An apparatus for preventing bird collisions with a window including a UV light source, a mask, and a first lens configured to direct UV light from the UV light source through the mask. The mask is at least partially transparent to UV light and includes a pattern that is at least partially opaque to UV light. The UV light passing through the mask contains the pattern. The pattern-containing UV light is projected onto a pane of glass to form a UV image visible to birds corresponding to the pattern on the pane. The image is configured to deter birds from flying into the pane of glass.