Stop birds from flying into your Windows with our WINDOW ALERT decals. Here's how they work and what birds can see.
Sold as a set of 4 Hummingbird decals.
Butterfly, Snowflake, and Leaf Designs also available
Birds enjoy sharper vision than humans. Birds can see certain light frequencies including ultraviolet that humans cannot see.
In fact, many songbirds have feathers that reflect ultraviolet light. This light is used to communicate species, gender, and perhaps even social standing. Birds can see this ultraviolet light under normal, daylight conditions. Humans require the assistance of a black light.
Why do birds see better than humans?
- Both birds and humans have photoreceptive 'cones' in the retina located at the back of the eye. These cones allow us to see color light. The human eye contains 10,000 cones per square millimeter. Songbirds, for example, have up to 12 times this amount or 120,000 cones per square millimeter.
- In humans, these photoreceptive cones consist of three types. Each cone is sensitive to red, green, or blue light. This is called tri-chromatic color vision. Birds have an extra cone for quad-chromatic color vision. This extra cone expands the visible light spectrum, allowing birds to see ultraviolet frequencies.
- During low-light conditions, both humans and birds rely on photoreceptive µcell rods¦ in the retina. The human eye has 200,000 cell rods per square millimeter. Some birds, such as owls, have up to 1,000,000 cell rods per square millimeter.
- Bird eyes, on average, account for 15% of the mass of the bird's entire head. Human eyes, by contrast, account for less than 2% of the head.
- Bird retinas, in contrast to humans, contain no blood vessels. This prevents light scattering and thus provides birds with greater visual acuity than humans.
Your favorite songbird will notice Window Alert decals the MOMENT you place them on your window.
How to place window decals
- Bird strikes often occur when birds can see through one window, across the inside of your home or office, and out another window. In short, they think they can fly through your home or office. In this case, position your decals to block this line of sight.
- Bird strikes occur when birds see open sky reflected in your window. This may occur, based on sunlight and the time of day, in certain windows of your home or certain areas of a large window. Use the decals to break up this reflection of open sky.
- Male birds often stake out a particular territory. When they see their own reflection in your window, they mistake it for an intruder and attack. This is particularly true of the Northern Cardinal. Place the decals on the window under attack.
- One every two or three square feet across the glass (the more decals the better).
- On the exterior side of TINTED glass.
- On the exterior side of CLEAR glass (interior possible, but MUCH less effective).
- For maximum UV reflectivity, replace decals every 2 years.
(Great product! With many birds attracted to the feeders around my house, flying into windows had been a problem in the past, but since I put up these decals, not a single bird has flown into a window. EVERYONE should use them!!!÷ Patricia v Monroe, CT
(I work at a car lot with a lot of glass. We've tried a lot of products and nothing has been as successful as WindowAlert in preventing unnecessary bird deaths.÷ Tony v Lexington, KY
(I received my order from last week- it's great. Please send me 50 more - we're also telling friends about them.÷ Debra v Seville, OH
"Last summer we purchased and installed your WindowAlert decals and we are elated with the outcome. Prior to the installation we were finding 12 to 18 dead birds (of all species) per year under our large picture windows. This was very disturbing to us as we built our mountain cabin to be in and with Mother Nature, and here we were killing it off. Since we installed the WindowAlert decals, we have had NO bird deaths, the decals really work. We highly recommend them. David and Nancy - Boulder, CO