How to keep birds from attacking their reflection in a window

BIRD COLUMN FOR May 14, 2006

By Benjamin P. Burtt

Topic: A way to keep Birds from Attacking their Reflection in a Window
A Readers Question: Mr. Burtt, We have a female cardinal that keeps trying to fly into our windows, what is up with this behavior? How can we deter her? L.B., Fayetteville, NY.

Dear L.B.: These birds are planning to nest somewhere near your house. The male and often the female of a species will try to drive away any other individual of the same species that appears near their nest or in the territory where they plan to nest.

A bird interprets its own reflection as an intruder and will waste so many hours trying to drive it away that the nest often fails. This time might better be spent in finding food or later in feeding young. For the home owner the thumps on the glass are annoying and the glass get dirty. These “attacks” from a distance of a foot or less seldom cause any serious injury, but sometimes the bird’s bill gets bloody.

A number of methods have been tried to reduce the reflection seen by the bird, but these have not been very effective. A new idea using feathers was proposed by Stiles Thomas of New Jersey in an article he wrote for Bird Watchers Digest. I tried it this spring and it stopped the cardinal “attacks” at my big window that had been going on for two months.

CAPTION: Note how well this window reflects the trees in our back yard. A bird that intends to nest nearby will often see its own reflection in this window. It will peck at its image and waste hours trying to drive the “intruder” away. These brightly colored feathers suspended from monofilament fishing line and moving in the wind apparently frighten the birds enough to keep them away from the window. It is called “FeatherGuard. Two of the FeatherGuard strings are draped across my window as show in the photograph.

Each “FeatherGuard” consists of a four foot length of monofilament fishing line fastened to the window with a small suction cup on each end. The line is threaded and knotted through a hole bored in the end of each feather shaft. The seven feathers dangle and move in the wind.

Apparently, the birds are frightened by the moving feathers. It is thought that the sight of loose feathers is a sign that a bird has been killed by a predator and so other birds instinctively avoid the area.

This device is also effective in preventing high speed collisions where birds are killed by hitting the reflection of your yard in the window.

You can inquire about the FeatherGuard or order one from Bird Watchers Digest by calling toll free ,1-800-879-2473. It will cost about $9 for the product and postage.

If you wish to order for a store that sells supplies for attracting birds or you are a nature center, you can inquire about getting some wholesale by calling the toll free number and asking for Josh or Andy for details. The mailing address is Bird Watchers Digest, PO. Box 110, Marietta, OH, 45750.

Benjamin P. Burtt writes a column every other week on birds in the Post Standard. Write to him by regular mail c/o Stars, P.0. Box 4915, Syracuse, N.Y. 13221 or via email at ( put "Birds" in the subject field).