a case of mistaken identity; they perceive their own reflection as a competitor, she said. This is the time of year when most birds establish their territories, find a mate, nest and raise their young. To ensure success, they defend their territory aggressively and will attempt to drive away any bird they view as a possible rival or a threat to their young. When they see their reflection in glass, they believe they're seeing an interloper in their territory and attack the image.
The solution is simple: Remove the reflection and the behavior will stop.
“We don’t want a bird wasting its energy,” Hurd said. “That energy needs to be spent on nesting. It’s never going to be able to drive that bird in the mirror away.”
These attacks commonly occur in spring and summer and will decrease as the breeding season progresses, she said. But there is a brief resurgence of the activity in the fall when a change in daylight triggers a false spring reaction in the birds.
Birds can attack their reflections with enough force to leave their imprint on the glass, but it’s not usually fatal. This behavior is different from deadly window strikes that happen when birds crash into glass in an attempt to fly through it.
Western bluebirds, Northern mockingbirds, American robins, song sparrows and California and spotted towhees are among the birds commonly known to attack their reflections.
Homeowners can discourage this activity by covering the outside of the window being attacked with newspaper, netting or soap to block the reflection temporarily. In addition, a couple of helium-filled Mylar balloons or just a few hanging strips of ribbon that sparkle and move in the breeze are enough to frighten away most birds.