Bird strikes on windows are said to be among the most serious anthropogenic causes of avian mortality and in the US alone more than 100 million birds are thought to die as a result of striking windows.
This figure can be attributed to the fact that, for birds, windows are not seen as obstacles, nor do they appear to reflect a habitat behind them.
Birds are able to see light in the ultraviolet (UV) spectrum, and in the natural world Orb Weaver spiders incorporate UV reflective strands of silk in their webs so birds will not fly through them.
Like the Orb Weaver web, the Ornilux glazing has lines coated onto the glass that are barely perceptible to humans but reflect the UV light, making the window visible to birds.
Dave Wyatt, head of the Arnold Group’s UK operations, told The Engineer via email that Ornilux glass is available in two insulating glass types: with low-emissivity (low-E) coating or solar control coating for windows and facades; and a triple-laminated glass type for outside applications such as guard rails and glass walls.
‘The production of the patterned Ornilux mikado coating is much more complex than, for example, standard low-E coatings,’ said Wyatt. ‘Therefore, the mikado-coated pane is the most expensive part of the product.
‘The production of the insulating glass itself is standard procedure, although it takes more time as we have to especially take care during production because of the high value of the coated glass.’
First glazing application
The product has now been used for the first time in the UK to glaze a new lookout tower and visitors centre on Holy Island, Lindisfarne, an area where around 300 bird species have been recorded.
In a statement, Euan Millar, director of Icosis, the architectural company behind the Lindisfarne project, said: ‘Considering the native bird populations on Holy Island, we were really keen to ensure that the buildings would be great for visitors but also have minimum impact on the natural environment.
‘With so much glass in the tower, we were concerned with birds striking the glazing in particular.’
Wyatt added that in the US bird-protection guidelines are already part of the general building code in some states and regions.
He said: ‘Organisations such as ABC [American Bird Conservancy] are working hard to make the problem of bird mortality due to human-build structures known all over the US.
‘This leads to change of behaviour and change of requirements for buildings. Bird protection could become a further factor that needs to be fulfilled for “green buildings”, for example.’