How can I stop birds from repeatedly hitting my windows?

Bird collisions with glass can occur for several reasons, reflection, transparency or for territory. Glass on our windows and doors can reflect surrounding vegetation or sky giving the illusion that it’s a landscape that birds can use. Transparency can also occur when a bird is able to see true habitat through a set of windows and perceives the space as a fly-through. For example, a transparency can occur at a corner where two panes of glass meet, or through a series of porch windows. Lastly, birds can hit glass because they see their reflection and believe another bird is encroaching on their territory.

There are simple, inexpensive, and attractive ways to help prevent any type of bird collision by making windows more visible to birds. To be effective, window patterns should be spaced in a 2-inch by 2-inch grid pattern and be placed on the outside of windows. For low-cost, temporary methods, individuals can make and hang a paracord bird curtain or create decorative patterns using tempera paint and stencils. For more long-term solutions, individuals can consider using dense decal markers (such as dots), external, or “fritted” glass that includes exterior patterns to make the glass visible to birds. 

Learn More: Threats to Birds - Collisions (USFWS)