The Glass Bird Trap, or the Invisible Boundaries of Bird Flight

Anyone who happened to be out and about on the university campus near the Zusebau building one fine afternoon recently might well have been surprised to see a group of children busily painting a small glass structure – used as a smoking shelter – white. Some passers-by were puzzled. “You’re really making it nice for the smokers!” commented others. 

The cheerful children belong to the Nature Conservation Children’s Group (NAJU) and are members of NABU. Our aim is to provide comprehensive nature and environmental education. This Thursday, our goal was to make a glass-walled building bird-safe. Flying free as a bird is enviable, yet we are scarcely aware of the dangers to which birds are exposed. Glass panes have become an integral part of our lives and are part of a modern ‘lifestyle’. However, glass also has its downsides: although birds rely primarily on their sight for navigation, they are unable to recognise glass. Every year, in Germany alone, over 100 million birds die as a result of collisions with glass. This makes death at windows one of the biggest bird conservation problems in built-up areas today. With the constant expansion of built-up areas and the growing popularity of glass, the problem is becoming increasingly acute.

Yet solutions do exist: making glass visible using certified bird protection markings. Sticking on silhouettes of birds of prey is of no use here. Naturally, the best approach is to incorporate protective measures from the outset when planning a building.

In Ilmenau, NABU has taken up the issue of birds colliding with glass and formed a working group. The group has already made contact with companies and organisations, including at a political level with the town and the district, and has successfully raised awareness of the issue through talks. 

The children’s group also wanted to get involved in bird conservation. We approached the Chancellor of the University of Ilmenau, and so we were allowed to make the fully glazed smoking shelter – where dead birds had also been found – bird-collision-proof.

First, the six panes had to be cleaned. The waterproof paints were applied to the outer panes for better visibility. Then trees were painted in a stylised manner. Stencils for leaves, birds and other elements had been prepared for the children; these were stuck on from the inside and traced from the outside. The children were very keen and soon began to create imaginative and free-form designs. After two hours, our ‘work of art’ was finished, with the children just as pleased as the adults who’d helped out. The children learnt a great deal that afternoon. It would be brilliant if our initiative were to set a precedent. 

Incidentally, in most collisions with glass, only so-called powder marks or inconspicuous feathers are left behind. Smaller birds leave no traces at all. Their carcasses are usually disposed of within a short time: at night by foxes, rats, cats and martens; during the day, mainly by crows and magpies. This explains why the scale of the problem is still underestimated. 

Information on bird strikes and detailed recommendations for action can be found at: www.nabu.de/glastod

An article by Petra Szigarski – supervisor of the NAJU group in Ilmenau