How It Works

Easy Installation

The Bird Crash Preventer is a ready-to-hang curtain that makes installation quick and easy. It eliminates the time-consuming job of measuring and tacking individual lines.

No assembly is required. The Bird Crash Preventer is preassembled and ready to hang on included brackets. It mounts on an outside wall.

The monofilament lines are factory-fastened to the the upper and lower curtain rods. The product arrives with the lines wound around one of the rods.

You screw two brackets to the wall above and two below the window and place the rod with the lines wound around it on the two upper brackets horizontally. Then you unroll enough line off of it to cover the window and lock the other rod in the lower two brackets. Screws and instructions are included. It’s pretty easy. (See pictures below.)


Maximum length is 84″ (214 cm) — which covers most windows as well as standard sliding glass door side panels.

Two widths are available: BB3 (36″ – 92cm) and BB4 (48″ – 122cm). For extra wide windows mount units side by side. It’s not necessary to cover every square inch of window to prevent bird strikes. For example, you can center a BB4 model (4-feet wide) on a 5-foot wide window, thus leaving 6″ (15 cm) gaps on each side.

Two sets of brackets are included (You select one type): 5″ stand-off brackets and “L” brackets. It’s most effective to leave a space between the lines and the glass. Most windows will use the 5″ brackets. If your glass is already recessed, as are most sliding door panels, you don’t need the 5″ brackets and would use the “L” brackets. instead. (See below.)

For sliding-door (patio-door) panels, use the included “L” brackets to secure the rod above the door. The product also includes eye-screws and plastic ties to attach the lower rod to a wood deck.

Sliding Door – Top


Sliding Door – Decking Attachemnt


Sliding Door - Installation

Sliding Door – Installation

Bird Crash Preventers are available in two colors: Dark Brown (similar to most “bronze” aluminum window sash) and White.

Why It Works

The primary reason that this product works is that birds see the monofilament lines and avoid them (few birds ever come in contact with the lines). The cushioning effect is only a secondary feature.

Customers report dramatic drops in bird strikes — typically over 90%.

What Experts Say

The Bird Crash Preventer was scientifically tested by the AMERICAN BIRD CONSERVANCY and proven to be highly effective. It has their recommendation.

Dr. Daniel Klem Jr.*, a leading authority on bird-window collisions, confirms that “that ‘strings are highly effective in protecting birds from striking windows, either by visually alerting them to the window hazard or physically preventing them from hitting the unyielding surface.”

David Allen Sibley, famous illustrator and author of The Sibley Guide to Birds, employed the “string” method as well. He “eliminated collisions entirely by tacking fishing lines vertically three inches apart in front of a window.” But, that’s a lot of work.

* Daniel Klem, Jr., Ph.D., D.Sc. Professor of Biology, and Sarkis Acopian Professor of Ornithology and Conservation Biology at Muhlenberg College, Allentown, PA USA