Every day, approximately 250 000 birds die in Europe from crashing into windows or other panes of glass. Over 70 species of birds are affected, from barn owl to yellowhammer. We, Dr. Friedrich Buer (biologist) and Martin Regner (social scientist) have found a completely new way of solving this problem, taking into consideration the differences in the physiology of vision between birds and human beings. Markings visible for birds but invisible for people could, in future, save birds from crashing into window panes. But is that so easy? We have explained our idea in a scientific essay published in the specialist journal “Vogel und Umwelt” (volume 13, publications in part 1, p. 31 - 41, Aug. 2002). Furthermore, we have put together a leaflet offering some helpful suggestions about what you can do yourself to prevent the death of birds crashing into window panes.
“Every year there are millions of collisions between birds and transparent or reflecting glass panes. Previous methods of protection are ineffective because they do not prevent birds from colliding with windows or they are unacceptable from the esthetical point of view. As birds can see ultraviolet (UV) light very well, it could be useful to stain glass panes ‘bird-coloured’ with pattern of transparent UV-absorbing material which could warn the birds against colliding with the pane. Web spiders protect their webs by the same effect against destruction by birds. That's why we call it ‘spider's web effect’. Power supply systems, windmills and airports will become safer, too. These patterns for men are invisible, because they can't see UV-light. Therefore we suggest to do experiments to protect birds based on the ‘spider's web effect’.”
Today, products are available which enables us to use the spider's web effect at home and elsewhere in order to prevent birds from crashing into panes: birdpen and birdsticker
The birdpen is a felt-tip. After cleaning your windows, you can use the birdpen to mark your windowpanes with uv-active patterns almost invisible to the human eye. Those markings have a durability of about half a year. The birdsticker is durable for up to 10 years. It is a kind of sticker, which is colorless and transparent for human eyes but visible for birds because of an uv-color in it. The birdsticker is weatherproof and endures cleaning of the windows. According to the manufacturer, the birdpen and the birdsticker are able to prevent nearly 70 % of the fatal incidents (see www.birdpen.de).
An even more simple method of preventing the death of birds crashing into window panes is: Just don't clean your windows anymore. Dust absorbs ultraviolet light, while it is reflected by clean parts of the panes. A contrasting pattern evolves and birds will be warned and veer off in time.