November 29, 2012
Accipiters, the number 1 cause of window strikes?
Accipiters, the number 1 cause of window strikes?
Back in the day, when this column appeared on the Environmental Page of the Arizona Republic (can you imagine a major metropolitan newspaper discontinuing their environmental page . . . sorry, I digress), one of the most frequent inquiries I received from readers was “How can I prevent bird strikes against my windows?”  The problem of course is that large glass surfaces in open areas reflect the sky, and neighborhood birds frequenting the area to access water or feeders may fly into windows they interpret as nothing but that sky.

In one of my columns titled “What Birds See”, I described cutting edge research at the time (2008) which proved that species we see as monochromatic, males and females wearing the same plumage, are actually dichromatic to one another because of birds’ ability to see reflected ultraviolet light emanating from feather patches on various parts of their bodies, typically those patches which look the drabbest to us.  In short, birds don’t see what we see.  They see a lot more.

It took three years of chemical engineering, but someone has finally figured out how to profit themselves and the birds they love with this discovery.  A small company in Bend, Oregon, WindowAlert, that sells a plethora of bird related products for backyard birders, is marketing two products touted to prevent bird strikes on your windows.  One is a series of decal sets with nature themes that utilizes the way birds see.  Here’s a quote from Window Alert’s website:  “The decals contain a component which brilliantly reflects ultraviolet sunlight.  The ultraviolet light is invisible to humans, but glows like a stoplight for birds.  Birds have vision that is up to 12 times better than that of humans.  WindowAlert helps birds see windows and avoid striking the glass.”

The second product, ready to ship the first of next year, is a “UV liquid” that comes in a squeeze bottle with a bingo marker.  You simply “paint” it on your windows, it dries to opaque, and reflects ultraviolet sunlight to let the birds know the glass is not open sky.  Consumer reviews on their website are overwhelmingly, though not entirely, enthusiastic about the decals.

I first heard about WindowAlert at a birding event I recently attended.  One of the event’s main attractions was a raptor rehabilitator who displayed several live “education” birds.  The most interesting thing he had to say was that the number one cause of window strikes is raptor sorties through residential feeding stations.  When a raptor suddenly appears, the small birds scatter in terror without any attention to their surroundings.

I’m not sure I believe this is the biggest cause of window strike, but I know it happens.  We’ve had two window strikes in eight years at our present location, and both were caused by raptor panic.  WindowAlert is not going to solve raptor panic, but for birders without feeders who are experiencing window strike or birds battling their reflection in glass doors, WindowAlert may be the answer.  We lose enough birds to feral cats and nighttime light disorientation.  If you’re losing birds to window strike, check out WindowAlert.