A glass inspired by spider's webs is being used to keep birds from smacking into windows.
Birds can't see glass well, and so many of them die when they hit picture windows. Humans can't see glass well either, which might explain why some people try to walk through glass doors. But most people know that the refection of the sky and landscape in a window isn't real — unfortunately, birds don't. According to the Fatal Light Awareness Program, a building with glass walls or windows can kill up to 10 birds per day, and estimates of worldwide deaths from such collisions reach hundreds of millions of birds each year.
On Lindisfarne Island, off the northeastern coast of England, local authorities wanted to do something about it. Hundreds of species of migratory birds pass through every year. So officials decided to cover a lookout tower with glass designed by Arnold Glas, a German company. Called Ornilux, the glass has a spiderweb-like pattern that humans can't see unless they stand very close (see image below, right). But because glass reflects ultarviolet light, birds can see the pattern very well.
Spider webs, particularly those of orb weaver spiders, work the same way, reflecting UV and alerting the bird that there is something there. While flying through a web wouldn't hurt a bird, the bird doesn't know that. So they avoid them.
The glass was tested in a flight tunnel in the United States. Birds were allowed to fly to one end of the tunnel which was covered with two types of glass, one with the UV-reflective coating. The birds avoided hitting the coated glass up to 68 percent of the time. (No birds were hurt in the testing because researchers used a net to prevent the birds from impacting the glass.)
The glass is also being used by a Canadian wildlife center, a German zoo and a mountain railway building in Austria.
Credit: Wikimedia Commns / Austin Marshall